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  • 251. Kahnberg, K E
    et al.
    Nyström, Elisabeth
    Umeå University, Faculty of Medicine, Odontology, Oral and Maxillofacial Surgery.
    Bartholdsson, L
    Combined use of bone grafts and Brånemark fixtures in the treatment of severely resorbed maxillae.1989In: International Journal of Oral & Maxillofacial Implants, ISSN 0882-2786, E-ISSN 1942-4434, Vol. 4, no 4, p. 297-304Article in journal (Refereed)
    Abstract [en]

    Bone grafts from the hip in combination with Brånemark self-tapping fixtures have been used to rehabilitate patients with extremely resorbed maxillae. Experiences and results from the first ten consecutive cases have been analyzed to form the basis for further use of the method. Eight of 57 fixtures placed have been lost to date. Surgical complications, including exposure of the bone transplant, have occurred in three patients. The method should be used with caution, and cases should be meticulously chosen to exclude those who do not have proper motivation to endure the long-lasting and demanding surgical and prosthetic procedures required. The combined use of implants and transplants should not be used routinely until a long-term evaluation of the method and results has been made.

  • 252. Kailembo, Alexander
    et al.
    Preet, Raman
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Stewart Williams, Jennifer
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health. 2.Research Centre for Generational Health and Ageing, Faculty of Health, University of Newcastle.
    Common risk factors and edentulism in adults, aged 50 years and over, in China, Ghana, India and South Africa: results from the WHO Study on global AGEing and adult health (SAGE)2016In: BMC Oral Health, ISSN 1472-6831, E-ISSN 1472-6831, Vol. 17, article id 29Article in journal (Refereed)
    Abstract [en]

    Background: Edentulism (loss of all teeth) is a final marker of disease burden for oral health common among older adults and poorer populations. Yet most evidence is from high-income countries. Oral health has many of the same social and behavioural risk factors as other non-communicable diseases (NCDs) which are increasing rapidly in low- and middle-income countries with ageing populations. The "common risk factor approach" (CRFA) for oral health addresses risk factors shared with NCDs within the broader social and economic environment. Methods: The aim is to improve understanding of edentulism prevalence, and association between common risk factors and edentulism in adults aged 50 years and above using nationally representative samples from China (N = 11,692), Ghana (N = 4093), India (N = 6409) and South Africa (N = 2985). The data source is the World Health Organization (WHO) Study on global AGEing and adult health (SAGE) Wave 1 (2007-2010). Multivariable logistic regression describes association between edentulism and common risk factors reported in the literature. Results: Prevalence of edentulism: in China 8.9 %, Ghana 2.9 %, India 15.3 %, and South Africa 8.7 %. Multivariable analysis: in China, rural residents were more likely to be edentulous (OR 1.36; 95 % CI 1.09-1.69) but less likely to be edentulous in Ghana (OR 0.53; 95 % CI 0.31-0.91) and South Africa (OR 0.52; 95 % CI 0.30-0.90). Respondents with university education (OR 0.31; 95 % CI 0.18-0.53) and in the highest wealth quintile (OR 0.68; 95 % CI 0.52-0.90) in China were less likely to be edentulous. In South Africa respondents with secondary education were more likely to be edentulous (OR 2.82; 95 % CI 1.52-5.21) as were those in the highest wealth quintile (OR 2.78; 95 % CI 1.16-6.70). Edentulism was associated with former smokers in China (OR 1.57; 95 % CI 1.10-2.25) non-drinkers in India (OR 1.65; 95 % CI 1.11-2.46), angina in Ghana (OR 2.86; 95 % CI 1.19-6.84) and hypertension in South Africa (OR 2.75; 95 % CI 1.72-4.38). Edentulism was less likely in respondents with adequate nutrition in China (OR 0.68; 95 % CI 0.53-0.87). Adjusting for all other factors, compared with China, respondents in India were 50 % more likely to be edentulous. Conclusions: Strengthening the CRFA should include addressing common determinants of health to reduce health inequalities and improve both oral and overall health.

  • 253. Kailembo, Alexander
    et al.
    Preet, Raman
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Stewart Williams, Jennifer
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health. Research Centre for Generational Health and Ageing, Faculty of Health, University of Newcastle, New Lambton Heights, Australia.
    Socioeconomic inequality in self-reported unmet need for oral health services in adults aged 50 years and over in China, Ghana, and India2018In: International Journal for Equity in Health, ISSN 1475-9276, E-ISSN 1475-9276, Vol. 17, article id 99Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The 2015 Global Burden of Disease Study estimated that oral conditions affect 3.5 billion people worldwide with a higher burden among older adults and those who are socially and economically disadvantaged. Studies of inequalities in the use of oral health services by those in need have been conducted in high-income countries but evidence from low- and middle-income countries (LMICs) is limited. This study measures and describes socioeconomic inequality in self-reported unmet need for oral health services in adults aged 50 years and over, in China, Ghana and India.

    METHODS: A cross-sectional analysis of national survey data from the WHO SAGE Wave 1 (2007-2010) was conducted. Study samples in China (n = 1591), Ghana (n = 425) and India (n = 1307) were conditioned on self-reported need for oral health services in the previous 12 months. The binary dependent variable, unmet need for oral health services, was derived from questions about self-reported need and service use. Prevalence was estimated by country. Unmet need was measured and compared in terms of relative levels of education and household wealth. The methods were logistic regression and the relative index of inequality (RII). Models were adjusted for age, sex, area of residence, marital status, work status and self-rated health.

    RESULTS: The prevalence of unmet need was 60, 80, and 62% in China, Ghana and India respectively. The adjusted RII for education was statistically significant for China (1.5, 95% CI:1.2-1.9), Ghana (1.4, 95% CI: 1.1-1.7), and India (1.5, 95% CI:1.2-2.0), whereas the adjusted RII for wealth was significant only in Ghana (1.3, 95% CI:1.1-1.6). Male sex was significantly associated with self-reported unmet need for oral health services in India.

    CONCLUSIONS: Given rapid population ageing, further evidence of socioeconomic inequalities in unmet need for oral health services by older adults in LMICs is needed to inform policies to mitigate inequalities in the availability of oral health services. Oral health is a universal public health issue requiring attention and action on multiple levels and across the public private divide.

  • 254. Kailembo, Alexander
    et al.
    Quiñonez, Carlos
    Lopez Mitnik, Gabriela V.
    Weintraub, Jane A.
    Stewart Williams, Jennifer
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health. Research Centre for Generational Health and Ageing, University of Newcastle, Callaghan, Australia.
    Preet, Raman
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Iafolla, Timothy
    Dye, Bruce A.
    Income and wealth as correlates of socioeconomic disparity in dentist visits among adults aged 20 years and over in the United States, 2011–20142018In: BMC Oral Health, ISSN 1472-6831, E-ISSN 1472-6831, Vol. 18, no 1, article id 147Article in journal (Refereed)
    Abstract [en]

    Background: Most studies in the United States (US) have used income and education as socioeconomic indicators but there is limited information on other indicators, such as wealth. We aimed to assess how two socioeconomic status measures, income and wealth, compare as correlates of socioeconomic disparity in dentist visits among adults in the US.

    Methods: Data from the National Health and Nutrition Examination Survey (NHANES) 2011–2014 were used to calculate self-reported dental visit prevalence for adults aged 20 years and over living in the US. Prevalence ratios using Poisson regressions were conducted separately with income and wealth as independent variables. The dependent variable was not having a dentist visit in the past 12 months. Covariates included sociodemographic factors and untreated dental caries. Parsimonious models, including only statistically significant (p < 0.05) covariates, were derived. The Akaike Information Criterion (AIC) measured the relative statistical quality of the income and wealth models. Analyses were additionally stratified by race/ethnicity in response to statistically significant interactions.

    Results: The prevalence of not having a dentist visit in the past 12 months among adults aged 20 years and over was 39%. Prevalence was highest in the poorest (58%) and lowest wealth (57%) groups. In the parsimonious models, adults in the poorest and lowest wealth groups were close to twice as likely to not have a dentist visit (RR 1.69; 95%CI: 1.51–1.90) and (RR 1.68; 95%CI: 1.52–1.85) respectively. In the income model the risk of not having a dentist visit were 16% higher in the age group 20–44 years compared with the 65+ year age group (RR 1.16; 95%CI: 1.04–1.30) but age was not statistically significant in the wealth model. The AIC scores were lower (better) for the income model. After stratifying by race/ethnicity, age remained a significant indicator for dentist visits for non-Hispanic whites, blacks, and Asians whereas age was not associated with dentist visits in the wealth model.

    Conclusions: Income and wealth are both indicators of socioeconomic disparities in dentist visits in the US, but both do not have the same impact in some populations in the US.

  • 255.
    Kalezic, Nebojsa
    Umeå University, Faculty of Medicine, Surgical and Perioperative Sciences.
    Autonomic reactivity in muscle pain: clinical and experimental assessment2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    There are numerous indications of possible involvement of the autonomic nervous system in the genesis of chronic pain. The possibility exists that sympathetic activation is related to motor dysfunction and changes in sensory processing, which have otherwise been implicated in musculoskeletal disorders.

    The primary aim of the thesis has been to investigate autonomic regulation at rest and in response to laboratory tests of autonomic function in subjects suffering from chronic pain in different localisations (lower back, neck-shoulder and neck-jaw), as well as to study the relations between autonomic regulation, proprioceptive acuity and clinical data. Secondary aim has been to assess autonomic regulation in fit, pain-free subjects in response to experimentally induced pain and in occupationally relevant settings.

    A total of 194 subjects suffering from chronic pain participated [low back pain (LBP) n=93; non-traumatic neck pain (NT) n=40, Whiplash associated disorder (WAD) n=40, Whiplash with temporomandibular dysfunction (WADj) n=21]. Each chronic pain group was subjected to a battery of autonomic function tests combining cognitive (Stroop Colour-Word conflict tests), physical (handgrip), sensory (unpleasant sound) and motor tasks (chewing tests) as well as the activation of reflex pathways (paced breathing and the orthostatic test) and compared to an age- and gender balanced control group. Autonomic regulation was also assessed in exposure to experimentally induced muscle pain in healthy subjects (n=24) in order to describe acute pain reaction. Further assessment was carried out during monotonous repetitive work and dynamic work in healthy subjects (n=10) and in a three-day monitoring of ambulance personnel (n=26) in occupational settings.

    Autonomic regulation was evaluated using cardiovascular (heart rate and heart rate variability, local blood flow and blood pressure), respiratory (breathing rate) electrodermal (skin conductance), muscular (trapezius and masseter EMG) and biochemical (insulin, cortisol, catecholamines) variables. Proprioceptive acuity was assessed using active-active repositioning tests. Pain levels were assessed using Visual-analogue or Numerical Rating scales. General health was evaluated through the Short-Form SF-36 Health Related Quality of Life questionnaire and Self-Efficacy Score questionnaires, whereas dysfunction was evaluated using the Oswestry Low Back Pain questionnaire, Pain Disability and Neck Disability Index questionnaires, the McKenzie evaluation and primary healthcare diagnoses. Self-reports of pain, stress and exertion were acquired prior to, during and post-testing.

    Chronic pain subjects were characterised by increased sympathetic and decreased parasympathetic activity as reflected in heart rate (LBP, WAD, WADj), heart rate variability (LBP, WAD, WADj), blood pressure (WADj) and electrodermal activity (LBP). In general, WAD showed more pain and dysfunction than NT, with lower self-efficacy and health-related quality of life. Differential reactivity was observed only in WAD, with increased responsiveness to sensory stimuli (heart rate variability, electrodermal activity), and motor tasks (heart rate) and a decreased response to cognitive challenge (heart rate variability, electrodermal activity). A significant part of WADj subjects showed sensorimotor impairment and low endurance in chewing tests, concomitant with a cardiovascular response that correlated with pain levels. Proprioceptive acuity was not found to be impaired among subjects suffering from chronic pain, and there were no indications of significant individual response specificity. Response to experimentally induced muscle pain in healthy subjects was also characterised by a prominent cardiovascular component. In simulated occupational settings autonomic activation and transient insulin resistance were detected in healthy subjects following monotonous repetitive work, with no similar effects following dynamic exercise. Modest deviations in circadian heart rate variability patterns during workdays were detected in ambulance personnel reporting more pronounced musculoskeletal symptoms, with no such effects on work-free days.

    Autonomic balance observed in chronic pain subjects was characterised by a trend towards increased sympathetic activity in comparison with pain-free controls. Moderate signs of affected reactivity to autonomic function tests were observed in patients with WAD, however no specific reaction patterns have been observed in any chronic pain group. Correspondence between the intensity of pain and autonomic activity was observed in acute pain and in chronic pain groups characterised by higher pain levels. As indicated by autonomic and neurohormonal changes in the recovery from real and simulated work, further studies with physiological monitoring of the effects of work-related stress are warranted for better understanding of the mechanism of musculoskeletal disorders.

