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  • 1.
    Abd Mohammed, Mena
    Umeå University, Faculty of Medicine, Department of Odontology.
    Dental treatment under general anesthesia for children in the county of Västerbotten2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 2.
    Abdalla, Lahood
    et al.
    Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Soltani, Bagir
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    The effect of calcium silicate-based cements on viability and differentiation of human stem cells from the dental apical papilla.: Future aspects in endodontic regeneration.2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Introduction:

    Pulp necrosis in immature permanent teeth stops root development and may lead to higher risk of cervical fractures and a challenging treatment. Regenerative endodontic treatment (RET) aims to continue tooth development and implies the use of calcium silicate-based cements, such as Mineral trioxide aggregate (MTA) and Biodentine to seal the root canal. However, its effect on stem cells has been poorly explored. 

    Aims: Examine the effect of two different calcium silicate-based cements on the viability and the odonto-/osteogenic potential of Stem Cells from Apical Papilla (SCAP).

    Material and method: 

    Isolated SCAPs from three healthy donors (donor I, II and III) were used and exposed for different concentration extracts of ProRoot® MTA and BiodentineTM for 21 days. Cell viability was studied using the neutral red cytotoxicity test. Osteogenic differentiation was analyzed by the alkaline phosphatase test (ALP).

    Results: 

    No difference in SCAPs viability was detected by the type of cements used, Biodentine or ProRoot MTA. However, material concentration could be associated with cells cytotoxicity.  Osteogenic differentiation was not based on the type of cement used but the environment conditions (aerobic/anaerobic) and the genetical background.

    Conclusions:

    The type of cement used in RET, Biodentine or MTA, showed similar effect on SCAPs viability and differentiation potential in vitro. Further studies should be performed to analyze their effect -in -vivo.

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  • 3.
    Abdul Hussain, Mauj
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Hawaz Ali, Suzan
    Umeå University, Faculty of Medicine, Department of Odontology.
    Contamination Controls for Root Canal Sample Analysis by Molecular Methods: A pilot study.2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    When exploring the root canal flora, before and after treatment, it is crucial to eliminate bacteria from the tooth surface before entering the pulp. If not, bacteria from the surface might contaminate the root canal sample resulting in false information. When using molecular techniques, not only bacteria are to be eliminated but also DNA from bacteria to avoid contamination from the surface. The aim of the study was to examine if DNA from bacteria can be eliminated using a modified disinfection protocol. Samples from the tooth surface were taken from ten intact teeth stored in ethanol/ glycerol (50 % / 50 %) prior to the experiment. The teeth were sampled before and after cleaning the surface with H2O2 (30 %), NaOCl (3 %) and EDTA (0.5 M). Samples were taken from buccal, occlusal and lingual enamel and dentin surfaces. All samples were analyzed with polymerase chain reaction and culture. In a second experiment, ten teeth were placed in a bacterial solution containing Enterococcus faecalis for three days and sampled as above. No growth could be detected using the conventional culture technique from the post-wash samples. The results show that the teeth could not entirely become free from bacterial DNA using the performed cleaning routine as all samples were positive for bacterial DNA after cleaning. The average amount of detectable bacterial DNA was decreased with 95 % after the cleaning procedure. The results confirm reduction of bacterial DNA after cleaning, however, detectable bacterial DNA is still evident after disinfection. 

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  • 4.
    Abdulkadir, Mohamed
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Daniel, Olsson
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Association between Oral Inflammatory Disease and Carotid Artery Disease assessed with Ultrasound2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 5.
    Aberg, Carola Höglund
    et al.
    Umeå University, Faculty of Medicine, Odontology. Umeå University, Faculty of Medicine, Odontology, Periodontology.
    Sjödin, Bengt
    Lakio, Laura
    Pussinen, Pirkko J
    Johansson, Anders
    Umeå University, Faculty of Medicine, Odontology. Umeå University, Faculty of Medicine, Odontology, Periodontology.
    Claesson, Rolf
    Umeå University, Faculty of Medicine, Odontology. Umeå University, Faculty of Medicine, Odontology, Oral Microbiology.
    Presence of Aggregatibacter actinomycetemcomitans in young individuals: a 16-year clinical and microbiological follow-up study.2009In: Journal of clinical periodontology, ISSN 1600-051X, Vol. 36, no 10, p. 815-22Article in journal (Refereed)
    Abstract [en]

    AIM: To look for clinical signs of periodontal disease in young adults who exhibited radiographic bone loss and detectable numbers of Aggregatibacter actinomycetemcomitans in their primary dentition. MATERIAL AND METHODS: Periodontal status and radiographic bone loss were examined in each of the subjects 16 years after the baseline observations. Techniques for anaerobic and selective culture, and checkerboard, were used to detect periodontitis-associated bacterial species. The isolated A. actinomycetemcomitans strains were characterized by polymerase chain reaction. RESULTS: Signs of localized attachment loss were found in three out of the 13 examined subjects. A. actinomycetemcomitans was recovered from six of these subjects and two of these samples were from sites with deepened probing depths and attachment loss. Among the isolated A. actinomycetemcomitans strains, serotypes a-c and e, but not d or f, were found. None of the isolated strains belonged to the highly leucotoxic JP2 clone, and one strain lacked genes for the cytolethal distending toxin. CONCLUSIONS: This study indicates that the presence of A. actinomycetemcomitans and early bone loss in the primary dentition does not necessarily predispose the individual to periodontal attachment loss in the permanent dentition.

  • 6. Abrahamsson, Helene
    et al.
    Eriksson, Lars
    Abrahamsson, Peter
    Häggman-Henrikson, Birgitta
    Umeå University, Faculty of Medicine, Department of Odontology. Department of Orofacial Pain and Jaw Function, Malmö University, 205 06 Malmö, Sweden.
    Treatment of temporomandibular joint luxation: a systematic literature review2020In: Clinical Oral Investigations, ISSN 1432-6981, E-ISSN 1436-3771, Vol. 24, no 1, p. 61-70Article, review/survey (Refereed)
    Abstract [en]

    Objectives: To evaluate the effectiveness of surgical and nonsurgical treatment of temporomandibular joint (TMJ) luxation.

    Materials and methods: This systematic literature review searched PubMed, the Cochrane Library, and Web of Science databases to identify randomized controlled trials on TMJ luxation treatment published between the inception of each database and 26 March 2018.

    Results: Two authors assessed 113 unique abstracts according to the inclusion criteria and read nine articles in full text. Eight articles comprising 338 patients met the inclusion criteria, but none of these evaluated surgical techniques. Three studies including 185 patients concerned acute treatment with manual reduction of luxation while five studies including 153 patients evaluated minimally invasive methods with injection of autologous blood or dextrose prolotherapy for recurrent TMJ luxation. These studies reported that mouth opening after treatment was reduced and that independent of type of injection, recurrences of TMJ luxation were rare in most patients.

    Conclusions: In the absence of randomized studies on surgical techniques, autologous blood injection in the superior joint space and pericapsular tissues with intermaxillary fixation seems to be the treatment for recurrent TMJ luxation that at present has the best scientific support. Well-designed studies on surgical techniques with sufficient numbers of patients, long-term follow-ups, and patient experience assessment are needed for selection of the optimal surgical treatment methods.

    Clinical relevance: Autologous blood injection combined with intermaxillary fixation can be recommended for patients with recurrence of TMJ luxation.

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  • 7.
    Aciz, Michel
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Akhter, Mahfuz
    Umeå University, Faculty of Medicine, Department of Odontology.
    Anti-Tumor Necrosis Factor-α Treatment in Periodontal Disease – a literature review2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this literature review was to summarize human studies on the effects of tumor necrosis factor-α (TNF-α) inhibitors on periodontal status. Today TNF-α inhibitors is an established treatment method with positive effects in Rheumatoid arthritis (RA) a disease similar to periodontitis. TNF-α inhibitors have in animal studies demonstrated positive results in experimental periodontitis.

     Literature search was made in PubMed. Included articles were clinical human studies examining the effects on bleeding on probing (BOP), gingival index (GI) or modified gingival index (MGI), clinical attachment level (CAL) and periodontal probing depth (PPD) in patients with autoimmune diseases and treated with TNF-α inhibitors. Animal studies and studies in languages other than English were excluded. The guidelines of The Swedish Council on Technology Assessment in Health Care (SBU) were used to evaluate the level of evidence in the included articles and they were graded according to the GRADE system.

    The search rendered 264 articles of which 17 were selected for abstract reading. Eight of these were read in full-text; one randomized clinical trial (RCT) of moderate quality, two cross-sectional studies and five longitudinal studies of low evidence.  Patients treated with anti-TNF-α compared to the untreated reference groups in the two cross-sectional studies demonstrated lower BOP and GI, while diverging results on attachment loss were shown. The longitudinal studies demonstrated diverging effects of anti-TNF-α treatment on all periodontal parameters. The RCT showed that anti-TNF-α as a complement to conventional periodontal treatment had positive effects on CAL, PPD, BOP and GI while anti-TNF-α treatment alone lacked significant effects on these parameters. There are limited publications within the field and the studies show heterogeneity in terms of study design. Anti-TNF-α treatment showed small significant positive effects on the periodontal parameters in some studies but diverging results were noted. Studies of sufficient scientific quality specifically addressing the effect of anti-TNF-α treatment on periodontitis are needed to elucidate the effects of anti-TNF-α treatment in periodontitis.

  • 8.
    Adam, Anushik
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Carlström, Celine
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    The role of the c-c chemokine receptors (CCR) 2 and 5 during osteoclast differentiation of CCR3-deficient cells2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background: Osteoclasts are the cells responsible for bone resorption and they are formed by the fusion of cells from the monocyte/macrophage lineage. The formation of osteoclasts is dependent on various signaling pathways, including those under the control of chemokines and their receptors. In vitro, the expression of C-C chemokine receptor 3 (CCR3) is upregulated during osteoclastogenesis and the lack of Ccr3 gene (Ccr3-/-) leads to an increased size and activity of osteoclasts. The increased size and activity of the Ccr3-/- osteoclasts correlated with an upregulation of the transcripts from the C-C chemokine receptor 2 (Ccr2) and C-C chemokine receptor 5 (Ccr5) genes. 

    Aim: The aim of this study is to see if the upregulation of Ccr2 and Ccr5 contributes to the phenotypes of Ccr3-/- osteoclasts. 