  • 256.
    Kalezic, Nebojsa
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Noborisaka, Yuka
    Nakata, Minori
    Crenshaw, Albert G
    Karlsson, Stefan
    Lyskov, Eugene
    Eriksson, Per-Olof
    Umeå University, Faculty of Medicine, Department of Odontology.
    Cardiovascular and muscle activity during chewing in whiplash-associated disorders (WAD)2010In: Archives of Oral Biology, ISSN 0003-9969, E-ISSN 1879-1506, Vol. 55, no 6, p. 447-453Article in journal (Refereed)
    Abstract [en]

    More intense response to chewing in WAD might indicate pronounced vulnerability to dynamic loading of the jaw-neck motor system with increased autonomic reactivity to the test. Premature termination and autonomic involvement without EMG signs of muscle fatigue may indicate central mechanisms behind insufficient endurance during chewing.

  • 257. Kanasi, E
    et al.
    Dogan, B
    Karched, M
    Thay, B
    Oscarsson, Jan
    Umeå University, Faculty of Medicine, Department of Odontology, Oral Microbiology.
    Asikainen, Sirkka
    Umeå University, Faculty of Medicine, Department of Odontology, Oral Microbiology.
    Lack of Serotype Antigen in A. actinomycetemcomitans2010In: Journal of Dental Research, ISSN 0022-0345, E-ISSN 1544-0591, Vol. 89, no 3, p. 292-6Article in journal (Refereed)
    Abstract [en]

    Aggregatibacter actinomycetemcomitans is divided into 6 serotypes. Occurrence of non-serotypeable strains is known, but background reasons are unclear. We hypothesized that non-serotypeable strains represent new serotypes or have altered expression of serotype-specific polysaccharide antigen (S-PA). We first characterized 311 strains from 189 individuals using both immunoassay- and PCR-based serotyping. Next, using natural human infection and rabbit immunization approaches, we clarified whether the phenotypically non-serotypeable strains expressed S-PA. Immunoassay identified serotypes a-f among 216 strains from 159 individuals. The remaining 95 strains from 30 individuals were phenotypically non-serotypeable. Yet, all these strains were identified by PCR-typing as serotype a-, b-, c-, or f. Non-serotypeability was confirmed by Western immunoblot with respective rabbit antisera. Patient sera remained non-reactive with autologous non-serotypeable strains at the serotype-specific region. Rabbit immunization with a phenotypically non-serotypeable strain induced no antibody production against S-PA. Thus, phenotypically non-serotypeable strains did not include novel serotypes, but lacked S-PA expression.

  • 258.
    Kanasi, Eleni
    Umeå University, Faculty of Medicine, Odontology.
    Molecular analysis of the oral microbiota of dental diseases2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Traditionally, bacterial culture has been used for bacterial detection, allowing study of living microorganisms. Molecular methods are rapid and allow simultaneous identification of numerous species and uncultivated phylotypes. The objective of this doctoral thesis was to investigate the role of the oral microbiota, including poorly characterized and uncultivated bacteria, in dental caries and periodontitis, by comprehensive molecular, clinical, and statistical methods. The microbiota of 275 pre-school children (75 with caries and 200 caries-free) was examined by whole genomic DNA probes, 16S rDNA cloning and sequencing, and PCR. Streptococcus mutans, exhibiting a combined association with Streptococcus sobrinus, was significantly associated with Early Childhood Caries (ECC). Plaque from children with Severe Early Childhood Caries (S-ECC) was diverse with 138 identified and 107 unidentified taxa, which possibly included novel phylotypes. Other species/phylotypes associated with childhood caries included Lactobacillus gasseri (p<0.01), Lactobacillus fermentum, Actinomyces israelii, and Actinomyces odontolyticus (all p<0.05, ECC), Veillonella parvula (p<0.01), Veillonella atypica (p<0.05), and Veillonella sp. HOT-780 (p<0.01, S-ECC). Lactobacillus acidophilus and Lactobacillus reuteri, both used as probiotic therapy species, were detected more frequently in caries-free children than those with ECC. Fastidious periodontal species, including Parvimonas micra, Aggregatibacter actinomycetemcomitans, Eubacterium brachy, Filifactor alocis (all p <0.05), and Porphyromonas gingivalis (p<0.01), were also more frequently detected in children with dental caries than in caries-free children. Other variables associated with ECC were race, dental visit, snacking (all p<0.05), and visible dental plaque (p<0.01). The oral microbiota of early periodontitis in young adults (N=141) was analyzed by whole genomic and oligonucleotide DNA probes, and PCR. Species detected more frequently in early periodontitis than periodontal health included Treponema denticola, F. alocis, Porphyromonas endodontalis, Bacteroidetes sp. HOT-274 (oral clone AU126), and A. odontolyticus (p<0.01) by oligonucleotide DNA probes, and P. gingivalis (p<0.001) and T. forsythia (p=0.03) by PCR. Subgingival samples exhibited a higher prevalence of periodontitis-associated species than samples from tongue surface, including A. actinomycetemcomitans, T. denticola, T. forsythia (all p<0.05), and uncultivated TM7, Treponema, and Actinobaculum clones (all p<0.05). P. gingivalis (p<0.01) by PCR was associated with periodontal disease progression. Early periodontitis was associated with older age (p=0.01), male gender (p=0.04), and cigarette smoking (p=0.05). The role of bacterial subgroups in periodontitis was examined by studying the serotypeability of 313 genotyped clinical A. actinomycetemcomitans isolates (189 subjects). A total of 95 strains (30 subjects) remained non-serotypeable, although PCR revealed presence of the serotype- specific genes. The absence of the immunodominant serotype-specific antigen was confirmed by immunoblot assays. No major DNA rearrangement in the studied serotype-specific gene clusters was found. In summary, detection of previously cultured species and uncultivated phylotypes revealed the diversity of the oral microbiota in dental diseases and health already early in life. Bacterial species have insufficiently characterized subgroups that may have attributes to evade the host response. Molecular approaches used in this study enable comprehensive, culture-independent characterization of the oral microbiome that may in the future lead to identification of diagnostic bacterial profiles for dental diseases.

  • 259.
    Kanasi, Eleni
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, Oral Microbiology.
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology, Cariology.
    Lu, Shulin Charles
    Kressin, Nancy R
    Nunn, Martha E
    Kent, Ralph Jr
    Tanner, Anne CR
    Microbial Risk Markers for Childhood Caries in Pediatricians’ Offices2010In: Journal of Dental Research, ISSN 0022-0345, E-ISSN 1544-0591, Vol. 89, no 4, p. 378-383Article in journal (Refereed)
    Abstract [en]

    Dental caries in pre-school children has significant public health and health disparity implications. To determine microbial risk markers for this infection, this study aimed to compare the microbiota of children with early childhood caries with that of caries-free children. Plaque samples from incisors, molars, and the tongue from 195 children attending pediatricians’ offices were assayed by 74 DNA probes and by PCR to Streptococcus mutans. Caries-associated factors included visible plaque, child age, race, and snacking habits. Species were detected more frequently from tooth than tongue samples. Lactobacillus gasseri (p < 0.01), Lactobacillus fermentum, Lactobacillus vaginalis, and S. mutans with Streptococcus sobrinus (all p < 0.05) were positively associated with caries. By multifactorial analysis, the probiotic Lactobacillus acidophilus was negatively associated with caries. Prevotella nigrescens was the only species (p < 0.05) significantly associated with caries by the ‘false discovery’ rate. Analysis of the data suggests that selected Lactobacillus species, in addition to mutans streptococci, are risk markers for early childhood caries.

  • 260. Kapferer-Seebacher, Ines
    et al.
    Lundberg, Pernilla
    Umeå University, Faculty of Medicine, Department of Odontology.
    Malfait, Franziska
    Zschocke, Johannes
    Periodontal manifestations of Ehlers-Danlos syndromes: a systematic review2017In: Journal of Clinical Periodontology, ISSN 0303-6979, E-ISSN 1600-051X, Vol. 44, no 11, p. 1088-1100Article, review/survey (Refereed)
    Abstract [en]

    Aim: Ehlers-Danlos syndromes (EDS) are a group of inherited connective tissue disorders, characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. Periodontal EDS (pEDS) is a specific EDS subtype caused by heterozygous mutations in complement 1 subunit genes C1R and C1S, with early severe periodontitis as predominant clinical feature. We aimed to systematically assess the spectrum of periodontal abnormalities in all EDS subtypes.

    Materials and Methods: An electronic and manual search was conducted in three databases (Medline, LIVIVO, CENTRAL). Publications of all study designs written in English/German without date restriction evaluating periodontal features in EDS were included.

    Results: Thirty articles on pEDS and thirteen articles on other EDS subtypes were analysed. In pEDS, early severe periodontitis (98.4%) and gingival recession (87.1%) are the predominant features. Reports on periodontal manifestations in other EDS subtypes are rare. Described were severe gingival enlargement in dermatosparaxis EDS, and localized periodontal breakdown related to teeth with shortened roots in classical EDS (n=3, respectively).

    Conclusion: Early severe periodontitis is the hallmark of pEDS; there is no evidence that it is part of the clinical phenotype of other EDS subtypes. Stringent analyses of periodontal manifestations in most EDS subtypes are missing. Prospero registration number CRD42017056889.

  • 261.
    Karched, Maribasappa
    Umeå University, Faculty of Medicine, Odontology.
    Vesicle-independent extracellular release and bioactivity of peptidoglycan-associated lipoprotein from Aggregatibacter actinomycetemcomitans2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aggregatibacter (Actinobacillus) actinomycetemcomitans is a Gram-negative coccobacillus of the Pasteurellaceae family. It is implicated in periodontitis, a common low-grade bacterial infection, but it can also cause non-oral infections. The main aim of this project was to identify and characterize in A. actinomycetemcomitans novel cell surface components bearing virulence potential that could contribute to systemic immunoinflammatory burden.

    We first established and evaluated a method for preparing homogeneous cell suspensions of autoaggregating clinical isolates of A. actinomycetemcomitans. The chosen method is based on a gradual dispersion of bacterial colonies into solution, which generated homogeneous suspensions without losing cell viability or fimbriation.

    When sera from two patients with A. actinomycetemcomitans-associated infections were used to probe A. actinomycetemcomitans outer membrane protein (OMP) preparations in western blot, strong reactions were found at 17 kDa. Interestingly, antiserum against CsgA, a major subunit of Eschirichia coli curli, also reacted with A. actinomycetemcomitans OMP preparations at 17 kDa size, that is the size of E. coli CsgA, suggesting antigenic crossreactivity. The 17 kDa A. actinomycetemcomitans OMP was subsequently identified as peptidoglycan-associated lipoprotein (PAL; AaPAL) by using immunoproteomics methods. Studies on the pal gene and its gene product showed that they were conserved among the clinical A. actinomycetemcomitans isolates representing all currently known serotypes. AaPAL expression was shown under different nutritional and atmospheric conditions that resembled those in periodontal pockets. PAL deficiency in turn led to pleiotropic effects on the phenotype of A. actinomycetemcomitans, such as cell elongation and decreased growth rate.

    To purify AaPAL we employed affinity chromatography using anti-AaPAL peptide antibodies. The extensive characterization of the purified AaPAL by SDS-PAGE gel staining and mass spectrometry demonstrated that the final purification product did not contain other bacterial proteins than AaPAL. The protein had not lost its antigenicity during purification, since it was recognized by sera from patients with A. actinomycetemcomitans-associated oral and nonoral infections. AaPAL also appeared to be a strongly immunoreactive antigen in patients with periodontitis whose serum IgG antibodies recognized in western blot a 17 kDa OMP in the parental strain but not in the pal-deficient mutant. In addition to its immunogenicity, AaPAL also induced proinflammatory cytokine and chemokine response from human whole blood as determined by a cytokine antibody array.

    A cell culture insert model was designed to study how bacterial components could be introduced to the host in infections. The experiments demonstrated that live bacteria released extracellularly free-soluble AaPAL, but also other components, via an unknown outer membrane vesicle-independent mechanism.

    The immunogenicity and proinflammatory potential of the previously uncharacterized outer membrane lipoprotein of A. actinomycetemcomitans, AaPAL, suggests that it contributes to the pathogenicity of this bacterium. That live A. actinomycetemcomitans cells released free-soluble cell components may represent a new pathogenic mechanism.

  • 262.
    Karched, Maribasappa
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Ihalin, Rikka
    Eneslätt, Kjell
    Zhong, D
    Oscarsson, Jan
    Umeå University, Faculty of Medicine, Department of Odontology, Oral Microbiology.
    Wai, Sun Nyunt
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Chen, C
    Asikainen, Sirkka
    Umeå University, Faculty of Medicine, Department of Odontology.
    Vesicle-independent extracellular release of a proinflammatory outer membrane lipoprotein in free-soluble form2008In: BMC Microbiology, ISSN 1471-2180, E-ISSN 1471-2180, Vol. 28, no 8:18Article in journal (Refereed)
    Abstract [sv]

    Aggregatibacter actinomycetemcomitans is an oral bacterium associated with aggressively progressing periodontitis. Extracellular release of bacterial outer membrane proteins has been suggested to mainly occur via outer membrane vesicles. This study investigated the presence and conservation of peptidoglycan-associated lipoprotein (AaPAL) among A. actinomycetemcomitans strains, the immunostimulatory effect of AaPAL, and whether live cells release this structural outer membrane lipoprotein in free-soluble form independent of vesicles. RESULTS: The pal locus and its gene product were confirmed in clinical A. actinomycetemcomitans strains by PCR-restriction fragment length polymorphism and immunoblotting. Culturing under different growth conditions revealed no apparent requirement for the AaPAL expression. Inactivation of pal in a wild-type strain (D7S) and in its spontaneous laboratory variant (D7SS) resulted in pleiotropic cellular effects. In a cell culture insert model (filter pore size 0.02 um), AaPAL was detected from filtrates when strains D7S and D7SS were incubated in serum or broth in the inserts. Electron microscopy showed that A. actinomycetemcomitans vesicles (0.05-0.2 um) were larger than the filter pores and that there were no vesicles in the filtrates. The filtrates were immunoblot negative for a cytoplasmic marker, cyclic AMP (cAMP) receptor protein. An ex vivo model indicated cytokine production from human whole blood stimulated by AaPAL. CONCLUSIONS: Free-soluble AaPAL can be extracellularly released in a process independent of vesicles.

  • 263. Karjalainen, S
    et al.
    Söderling, E
    Saarinen, M
    Larsson, B
    Umeå University, Faculty of Medicine, Department of Odontology.
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology.
    Simell, O
    Niinikoski, H
    Effect of infancy-onset dietary intervention on salivary cholesterol of children: a randomized controlled trial2011In: Journal of Dental Research, ISSN 0022-0345, E-ISSN 1544-0591, Vol. 90, no 7, p. 868-873Article in journal (Refereed)
    Abstract [en]

    This study investigated salivary cholesterol of children from 6 to 16 years of age in response to dietary intervention. One thousand sixty-two infants started in the prospective, randomized project. At 3 years of age, every fifth child was invited into the study (n=178). Of these, 148 enrolled, and 86 completed the oral sub-study at 16 years of age. The intervention aimed at restricting the child's saturated fat and cholesterol intake. Control children received no special recommendations. Every third year, paraffin-stimulated saliva samples (10.0 mL) were collected for cholesterol assays. Nutrient intakes and serum total cholesterol concentrations were regularly followed up by means of 4-day food records and blood samples. Intake of saturated fatty acids (SAFA) was lower in the intervention than in the control group (p<0.001). Salivary cholesterol concentration increased from 1.9 (±1.1) µmol/L at 6 years of age to 16.0 (±9.0) µmol/L at 16 years of age. The increase was smaller in the intervention than in the control group (p<0.001). The ratios of salivary to serum cholesterol concentrations tended to be higher in boys than in girls (p=0.07). Thus, dietary intervention was reflected in children's salivary cholesterol values more sensitively than in serum cholesterol values. (clinicaltrials.gov NCT00223600).

  • 264. Karlsson, Karolina
    et al.
    Derks, Jan
    Håkansson, Jan
    Wennström, Jan L.
    Molin Thorén, Margareta
    Umeå University, Faculty of Medicine, Department of Odontology.
    Petzold, Max
    Berglundh, Tord
    Technical complications following implant-supported restorative therapy performed in Sweden2018In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 29, no 6, p. 603-611Article in journal (Refereed)
    Abstract [en]

    Objective: The aim of this study was to evaluate the occurrence and consequences of technical complications in implant-supported restorative therapy.

    Material & Methods: The occurrence and consequences of technical complications in implant-supported restorative therapy over a mean follow-up period of 5.3years were assessed based on documentation in files from 2,666 patients. Risk indicators were identified by the use of survival models, considering repeated events. Results were expressed as hazard ratios (HR) including 95% confidence intervals.

    Results: Technical complications occurred in 24.8% of the patients. Chipping and loss of retention were the most common, affecting 11.0% and 7.9% of supraconstructions, respectively, while implant-related complications (e.g., implant fracture) were rare. More than 50% of the affected patients experienced technical complications more than once and almost all reported complications led to interventions by a dental professional. The extent of the supraconstruction was the strongest risk indicator for both chipping (HR<0.2) and loss of retention (HR>3).

    Conclusion: Over a 5-year period, technical complications in implant-supported restorative therapy occurred frequently and their management required professional intervention.

  • 265.
    Kassem, Ali
    Umeå University, Faculty of Medicine, Department of Odontology.
    Toll-like receptors (TLRs) and inflammatory bone modeling2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Patients with inflammatory or infectious conditions such as periodontitis, peri-implantitis, osteomyelitis, rheumatoid arthritis, septic arthritis and loosened joint prosthesis display varying severity of destruction in the adjacent bone tissue. Bone loss in inflammatory diseases is considered a consequence of cytokine induced RANKL and subsequent enhanced osteoclast formation. Hence, osteotropic cytokines and their receptors have been suggested to be important for the pathogenesis of inflammation-induced osteolysis. It is, here, suggested that bacterial components, so called “pathogen associated molecular patterns=PAMPs”, may also be involved. Varieties of cells express receptors for PAMPs, including Toll-like receptors (TLRs) which are the first line of defence in the innate immune system. LPS (lipopolysaccharide), fimbria and lipoproteins from pathogenic bacteria such as P. gingivalis, S. aureus are ligands for TLR2 and flagellin from pathogenic flagellated bacteria like S. typhimurium is a ligand for TLR5.

     

    Since the susceptibility to, or the severity of inflammation-associated bone diseases are likely related to differences in the tissue response, and the mechanisms by which PAMPs interact with bone cells are not fully understood, we aimed to elucidate the importance of different TLRs for inflammation induced bone loss by conducting in vitro and in vivo investigations.

    Activation of TLR2 and TLR5 in organ cultured mouse parietal bones increased bone resorption in a time- and concentration-dependent manner by a process inhibited by OPG and bisphosphonate, showing the crucial role of RANKL-induced osteoclast formation. In addition, the number of osteoclasts, expression of osteoclastic genes and osteoclastogenic transcription factors were increased. In the bones and in osteoblasts isolated from the bones, TLR2 agonists increased the expression of RANKL without affecting OPG, while TLR5 activation resulted in enhanced RANKL and decreased OPG. Activation of both TLR2 and TLR5 stimulated the expression in both bones and osteoblasts of prostaglandins and pro-inflammatory cytokines, known to stimulate RANKL. By blocking the cytokines and prostaglandin, we showed that TLR2 and TLR5 induced bone resorption and RANKL expression are independent of these molecules.

    Activation of TLR2, but not TLR5, in mouse bone marrow macrophage cultures inhibited RANKL-induced osteoclast formation, an effect not observed in committed pre-osteoclasts.

    Local administration in vivo of TLR2 and TLR5 agonists on the top of mouse skull bones enhanced local and systemic osteoclast formation and bone resorption. Using knockout mice, we showed that the effects by LPS from P. gingivalis (used as TLR2 agonist) and flagellins (used as TLR5 agonists) are explicit for TLR2 and TLR5 ex vivo and in vivo, respectively.

    These data show that stimulation of TLR2 and TLR5 results in bone resorption in vitro and in vivo mediated by increased RANKL in osteoblasts and thus may be one mechanism for developing inflammatory bone loss.

    Interestingly, histological analyses of skull bones of mice treated locally with TLR2 and TLR5 agonists revealed that the bones not only reacted with locally increased osteoclastogenesis (osteoclast formation), but also with locally increased new bone formation. This was observed on both periosteal and endosteal sides of the bones, as well as in the bone marrow compartment. The formation of new bone was seen close to osteoclasts in some parts, but also in other areas, distant from these cells. The response was associated with active, cuboidal osteoblasts, extensive cell proliferation and increased expression of genes coding for bone matrix proteins and osteoblastic transcription factors.

    In conclusion, activation of TLR2 and TLR5 in osteoblasts results in bone loss associated with enhanced osteoclast formation and bone resorption, as well as with increased osteoblast differentiation and new bone formation, indicating that inflammation causes bone modeling. The data provide an explanation why LPS from P. gingivalis and flagellin from flagella-expressing bacteria can stimulate bone loss. Since TLR2 and TLR5 can be activated not only by bacterial components, but also by endogenous ligands produced in inflammatory processes, the data also contribute to the understanding of inflammation induced bone loss in autoimmune diseases. Hopefully, these findings will contribute to the development of treatment strategies for inflammation induced bone loss.

  • 266.
    Kassem, Ali
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Lindholm, Catharina
    Lerner, Ulf
    Umeå University, Faculty of Medicine, Department of Odontology.
    Toll-Like Receptor 2 Stimulation on Osteoblasts Mediates Staphylococcus aureus-Induced Bone Resorption and Osteoclastogenesis through Enhanced RANKL Manuscript (preprint) (Other academic)
    Abstract [en]

    Severe Staphylococcus aureus (S. aureus) infections pose an immense threat to population health and constitute a great burden for the health care worldwide. Inter alia, S. aureus septic arthritis is a disease with high mortality and morbidity caused by destruction of the infected joints and systemic bone loss, osteoporosis. Toll-Like receptors (TLRs) are innate immune cell receptors recognizing a variety of microbial molecules and structures. S. aureus recognition via TLR2 initiates a signaling cascade resulting in production of various cytokines, but the mechanisms by which S. aureus causes rapid and excessive bone loss are still unclear. Therefore, we investigated how S. aureus regulates periosteal/endosteal osteoclast formation and bone resorption.

    S. aureus stimulation of neonatal mouse parietal bone induced ex vivo bone resorption and osteoclastic gene expression. This effect was associated with increased mRNA and protein expression of receptor activator of NF-kB ligand (RANKL) without significant change in osteoprotegerin (OPG) expression. S. aureus also increased the expression of proinflammatory cytokines and prostaglandins in parietal bones but the stimulatory effect of S. aureus on bone resorption and Tnfsf11 mRNA expression was independent of these cytokines and prostaglandins. Stimulation of isolated periosteal osteoblasts with S. aureus also resulted in increased expression of Tnfsf11 mRNA, an effect lost in osteoblasts from Tlr2 knockout mice. S. aureus stimulated osteoclastogenesis in isolated periosteal cells without affecting RANKL-stimulated resorption.  In contrast, S. aureus inhibited RANKL-induced osteoclast formation in bone marrow macrophages. These data show that S. aureus enhances bone resorption and periosteal osteoclast formation by increasing osteoblast RANKL production through TLR2. In contrast, S. aureus inhibits osteoclastogenesis from bone marrow derived precursors. Our study indicates the importance of using different in vitro approaches for studies of regulation of osteoclastogenesis by S. aureus to obtain better understanding of the complex mechanisms of S. aureus bone destruction in vivo.

  • 267.
    Kassem, Ali
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Lindholm, Catharina
    Lerner, Ulf H.
    Umeå University, Faculty of Medicine, Department of Odontology. Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition at Institute for Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
    Toll-Like Receptor 2 Stimulation of Osteoblasts Mediates Staphylococcus Aureus Induced Bone Resorption and Osteoclastogenesis through Enhanced RANKL2016In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 6, article id e0156708Article in journal (Refereed)
    Abstract [en]

    Severe Staphylococcus aureus (S. aureus) infections pose an immense threat to population health and constitute a great burden for the health care worldwide. Inter alia, S. aureus septic arthritis is a disease with high mortality and morbidity caused by destruction of the infected joints and systemic bone loss, osteoporosis. Toll-Like receptors (TLRs) are innate immune cell receptors recognizing a variety of microbial molecules and structures. S. aureus recognition via TLR2 initiates a signaling cascade resulting in production of various cytokines, but the mechanisms by which S. aureus causes rapid and excessive bone loss are still unclear. We, therefore, investigated how S. aureus regulates periosteal/endosteal osteoclast formation and bone resorption. S. aureus stimulation of neonatal mouse parietal bone induced ex vivo bone resorption and osteoclastic gene expression. This effect was associated with increased mRNA and protein expression of receptor activator of NF-kappa B ligand (RANKL) without significant change in osteoprotegerin (OPG) expression. Bone resorption induced by S. aureus was abolished by OPG. S. aureus increased the expression of osteoclastogenic cytokines and prostaglandins in the parietal bones but the stimulatory effect of S. aureus on bone resorption and Tnfsf11 mRNA expression was independent of these cytokines and prostaglandins. Stimulation of isolated periosteal osteoblasts with S. aureus also resulted in increased expression of Tnfsf11 mRNA, an effect lost in osteoblasts from Tlr2 knockout mice. S. aureus stimulated osteoclastogenesis in isolated periosteal cells without affecting RANKL-stimulated resorption. In contrast, S. aureus inhibited RANKL-induced osteoclast formation in bone marrow macrophages. These data show that S. aureus enhances bone resorption and periosteal osteoclast formation by increasing osteoblast RANKL production through TLR2. Our study indicates the importance of using different in vitro approaches for studies of how S. aureus regulates osteoclastogenesis to obtain better understanding of the complex mechanisms of S. aureus induced bone destruction in vivo.