    Methods: In this study, we used antagonists of CCR2 and CCR5 (RS 504393 and Maraviroc) to investigate the effect of the respective receptor on osteoclastogenesis in Ccr3+/+ and Ccr3-/- cells.  For this experiment we obatianed Bone marrow macrophages (BMMs) from Ccr3+/+ and Ccr3-/- mice for osteoclastformation. tartrate-resistant acid phosphatase (Trap) staining was thereafter added to the cultures to be able to analyze the results visually and statistically.  

    Results: At the concentration of 5μM (RS 504393 ) and 7.5 μM (Maraviroc ) the osteoclastogenesis was inhibited. Lower concentrations than 5μM of RS 504393 and 7.5 μM of Maraviroc, the size of the osteoclasts formed in cultures were significantly bigger than those formed in the controls. Further, this effect was largely independent of the genotype of the cells. In addition, the inhibition of CCR2 with RS 504393 suggest that the number of Ccr3+/+ and Ccr3-/-osteoclasts increased compared to the control groups. 

    Conclusion: The observation that the inhibition of CCR2 or CCCR5 appears to promote osteoclastogenesis implies that the increased expression of Ccr2 and Ccr5 may not underly the phenotypes of Ccr3-/- osteoclasts. This as the osteoclasts became larger overall when antagonists of each receptor were added. 

  • 9.
    Adam, Safa Mohammed
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Ohlsson, Sofie
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Quality Assessment of Panoramic Radiographs Performed in Västerbotten County Council2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background: Panoramic radiography provides an overview of the teeth, jawbone and surrounding bony/calcified structures. The examination is, however, challenging to perform without errors. Poor-quality panoramic radiographs can result in misinterpretations, repeated or supplementary examinations, increasing the radiation dose.  

    Aim: To assess the overall quality of a sample of panoramic radiographs performed in Västerbotten county council and to investigate whether the patients’ gender and/or age influence image quality.

    Methods: A total of 274 digital panoramic radiographs were assessed by two observers for the presence of errors, following an assessment protocol. The general image quality was classified and the causes of imaging errors were evaluated.  

    Results: The most common error was turned patient head, and the least frequent was the presence of external artifacts. Only five radiographs were without error (1.8%), 31.4% were adequate, 51.5% poor but diagnosable, and 15.3% undiagnosable. No major differences in image quality were found between gender (P=0.138) or between adults and children (p=0.607). Younger children had a significantly higher incidence of image errors compared to older children (P=0.021). The most common cause of undiagnosable radiographs among adults was incorrect tongue position and among children, movement during exposure.  

    Conclusion: Image quality in panoramic radiographs performed in Västerbotten county council can improve, since more than every seventh radiograph was considered undiagnosable and less than 2% were deemed excellent. It is more challenging to perform panoramic examinations on smaller children. By reducing the number of image errors, retakes and additional radiation dose to the patient can be avoided.  

  • 10.
    Adawi, Nadia
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Jewaratnam, Sukanya
    Umeå University, Faculty of Medicine, Department of Odontology.
    Tooth Extraction and Implant Placement Causes Changes in Both Muscle Fiber Composition and Motor Cortex in Rats. Experimental study2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Tooth loss has been shown to induce neuroplastic changes in the sensorimotor cortical area of the brain that represents jaw muscles. Dental implants placed into extraction sites reversed these changes. Since muscles are highly plastic, we hypothesize that the cortical changes after dental extraction also are reflected in jaw-opening muscles and that these changes are prevented/reversed following dental implant placement.

     

    Fifteen rats were randomly allocated in four groups; extraction 1 (Ext-1, n=4), extraction 2 (Ext-2, n=4), implant group (n=4) and control group (n=3). The anterior digastric (AD) muscle was obtained from the extraction groups after 1 and 2 months, respectively, and from the implant group after 3 weeks. The samples were analyzed with immunohistochemical and morphological techniques. Our results showed; 1) intermediate and low oxidative fast MyHCII fibers predominated AD muscle, 2) oxidative capacity of fibers was higher in the central region, 3) extraction caused a shift towards fibers with lower oxidative capacity in the central region, 4) placement of dental implants increased the oxidative capacity of fibers in both central and peripheral region.

     

    We conclude that in the AD muscle, loss of teeth cause a tendency to shift against fibers with faster contraction properties and lower oxidative capacity, while treatment with implants tends to reverse it. Interestingly, these alterations followed the change pattern of the cortical motor area for the AD muscle i.e. larger proportion of fibers with higher oxidative capacity and fine motor control were associated with increased motor representation sites (MRS) for the AD muscle.

     

  • 11.
    Addi, Simon
    et al.
    Umeå University, Faculty of Medicine, Odontology, Dental Materials Science.
    Hedayati-Khams, Arjang
    Umeå University, Faculty of Medicine, Odontology, Dental Materials Science.
    Poya, Amin
    Umeå University, Faculty of Medicine, Odontology, Dental Materials Science.
    Sjögren, Göran
    Umeå University, Faculty of Medicine, Odontology, Dental Materials Science.
    Interface gap size of manually and CAD/CAM-manufactured ceramic inlays/onlays in vitro.2002In: Journal of Dentistry, ISSN 0300-5712, E-ISSN 1879-176X, Vol. 30, no 1, p. 53-58Article in journal (Refereed)
    Abstract [en]

    Objectives : To determine the fit of ceramic inlays manufactured using a recently introduced CAD/CAM-system (Decim) and of two types of laboratory-made heat-pressed ceramics (IPS Empress and Opc).

    Materials and methods : Extracted human premolars were prepared to receive mesio-occlusodistal (MOD) ceramic inlays, for which 10 Denzir, 10 IPS Empress, and 10 Opc were fabricated. The Denzir restorations were produced by the manufacturer of the CAD/CAM-system, and the IPS Empress and Opc by student dental technicians. Before luting the internal fit on the diestone models and on the premolars was determined using replicas. After luting on the premolars with a resin composite the marginal and internal fit were measured. The values were analyzed statistically using ANOVA and Scheffe's test at a significance level of p<0.05.

    Results : Before luting there were no significant differences ( p>0.05) in the internal gap width between the three systems studied when placed on their matching diestone models. When placed on the premolars a significant difference ( p<0.01) in the internal fit was seen between Empress and Opc before luting, whereas there were no significant differences ( p>0.05) between Empress and Denzir and between Opc and Denzir. Between the diestone models and the premolars there were significant differences ( p<0.01) in the internal fit, except for IPS Empress. After luting there were no significant differences ( p>0.05) between IPS Empress and Denzir, whereas the marginal gap width was significantly wider ( p<0.001) for Opc than for IPS Empress and Denzir. The internal fit was significantly ( p<0.001) wider for Opc than for IPS Empress, whereas there were no significant differences ( p>0.05) between IPS Empress and Denzir or between Opc and Denzir.

    Conclusion : After luting there were only slight differences in the fit between the restorations fabricated using the three different manufacturing techniques and ceramics. Therefore, long-term follow-up studies are needed to assess the clinical significance of the slight differences between the three systems.

  • 12.
    Adjez, Timor
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Torshage, Wilhelm
    Umeå University, Faculty of Medicine, Department of Odontology.
    Comparison of image quality in radiographs acquired with different panoramic machines in Västerbotten2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 13.
    Afaag, Ali
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Sandelin, Benjamin
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Polymerization Shrinkage of Dental Composites Registered by a Video-imaging Device. A pilot study2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The use of composite materials for dental fillings has become more common due to demands for more esthetic filling materials and a national ban against using mercury-containing products, among others dental amalgam. However, one of the drawbacks with composites is their polymerization shrinkage. Filler particles are incorporated into composites among other things to minimize the shrinkage. The sizes of the filler particles have in recent years become smaller and most composites have nano-particles incorporated.

    The aims of the study were to investigate if a) the filler load, b) the curing time and c) tested after "best-before date" will affect the polymerization shrinkage of commercial dental composites. The hypotheses are that high filler loads will result in low shrinkage, and that different curing times and tested after "best-before date" will not significantly affect the shrinkage.

    The polymerization shrinkage of ten commercial composites was studied and three different curing times were used. 150 specimens were manually formed and AcuVol was used to register the volumetric shrinkage.

    The mean volumetric polymerization shrinkage values of the composites ranged between 1.8% and 5.0% for the recommended curing times. The composite with the highest filler load (Kalore) had the lowest mean shrinkage, and the composite with the lowest filler load (SDR) had the highest mean shrinkage.

    The video-imaging device could be used to register the polymerization shrinkage of dental composites. The composites polymerization shrinkage was related to the filler loads when the composites were arranged in groups based on their type. No conclusion could be made about the effect of different curing times and "best-before date".

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  • 14. Aglago, Elom K.
    et al.
    Rinaldi, Sabina
    Freisling, Heinz
    Jiao, Li
    Hughes, David J.
    Fedirko, Veronika
    Schalkwijk, Casper G.
    Weiderpass, Elisabete
    Dahm, Christina C.
    Overvad, Kim
    Eriksen, Anne Kirstine
    Kyrø, Cecilie
    Boutron-Ruault, Marie-Christine
    Rothwell, Joseph A.
    Severi, Gianluca
    Katzke, Verena
    Kühn, Tilman
    Schulze, Matthias B.
    Aleksandrova, Krasimira
    Masala, Giovanna
    Krogh, Vittorio
    Panico, Salvatore
    Tumino, Rosario
    Naccarati, Alessio
    Bueno-de-Mesquita, Bas
    van Gils, Carla H.
    Sandanger, Torkjel M.
    Gram, Inger T.
    Skeie, Guri
    Quirós, J. Ramón
    Jakszyn, Paula
    Sánchez, Maria-Jose
    Amiano, Pilar
    Huerta, José María
    Ardanaz, Eva
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology. Umeå University, Faculty of Medicine, Department of Odontology.
    Harlid, Sophia
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Perez-Cornago, Aurora
    Mayén, Ana-Lucia
    Cordova, Reynalda
    Gunter, Marc J.
    Vineis, Paolo
    Cross, Amanda J.
    Riboli, Elio
    Jenab, Mazda
    Soluble Receptor for Advanced Glycation End-products (sRAGE) and Colorectal Cancer Risk: A Case-Control Study Nested within a European Prospective Cohort2021In: Cancer Epidemiology, Biomarkers and Prevention, ISSN 1055-9965, E-ISSN 1538-7755, Vol. 30, no 1, p. 182-192Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Overexpression of the receptor for advanced glycation end-product (RAGE) has been associated with chronic inflammation, which in turn has been associated with increased colorectal cancer risk. Soluble RAGE (sRAGE) competes with RAGE to bind its ligands, thus potentially preventing RAGE-induced inflammation.