  • 268.
    Kelk, Peyman
    Umeå University, Faculty of Medicine, Odontology, Periodontology. Umeå University, Faculty of Medicine, Clinical Microbiology, Clinical Bacteriology.
    Inflammatory cell death of human macrophages induced by Aggregatibacter actinomycetemcomitans leukotoxin2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aggregatibacter (Actinobacillus) actinomycetemcomitans is a bacterium mainly associated with aggressive forms of periodontitis. Among its virulence factors, a leukotoxin is suggested to play an important role in the pathogenicity. Periodontal infections with strains producing high levels of the leukotoxin are strongly associated with severe disease. Leukotoxin selectively kills human leukocytes and can disrupt the local defense mechanisms. Previous studies examining the role of the leukotoxin in host-parasite interactions have mainly focused on polymorphonuclear leukocytes (PMNs). In the inflamed periodontium, macrophages play a significant role in the regulation of the inflammatory reactions and the tissue breakdown and remodeling.

    Thus, the aim of this dissertation was to investigate death mechanisms of human macrophages exposed to leukotoxin.

    Human lymphocytes, PMNs, and monocytes/macrophages isolated from venous blood were exposed to purified leukotoxin or live A. actinomycetemcomitans strains producing variable levels or no leukotoxin. Different target cells were characterized by their expression of cell surface molecules. Cell death and viability were studied by examining cell membrane integrity and morphological alterations. Further, processes and cellular markers involved in apoptosis and necrosis were investigated. The expression and activation of pro-inflammatory cytokines of the leukotoxin-challenged leukocytes were examined at the mRNA and protein level. The biological activity of the secreted cytokines was investigated by testing the culture supernatants in a bone resorption assay. Additionally, different intracellular signaling pathways involved in the pro-inflammatory response from the macrophages were examined.

    Monocytes/macrophages were the most sensitive leukocytes for A. actinomycetemcomitans leukotoxin-induced lysis. This process in monocytes/ macrophages involved caspase-1 activation, and in addition, leukotoxin triggered abundant activation and secretion of IL-1β from these cells. The secreted IL-1β was mainly the 17 kDa bioactive protein and stimulated bone resorption. This activity could be blocked by an IL-1 receptor antagonist. When live bacteria were used, the A. actinomycetemcomitans-induced IL-1β secretion from human macrophages was mainly caused by the leukotoxin. Closer examination of the macrophages exposed to leukotoxin revealed that the induced cell death proceeded through a process that differed from classical apoptosis and necrosis. Interestingly, this process resembled a newly discovered death mechanism termed pyroptosis. The extensive leukotoxin induced IL-1β secretion did not correlate to increased levels of mRNA for IL-1β. It was mainly mediated by caspase-1 activation, since blocking it by a specific inhibitor also abolished the secretion of IL-1β. A similar pattern, but at much lower level, was seen for IL-18.

    In conclusion, these results show that A. actinomycetemcomitans leukotoxin induces a death process in human macrophages leading to a specific and excessive pro-inflammatory response. Our results indicate that this novel virulence mechanism of leukotoxin may play an important role in the pathogenic potential of A. actinomycetemcomitans.

  • 269.
    Kelk, Peyman
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, Periodontology. Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Abd, Hadi
    Centre for Microbiological Preparedness, Swedish Institute for Infectious Disease Control, Solna, Sweden.
    Claesson, Rolf
    Umeå University, Faculty of Medicine, Department of Odontology, Oral Microbiology.
    Sandström, Gunnar
    Centre for Microbiological Preparedness, Swedish Institute for Infectious Disease Control, Solna, Sweden ; Department of Laboratory Medicine, Division of Clinical Microbiology, Karolinska Institute, Stockholm, Sweden.
    Sjöstedt, Anders
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Johansson, Anders
    Umeå University, Faculty of Medicine, Department of Odontology, Periodontology.
    Inflammatory cell death of human macrophages in response to Aggregatibacter actinomycetemcomitans leukotoxinManuscript (Other academic)
    Abstract [en]

    Aggregatibacter (Actinobacillus) actinomycetemcomitans is a facultative anaerobic gram-negative bacterium associated with severe forms of periodontitis. A leukotoxin, which belongs to the Repeats in Toxin (RTX) family, is believed to be one of its virulence factors and to play an important role in the bacterium's pathogenicity. This toxin selectively kills human leukocytes by inducing apoptosis and lysis. Here we report that leukotoxin-induced cell death of macrophages proceeded through a process that differs from the classical characteristics of apoptosis and necrosis. Interestingly, this process resembled pyroptosis, and resulted in an extensive leukotoxin-induced interleukin-1β (IL-1β) secretion. This activation was mainly mediated by caspase-1 activation, while the levels of mRNA for IL-1β were not affected by the leukotoxin. A similar pattern was seen for IL-18, but the level of that cytokine was about 30 times lower. Both of these cytokines are synthesized as biologically inactive precursors and need active caspase-1 for their activation and secretion. In conclusion, A. actinomycetemcomitans leukotoxin induces a pyroptosis-like cell death in human macrophages and that leads to a specific and excessive pro-inflammatory response. This novel virulence mechanism of the leukotoxin may play an important role in the pathogenic potential of this bacterium.

  • 270. Keller, Mette Kirstine
    et al.
    Hasslöf, Pamela
    Umeå University, Faculty of Medicine, Department of Odontology, Pediatric Dentistry.
    Stecksén-Blicks, Christina
    Umeå University, Faculty of Medicine, Department of Odontology, Pediatric Dentistry.
    Twetman, Svante
    Co-aggregation and growth inhibition of probiotic lactobacilli and clinical isolates of mutans streptococci: an in vitro study2011In: Acta Odontologica Scandinavica, ISSN 0001-6357, E-ISSN 1502-3850, Vol. 69, no 5, p. 263-268Article in journal (Refereed)
    Abstract [en]

    Objective: Co-aggregation and growth inhibition abilities of probiotic bacteria may play a key role in their interference with the oral biofilm. The aim was to investigate the in vitro ability of selected commercial probiotic lactobacilli to co-aggregate and inhibit growth of oral mutans steptococci isolated from adults with contrasting levels of caries.

    Materials and methods: Mutans streptococci (MS) strains were isolated from caries-free (n = 3) and caries-susceptible (n = 5) young adults and processed with eight commercial probiotic lactobacilli strains. One laboratory reference strain (S. mutans Ingbritt) was selected as control. Co-aggregation was determined spectrophotometrically and growth inhibition was assessed with the agar overlay technique.

    Results: All probiotic lactobacilli showed an ability to co-aggregate with the isolated MS strains. Statistically significant differences (p < 0.05) were found between strains from different individuals when compared with the reference strain. The selected lactobacilli inhibited MS growth, but the ability varied between the strains and was clearly related to pH. No differences were observed between the different MS strains from caries-free and caries-susceptible individuals.

    Conclusions: The selected lactobacilli displayed co-aggregation activity and inhibited growth of clinical mutans streptococci. The growth inhibition was strain-specific and dependent on pH and cell concentration. The findings indicate that the outcome of lactobacilli-derived probiotic therapy might vary between individuals and depend on the specific strain used.

  • 271. Keller, MK
    et al.
    Hasslöf, Pamela
    Umeå University, Faculty of Medicine, Department of Odontology, Pediatric Dentistry.
    Dahlen, G
    Stecksen-Blicks, Christina
    Umeå University, Faculty of Medicine, Department of Odontology, Pediatric Dentistry.
    Twetman, S
    Probiotic supplements (Lactobacillus reuteri DSM 17938 and ATCC PTA 5289) do not affect regrowth of mutans streptococci after full-mouth disinfection with chlorhexidine: a randomized controlled multicenter trial2012In: Caries Research, ISSN 0008-6568, E-ISSN 1421-976X, Vol. 46, no 2, p. 140-146Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate the effectiveness of tablets containing two probiotic Lactobacillus reuteri strains in inhibiting regrowth of salivary mutans streptococci (MS) after full-mouth disinfection (FMD) with chlorhexidine. The null hypothesis was that the levels of MS would not differ in comparison with a placebo protocol. The study population was comprised of 62 young adults (mean age 23 years) with moderate or high counts of salivary MS who volunteered after informed consent. The study was a double-blinded randomized controlled trial with two parallel groups. After a 3-day chlorhexidine regimen, the subjects were randomly assigned to a test group (n = 32) with probiotic lozenges (2/day) or a placebo group (n = 30). The intervention period was 6 weeks, and stimulated whole saliva was collected at baseline and after 1, 6, and 12 weeks. The samples were processed for MS by a chair-side test and DNA-DNA hybridization as an estimate of 19 bacterial strains associated with oral health and disease. There was no significant difference between the groups at inclusion, and FMD reduced the salivary MS levels significantly in both groups. The MS suppression lasted less than 6 weeks and there were no statistical differences in salivary MS regrowth between the test and control groups at any of the follow-ups. Likewise, there were no major differences in the regrowth patterns of the checkerboard panel between the two groups. We conclude that daily oral administration of L. reuteri did not seem to affect or delay the regrowth of salivary MS after FMD with chlorhexidine. Copyright (c) 2012 S. Karger AG, Basel

  • 272.
    Kemoli, Arthur
    et al.
    University of Nairobi, Kenya.
    Gjørup, Hans
    Aarhus University, Denmark.
    Nørregaard, Marie-Louise Milvang
    Aarhus University, Denmark.
    Lindholm, Mark
    Umeå University, Faculty of Medicine, Department of Odontology.
    Mulli, Tonnie
    Nairobi University, Kenya.
    Johansson, Anders
    Umeå University, Faculty of Medicine, Department of Odontology.
    Haubek, Dorte
    Aarhus University, Denmark.
    Prevalence and impact of infant oral mutilation on dental occlusion and oral health-related quality of life among Kenyan adolescents from Maasai Mara2018In: BMC Oral Health, ISSN 1472-6831, E-ISSN 1472-6831, Vol. 18, no 1, article id 173Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Infant Oral Mutilation (IOM) includes germectomy and early extraction of primary and permanent incisors and canines, primarily in the lower jaw. The aim of the present study was to examine the prevalence and impact of IOM, involving the removal of mandibular permanent incisors and/or canines, on dental occlusion and Oral Health-Related Quality of Life (OHRQoL) among Kenyan adolescents from Maasai Mara.

    METHODS: In a cross-sectional study, 284 adolescents (14-18 yrs. of age) participated in an oral examination and an interview, using a structured questionnaire on age, gender, medical history, and IOM practice. For the analysis of the dental occlusion, participants with IOM, in terms of absence of two or more permanent teeth in the mandibular incisor and/or canine tooth segments (IOM group), were compared to participants who had all six incisors and canines present in the oral cavity (control group). OHRQoL was assessed using child perception questionnaire (CPQ11-14).

    RESULTS: The majority of the participants (61%) had been exposed to IOM, among whom 164 (95%) had absence of two mandibular central incisors. More individuals in the IOM group had maxillary overjet exceeding 5 mm than in the control group (50.9% vs. 20%, p <  0.001). Nineteen (11%) subjects in the IOM group had mesial occlusion in contrast to none in the control group (p <  0.001). The mean and median total CPQ scores and the mean and median CPQ domain scores were low in both groups with no significant differences between the groups.

    CONCLUSIONS: Approximately two-thirds of the study population presented with IOM, with the majority of them missing two mandibular permanent central incisors. Although some participants with IOM had substantial maxillary overjet and mesial occlusion, only few of them showed substantial effect on their OHRQoL.