    METHODS: To investigate whether sRAGE and related genetic variants are associated with colorectal cancer risk, we conducted a nested case-control study in the European Prospective Investigation into Cancer and Nutrition (EPIC). Plasma sRAGE concentrations were measured by ELISA in 1,361 colorectal cancer matched case-control sets. Twenty-four SNPs encoded in the genes associated with sRAGE concentrations were available for 1,985 colorectal cancer cases and 2,220 controls. Multivariable adjusted ORs and 95% confidence intervals (CIs) were computed using conditional and unconditional logistic regression for colorectal cancer risk and circulating sRAGE and SNPs, respectively.

    RESULTS: Higher sRAGE concentrations were inversely associated with colorectal cancer (ORQ5vs.Q1, 0.77; 95% CI, 0.59-1.00). Sex-specific analyses revealed that the observed inverse risk association was restricted to men (ORQ5vs.Q1, 0.63; 95% CI, 0.42-0.94), whereas no association was observed in women (ORQ5vs.Q1, 1.00; 95% CI, 0.68-1.48; Pheterogeneity for sex = 0.006). Participants carrying minor allele of rs653765 (promoter region of ADAM10) had lower colorectal cancer risk (C vs. T, OR, 0.90; 95% CI, 0.82-0.99).

    CONCLUSIONS: Prediagnostic sRAGE concentrations were inversely associated with colorectal cancer risk in men, but not in women. An SNP located within ADAM10 gene, pertaining to RAGE shedding, was associated with colorectal cancer risk.

    IMPACT: Further studies are needed to confirm our observed sex difference in the association and better explore the potential involvement of genetic variants of sRAGE in colorectal cancer development.

  • 15.
    Agler, Cary S.
    et al.
    Oral and Craniofacial Health Sciences, UNC School of Dentistry, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Shungin, Dmitry
    Umeå University, Faculty of Medicine, Department of Odontology. Broad Institute of the Massachusetts Institute of Technology and Harvard University, MA, Cambridge, United States.
    Ferreira Zandoná, Andrea G.
    Department of Comprehensive Dentistry, Tufts University School of Dental Medicine, Tufts University, MA, Boston, United States.
    Schmadeke, Paige
    Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States; Biospecimen Core Processing Facility, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Basta, Patricia V.
    Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States; Biospecimen Core Processing Facility, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Luo, Jason
    Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina, NC, Chapel Hill, United States; Mammalian Genotyping Core, University of North Carolina, NC, Chapel Hill, United States.
    Cantrell, John
    Oral and Craniofacial Health Sciences, UNC School of Dentistry, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Pahel, Thomas D.
    Oral and Craniofacial Health Sciences, UNC School of Dentistry, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Meyer, Beau D.
    Department of Pediatric Dentistry, UNC School of Dentistry, CB#7450, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Shaffer, John R.
    Center for Craniofacial and Dental Genetics, School of Dental Medicine, University of Pittsburgh, PA, Pittsburgh, United States; Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, PA, Pittsburgh, United States; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, PA, Pittsburgh, United States.
    Schaefer, Arne S.
    Department of Periodontology, Institute of Dental, Oral and Maxillary Medicine, Charité—University Medicine Berlin, Berlin, Germany.
    North, Kari E.
    Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States; Carolina Center for Genome Sciences, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Divaris, Kimon
    Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States; Department of Pediatric Dentistry, UNC School of Dentistry, CB#7450, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Protocols, methods, and tools for genome-wide association studies (GWAS) of dental traits2019In: Odontogenesis: methods and protocols / [ed] Petros Papagerakis, Humana Press, 2019, , p. 17p. 493-509Chapter in book (Refereed)
    Abstract [en]

    Oral health and disease are known to be influenced by complex interactions between environmental (e.g., social and behavioral) factors and innate susceptibility. Although the exact contribution of genomics and other layers of "omics" to oral health is an area of active research, it is well established that the susceptibility to dental caries, periodontal disease, and other oral and craniofacial traits is substantially influenced by the human genome. A comprehensive understanding of these genomic factors is necessary for the realization of precision medicine in the oral health domain. To aid in this direction, the advent and increasing affordability of high-throughput genotyping has enabled the simultaneous interrogation of millions of genetic polymorphisms for association with oral and craniofacial traits. Specifically, genome-wide association studies (GWAS) of dental caries and periodontal disease have provided initial insights into novel loci and biological processes plausibly implicated in these two common, complex, biofilm-mediated diseases. This paper presents a summary of protocols, methods, tools, and pipelines for the conduct of GWAS of dental caries, periodontal disease, and related traits. The protocol begins with the consideration of different traits for both diseases and outlines procedures for genotyping, quality control, adjustment for population stratification, heritability and association analyses, annotation, reporting, and interpretation. Methods and tools available for GWAS are being constantly updated and improved; with this in mind, the presented approaches have been successfully applied in numerous GWAS and meta-analyses among tens of thousands of individuals, including dental traits such as dental caries and periodontal disease. As such, they can serve as a guide or template for future genomic investigations of these and other traits.

  • 16. Agogo, George O.
    et al.
    van der Voet, Hilko
    van 't Veer, Pieter
    Ferrari, Pietro
    Muller, David C.
    Sanchez-Cantalejo, Emilio
    Bamia, Christina
    Braaten, Tonje
    Knuppel, Sven
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology.
    van Eeuwijk, Fred A.
    Boshuizen, Hendriek C.
    A method for sensitivity analysis to assess the effects of measurement error in multiple exposure variables using external validation data2016In: BMC Medical Research Methodology, E-ISSN 1471-2288, Vol. 16, article id 139Article in journal (Refereed)
    Abstract [en]

    Background: Measurement error in self-reported dietary intakes is known to bias the association between dietary intake and a health outcome of interest such as risk of a disease. The association can be distorted further by mismeasured confounders, leading to invalid results and conclusions. It is, however, difficult to adjust for the bias in the association when there is no internal validation data. Methods: We proposed a method to adjust for the bias in the diet-disease association (hereafter, association), due to measurement error in dietary intake and a mismeasured confounder, when there is no internal validation data. The method combines prior information on the validity of the self-report instrument with the observed data to adjust for the bias in the association. We compared the proposed method with the method that ignores the confounder effect, and with the method that ignores measurement errors completely. We assessed the sensitivity of the estimates to various magnitudes of measurement error, error correlations and uncertainty in the literature-reported validation data. We applied the methods to fruits and vegetables (FV) intakes, cigarette smoking (confounder) and all-cause mortality data from the European Prospective Investigation into Cancer and Nutrition study. Results: Using the proposed method resulted in about four times increase in the strength of association between FV intake and mortality. For weakly correlated errors, measurement error in the confounder minimally affected the hazard ratio estimate for FV intake. The effect was more pronounced for strong error correlations. Conclusions: The proposed method permits sensitivity analysis on measurement error structures and accounts for uncertainties in the reported validity coefficients. The method is useful in assessing the direction and quantifying the magnitude of bias in the association due to measurement errors in the confounders.

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  • 17. Agogo, George O.
    et al.
    van der Voet, Hilko
    van't Veer, Pieter
    Ferrari, Pietro
    Leenders, Max
    Muller, David C.
    Sanchez-Cantalejo, Emilio
    Bamia, Christina
    Braaten, Tonje
    Knueppel, Sven
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology.
    van Eeuwijk, Fred A.
    Boshuizen, Hendriek
    Use of Two-Part Regression Calibration Model to Correct for Measurement Error in Episodically Consumed Foods in a Single-Replicate Study Design: EPIC Case Study2014In: PLOS ONE, E-ISSN 1932-6203, Vol. 9, no 11, p. e113160-Article in journal (Refereed)
    Abstract [en]

    In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted twopart regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM) and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC) study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.

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  • 18. Agudo, Antonio
    et al.
    Bonet, Catalina
    Travier, Noemie
    Gonzalez, Carlos A.
    Vineis, Paolo
    Bueno-de-Mesquita, H. Bas
    Trichopoulos, Dimitrios
    Boffetta, Paolo
    Clavel-Chapelon, Francoise
    Boutron-Ruault, Marie-Christine
    Kaaks, Rudolf
    Lukanova, Annekatrin
    Schuetze, Madlen
    Boeing, Heiner
    Tjonneland, Anne
    Halkjaer, Jytte
    Overvad, Kim
    Dahm, Christina C.
    Ramon Quiros, J.
    Sanchez, Maria-Jose
    Larranaga, Nerea
    Navarro, Carmen
    Ardanaz, Eva
    Khaw, Kay-Tee
    Wareham, Nicholas J.
    Key, Timothy J.
    Allen, Naomi E.
    Trichopoulou, Antonia
    Lagiou, Pagona
    Palli, Domenico
    Sieri, Sabina
    Tumino, Rosario
    Panico, Salvatore
    Boshuizen, Hendriek
    Buchner, Frederike L.
    Peeters, Petra H. M.
    Borgquist, Signe
    Almquist, Martin
    Hallmans, Göran
    Umeå University, Faculty of Medicine, Department of Biobank Research.
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Gram, Inger T.
    Lund, Eiliv
    Weiderpass, Elisabete
    Romieu, Isabelle
    Riboli, Elio
    Impact of Cigarette Smoking on Cancer Risk in the European Prospective Investigation into Cancer and Nutrition Study2012In: Journal of Clinical Oncology, ISSN 0732-183X, E-ISSN 1527-7755, Vol. 30, no 36, p. 4550-4557Article in journal (Refereed)
    Abstract [en]

    Purpose Our aim was to assess the impact of cigarette smoking on the risk of the tumors classified by the International Agency for Research on Cancer as causally associated with smoking, referred to as tobacco-related cancers (TRC). Methods The study population included 441,211 participants (133,018 men and 308,193 women) from the European Prospective Investigation Into Cancer and Nutrition. We investigated 14,563 participants who developed a TRC during an average follow-up of 11 years. The impact of smoking cigarettes on cancer risk was assessed by the population attributable fraction (AF(p)), calculated using the adjusted hazard ratios and 95% CI for current and former smokers, plus either the prevalence of smoking among cancer cases or estimates from surveys in representative samples of the population in each country. Results The proportion of all TRC attributable to cigarette smoking was 34.9% (95% CI, 32.5 to 37.4) using the smoking prevalence among cases and 36.2% (95% CI, 33.7 to 38.6) using the smoking prevalence from the population. The AF(p) were above 80% for cancers of the lung and larynx, between 20% and 50% for most respiratory and digestive cancers and tumors from the lower urinary tract, and below 20% for the remaining TRC. Conclusion Using data on cancer incidence for 2008 and our AF(p) estimates, about 270,000 new cancer diagnoses per year can be considered attributable to cigarette smoking in the eight European countries with available data for both men and women (Italy, Spain, United Kingdom, the Netherlands, Greece, Germany, Sweden, Denmark). 