  • 273.
    Kindstedt, Elin
    Umeå University, Faculty of Medicine, Department of Odontology.
    Novel Insights into Inflammatory Disturbed Bone Remodelling2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Bone is a dynamic tissue that is continuously remodelled, a process that requires equal amounts of osteoclastic bone resorption and osteoblastic bone formation. Inflammation may disturb the equilibrium and result in local and/or systemic bone loss. Negative bone mass balance occurs in several chronic inflammatory diseases, e.g. periodontitis and rheumatoid arthritis (RA). The aetiology of periodontitis is infectious, while RA is an autoimmune disease. Despite aetiological differences, an association between the two diseases has been established but it is not known if they are causally related. Periodontitis may develop when the inflammatory process, initially restricted to the gingiva (gingivitis), further invades the periodontium and causes bone resorption. The cellular and molecular mechanisms underlying the transition from gingivitis to periodontitis are not fully elucidated. Osteoclast formation is dependent on receptor activator of nuclear factor kappa B ligand (RANKL), but how osteoclast precursors are recruited to the jawbone is poorly understood. A family of cytokines named chemokines has been reported to possess such properties and increasing evidence points towards their involvement in the pathogenesis of chronic inflammatory diseases.

    The overall aim of this thesis was to gain extended knowledge about the role of chemokines and a newly discovered family of leukocytes named innate lymphoid cells (ILCs) in periodontitis and concomitant inflammatory disturbed bone remodelling. Furthermore, the aim was also to study the association between periodontitis and RA.

    We identified increased serum levels of monocyte chemoattractant protein (MCP)-1 and CCL11 in individuals with periodontitis. Moreover, a robust correlation between the two chemokines and periodontitis was detected in a weighted analysis of inflammatory markers, subject characteristics and periodontitis parameters. We detected higher MCP-1 levels in periodontitis tissue compared to non-inflamed. Furthermore we demonstrated that human gingival fibroblasts express MCP-1 and CCL11 in response to pro-inflammatory cytokines through NF-κB signalling. Using an inflammatory bone lesion model and primary cell cultures, we discovered that osteoblasts express CCL11 in vivo and in vitro and that the expression increased under inflammatory conditions. Osteoclasts did not express CCL11, but its high affinity receptor CCR3 was upregulated during osteoclast differentiation and found to co-localise with CCL11 on the surface of osteoclasts. Exogenous CCL11 was internalised in osteoclasts, stimulated the migration of osteoclast precursors and increased bone resorption in vitro.

    To analyse if periodontitis precedes RA we analysed marginal jawbone loss in dental radiographs taken in pre-symptomatic RA cases and matched controls. The prevalence of jawbone loss was higher among cases, and the amount of jawbone loss correlated with plasma levels of RANKL.

    In the search of the newly discovered ILCs, we performed flow cytometry analyses on gingivitis and periodontitis tissue samples. We detected twice as many ILCs in periodontitis as in gingivitis. In addition we found RANKL expression on ILC1s (an ILC subset).

    In conclusion, we demonstrated that CCL11 is systemically and locally increased in periodontitis and that the CCL11/CCR3 axis may be activated in inflammatory disturbed bone remodelling. We also found that marginal jawbone loss correlated with plasma levels of RANKL and preceded clinical onset of symptoms of RA. Furthermore, we demonstrated that ILCs are present in periodontitis and represent a previously unknown source of RANKL. 

  • 274.
    Kindstedt, Elin
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Holm, Cecilia Koskinen
    Umeå University, Faculty of Medicine, Department of Odontology.
    Palmqvist, Py
    Umeå University, Faculty of Medicine, Department of Odontology.
    Sjöström, Mats
    Umeå University, Faculty of Medicine, Department of Odontology.
    Lejon, Kristina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Lundberg, Pernilla
    Umeå University, Faculty of Medicine, Department of Odontology.
    Innate lymphoid cells are present in gingivitis and periodontitis2019In: Journal of Periodontology, ISSN 0022-3492, E-ISSN 1943-3670, Vol. 90, no 2, p. 200-207Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Innate lymphoid cells (ILCs) are the most recently identified leukocytes of the immune system and these cells are increasingly acknowledged to play important roles in host defence and tissue repair. ILCs are also contributors of inflammatory diseases such as asthma and colitis. We analyzed the presence and relative proportions of the different ILC subsets (ILC1, ILC2 and ILC3) in gingivitis and periodontitis. Further, we investigated if ILCs express receptor activator of nuclear factor kappa-B ligand (RANKL), a cytokine crucial for osteoclast differentiation and bone resorption.

    METHODS: We collected gingivitis and periodontitis soft tissue and characterized ILC subsets including RANKL expression in single-cell suspensions using flow cytometry.

    RESULTS: ILCs were detected both in gingivitis and periodontitis. The majority of ILCs, in both conditions, were ILC1s. Furthermore, RANKL expression was detected on a fraction of the ILC1s.

    CONCLUSIONS: Our discovery of the presence of ILCs both in gingivitis and periodontitis and concomitant expression of RANKL on a fraction of the ILC1 population suggest that these cells may be of importance in periodontal disease. In addition, our findings provide a new insight into the field of oral immunology.

  • 275.
    Kindstedt, Elin
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Koskinen Holm, Cecilia
    Umeå University, Faculty of Medicine, Department of Odontology.
    Palmqvist, Py
    Umeå University, Faculty of Medicine, Department of Odontology.
    Sjöström, Mats
    Umeå University, Faculty of Medicine, Department of Odontology.
    Lejon, Kristina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Lundberg, Pernilla
    Umeå University, Faculty of Medicine, Department of Odontology.
    Discovery of Innate Lymphoid Cells in Gingivitis and PeriodontitisManuscript (preprint) (Other academic)
    Abstract [en]

    AIM: Innate lymphoid cells (ILCs) are the most recently identified leukocytes of the immune system and these cells are increasingly acknowledged to play important roles in host defence and tissue repair. ILCs can also contribute to inflammatory diseases such as asthma and colitis. We analysed the presence and proportions of the different ILC subsets (ILC1, ILC2 and ILC3) in gingivitis and periodontitis. Furthermore, we investigated if ILCs express nuclear factor kappa-B ligand (RANKL), a cytokine crucial for osteoclast differentiation and bone resorption.

    MATERIALS AND METHODS: We collected gingivitis and periodontitis soft tissue and characterised ILC subsets including RANKL expression in single cell suspensions using flow cytometry.

    RESULTS: Although not statistically significant, the total number of ILCs detected was twice as many in periodontitis compared to gingivitis. The majority of ILCs, in both conditions, were ILC1s with a 2.5-fold increase of ILC1s in periodontitis compared to gingivitis. Furthermore, we found RANKL expression exclusively expressed on ILC1s.

    CONCLUSIONS: Our discovery of the presence of ILCs in gingivitis and periodontitis and concomitant expression of RANKL in ILC1 suggest that these cells may be of importance in periodontal disease. In addition, our findings provide new insights into the field of oral immunology. 

  • 276. Klingberg, Gunilla
    et al.
    Andersson-Wenckert, Ingrid
    Umeå University, Faculty of Medicine, Department of Odontology.
    Grindefjord, Margaret
    Lundin, Sven-Ake
    Ridell, Karin
    Tsilingaridis, Georgios
    Ullbro, Christer
    Specialist paediatric dentistry in Sweden 2008-a 25-year perspective2010In: International Journal of Paediatric Dentistry, ISSN 0960-7439, E-ISSN 1365-263X, Vol. 20, no 5, p. 313-321Article in journal (Refereed)
    Abstract [en]

    Background. Paediatric dentistry in Sweden has been surveyed four times over the past 25 years. During this period postgraduate training, dental health, and the organization of child dental care have changed considerably. Aim. To investigate services provided by specialists in paediatric dentistry in Sweden in 2008, and to compare with data from previous surveys. Design. The same questionnaire was sent to all 30 specialist paediatric dental clinics in Sweden that had been used in previous surveys. Comparisons were made with data from 1983, 1989, 1996 and 2003. Results. Despite an unchanged number of specialists (N = 81 in 2008), the number of referrals had increased by 16% since 2003 and by almost 50% since 1983. There was greater variation in reasons for referrals. The main reason was still dental anxiety/behaviour management problems in combination with dental treatment needs (27%), followed by medical conditions/disability (18%), and high caries activity (15%). The use of different techniques for conscious sedation as well as general anaesthesia had also increased. Conclusions. The referrals to paediatric dentistry continue to increase, leading to a heavy work load for the same number of specialists. Thus, the need for more paediatric dentists remains.

  • 277.
    Klämfeldt, Agneta
    Umeå University, Faculty of Medicine, Department of Odontology, Oral and Maxillofacial Surgery. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Metabolism of articular cartilage proteoglycans in vitro: effects of synovial membrane products and mechanical pressure1982Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The effect of synovial membrane products and mechanical pressure upon the metabolism of articular cartilage proteoglycans has been studied in vitro. The degradation of cartilage proteoglycans was studied in an organ culture system and measured as the release of [35S ] sulphate from prelabelled cartilage. The effect of synovial membrane products upon the synthesis of proteoglycans was studied in a chondrocyte monolayer system and the effect of mechanical pressure upon the synthesis of proteoglycans in an organ culture system. In both types of experiments [35S] sulphate was used as precursor.

    The findings may be summarized as follows

    1 Conditioned synovial medium (control-SM) enhanced the degradation and reduced the synthesis of cartilage proteoglycans. In addition the degradation was further enhanced when the synovial tissue had been cultured in the presence of dextran sulphate.

    2 Conditioned medium from synovial tissue cultured in the presence of indo-methacin (indo-SM), significantly reduced the synthesis of cartilage proteoglycans in chondrocyte cultures and reduced, although non-significantly, the degradation of proteoglycans in whole cartilage cultures.

    3 Addition o f the prostaglandins E1 or E2 (PGE1 or PGE2 ) together with indo-SM to the cartilage cultures greatly enhanced cartilage degradation whereas the addition of PGE1 or PGE2 together with control-SM had no effect compared with that of control-SM alone.

    4 Conditioned medium from synovial tissue cultured in the presence of low doses of glucocorticoids reduced cartilage degradation compared with control-SM. However, addition of control-SM together w ith low concentrations of glucocorticoids to the cartilage cultures significantly enhanced cartilage degradation.

    5 Conditioned medium from synovial tissue cultured with actinomycin D or cycloheximide did not enhance cartilage degradation compared with cartilage cultured alone.

    6 A continuous pressure of approximately 30 kgfcm-2 on cultures of cartilage reduced both the synthesis and the degradation o f cartilage proteoglycans.

    Although it is difficult to extrapolate from the in vitro to the in vivo situation, it is proposed that some factor(s) from the synovial membrane have the capacity to enhance the degradation and reduce the synthesis o f articular cartilage proteoglycans. From these experiments it cannot be completely excluded that treatm ent of arthritic joints with non-steroidal or streroidal anti-inflammatory drugs may result under certain conditions in enhanced joint damage. It is also suggested that under certain conditions the metabolism o f cartilage proteoglycans could be directly affected by mechanical stress.

  • 278. Koch, Göran
    et al.
    Poulsen, Sven
    Twetman, Svante
    University of Copenhagen.
    Stecksén-Blicks, Christina
    Umeå University, Faculty of Medicine, Department of Odontology.
    Caries Prevention2016In: Pediatric dentistry: a clinical approach / [ed] Göran Koch, Sven Poulsen, Ivar Espelid, Dorte Haubek, Wiley-Blackwell, 2016, 3, p. 114-129Chapter in book (Other academic)
    Abstract [en]

    Concepts of caries prevention

    Erupting teeth are healthy, and the first carious lesion and its restoration marks the initiation of a series of treatments that during the tooth’s lifetime will end up in more and more complicated restorations. Today there is sufficient scientific knowledge about the etiology of caries and about factors that interfere in this process in order for us to develop effective preventive strategies. There is no excuse not to use this knowledge in attempts to control caries. Therefore, caries prevention should be given a high priority by the dental profession as well as by governmental authorities. In this context, the pediatric dentist has a very specific responsibility in meeting the challenge of keeping children and adolescents free from caries. For example, very young children with early signs of caries should be given special attention, as they tend to develop more caries compared to children without early signs of caries.