  • 19. Ahlgren, Camilla
    et al.
    Molin, Margareta
    Umeå University, Faculty of Medicine, Odontology, Prosthetic Dentistry. Umeå University, Faculty of Medicine, Odontology.
    Lundh, Thomas
    Nilner, Krister
    Levels of gold in plasma after dental gold inlay insertion.2007In: Acta odontologica Scandinavica, ISSN 1502-3850, Vol. 65, no 6, p. 331-4Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Several studies have reported increased levels of gold (Au) in the blood of patients with dental gold restorations. This study analyzed gold levels in blood plasma before dental gold inlay insertion, 0-12 months after, and 15 years after. MATERIAL AND METHODS: Plasma samples from 9 patients were taken before and 0-10 months after gold inlay insertion. Fifteen years after gold inlay insertion, further blood samples taken from 8 of these patients were analyzed for gold using inductively coupled plasma mass spectrometry. An oral examination was also carried out before and 15 years after gold inlay insertion. RESULTS: Gold levels in plasma were significantly higher 0-12 months after gold inlay insertion than before treatment (p=0.008). No significant difference in gold plasma levels was found between 0-12 months after and 15 years after insertion (p=0.109), although there was a significant correlation between the number of gold alloy surfaces and the amount of gold in plasma 15 years after insertion (p=0.028). CONCLUSIONS: This study supports a dose-related release of gold into plasma from dental gold restorations, a release that appears to be stable over time.

  • 20.
    Ahlmén, Rebecca
    Umeå University, Faculty of Medicine, Department of Odontology.
    1a,25-Dihydroxyvitamin D3 Inhibits the Expression of Interleukin-1b in Human Gingival Fibroblasts2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The level of osteotropic cytokines is a crucial factor for alveolar bone loss in patients with periodontal disease. These cytokines,are produced by infiltrating immune cells as an inflammatory response. Besides their immunoregulatory function, certain osteotropic cytokines present in periodontitis can stimulate osteoclastogenes and alveolar bone resorption. Also resident cells, including gingival fibroblasts, produce these types of cytokines, a production which is regulated by different local inflammatory mediators. The role of systemic factors, such as hormones, in regulation of cytokine expression in gingival fibroblasts is, however, much less investigated. The aim of the present study was to investigate how vitamin D (1a,25-dihydroxyvitamin D3) affects the production of certain osteotropic cytokines in human gingival fibroblasts (HGF).

     

    The fibroblasts were isolated from patients with clinically healthy gingiva. The evaluation of cytokine expression was made using RT-PCR after incubation of the fibroblasts in the presence or absence of 1a,25-Dihydroxyvitamin D3. Assessments of protein expression of cytokines and hormone receptors were performed using Western blot or ELISA.

     

    In TNF-a stimulated HGFs, 1a,25-dihydroxyvitamin D3 caused a time- and concentration dependent decreased expression of IL-1β mRNA with no significant effect on the expression of IL-6 mRNA.  1a,25-dihydroxyvitamin D3 inhibited also the increased intracellular levels of pro-IL-1b in TNF-a stimulated cells. Western blot analysis demonstrated that HGF expressed vitamin D receptor protein as well as its dimerizing partner retinoid X receptor-a. These data show that vitamin D is a potent regulator of IL-1b in HGF which may help to explain the anti-inflammatory effect by vitamin D in vivo.

  • 21.
    Ahlqvist, Jan
    Umeå University, Faculty of Medicine, Department of Odontology.
    The temporomandibular joint: Tomopraphic and CT assesment of its bone demarcations with reference to adjacent organs1998Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The wall of the temporal bone separating the temporomandibular joint (TMJ) from surroundings organs, can be very thin and also have development defects. Distortion effects in the radiographic reproduction of these bone walls can result in misinterpretations when exanimating suspected pathologic changes in the region. These areas need to be radiographic identified prior to taking any invasive measures. Incorrect assessment of bone thickness may lead to serious sequelae due to the risk of penetration injury during invasive investigation or treatment of the TMJ or ear. The purpose of this project was to gain more detailed knowledge about the anatomy and topography of the TMJ with special reference to its bone demarcations regarding adjacent organs and to evaluate the tomographic and computed tomographic (CT) depiction of these bone walls. To obtain a basic analysis of the tissue anatomy and tomographic and CT reproduction of the TMJ region, autopsy specimens were studied. After CT and conventional tomography, the specimens were sectioned in a microtom. Three- dimensional orientation systems allowed identification of section depth in the radiograms and in the histologic sections, allowing the radiograms in turn to be correlated with the true anatomy. The angle of inclination relative to the perpendicular to established imaging planes the bone walls studied was examined in three projections in order to identify regions where the bone demarcation showed an unfavorable inclination regarding the possibility of valid radiographic representation. The thickness of the bone wall between the TMJ and the middle cranial fossa, measured in the thinnest part, varied between 0.08 and 3.62 mm, averaging 1.14 mm. The bone wall between the TMJ and the middle ear showed less variation in thickness ranging from 0.00 to 1.80 mm. The thickness of the bone wall separating the TMJ from the external auditory canal varied between  1.50 mm (lateral part) and 1.21 mm (central part), with a range of between 0.21 and 4.10 mm. Development defects of this bone wall were found in 5.2 % of the examined joints. The validity in tomographic depiction of these walls was highly dependent on an optimal orientation of the bone wall in relation to the image plane. The variations in the anatomy and sagittal dimension of the external auditory canal led to variations in tomographic blurring, and suggested the need for examinations after patient repositioning in cases of suspected bone resorbing lesions so that image aberration due to unfavorable inclination of the bone wall relative to the image plane may be excluded. CT of these bone walls was valid (± 10 %) for walls thicker than approximately 1 mm, forming an angle of less than 35® with the perpendicular to the scan plane when the bone wall thickness was determined as the full-width-at-half-maximum (FWHM). For bone walls thinner than 1 mm, and for those thicker than 1 mm and at an angle exceeding 35®, partial volume averaging effects resulted in a progressively increasing magnification of bone dimensions. Observer estimations of bone thickness from images obtained using conventional bone window settings (c=400, W=2000) showed good agreement for bone walls thicker than 1 mm and with an angle of inclination relative to the perpendicular to the image plane of less than approximately 25®. For bone walls thinner than 1 mm and for thicker than 1 mm with an inclination exceeding approximately 25®, the estimations resulted in a progressively increasing overestimation amounting 200% for gracile bone walls with an inclination of 45® to 50®. Determination of width or absence of the central white zone in images obtained with the described parameters could help to reduce the risk of overestimation of bone thickness. A considerable part of the bone walls separating the TMJ from the middle cranial fossa and the external auditory canal/middle ear, respectively, have dimensions and inclinations to established imaging planes used at TMJ examinations that make the depiction of these walls highly susceptible to image distortion. 

  • 22.
    Ahlqvist, Jan B
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Nilsson, Tore A
    Umeå University, Faculty of Medicine, Department of Odontology.
    Hedman, Leif R
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Desser, Terry S
    Dev, Parvati
    Johansson, Magnus
    Umeå University, Faculty of Medicine, Department of Odontology.
    Youngblood, Patricia L
    Cheng, Robert P
    Gold, Garry E
    A randomized controlled trial on 2 simulation-based training methods in radiology: effects on radiologic technology student skill in assessing image quality.2013In: Simulation in Healthcare: The Journal of the Society for Simulation in Healthcare, ISSN 1559-2332, E-ISSN 1559-713X, Vol. 8, no 6, p. 382-387Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: A simulator for virtual radiographic examinations was developed. In the virtual environment, the user can perform and analyze radiographic examinations of patient models without the use of ionizing radiation. We investigated if this simulation technique could improve education of radiology technology students. We compared student performance in the assessment of radiographic image quality after training with a conventional manikin or with the virtual radiography simulator.

    METHODS: A randomized controlled experimental study involving 31 first-year radiology technology students was performed. It was organized in 4 phases as follows: (I) randomization to control or experimental group based on the results of an anatomy examination; (II) proficiency testing before training; (III) intervention (control group, exposure and analysis of radiographic images of the cervical spine of a manikin; experimental group, exposure and analysis of the cervical spine images in the virtual radiography simulator); and (IV) proficiency testing after training.

    RESULTS: The experimental group showed significantly higher scores after training compared with those before training (P < 0.01). A linear mixed-effect analysis revealed a significant difference between the control and experimental groups regarding proficiency change (P = 0.01).

    CONCLUSIONS: Virtual radiographic simulation is an effective tool for learning image quality assessment. Simulation can therefore be a valuable adjunct to traditional educational methods and reduce exposure to x-rays and tutoring time.

  • 23.
    Ahlqvist, Jan, Birger
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Borg, Kennet
    Gunne, Johan
    Nilson, Hans
    Olsson, Morgan
    Åstrand, Per
    Osseointegrated implants in edentulous jaws: a 2-year longitudinal study.1990In: International Journal of Oral & Maxillofacial Implants, ISSN 0882-2786, E-ISSN 1942-4434, Vol. 5, no 2, p. 155-163Article in journal (Refereed)
    Abstract [en]

    Osseointegrated implants in 50 edentulous jaws were studied during a 2-year observation period. The implant survival rate was 89% in the maxillae and 97% in the mandibles. The marginal bone loss averaged 1.7 mm in the maxillae and 1.1 mm in the mandibles. Most of this bone loss occurred during the first year. The bone loss was greater in jaws with a preoperatively minor resorption of the alveolar ridge than in those with moderate or advanced resorption. The bone loss was also greater at the medially positioned implants than at those more posterior.

  • 24.
    Ahlqvist, Jan
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Bryndahl, Frerik
    Umeå University, Faculty of Medicine, Department of Odontology.
    Eckerdal, Olof
    Isberg, Annika
    Sources of radiographic distortion in conventional and computed tomography of the temporal bone.1998In: Dento-Maxillo-Facial Radiology, ISSN 0250-832X, E-ISSN 1476-542X, Vol. 27, no 6, p. 351-7Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: To identify those bony regions of the glenoid fossa where, due to the inclination, there is an increased risk of radiographic distortion in conventional and computed tomography (CT).

    METHODS: The inclination of the roof and posterior wall of the glenoid fossa was determined relative to established imaging planes. Measurements were performed on 50 corrected coronal MR and 50 axial CT images and 200 sagittal cryosections of 50 temporomandibular joints (TMJs). The location of regions with unfavourable bone wall inclination was identified using the condyle as a reference.

    RESULTS: The inclination of parts of the fossa roof exceeded the limit for reliable depiction in corrected sagittal and coronal planes in 40% and 8% of the joints respectively. The inclination of parts of the posterior wall of the fossa exceeded the limit for reliable depiction in corrected sagittal and in true sagittal planes in 100% and 84% of the joints respectively. In 84% of the joints the inclination exceeded the limit for reliable depiction in the axial plane. For both bone walls the regions with unfavourable inclination were in the medial part of the joint.

    CONCLUSIONS: The angulation of parts of the roof and posterior wall of the glenoid fossa in relation to established imaging planes makes them highly susceptible to distortion. The oblique coronal projection is well suited for depiction of the roof of the fossa and preferable to a sagittal projection. An oblique axial projection is required for the posterior wall.

  • 25.
    Ahlqvist, Jan
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Isberg, A M
    Umeå University, Faculty of Medicine, Department of Odontology.
    Bone demarcation of the temporomandibular joint. Validity of clinical assessment of bone thickness by means of CT.1998In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 39, no 6, p. 649-55Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To study the CT depiction of bone demarcations in the temporomandibular joint, using conventional window level and window width; and to evaluate observer performance in estimating bone thickness in these images.

    MATERIAL AND METHODS: Seven joint specimens were imaged by CT and then cryosectioned. The measurements of bone wall thickness in the images were compared to the true bone thickness at each cutting level. In addition, 4 experienced radiologists estimated the thickness of the bone walls in the images.

    RESULTS: The relative difference between the CT reproduction and the true bone thickness was small for bone walls thicker than 2 mm. This difference increased with the decrease in bone thickness and the increase in the inclination of the bone wall from the perpendicular to the image plane. Bone walls thinner than 1 mm were reproduced as considerably thicker than their true thickness. This resulted in a clinical overestimation of bone thickness.

    CONCLUSION: Both the CT representation and the interpretation of bone demarcation in the temporomandibular joint may constitute a problem. Partial volume averaging effects can result in an overestimation of bone dimensions amounting to 200% for thin bones. The central white zone in images of thin bone walls obtained with the parameters described here could serve as an indicator that could help to reduce the risk of overestimating bone thickness.

  • 26.
    Ahlqvist, Jan
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Isberg, Annika
    Umeå University, Faculty of Medicine, Department of Odontology.
    Validity of computed tomography in imaging thin walls of the temporal bone1999In: Dento-Maxillo-Facial Radiology, ISSN 0250-832X, E-ISSN 1476-542X, Vol. 28, no 1, p. 13-19Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: To evaluate the validity of computed tomography (CT) for reproduction of the bone margins of the temporomandibular joint (TMJ).

    METHODS: Seven TMJ specimens were examined with a CT and then cryosectioned. The bone separating the TMJ from the middle cranial fossa, middle ear and external auditory canal was measured as the full width at half maximum (FWHM). Measurements were compared with the true thickness of the bone wall.

    RESULTS: There was good agreement when the bone walls were thicker than 1 mm: accuracy was influenced only by the angle of the bone wall to the scanning plane. Conversely, bone walls thinner than 1 mm were reproduced with a magnification that increased with decreasing bone thickness. The difference increased further as the inclination of the bone wall became greater.

    CONCLUSION: Measurements performed at FWHM are reliable within +/- 10% for bone walls more than approximately 1 mm thick which form an angle of less than 35 degrees to the perpendicular of the scanning plane. For bone walls thinner than 1 mm and for those thicker than 1 mm with an inclination exceeding approximately 35 degrees, partial volume effects result in a progressively increasing magnification of bone thickness.

  • 27.
    Ahlqvist, Jan
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Levring Jäghagen, Eva
    Umeå University, Faculty of Medicine, Department of Odontology.
    Strålande lärande utan strålning: virtuell radiografi och gamification2017In: Universitetspedagogiska konferensen 2017: undervisning i praktiken – föreläsning, flexibelt eller mitt emellan?, Umeå: Universitetspedagogik och lärandestöd (UPL), Umeå universitet , 2017, p. 5-7Conference paper (Other academic)
  • 28. Ahlstrand, Tuuli
    et al.
    Kovesjoki, Laura
    Maula, Terhi
    Oscarsson, Jan
    Umeå University, Faculty of Medicine, Department of Odontology.
    Ihalin, Riikka
    Aggregatibacter actinomycetemcomitans LPS binds human interleukin-82019In: Journal of Oral Microbiology, E-ISSN 2000-2297, Vol. 11, no 1Article in journal (Refereed)
    Abstract [en]

    Various gram-negative species sequester host cytokines using outer membrane proteins or surface modulation by sulfated polysaccharides. An outer membrane lipoprotein (BilRI) of the periodontal pathogen Aggregatibacter actinomycetemcomitans binds several cytokines, including interleukin (IL)-8. Because IL-8 is positively charged at physiological pH, we aimed to determine whether IL-8 interacts with negatively charged lipopolysaccharide (LPS). Binding was investigated using electrophoretic mobility shift assays and microwell-based time-resolved fluorometric immunoassay. LPS from each tested strain of A. actinomycetemcomitans (N = 13), Pseudomonas aeruginosa (N = 1) and Escherichia coli (N = 1) bound IL-8. The K-d value of the A. actinomycetemcomitans LPS-IL-8 interaction varied between 1.2-17 mu M irrespective of the serotype and the amount of phosphorus in LPS and was significantly lower than that of the BilRI-IL-8 interaction. Moreover, IL-8 interacted with whole A. actinomycetemcomitans cells and outer membrane vesicles. Hence, LPS might be involved in binding of IL-8 to the outer membrane of A. actinomycetemcomitans. This raises an interesting question regarding whether other gram-negative periodontal pathogens use LPS for IL-8 sequestering in vivo.

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  • 29. Ahlstrand, Tuuli
    et al.
    Tuominen, Heidi
    Beklen, Arzu
    Torittu, Annamari
    Oscarsson, Jan
    Umeå University, Faculty of Medicine, Department of Odontology.
    Sormunen, Raija
    Pöllänen, Marja T.
    Permi, Perttu
    Ihalin, Riikka
    A novel intrinsically disordered outer membrane lipoprotein of Aggregatibacter actinomycetemcomitans binds various cytokines and plays a role in biofilm response to interleukin-1β and interleukin-82017In: Virulence, ISSN 2150-5594, E-ISSN 2150-5608, Vol. 8, no 2, p. 115-134Article in journal (Refereed)
    Abstract [en]

    Intrinsically disordered proteins (IDPs) do not have a well-defined and stable 3-dimensional fold. Some IDPs can function as either transient or permanent binders of other proteins and may interact with an array of ligands by adopting different conformations. A novel outer membrane lipoprotein, bacterial interleukin receptor I (BilRI) of the opportunistic oral pathogen Aggregatibacter actinomycetemcomitans binds a key gatekeeper proinflammatory cytokine interleukin (IL)-1β. Because the amino acid sequence of the novel lipoprotein resembles that of fibrinogen binder A of Haemophilus ducreyi, BilRI could have the potential to bind other proteins, such as host matrix proteins. However, from the tested host matrix proteins, BilRI interacted with neither collagen nor fibrinogen. Instead, the recombinant non-lipidated BilRI, which was intrinsically disordered, bound various pro/anti-inflammatory cytokines, such as IL-8, tumor necrosis factor (TNF)-α, interferon (IFN)-γ and IL-10. Moreover, BilRI played a role in the in vitro sensing of IL-1β and IL-8 because low concentrations of cytokines did not decrease the amount of extracellular DNA in the matrix of bilRI− mutant biofilm as they did in the matrix of wild-type biofilm when the biofilms were exposed to recombinant cytokines for 22 hours. BilRI played a role in the internalization of IL-1β in the gingival model system but did not affect either IL-8 or IL-6 uptake. However, bilRI deletion did not entirely prevent IL-1β internalization, and the binding of cytokines to BilRI was relatively weak. Thus, BilRI might sequester cytokines on the surface of A. actinomycetemcomitans to facilitate the internalization process in low local cytokine concentrations.

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  • 30. Ahmad, S
    et al.
    Poveda, A
    Shungin, Dmitry
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine. Umeå University, Faculty of Medicine, Department of Odontology. Department of Clinical Sciences, Genetic and Molecular Epidemiology Unit, Lund University Diabetes Center, Lund University, Malmö, Sweden.
    Barroso, I
    Hallmans, Göran
    Umeå University, Faculty of Medicine, Department of Biobank Research. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Nutritional Research.
    Renström, Frida
    Umeå University, Faculty of Medicine, Department of Biobank Research. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Nutritional Research. Department of Clinical Sciences, Genetic and Molecular Epidemiology Unit, Lund University Diabetes Center, Lund University, Malmö, Sweden.
    Franks, Paul W
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine. Department of Clinical Sciences, Genetic and Molecular Epidemiology Unit, Lund University Diabetes Center, Lund University, Malmö, Sweden; Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.
    Established BMI-associated genetic variants and their prospective associations with BMI and other cardiometabolic traits: the GLACIER Study2016In: International Journal of Obesity, ISSN 0307-0565, E-ISSN 1476-5497, Vol. 40, no 9, p. 1346-1352Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Recent cross-sectional genome-wide scans have reported associations of 97 independent loci with body mass index (BMI). In 3541 middle-aged adult participants from the GLACIER Study, we tested whether these loci are associated with 10-year changes in BMI and other cardiometabolic traits (fasting and 2-h glucose, triglycerides, total cholesterol, and systolic and diastolic blood pressures).