  • 279.
    Kohestani, Cimia
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Lam, Jonas
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Change of convergence angle depending on distance between clinical abutment teeth2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The clinical knowledge and skills of dental students attending to different Swedish universities is constantly under discussion. In this study ten students attending their eighth semester at the Department of Odontology, Faculty of Medicine, Umea University Sweden were recruited to evaluate if it would be more challenging to prepare abutment teeth for fixed partial dentures (FPD) with the abutment teeth far apart in the dental arch. Questioning whether it is more difficult to achieve an adequate total convergence angle (TOC) for FPD with abutment teeth closer to each other than one with them further apart. The hypothesis that teeth further apart give a larger TOC. For the experiment the students used dental mannequins with plastic maxillae and plastic teeth provided by the simulation clinic at the university. Their task was to prepare for two separate FPD, one with the abutment teeth 14; 16 and a second 21; 13; 15. After preparation, the teeth were drilled and had metal posts placed in them, the posts representing a normal that the TOC could be measured against. Still photos of the plastic maxillae were taken using the program Shape 3D Viewer. A tangent was drawn to measure the TOC. An adequate TOC for crown retention was considered: 10-22 degrees in both mesio-distal and bucco-palatinal plane axis. The results for the two tested models of FPD were relatively similar, likely because the students got to practice preparation for the shorter and FPD first. In conclusion, this study showed no noteworthy difference between the first and second FPD preparation.

  • 280.
    Konradsson, Katarina
    et al.
    Umeå University, Faculty of Medicine, Odontology, Dental Hygiene.
    Claesson, Rolf
    Umeå University, Faculty of Medicine, Odontology, Oral Microbiology.
    van Dijken, Jan
    Umeå University, Faculty of Medicine, Odontology, Dental Hygiene.
    Mutans streptococci and lactobacilli in plaque on a leucite-reinforced dental ceramic and on a calcium aluminate cement.2006In: Clinical Oral Investigations, ISSN 1432-6981, E-ISSN 1436-3771, Vol. 10, no 3, p. 175-180Article in journal (Refereed)
    Abstract [en]

    In this in vivo study, the proportions of mutans streptococci and lactobacilli in plaque were examined (1) on proximal surfaces of bonded, leucite-reinforced ceramic crowns and (2) on class V restorations of calcium aluminate cement (CAC). The examined proportions were intraindividually compared with those of resin composite and enamel. Mutans streptococci and lactobacilli in samples from plaque that was accumulated for 10 days on the following surfaces were determined by cultivation on blood agar plates and species-selective plates: (1) proximal leucite-reinforced ceramic crown, class II composite and enamel (n=11); and (2) class V restoration of CAC and composite, and enamel (n=17). Mutans streptococci and lactobacilli in the samples were distributed in three groups: 0, >0-1, and >1% of total bacteria. The surfaces with detected mutans streptococci were similarly distributed between the materials and enamel. The highest proportion of mutans streptococci and lactobacilli were observed on ceramic followed by composite and enamel. A higher proportion of lactobacilli, but not of mutans streptococci, was detected on enamel compared to CAC and composite. However, no significant differences were found between the surfaces. Conclusively, the materials investigated did not show different relative proportions of mutans streptococci and lactobacilli in plaque, compared to enamel.

  • 281.
    Koskinen, Cecilia
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Persson, Emelie
    Umeå University, Faculty of Medicine, Department of Odontology.
    Baldock, Paul
    Stenberg, Åsa
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
    Boström, Ingrid
    Umeå University, Faculty of Medicine, Department of Odontology.
    Matozaki, Takashi
    Oldenborg, Per-Arne
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
    Lundberg, Pernilla
    Umeå University, Faculty of Medicine, Department of Odontology.
    Lack of CD47 impairs bone cell differentiation and results in an osteopenic phenotype in vivo due to impaired signal regulatory protein α (SIRPα) signaling2013In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 288, no 41, p. 29333-29344Article in journal (Refereed)
    Abstract [en]

    Here, we investigated whether the cell surface glycoprotein CD47 was required for normal formation of osteoblasts and osteoclasts and to maintain normal bone formation activity in vitro and in vivo. In parathyroid hormone or 1α,25(OH)2-vitamin D3 (D3)-stimulated bone marrow cultures (BMC) from CD47(-/-) mice, we found a strongly reduced formation of multinuclear tartrate-resistant acid phosphatase (TRAP)(+) osteoclasts, associated with reduced expression of osteoclastogenic genes (nfatc1, Oscar, Trap/Acp, ctr, catK, and dc-stamp). The production of M-CSF and RANKL (receptor activator of nuclear factor κβ ligand) was reduced in CD47(-/-) BMC, as compared with CD47(+/+) BMC. The stromal cell phenotype in CD47(-/-) BMC involved a blunted expression of the osteoblast-associated genes osterix, Alp/Akp1, and α-1-collagen, and reduced mineral deposition, as compared with that in CD47(+/+) BMC. CD47 is a ligand for SIRPα (signal regulatory protein α), which showed strongly reduced tyrosine phosphorylation in CD47(-/-) bone marrow stromal cells. In addition, stromal cells lacking the signaling SIRPα cytoplasmic domain also had a defect in osteogenic differentiation, and both CD47(-/-) and non-signaling SIRPα mutant stromal cells showed a markedly reduced ability to support osteoclastogenesis in wild-type bone marrow macrophages, demonstrating that CD47-induced SIRPα signaling is critical for stromal cell support of osteoclast formation. In vivo, femoral bones of 18- or 28-week-old CD47(-/-) mice showed significantly reduced osteoclast and osteoblast numbers and exhibited an osteopenic bone phenotype. In conclusion, lack of CD47 strongly impairs SIRPα-dependent osteoblast differentiation, deteriorate bone formation, and cause reduced formation of osteoclasts.

  • 282.
    Kou, Wen
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, Dental Materials Science.
    Li, Decong
    Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.
    Qiao, Jiyan
    Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.
    Chen, Li
    Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.
    Ding, Yansheng
    Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.
    Sjögren, Göran
    Umeå University, Faculty of Medicine, Department of Odontology, Dental Materials Science.
    A 3D numerical simulation of stress distribution and fracture process in a zirconia-based FPD framework2011In: Journal of Biomedical Materials Research. Part B - Applied biomaterials, ISSN 1552-4973, E-ISSN 1552-4981, Vol. 96B, no 2, p. 376-385Article in journal (Refereed)
    Abstract [en]

    In this study, a numerical approach to the fracture behavior in a three-unit zirconia-based fixed partial denture (FPD) framework was made under mechanical loading using a newly developed three-dimensional (3D) numerical modeling code. All the materials studied were treated heterogeneously and Weibull distribution law was applied to describe the heterogeneity. The Mohr-Coulomb failure criterion with tensile strength cut-off was utilized to judge whether the material was in an elastic or failed state. For validation, the fracture pattern obtained from the numerical modeling was compared with a laboratory test; they largely correlated with each other. Similar fracture initiation sites were detected both in the numerical simulation and in an earlier fractographic analysis. The numerical simulation applied in this study clearly described the stress distribution and fracture process of zirconia-based FPD frameworks, information that could not be gained from the laboratory tests alone. Thus, the newly developed 3D numerical modeling code seems to be an efficient tool for prediction of the fracture process in ceramic FPD frameworks.

  • 283.
    Kou, Wen
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, Dental Materials Science.
    Molin, Margareta
    Umeå University, Faculty of Medicine, Department of Odontology, Prosthetic Dentistry.
    Sjögren, Göran
    Umeå University, Faculty of Medicine, Department of Odontology, Dental Materials Science.
    Surface roughness of five different dental ceramic core materials after grinding and polishing2006In: Journal of Oral Rehabilitation, ISSN 0305-182X, E-ISSN 1365-2842, Vol. 33, no 2, p. 117-124Article in journal (Refereed)
    Abstract [en]

    In clinical practice, core materials can be exposed after adjustments are made to previously-luted all-ceramic restorations. The purpose of this study was to evaluate the surface roughness of five different dental ceramic core materials after grinding and polishing. Five different ceramic core materials, Vita In-Ceram Alumina, Vita In-Ceram Zirconia, IPS Empress 2, Procera AllCeram, and Denzir were evaluated. Vita Mark II was used as a reference material. The surface roughness, Ra value (mum), was registered using a profilometer. The measurements were made before and after grinding with diamond rotary cutting instruments and after polishing with the Sof-Lex system. The surface of representative specimens was evaluated qualitatively using scanning electron microscopy (SEM). Results were statistically analysed using analysis of variance (anova) supplemented with Scheffe's and Bonferroni multiple-comparison tests. Before grinding, Procera AllCeram and Denzir had the smoothest surfaces, while IPS Empress 2 had the coarsest. After grinding, all materials except IPS Empress 2 became coarser. Polishing with Sof-Lex provided no significant (P > 0.05) differences between Denzir, Vita Mark II and IPS Empress 2 or between Procera AllCeram and In-Ceram Zirconia. There were no significant differences (P > 0.05) either between the ground and the polished Procera AllCeram or In-Ceram Alumina specimens. Polishing of Denzir, IPS Empress 2 and In-Ceram Zirconia made the surfaces smoother compared with the state after grinding, whereas the polishing effect on Procera AllCeram and In-Ceram Alumina was ineffective. The findings of the SEM evaluation were consistent with the profilometer readings.

  • 284.
    Kou, Wen
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, Dental Materials Science.
    Qiao, Jiyan
    Chinese Academy of Sciences, Beijing, China.
    Li, Decong
    Chinese Academy of Sciences, Beijing, China.
    Chen, Li
    Chinese Academy of Sciences, Beijing, China.
    Ding, Yansheng
    Chinese Academy of Sciences, Beijing, China.
    Sjögren, Göran
    Umeå University, Faculty of Medicine, Department of Odontology, Dental Materials Science.
    A 3-D numerical simulation of the fracture process in three-unit FPD frameworks2009Conference paper (Other academic)
  • 285.
    Kou, Wen
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, Dental Materials Science. Umeå University, Faculty of Medicine, Department of Odontology.
    Sjögren, Göran
    Umeå University, Faculty of Medicine, Department of Odontology, Dental Materials Science.
    Fracture behaviour of zirconia FPDs substructures: fractographic analysis of zirconia2010In: Journal of Oral Rehabilitation, ISSN 0305-182X, E-ISSN 1365-2842, Vol. 37, no 4, p. 292-299Article in journal (Refereed)
    Abstract [en]

     The purpose of this study was to evaluate the occurrence of superficial flaws after machining and to identify fracture initiation and propagation in three-unit heat-treated machined fixed partial dentures (FPDs) substructures made of hot isostatic pressed (HIPed) yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) after loaded to fracture. Four three-unit HIPed Y-TZP-based FPDs substructures were examined. To evaluate the occurrence of superficial flaws after machining, the surfaces were studied utilizing a fluorescent penetrant method. After static loading to fracture, characteristic fracture features on both mating halves of the fractured specimens were studied using a stereomicroscope and a scanning electron microscope. Grinding grooves were clearly visible on the surfaces of the machined FPDs substructures, but no other flaws could be seen with the fluorescent penetrant method. After loading to fracture, the characteristic fracture features of arrest lines, compression curl, fracture mirror, fracture origin, hackle and twist hackle were detected. These findings indicated that the decisive fracture was initiated at the gingival embrasure of the pontic in association with a grinding groove. Thus, in three-unit heat-treated machined HIPed Y-TZP FPDs substructures, with the shape studied in this study, the gingival embrasure of the pontic seems to be a weak area providing a location for tensile stresses when they are occlusally loaded. In this area, fracture initiation may be located to a grinding groove.

  • 286.
    Kou, Wen
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Tsukasa, Akasaka
    Department of Biomedical Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan..
    Watari, Fumio
    Department of Biomedical Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan..
    Sjögren, Göran
    Umeå University, Faculty of Medicine, Department of Odontology.
    An in vitro evaluation of the biological effects of carbon nanotube-coated dental zirconia2013In: ISRN Dentistry, ISSN 2090-4371, E-ISSN 2090-438X, Vol. 2013, no Article ID 296727Article in journal (Refereed)
    Abstract [en]

    The purpose of this study is to evaluate functionalized multiwalled carbon nanotubes (fMWCNTs) as a potential coating material for dental zirconia from a biological perspective: its effect on cell proliferation, viability, morphology, and the attachment of an osteoblast-like cell. Osteoblast-like (Saos-2) cells were seeded on uncoated and fMWCNT-coated zirconia discs and in culture dishes that served as controls. The seeding density was 104 cells/cm2, and the cells were cultured for 6 days. Cell viability, proliferation and attachment of the Saos-2 cells were studied. The results showed that Saos-2 cells were well attached to both the uncoated and the fMWCNT-coated zirconia discs. Cell viability and proliferation on the fMWCNT-coated zirconia discs were almost the same as for the control discs. Better cell attachment was seen on the fMWCNT-coated than on the uncoated zirconia discs. In conclusion, fMWCNTs seem to be a promising coating material for zirconia-based ceramic surfaces to increase the roughness and thereby enhance the osseointegration of zirconia implants.