    METHODS: A BMI-specific genetic risk score (GRS) was calculated by summing the BMI-associated effect alleles at each locus. Trait-specific cardiometabolic GRSs comprised only the loci that show nominal association (P⩽0.10) with the respective trait in the original cross-sectional study. In longitudinal genetic association analyses, the second visit trait measure (assessed ~10 years after baseline) was used as the dependent variable and the models were adjusted for the baseline measure of the outcome trait, age, age(2), fasting time (for glucose and lipid traits), sex, follow-up time and population substructure.

    RESULTS: The BMI-specific GRS was associated with increased BMI at follow-up (β=0.014 kg m(-2) per allele per 10-year follow-up, s.e.=0.006, P=0.019) as were three loci (PARK2 rs13191362, P=0.005; C6orf106 rs205262, P=0.043; and C9orf93 rs4740619, P=0.01). Although not withstanding Bonferroni correction, a handful of single-nucleotide polymorphisms was nominally associated with changes in blood pressure, glucose and lipid levels.

    CONCLUSIONS: Collectively, established BMI-associated loci convey modest but statistically significant time-dependent associations with long-term changes in BMI, suggesting a role for effect modification by factors that change with time in this population.

  • 31. Ahmad, S.
    et al.
    Zhao, W.
    Renström, F.
    Rasheed, A.
    Zaidi, M.
    Samuel, M.
    Shah, N.
    Mallick, N. H.
    Shungin, Dmitry
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine. Umeå University, Faculty of Medicine, Department of Odontology.
    Zaman, K. S.
    Ishaq, M.
    Rasheed, S. Z.
    Memon, F-ur-R
    Hanif, B.
    Lakhani, M. S.
    Ahmed, F.
    Kazmi, S. U.
    Deloukas, P.
    Frossard, P.
    Franks, P. W.
    Saleheen, D.
    A novel interaction between theFLJ33534locus and smokingin obesity: a genome-wide study of 14 131 Pakistani adults2016In: International Journal of Obesity, ISSN 0307-0565, E-ISSN 1476-5497, Vol. 40, no 1, p. 186-190Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Obesity is a complex disease caused by the interplay of genetic and lifestyle factors, but identification of gene-lifestyle interactions in obesity has remained challenging. Few large-scale studies have reported use of genome-wide approaches to investigate gene-lifestyle interactions in obesity. METHODS: In the Pakistan Risk of Myocardial Infraction Study, a cross-sectional study based in Pakistan, we calculated body mass index (BMI) variance estimates (square of the residual of inverse-normal transformed BMI z-score) in 14 131 participants and conducted genome-wide heterogeneity of variance analyses (GWHVA) for this outcome. All analyses were adjusted for age, age(2), sex and genetic ancestry. RESULTS: The GWHVA analyses identified an intronic variant, rs140133294, in the FLJ33544 gene in association with BMI variance (P-value = 3.1 x 10(-8)). In explicit tests of gene x lifestyle interaction, smoking was found to significantly modify the effect of rs140133294 on BMI (Pinteraction = 0.0005), whereby the minor allele (T) was associated with lower BMI in current smokers, while positively associated with BMI in never smokers. Analyses of ENCODE data at the FLJ33534 locus revealed features indicative of open chromatin and high confidence DNA-binding motifs for several transcription factors, providing suggestive biological support for a mechanism of interaction. CONCLUSIONS: In summary, we have identified a novel interaction between smoking and variation at the FLJ33534 locus in relation to BMI in people from Pakistan.

  • 32. Ahmad, Shafqat
    et al.
    Rukh, Gull
    Varga, Tibor V
    Ali, Ashfaq
    Kurbasic, Azra
    Shungin, Dmitry
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine. Umeå University, Faculty of Medicine, Department of Odontology. Lund University.
    Ericson, Ulrika
    Koivula, Robert W
    Chu, Audrey Y
    Rose, Lynda M
    Ganna, Andrea
    Qi, Qibin
    Stancakova, Alena
    Sandholt, Camilla H
    Elks, Cathy E
    Curhan, Gary
    Jensen, Majken K
    Tamimi, Rulla M
    Allin, Kristine H
    Jorgensen, Torben
    Brage, Soren
    Langenberg, Claudia
    Aadahl, Mette
    Grarup, Niels
    Linneberg, Allan
    Pare, Guillaume
    Magnusson, Patrik KE
    Pedersen, Nancy L
    Boehnke, Michael
    Hamsten, Anders
    Mohlke, Karen L
    Pasquale, Louis T
    Pedersen, Oluf
    Scott, Robert A
    Ridker, Paul M
    Ingelsson, Erik
    Laakso, Markku
    Hansen, Torben
    Qi, Lu
    Wareham, Nicholas J
    Chasman, Daniel I
    Hallmans, Göran
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Nutritional Research. Umeå University, Faculty of Medicine, Department of Biobank Research.
    Hu, Frank B
    Renström, Frida
    Orho-Melander, Marju
    Franks, Paul W.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine. Lund University and Harvard University.
    Gene x physical activity interactions in obesity: combined analysis of 111,421 individuals of European ancestry2013In: PLOS Genetics, ISSN 1553-7390, E-ISSN 1553-7404, Vol. 9, no 7, p. e1003607-Article in journal (Refereed)
    Abstract [en]

    Numerous obesity loci have been identified using genome-wide association studies. A UK study indicated that physical activity may attenuate the cumulative effect of 12 of these loci, but replication studies are lacking. Therefore, we tested whether the aggregate effect of these loci is diminished in adults of European ancestry reporting high levels of physical activity. Twelve obesity-susceptibility loci were genotyped or imputed in 111,421 participants. A genetic risk score (GRS) was calculated by summing the BMI-associated alleles of each genetic variant. Physical activity was assessed using self-administered questionnaires. Multiplicative interactions between the GRS and physical activity on BMI were tested in linear and logistic regression models in each cohort, with adjustment for age, age(2), sex, study center (for multicenter studies), and the marginal terms for physical activity and the GRS. These results were combined using meta-analysis weighted by cohort sample size. The meta-analysis yielded a statistically significant GRS x physical activity interaction effect estimate (P-interaction = 0.015). However, a statistically significant interaction effect was only apparent in North American cohorts (n = 39,810, P-interaction = 0.014 vs. n = 71,611, P-interaction = 0.275 for Europeans). In secondary analyses, both the FTO rs1121980 (P-interaction = 0.003) and the SEC16B rs10913469 (P-interaction = 0.025) variants showed evidence of SNP x physical activity interactions. This meta-analysis of 111,421 individuals provides further support for an interaction between physical activity and a GRS in obesity disposition, although these findings hinge on the inclusion of cohorts from North America, indicating that these results are either population-specific or non-causal.

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  • 33.
    Ahmed, Hammad
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Batinic, Mario
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Prevalence and Risk Factors of Neck Pain Among Dentists and Dental Hygienists2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    During the past years it has been reported that musculoskeletal disorders (MSD) have increased in working life. The body region with the highest prevalence of reported pain is the neck region. Several studies show that MSD in the neck region varies between 20–68% among dentists and dental hygienists. The dental personnel work with a limited field of vision and space, which often results in an unnatural work posture. The aim of this study was to evaluate the prevalence of neck pain in dentists and dental hygienists working in the county of Västra Götaland, Sweden and to explore possible work-related and individual risk factors. The study was based on a questionnaire, which was sent out to all dentists and dental hygienists (n = 473) who worked at Folktandvården (response rate 60%). The overall prevalence of neck pain (neck pain every day the past month) was 23%. Female dentists and dental hygienists had an increased risk of neck pain compared to male dentists (OR 2.68, 95% CI 1.22 - 6.75). Dental personnel that experienced severe stress tended to have an increased risk of neck pain compared to those who perceived low stress (OR 2.08, 95% CI 0.94 - 4.53). We conclude that neck pain is a common problem among dental personnel in the county of Västra Götaland. Female dentists and female dental hygienists are at greater risk concerning the prevalence of neck pain.

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  • 34. Akkaoui, Sanae
    et al.
    Johansson, Anders
    Umeå University, Faculty of Medicine, Department of Odontology.
    Yagoubi, Maâmar
    Haubek, Dorte
    Aarhus University Denmark.
    El Hamidi, Adnane
    Mohammed V University in Rabat, Morocco.
    Rida, Sana
    Mohammed V University in Rabat, Morocco.
    Claesson, Rolf
    Umeå University, Faculty of Medicine, Department of Odontology.
    Ennibi, OumKeltoum
    Mohammed V University in Rabat, Morocco.
    Chemical Composition, Antimicrobial activity, in Vitro Cytotoxicity and Leukotoxin Neutralization of Essential Oil from Origanum vulgare against Aggregatibacter actinomycetemcomitans2020In: Pathogens, E-ISSN 2076-0817, Vol. 9, no 3, article id 192Article in journal (Refereed)
    Abstract [en]

    In this study, the essential oil of Origanum vulgare was evaluated for putative antibacterial activity against six clinical strains and five reference strains of Aggregatibacter actinomycetemcomitans, in comparison with some antimicrobials. The chemical composition of the essential oil was analyzed, using chromatography (CG) and gas chromatography-mass spectrometry coupled (CG-MS). The major compounds in the oil were Carvacrol (32.36%), α-terpineol (16.70%), p-cymene (16.24%), and Thymol (12.05%). The antimicrobial activity was determined by an agar well diffusion test. A broth microdilution method was used to study the minimal inhibitory concentration (MIC). The minimal bactericidal concentration (MBC) was also determined. The cytotoxicity of the essential oil (IC50) was <125 µg/mL for THP-1 cells, which was high in comparison with different MIC values for the A. actinomycetemcomitans strains. O. vulgare essential oil did not interfere with the neutralizing capacity of Psidium guajava against the A. actinomycetemcomitans leukotoxin. In addition, it was shown that the O. vulgare EO had an antibacterial effect against A. actinomycetemcomitans on a similar level as some tested antimicrobials. In view of these findings, we suggest that O.vulgare EO may be used as an adjuvant for prevention and treatment of periodontal diseases associated to A. actinomycetemcomitans. In addition, it can be used together with the previously tested leukotoxin neutralizing Psidium guajava.