  • 287. Kragelund, C
    et al.
    Reibel, J
    Hadler-Olsen, E S
    Hietanen, J
    Johannessen, A C
    Kenrad, B
    Nylander, Karin
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Puranen, M
    Rozell, B
    Salo, T
    Syrjänen, S
    Søland, T M
    van der Waal, I
    van der Wal, J E
    Warfvinge, G
    Scandinavian fellowship for oral pathology and oral medicine: statement on oral pathology and oral medicine in the European dental curriculum2010In: Journal of Oral Pathology & Medicine, ISSN 0904-2512, E-ISSN 1600-0714, Vol. 39, no 10, p. 800-801Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: For many years, dentists have migrated between the Scandinavian countries without an intentionally harmonized dental education. The free movement of the workforce in the European Union has clarified that a certain degree of standardization or harmonization of the European higher education acts, including the dental education, is required. As a result of the Bologna process, the Association for Dental Education in Europe and the thematic network DentEd have generated guidelines in the document 'Profile and Competences for the European Dentist' (PCD). This document is meant to act as the leading source in revisions of dental curricula throughout Europe converging towards a European Dental Curriculum. In order to render the best conditions for future curriculum revisions providing the best quality dentist we feel obliged to analyse and comment the outlines of oral pathology and oral medicine in the PCD.

    METHODS: The representatives agreed upon definitions of oral pathology and oral medicine, and competences in oral pathology and oral medicine that a contemporary European dentist should master. The competences directly related to oral pathology and oral medicine were identified, within the PCD.

    RESULTS: The subject representatives suggested eighteen additions and two rewordings of the PCD, which all were substantiated by thorough argumentation.

    PERSPECTIVES: Hopefully, this contribution will find support in future revisions of the PCD in order to secure the best quality dental education.

  • 288. Kragelund, C.
    et al.
    Reibel, J.
    Hietanen, J.
    Hadler-Olsen, E.
    Johannessen, A. C.
    Kenrad, B.
    Nylander, Karin
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Puranen, M.
    Salo, T.
    Syrjanen, S.
    Soland, T. M.
    van der Waal, I.
    van der Wal, J. E.
    Warfvinge, G.
    Scandinavian fellowship for oral pathology and oral medicine: guidelines for oral pathology and oral medicine in the dental curriculum2012In: European journal of dental education, ISSN 1396-5883, E-ISSN 1600-0579, Vol. 16, no 4, p. 246-253Article in journal (Refereed)
    Abstract [en]

    In Scandinavia, as in many European countries, most patients consult their general dentist once a year or more. This gives the dentist a unique opportunity and an obligation to make an early diagnosis of oral diseases, which is beneficial for both the patient and the society. Thus, the dentist must have knowledge of clinical symptoms, local and systemic signs and clinical differential diagnoses to make an accurate diagnosis. The dentist must be competent in selecting appropriate diagnostic tests, for example, tissue biopsy and microbiological samples, and conducting them correctly, as well as in interpreting test results and taking appropriate action accordingly. Furthermore, the dentist must be aware of diseases demanding multidisciplinary cooperation and be able to recognise his/her professional limitation, and to refer to other specialists when required. The dental curriculum changes over time as new approaches, treatments and diagnostic possibilities develop. Likewise, the role of the dentist in the community changes and may vary in different countries. As members of the Scandinavian Fellowship for Oral Pathology and Oral Medicine and subject representatives of oral pathology and oral medicine, we feel obliged to contribute to the discussion of how the guidelines of the dental curriculum support the highest possible standards of dental education. This article is meant to delineate a reasonable standard of oral pathology and oral medicine in the European dental curriculum and to guide subject representatives in curriculum development and planning. We have created an advisory topic list in oral pathology and oral medicine.

  • 289.
    Kreiner, Marcelo
    Umeå University, Faculty of Medicine, Department of Odontology, Oral and Maxillofacial Radiology.
    Craniofacial pain of cardiac origin: an interdisciplinary study2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Referred pain is frequently associated with misdiagnosis and unnecessary therapy directed to the pain location instead of its origin. When craniofacial pain is the sole symptom of myocardial ischemia, failure to recognize its cardiac source can endanger the patient. In particular, patients with acute myocardial infarction (AMI) who do not experience chest pain run a very high risk of misdiagnosis and death. Pain that is limited to the craniofacial region during myocardial ischemia has so far been described only in case reports and its overall prevalence is unknown. Experimental research in animals suggests a vagal involvement in the pathological mechanisms of cardiac pain referred to the face.

    The aim of this study was to gain knowledge about the prevalence, clinical characteristics and possible mechanisms of craniofacial pain of cardiac origin, in order to improve the clinician’s ability to make a correct diagnosis. It was hypothesized that the quality of craniofacial pain from cardiac versus dental origin would differ, implying a high diagnostic validity. It was also hypothesized that craniofacial pain can be the sole symptom of a prodromal (pre-infarction) angina episode and that this pain location would be especially associated with cardiac ischemia in the areas more densely innervated by vagal afferent fibres.

    The study group was comprised of consecutive patients who experienced craniofacial pain of a verified cardiac (n=326) or dental (n=359) origin. Demographic details on age, gender and pain characteristics (location, quality and intensity) were assessed in both groups. Cardiovascular risk factors, cardiac diagnosis and ECG signs of ischemia were also assessed in the cardiac pain group. Ethics approval and informed consent for each patient was obtained.

    Craniofacial pain was found to be the sole symptom of myocardial ischemia in 6% of patients and was the sole symptom of an AMI in 4% of patients; this craniofacial pain was more prevalent in women (p=0.031). In those patients without chest pain, it was the most frequent pain location and was the only symptom of prodromal angina in 5% of AMI patients. The craniofacial pain included the throat, the jaws, the temporomandibular joints/ears and the teeth, mainly bilaterally. The pain quality descriptors “pressure” and “burning” were statistically associated with pain of cardiac origin, while “throbbing” and “aching” were associated with an odontogenic cause (p<0.001). In myocardial ischemia patients, the occurrence of craniofacial pain was associated with an inferior localization of ischemia in the heart (p<0.001).

    In conclusion, this study showed that pain in the craniofacial region could be the sole symptom of cardiac ischemia and AMI, particularly in women. Craniofacial pain of cardiac origin was commonly bilateral, with the quality pain descriptors “pressure” and “burning”, and pain provocation with physical activity and pain relief at rest. The association between the presence of craniofacial pain and inferior wall ischemia suggests a vagal involvement in the mechanisms of cardiac pain referred to the craniofacial region. Since the possibility of misdiagnosis and death in this group of patients is high, awareness of this clinical presentation needs to be brought to the attention of researchers, clinicians and the general public.

  • 290.
    Kreiner, Marcelo
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, Oral and Maxillofacial Radiology.
    Alvarez, Ramón
    Waldenström, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Michelis, Virginia
    Muñiz, Rosana
    Isberg, Annika
    Umeå University, Faculty of Medicine, Department of Odontology, Oral and Maxillofacial Radiology.
    Craniofacial pain of cardiac origin is associated with inferior wall ischemia2014In: Journal of oral & facial pain and headache, ISSN 2333-0384, Vol. 28, no 4, p. 317-321Article in journal (Refereed)
    Abstract [en]

    Aims: To investigate possible associations between the presence of craniofacial pain of cardiac origin and the location of cardiac ischemia and conventional risk factors. Methods: A total of 326 consecutive patients with confirmed myocardial ischemia (192 males, 134 females, mean age 64 years) were studied. Demographic details, health history, risk factors, prodromal symptoms, electrocardiogram (ECG) findings, and pain characteristics during the ischemic episode were assessed. The location of the ischemia according to the ECG findings was categorized as anterior, inferior, or lateral. Univariate chi-square analyses and a multivariate logistic regression model were used for data analysis. Two age subgroups (< 65 and > 65) were established when controlling for covariates. Results: Craniofacial pain of cardiac origin was significantly associated with an inferior localization of cardiac ischemia (P < .001) and was more frequently reported in diabetic patients (P = .014). Thirty-eight patients (12%) did not experience chest pain during the myocardial ischemia. Nine patients (3%) experienced a prodromal angina episode without chest pain. Conclusion: The occurrence of craniofacial pain during myocardial ischemia, with or without an acute myocardial infarction, was associated with ischemia within the inferior wall. This result suggests the involvement of the vagal afferent system in the mechanisms of craniofacial pain of cardiac origin.

  • 291.
    Kreiner, Marcelo
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, Oral and Maxillofacial Radiology.
    Falace, D
    Michelis, V
    Okeson, JP
    Isberg, Annika
    Umeå University, Faculty of Medicine, Department of Odontology.
    Quality difference in craniofacial pain of cardiac vs. dental origin2010In: Journal of Dental Research, ISSN 0022-0345, E-ISSN 1544-0591, Vol. 89, no 9, p. 965-969Article in journal (Refereed)
    Abstract [en]

    Craniofacial pain, whether odontogenic or caused by cardiac ischemia, is commonly referred to the same locations, posing a diagnostic challenge. We hypothesized that the validity of pain characteristics would be high in assessment of differential diagnosis. Pain quality, intensity, and gender characteristics were assessed for referred craniofacial pain from dental (n = 359) vs. cardiac (n = 115) origin. The pain descriptors "pressure" and "burning" were statistically associated with pain from cardiac origin, while "throbbing" and "aching" indicated an odontogenic cause. No gender differences were found. These data should now be added to those craniofacial pain characteristics already known to point to acute cardiac disease rather than dental pathology, i.e., pain provocation/aggravation by physical activity, pain relief at rest, and bilateralism. To initiate prompt and appropriate treatment, dental and medical clinicians as well as the public should be alert to those clinical characteristics of craniofacial pain of cardiac origin.

  • 292. Kumar, Abhishek
    et al.
    Tanaka, Yuto
    Takahashi, Kazutaka
    Grigoriadis, Anastasios
    Wiesinger, Birgitta
    Umeå University, Faculty of Medicine, Department of Odontology. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Svensson, Peter
    Trulsson, Mats
    Vibratory stimulus to the masseter muscle impairs the oral fine motor control during biting tasks2019In: Journal of Prosthodontic Research, ISSN 1883-1958, E-ISSN 2212-4632, Vol. 63, no 3, p. 354-360Article in journal (Refereed)
    Abstract [en]

    Purpose: To investigated the effect of vibratory stimulus on masseter muscles during oral fine motor biting tasks.

    Methods: Sixteen healthy individuals (age: 24.5 ± 2.4 years) participated in experiment I during which the participants were asked to “hold and split” half a roasted peanut placed on a force transducer with their front teeth. The participant performed ten series with ten trials of the “hold and split” behavioral task while vibratory stimulus was applied on the masseter muscle every alternate series. Further, fourteen participants participated (age: 25.2 ± 4.8 years) in experiment II during which they performed a series each of the behavioral task at baseline, an adjusted baseline without and with vibration as well as with and without visual feedback. Hold and split forces along with the variability of hold force and duration and force rate during the split were measured.

    Results: The results of the study showed an increase in the magnitude of the hold force (P = 0.002), force rate during the split (P < 0.001) and a significant decrease in the duration of split (P < 0.001) due to the vibratory stimulus. However, there was no significant effect of the vibratory stimulus on the variability of hold forces (P = 0.879) or mean split force (P = 0.683) during the “hold and split” behavioral task. The results of experiment II also showed an increase in hold force due to the vibratory stimulus (P < 0.001).

    Conclusions: Vibratory stimulus to the masseter muscles impairs the oral force control during a standardized biting task and provide further insight into the sensorimotor regulation of the masticatory system.

  • 293. Kwamin, Francis
    et al.
    Gref, Rolf
    Haubek, Dorte
    Johansson, Anders
    Umeå University, Faculty of Medicine, Department of Odontology, Molecular Periodontology.
    Interactions of extracts from selected chewing stick sources with Aggregatibacter actinomycetemcomitans2012In: BMC Research Notes, ISSN 1756-0500, E-ISSN 1756-0500, Vol. 5, p. 203-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Aggregatibacter actinomycetemcomitans produces a leukotoxin that activates a pro-inflammatory death of human monocytes/macrophages. A specific clone of this bacterium (JP2) has a 530-base pair deletion in the leukotoxin promoter gene that causes a significantly enhanced expression of leukotoxin. This specific clone of A. actinomycetemcomitans is common in some African populations and has a strong association with periodontal attachment loss in adolescents in these populations. Chewing sticks of plant origin are commonly used as oral hygiene tool in Africa, but their role as a therapeutic agent in periodontal disease is poorly investigated. RESULTS: Ethanol extracts were made from 7 common plants used as chewing sticks in West-Africa. None of the tested extracts inhibited growth of A. actinomycetemcomitans. However, extracts from Psidium guajava (Guava) completely neutralized the cell death and pro-inflammatory response of human leukocytes induced by the leukotoxin. None of the six other tested chewing stick extracts showed this effect. CONCLUSIONS: The discovery that extracts from Guava efficiently neutralizes A. actinomycetemcomitans leukotoxicity might lead to novel therapeutic agents and strategies for prevention and treatment of aggressive forms of periodontitis induced by infections with the highly leukotoxic JP2 clone of this bacterium.

  • 294.
    Källestål, Carina
    Umeå University, Faculty of Medicine, Department of Odontology.
    Periodontal conditions in Swedish adolescents1991Doctoral thesis, comprehensive summary (Other academic)
  • 295.
    Källestål, Carina
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Public Health Sciences. National Institute of Public Health, Stockholm.
    The effect of five years' implementation of caries-preventive methods in Swedish high-risk adolescents2005In: Caries Research, ISSN 0008-6568, E-ISSN 1421-976X, Vol. 39, no 1, p. 20-26Article in journal (Refereed)
    Abstract [en]

    Aim: To study the effectiveness of four different preventive programmes within a group of adolescents at high risk of caries.

    Subjects and Methods: In 1995, a cohort of 12-year-olds was examined for caries and completed a questionnaire. Subjects identified as being at high risk were examined every year until 2000 when they were 17 years old. This high-risk group was subdivided into four groups, each individual randomly assigned to one of four preventive programmes: ( A) information on tooth-brushing techniques; ( B) prescription of fluoride lozenges; ( C) semi-annual applications of fluoride varnish; ( D) quarterly appointments where participants were given individualised information on oral hygiene and diet as well as an application of fluoride varnish. The outcomes examined were the caries increment in dentine, enamel and fillings. Poisson regression was used to assess the influence of background, preventive factors and habits.

    Results: The number of 12-year-olds in the high-risk group was 1,134 in 1995, of which 925 were still participants in 2000. The differences between the programmes in mean 5-year increment were not significant. Less risk of caries increment was shown for those who had at least one sealant and for those who belonged to the fluoride varnish group ( C). A higher risk was observed for adolescents from working-class homes, and for those who reported often eating sweets and not brushing their teeth twice a day at all examinations during the whole study period.

    Conclusions: The preventive programmes tested were equal in showing low efficiency in adolescents with high caries risk.

  • 296.
    Lampa, Ewa
    Umeå University, Faculty of Medicine, Department of Odontology.
    Pain and disability in the jaw and neck regions after whiplash trauma: a short- and long-term perspective2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Whiplash trauma, a hyperextension-flexion trauma to the neck that is often related to a car accident, affects tens of thousands in Sweden every year. A significant proportion will develop long-term symptoms including neck pain and dysfunction – this is embraced as Whiplash associated disorders (WAD). Some individuals also develop pain and dysfunction in the orofacial region that is denoted as Temporomandibular disorder (TMD). TMD is common in the population with a prevalence of about 10% but the relation to whiplash trauma is still unclear. The limited number of prospective studies on TMD after whiplash trauma show diverging results, but it has been suggested that TMD develops over time and not in close proximity to the trauma. Prospective studies are needed to determine the course of jaw pain and disability after whiplash trauma.

    The general aim of this thesis was to evaluate the presence and course of pain and disability in the jaw and neck regions at the acute and chronic stages after whiplash trauma.

    This prospective cohort study included at baseline 176 cases with a recent whiplash trauma, and 116 age and gender matched controls without a history of neck trauma that were recruited from the general population. The cases had visited the emergency department at Umeå university hospital, Sweden, with neck pain within 72 hours following a car accident and had been diagnosed with neck distortion by a physician. The cases were examined within one month after the trauma (December 2010 to January 2016) and at a 2-year followup (December 2012 to January 2018). All participants completed questionnaires regarding pain and disability in the jaw and neck regions, physical symptoms (pain and non-pain items), and depression. At baseline, 80 of the cases and 80 of the controls also completed a 5-minute chewing capacity test. At the 2- year follow-up, 119 cases (68%) and 104 controls (90%) were re-examined with the same questionnaires.

    Compared to controls, within one month after a whiplash trauma cases reported significantly more pain in the jaw and neck regions with a positive correlation between the intensity of pain in these regions (Paper I). In the acute stage after trauma, cases, compared to controls, showed a reduced chewing capacity, and this was related to the severity of neck disability (Paper II). For cases, jaw and neck pain correlated positively to each other, to non-specific physical symptoms, and to depression at both the acute (Paper III) and chronic stages (Paper IV). About one third (34%) of the cases reported orofacial pain at baseline, and for a majority of these, the pain persisted at the 2-year follow-up (Paper IV).

    The presence of orofacial pain early after a whiplash trauma indicates involvement of central sensitization and spread of pain between the jaw and neck regions. The positive correlations between pain in the jaw and neck regions, and to psychosocial factors, underline the integration of these regions and the importance of a biopsychosocial perspective. The impaired jaw function shortly after a neck trauma further underlines the close sensorimotor relationship between the trigeminal and cervical regions. The finding that orofacial pain is common shortly after whiplash trauma, and often persists into the chronic stage, indicates that assessment in the acute stage should include both the neck and jaw regions. From this, it follows that multidisciplinary teams that entail both medical professions and dentists specialised in orofacial pain can be beneficial in the early assessment after whiplash trauma.

  • 297.
    Lampa, Ewa
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Wänman, Anders
    Umeå University, Faculty of Medicine, Department of Odontology.
    List, Thomas
    Häggman-Henrikson, Birgitta
    Relationship Between Psychosocial Factors and Pain in the Jaw and Neck Regions Shortly After Whiplash Trauma2019In: Journal of Oral & Facial Pain and Headache, ISSN 2333-0384, Vol. 33, no 2, p. 213-219Article in journal (Refereed)
    Abstract [en]

    Aims: To assess jaw pain shortly after whiplash trauma in relation to neck pain, physical symptoms, depression, and jaw pain-related disability.

    Methods: A total of 181 cases (106 women and 75 men, mean ages 33.7 and 36.8 years, respectively) were examined within 1 month after a whiplash trauma and compared to 117 controls (68 women and 49 men, 34.2 and 30.9 years, respectively). Participants rated current jaw and neck pain intensity on a numeric rating scale and rated nonspecific physical symptoms and depression symptoms on subscales of the Symptom Checklist-90-Revised. The nonspecific physical symptoms were further analyzed with and without pain items. Disability related to jaw pain and neck pain was also assessed. Differences between groups were calculated using Mann-Whitney U test, and correlations were measured using Spearman correlation.

    Results: Compared to controls, cases reported higher current jaw and neck pain intensity (P < .0001), together with higher scores for physical nonpain and pain symptoms, depression, and jaw pain-related disability (P < .0001 for all). For cases, there were moderate correlations between nonspecific physical symptoms and jaw pain and neck pain, as well as between jaw pain-related disability and jaw pain and neck pain (r = 0.43 to 0.77, P < .0001 for all). Low correlations were observed between depression and jaw pain and neck pain (r = 0.34 to 0.39, both P < .0001).

    Conclusion: Shortly after a whiplash trauma, pain in the jaw and neck regions is associated with the severity of psychosocial factors. Thus, psychosocial factors may play a role in the development of pain in the jaw region after whiplash trauma.

  • 298.
    Lampa, Ewa
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Wänman, Anders
    Umeå University, Faculty of Medicine, Department of Odontology.
    Nordh, Erik
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Häggman-Henrikson, Birgitta
    Umeå University, Faculty of Medicine, Department of Odontology. Department of Orofacial pain and Jaw function, Malmö University, Malmö, Sweden.
    Effects on jaw function shortly after whiplash trauma2017In: Journal of Oral Rehabilitation, ISSN 0305-182X, E-ISSN 1365-2842, Vol. 44, no 12, p. 941-947Article in journal (Refereed)
    Abstract [en]

    Normal jaw function involves muscles and joints of both jaw and neck. A whiplash trauma may disturb the integrated jaw-neck sensory-motor function and thereby impair chewing ability; however, it is not known if such impairment is present shortly after a neck trauma or develops over time. The aim was to evaluate jaw function after a recent whiplash trauma. Eighty cases (47 women) were examined within 1 month after a whiplash trauma and compared to 80 controls (47 women) without neck trauma. Participants completed the Jaw disability checklist (JDC) and Neck Disability Index (NDI) questionnaires and performed a 5-minute chewing test. Elicited fatigue and pain during chewing were noted, and group differences were evaluated with Fisher's exact test and Mann-Whitney U-test. Compared to controls, cases had higher JDC (P<.0001) and NDI scores (15% vs 2%, P<.0001), and reported more fatigue (53% vs 31%, P=.006) and pain (30% vs 10%, P=.003) during the chewing test. Cases also had a shorter onset time for fatigue and pain (both P=.001) Furthermore, cases reporting symptoms during chewing had higher JDC and NDI scores compared to cases not reporting symptoms (both P=.01). Symptoms mainly occurred in the trigeminal area for both groups, but also in spinal areas more often for cases than for controls. Taken together, the results indicate that jaw-neck sensory-motor function is impaired already within 1month after a whiplash trauma. The association between neck disability and jaw impairment underlines the close functional relationship between the regions, and stresses the importance of multidisciplinary assessment.

  • 299.
    Lampa, Ewa
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Wänman, Anders
    Umeå University, Faculty of Medicine, Department of Odontology.
    Nordh, Erik
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Stålnacke, Britt-Marie
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Rehabilitation Medicine.
    Häggman-Henrikson, Birgitta
    The Course of Orofacial Pain and Jaw Disability after Whiplash Trauma: A 2-year Prospective StudyManuscript (preprint) (Other academic)
  • 300. Leenders, Max
    et al.
    Boshuizen, Hendriek C.
    Ferrari, Pietro
    Siersema, Peter D.
    Overvad, Kim
    Tjonneland, Anne
    Olsen, Anja
    Boutron-Ruault, Marie-Christine
    Dossus, Laure
    Dartois, Laureen
    Kaaks, Rudolf
    Li, Kuanrong
    Boeing, Heiner
    Bergmann, Manuela M.
    Trichopoulou, Antonia
    Lagiou, Pagona
    Trichopoulos, Dimitrios
    Palli, Domenico
    Krogh, Vittorio
    Panico, Salvatore
    Tumino, Rosario
    Vineis, Paolo
    Peeters, Petra H. M.
    Weiderpass, Elisabete
    Engeset, Dagrun
    Braaten, Tonje
    Luisa Redondo, Maria
    Agudo, Antonio
    Sanchez, Maria-Jose
    Amiano, Pilar
    Huerta, Jose-Maria
    Ardanaz, Eva
    Drake, Isabel
    Sonestedt, Emily
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Winkvist, Anna
    Khaw, Kay-Tee
    Wareham, Nick J.
    Key, Timothy J.
    Bradbury, Kathryn E.
    Johansson, Mattias
    Licaj, Idlir
    Gunter, Marc J.
    Murphy, Neil
    Riboli, Elio
    Bueno-de-Mesquita, H. Bas
    Fruit and vegetable intake and cause-specific mortality in the EPIC study2014In: European Journal of Epidemiology, ISSN 0393-2990, E-ISSN 1573-7284, Vol. 29, no 9, p. 639-652Article in journal (Refereed)
    Abstract [en]

    Consumption of fruits and vegetables is associated with a lower overall mortality. The aim of this study was to identify causes of death through which this association is established. More than 450,000 participants from the European Prospective Investigation into Cancer and Nutrition study were included, of which 25,682 were reported deceased after 13 years of follow-up. Information on lifestyle, diet and vital status was collected through questionnaires and population registries. Hazard ratios (HR) with 95 % confidence intervals (95 % CI) for death from specific causes were calculated from Cox regression models, adjusted for potential confounders. Participants reporting consumption of more than 569 g/day of fruits and vegetables had lower risks of death from diseases of the circulatory (HR for upper fourth 0.85, 95 % CI 0.77-0.93), respiratory (HR for upper fourth 0.73, 95 % CI 0.59-0.91) and digestive system (HR for upper fourth 0.60, 95 % CI 0.46-0.79) when compared with participants consuming less than 249 g/day. In contrast, a positive association with death from diseases of the nervous system was observed. Inverse associations were generally observed for vegetable, but not for fruit consumption. Associations were more pronounced for raw vegetable consumption, when compared with cooked vegetable consumption. Raw vegetable consumption was additionally inversely associated with death from neoplasms and mental and behavioral disorders. The lower risk of death associated with a higher consumption of fruits and vegetables may be derived from inverse associations with diseases of the circulatory, respiratory and digestive system, and may depend on the preparation of vegetables and lifestyle factors.

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