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  • 35.
    Ala, Sofia
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Asplund, André
    Umeå University, Faculty of Medicine, Department of Odontology.
    Oral Hygiene at Nursing Homes for Older People as Disclosed in Interviews with Nursing Staff2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As the elderly population increases and many elderly keep their natural teeth, a consequence of this is an increased need for oral care to maintain a good oral health. In 2012 about 86,800 people older than 65 years lived in nursing homes in Sweden according to the National Board of Health and Welfare, cared for by nursing aides and nursing assistants. The aim of this study was to explore nursing staffs’ experiences of oral hygiene in two different nursing homes in rural parts of northern Sweden. We chose to use a qualitative approach with fourteen individual semi-structured interviews with the nursing staff. Qualitative content analysis was used to analyze the interviews. Our results showed that the nursing staff are well aware of the importance and need of oral care and having the best ambitions to do a good job. Although this attitude exists we found that the reality was a struggle to handle. This was mainly attributed to an effect of lack of resources and problems related to residents’ cooperation. The nursing staff were willing to do their best in every situation when helping the older persons with their oral hygiene. It is also of great importance to the nursing staff to respect the older person's autonomy and not to harm them. Sometimes these two concepts are not possible to combine which leads to the nursing staff having a moral struggle trying to do their best while still respecting the older person’s autonomy.

     

  • 36.
    Al-Ameri, Mona
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Normark, Theresia
    Umeå University, Faculty of Medicine, Department of Odontology.
    Rhythmical Jaw Opening-Closing Patterns in Healthy Individuals2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Pain affects movements, hampers normal function and may induce dysfunction in jaw system. The aim of this study was to examine if the pattern and stability of a rhythmical jaw opening- closing task changed during a five minute session, in healthy individuals. The analyses included nine men and nine women (mean age 26.7 years; SD 5.3). The participants were instructed to perform rhythmical jaw opening-closing movements with a pace of one per second and amplitude of approximately 20 mm during a five minutes period. The jaw movements were recorded with a 3D optoelectronic recording system. The parameters’ analyses were jaw opening-closing amplitudes and cycle times, to analyze if these parameters differed between men and women and to evaluate if the task evoked tiredness or pain in the jaws. The ten first jaw opening-closing amplitudes and cycle times at each sequence were analysed and compared within individuals and between the groups. Non-parametrical statistics were used. A P-value <0.05 was considered statistically significant. The results showed for both men and women a significant decrease in amplitude and cycle time between the first and the other sequences. The results showed for both men and women that the rhythmical jaw opening-closing task induces self-reported tiredness in the jaws. In conclusion, individuals seem to adhere to pace by reducing amplitude and cycle time during continuous jaw opening-closing tasks. When used as exercise for rehabilitation of the jaw function both patients and dentists should be aware of this behavior.

  • 37.
    Alatwan, Sham
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Hermes, Sima
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    The Effect of Natural Therapeutic Agents on Virulence of Aggregatibacter actinomycetemcomitans2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    ABSTRACT 

    Background

    Adolescent carriers of Aggregatibacter actinomycetemcomitans JP2 genotype have an increased risk of developing periodontitis due to the high leukotoxin (LtxA) production of the bacterium. LtxA contributes to marginal bone loss by killing immunity cells, activating the proinflammatory interleukin-1β (IL-1β) which in turn activates the osteoclasts. A possible strategy to prevent periodontitis might be to neutralize LtxA in JP2-infected individuals. 

     

    Aim

    To investigate whether plant extracts from Matcha or Guava leaves can prolong the viability of macrophages in cell cultures by neutralizing the highly leukotoxic JP2 genotype bacteria.

     

    Material and methods

    A. actinomycetemcomitans JP2 genotype was pretreated with extracts from either Matcha or Guava leaves. Later, the extracts were rinsed before JP2 was exposed to macrophage cell cultures. The experiment was repeated, where JP2 was persistently treated with the extracts instead, i.e., extracts were not rinsed. The macrophage viability after bacterial exposure was analyzed and compared to untreated JP2 bacteria exposed to macrophages. IL-1β secretion in the cell culture medium was quantified in all group samples. 

     

    Results

    Pretreatment of A. actinomycetemcomitans JP2 genotype with Matcha or Guava leaf extracts moderately neutralized LtxA activity, which resulted in prolonged macrophage viability and decreased IL-1β secretion. These effects of prolonged macrophage viability were enhanced when extracts were persistently present during the exposure. 

     

    Conclusion

    The results indicate that Matcha and Guava leaf extracts have effects on the virulence of A. actinomycetemcomitans JP2 genotype that may be useful in future treatment strategies to prevent periodontitis in JP2 carriers.

  • 38.
    Al-Bayati, Asal
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Laskar, Taha
    Umeå University, Faculty of Medicine, Department of Odontology.
    Caries Development At Different Tooth Surfaces In Swedish Adolescents Undergoing Orthodontic Treatment2023Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Introduction

    Dental caries is the most common chronic infectious disease and is associated with plaque, bacteria, diet and saliva. Previous caries experience predicts 1/3 of future caries development. However, there is a lack of knowledge regarding the natural history of caries development at different surfaces and their relative ability to predict caries progression.  

    Aim

    The aim of this study was to describe the caries experience and progression of caries at different tooth surfaces during 5 years in patients undergoing orthodontic multibracket treatment.

    Methods

    In the previously conducted 452-study, children were examined at 12 and 17 years of age. There were 66 patients with multibrackets at the follow-up who we analyzed. Degrees of caries, fillings and missing tooth were registered in an excel file according to the dental statuses (baseline and follow up).  Excel and SPSS were used to compare the files and create figures. 

    Results

    The most affected pair of surfaces at 12 years of age are 36/46 buccally, then occlusally and at 17 years of age 36/46 occlusally and then approximally. The progression of caries and fillings during five years mostly affects 37/47 occlusally and then 17/27 occlusally. A progression also occurred at buccal surfaces 13-23.

    Conclusion 

    The results show that occlusal and approximal surfaces at molars experience caries most frequently and the progression is highest for the second molars. There was also a progression of caries noted on 13-23 which could be associated with the multibrackets. This information may be important in future risk assessment models.

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  • 39.
    Albertsson, Hanna
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Isik, Melina
    Umeå University, Faculty of Medicine, Department of Odontology.
    Regional differences or similarities in human tooth biofilm microbiota: a pilot study2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background: More than 700 oral bacterial species have been found and together they make out the oral microbiota. Specific species have shown to correlate with various oral diseases such as caries and periodontitis, but also systemic diseases. Most studies have looked at the whole microbiota but the knowledge about tooth site-specific variation within supragingival plaque after lack of oral hygiene in healthy participants is limited. 

    Aim: This pilot study aimed to characterize variations in the supragingival plaque with regards to the; anterior (incisors and canines) and posterior (molars and premolars) teeth, upper and lower jaw, and left versus right tooth arches.

    Method: After three days of accumulating plaque, supragingival tooth biofilm was collected from 16 different tooth sites, from six healthy participants. Bacterial DNA was extracted, and 16s rRNA gene (V3-V4) was amplified by PCR and sequenced on an Illumina MiSeq platform. Sequences were blasted and taxonomically allocated using the Human Oral Microbiome Database.

    Result: In summary, 50 species showed a difference between the anterior and the posterior region, 30 species differed between the upper and lower jaw, and three species differed between the left and right sides. 

    Conclusion: This study indicates a difference in oral microbiota composition in supragingival plaque on different tooth regions. These findings emphasize the choice of method when analyzing the oral microbiota—also highlighting the importance of further understanding the dynamic forces driving local enrichment and reduction of specific species. 

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  • 40.
    Albertsson, Katarina Wikén
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    van Dijken, Jan W V
    Umeå University, Faculty of Medicine, Department of Odontology.
    Awareness of toothbrushing and dentifrice habits in regularly dental care receiving adults2010In: Swedish Dental Journal, ISSN 0347-9994, Vol. 34, no 2, p. 71-78Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate toothbrushing and dentifrice habits in a Swedish adult population with relatively high caries frequency, which received regularly dental care and to evaluate the awareness of their toothbrush technique. Sixty adult participants with high caries frequency, 29 woman and 31 men, answered a self-reporting questionnaire with 42 questions concerning their oral care, brushing technique and -habits.The responses were related to their clinical behaviour observed during a customary toothbrushing session. Fifty-three participants fulfilled both the questionnaire and the clinical observation. Half of these used toothpaste containing 1450-1500 ppm fluoride but only one of all participants was aware of the fluoride concentration used. The majority used a manual toothbrush and 95% brushed their teeth twice a day using 0.9 g toothpaste. A wide range of brushing methods and habits was observed. Sixty percent did not brush systematically. Spitting of toothpaste-saliva during brushing was performed by 60% and after brushing by 15%.The observed brushing times were significantly higher than the self reported. The observed brushing times were <1 min: 3.4%, 1-2 min: 36.7% and >2 min: 47.0%. There was a significant correlation between observed brushing time and caries activity. Rinsing with water after brushing was performed once (32%) or twice (44%) during the observations. Only 9% rinsed with toothpaste slurry after brushing. It can be concluded that the awareness of the individual toothbrushing, post-brushing behaviour and the use of fluoride toothpaste was non-optimal in the adult participants. Oral health promotion by optimalized use of fluoride toothpaste and improved post-brushing behaviour should be recommended.

  • 41. Al-Delaimy, W K
    et al.
    Slimani, N
    Ferrari, P
    Key, T
    Spencer, E
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Odontology, Cariology.
    Johansson, G
    Mattisson, I
    Wirfalt, E
    Sieri, S
    Agudo, A
    Celentano, E
    Palli, D
    Sacerdote, C
    Tumino, R
    Dorronsoro, M
    Ocké, M C
    Bueno-De-Mesquita, H B
    Overvad, K
    Chirlaque, Ma D
    Trichopoulou, A
    Naska, A
    Tjonneland, A
    Olsen, A
    Lund, E
    Skeie, G
    Ardanaz, E
    Kesse, E
    Boutron-Ruault, M-C
    Clavel-Chapelon, F
    Bingham, S
    Welch, A A
    Martinez-Garcia, C
    Nagel, G
    Linseisen, J
    Quirós, J R
    Peeters, P H M
    van Gils, C H
    Boeing, H
    van Kappel, A L
    Steghens, J-P
    Riboli, E
    Plasma carotenoids as biomarkers of intake of fruits and vegetables: ecological-level correlations in the European Prospective Investigation into Cancer and Nutrition (EPIC).2005In: European Journal of Clinical Nutrition, ISSN 0954-3007, E-ISSN 1476-5640, Vol. 59, no 12, p. 1397-408Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: The aim of this study was to assess the ability of a single 24-h dietary recall (24HDR) and food questionnaires (FQ) to predict plasma carotenoid levels at the ecological level by assessing the relationship between mean plasma carotenoid levels and mean intake of fruit and vegetables measured by 24HDR and FQ across 16 European regions. DESIGN: A random subsample of 3089 subjects was included, stratified by age and gender. They provided blood samples and dietary information between 1992 and 2000 as part of the European Prospective Investigation into Cancer and Nutrition. RESULTS: Using Spearman's correlation coefficients, the correlations between mean regional 24HDR fruit and vegetable variables and corresponding mean plasma carotenoid levels were generally higher than the correlations using FQ means. The highest correlation was between the 24HDR citrus fruit variable and beta-cryptoxanthin (r = 0.90). For 24HDR, total fruits and vegetables were highly correlated with lutein, zeaxanthin, and beta-cryptoxanthin (r = 0.83-0.87), while vegetables were more closely related with lutein (r = 0.69) and zeaxanthin (r = 0.68), and fruits correlated with zeaxanthin (r = 0.87) and beta-cryptoxanthin (r = 0.84). Root vegetables (r = 0.81) and total carrots (r = 0.71) were well correlated with alpha-carotene. In the multivariate models adjusting for age, body mass index, and season, and using observations of means stratified by sex and region, the association was generally higher for 24HDR compared to FQ. CONCLUSION: Mean regional intakes of fruits and vegetables in several European countries were closely correlated with corresponding mean plasma levels of individual carotenoids. Fruits and vegetables measured by 24HDR were generally better able to predict plasma carotenoids at the ecological level.

  • 42. Al-Delaimy, WK
    et al.
    Ferrari, P
    Slimani, N
    Pala, V
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Odontology, Cariology.
    Nilsson, S
    Mattisson, I
    Wirfalt, E
    Galasso, R
    Palli, D
    Vineis, P
    Tumino, R
    Dorronsoro, M
    Pera, G
    Ocké, MC
    Bueno-de-Mesquita, HB
    Overvad, K
    Chirlaque, M
    Trichopoulou, A
    Naska, A
    Tjonneland, A
    Olsen, A
    Lund, E
    Alsaker, EH
    Barricarte, A
    Kesse, E
    Boutron-Ruault, MC
    Clavel-Chapelon, F
    Key, TJ
    Spencer, E
    Bingham, S
    Welch, AA
    Sanchez-Perez, MJ
    Nagel, G
    Linseisen, J
    Quirós, JR
    Peeters, PH
    van Gils, CH
    Boeing, H
    van Kappel, AL
    Steghens, JP
    Riboli, E
    Plasma carotenoids as biomarkers of intake of fruits and vegetables: individual-level correlations in the European Prospective Investigation into Cancer and Nutrition (EPIC).2005In: European Journal of Clinical Nutrition, ISSN 0954-3007, E-ISSN 1476-5640, Vol. 59, no 12, p. 1387-1396Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: The aim in this study was to assess the association between individual plasma carotenoid levels (alpha-carotene, beta-carotene, lycopene, beta-cryptoxanthin, lutein, zeaxanthin) and fruit and vegetable intakes recorded by a calibrated food questionnaire (FQ) and 24-h dietary recall records (24HDR) in nine different European countries with diverse populations and widely varying intakes of plant foods. DESIGN: A stratified random subsample of 3089 men and women from nine countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC), who had provided blood samples and dietary and other lifestyle information between 1992 and 2000, were included. RESULTS: beta-Cryptoxanthin was most strongly correlated with total fruits (FQ r = 0.52, 24HDR r = 0.39), lycopene with tomato and tomato products (FQ r = 0.38, 24HDR r = 0.25), and alpha-carotene with intake of root vegetables (r = 0.39) and of total carrots (r = 0.38) for FQ only. Based on diet measured by FQ and adjusting for possible confounding by body mass index (BMI), age, gender, smoking status, alcohol intake, and energy intake, the strongest predictors of individual plasma carotenoid levels were fruits (R(partial)(2) = 17.2%) for beta-cryptoxanthin, total carrots ((partial)(2) = 13.4%) and root vegetables (R(partial)(2) = 13.3%) for alpha-carotene, and tomato products (R(partial)(2) = 13.8%) for lycopene. For 24HDR, the highest R(partial)(2) was for fruits in relation to beta-cryptoxanthin (7.9%). CONCLUSIONS: Intakes of specific fruits and vegetables as measured by food questionnaires are good predictors of certain individual plasma carotenoid levels in our multicentre European study. At individual subject levels, FQ measurements of fruits, root vegetables and carrots, and tomato products are, respectively, good predictors of beta-cryptoxanthin, alpha-carotene, and lycopene in plasma.

  • 43. Al-Delaimy, WK
    et al.
    Van Kappel, AL
    Ferrari, P
    Slimani, N
    Steghens, JP
    Bingham, S
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Odontology, Cariology.
    Wallström, P
    Overvad, K
    Tjonneland, A
    Key, TJ
    Welch, AA
    Bas Bueno-De-Mesquita, H
    Peeters, PH
    Boeing, H
    Linseisen, J
    Clavel-Chapelon, F
    Guibout, C
    Navarro, C
    Quiros, JR
    Palli, D
    Celentano, E
    Trichopoulou, A
    Benetou, V
    Kaaks, R
    Riboli, E
    Plasma levels of six carotenoids in nine European countries: report from the European Prospective Investigation into Cancer and Nutrition (EPIC).2004In: Public Health Nutrition, ISSN 1368-9800, E-ISSN 1475-2727, Vol. 7, no 6, p. 713-722Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: In addition to their possible direct biological effects, plasma carotenoids can be used as biochemical markers of fruit and vegetable consumption for identifying diet-disease associations in epidemiological studies. Few studies have compared levels of these carotenoids between countries in Europe. OBJECTIVE: Our aim was to assess the variability of plasma carotenoid levels within the cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS: Plasma levels of six carotenoids--alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein and zeaxanthin--were measured cross-sectionally in 3043 study subjects from 16 regions in nine European countries. We investigated the relative influence of gender, season, age, body mass index (BMI), alcohol intake and smoking status on plasma levels of the carotenoids. RESULTS: Mean plasma level of the sum of the six carotenoids varied twofold between regions (1.35 micromol l(-1) for men in Malmö, Sweden vs. 2.79 micromol l(-1) for men in Ragusa/Naples, Italy; 1.61 micromol l(-1) for women in The Netherlands vs. 3.52 micromol l(-1) in Ragusa/Naples, Italy). Mean levels of individual carotenoids varied up to fourfold (alpha-carotene: 0.06 micromol l(-1) for men in Murcia, Spain vs. 0.25 micromol l(-1) for vegetarian men living in the UK). In multivariate regression analyses, region was the most important predictor of total plasma carotenoid level (partial R(2)=27.3%), followed by BMI (partial R(2)=5.2%), gender (partial R(2)=2.7%) and smoking status (partial R(2)=2.8%). Females had higher total carotenoid levels than males across Europe. CONCLUSIONS: Plasma levels of carotenoids vary substantially between 16 different regions in Italy, Greece, Spain, France, Germany, the UK, Sweden, Denmark and The Netherlands. Compared with region of residence, the other demographic and lifestyle factors and laboratory measurements have limited predictive value for plasma carotenoid levels in Europe.

  • 44. Aleksandrova, Krasimira
    et al.
    Boeing, Heiner
    Nöthlings, Ute
    Jenab, Mazda
    Fedirko, Veronika
    Kaaks, Rudolf
    Lukanova-McGregor, Annekatrin
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology. Division of Cancer Epidemiology, German Cancer Research Center, Heidelberg, Germany.
    Trichopoulou, Antonia
    Trichopoulos, Dimitrios
    Boffetta, Paolo
    Trepo, Elisabeth
    Westhpal, Sabine
    Duarte-Salles, Talita
    Stepien, Magdalena
    Overvad, Kim
    Tjønneland, Anne
    Halkjær, Jytte
    Boutron-Ruault, Marie-Christine
    Dossus, Laure
    Racine, Antoine
    Lagiou, Pagona
    Bamia, Christina
    Benetou, Vassiliki
    Agnoli, Claudia
    Palli, Domenico
    Panico, Salvatore
    Tumino, Rosario
    Vineis, Paolo
    Bueno-de-Mesquita, Bas
    Peeters, Petra H
    Gram, Inger Torhild
    Lund, Eiliv
    Weiderpass, Elisabete
    Quirós, J Ramón
    Agudo, Antonio
    Sánchez, María-José
    Gavrila, Diana
    Barricarte, Aurelio
    Dorronsoro, Miren
    Ohlsson, Bodil
    Lindkvist, Björn
    Johansson, Anders
    Umeå University, Faculty of Medicine, Department of Odontology. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Nutritional Research.
    Sund, Malin
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Khaw, Kay-Tee
    Wareham, Nicholas
    Travis, Ruth C
    Riboli, Elio
    Pischon, Tobias
    Inflammatory and metabolic biomarkers and risk of liver and bilary tract cancer2014In: Hepatology, ISSN 0270-9139, E-ISSN 1527-3350, Vol. 60, no 3, p. 858-871Article in journal (Refereed)
    Abstract [en]

    Obesity and associated metabolic disorders have been implicated in liver carcinogenesis; however there is little data on the role of obesity-related biomarkers on liver cancer risk. We studied prospectively the association of inflammatory and metabolic biomarkers with risks of hepatocellular carcinoma (HCC), intra-hepatic bile duct (IBD) and gallbladder and bilary tract cancers outside of the liver (GBTC) in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC). Over an average of 7.7 years, 296 participants developed HCC (n=125), GBTC (n=137) or IBD (n=34). Using risk set sampling, controls were selected in a 2:1 ratio and matched for recruitment center, age, sex, fasting status, time of blood collection. Baseline serum concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), C-peptide, total, high-molecular-weight (HMW) adiponectin, leptin, fetuin-a, and glutamatdehydrogenase (GLDH) were measured and incidence rate ratios (IRRs) and 95% confidence intervals (CI-s) estimated using conditional logistic regression. After adjustment for lifestyle factors, diabetes, hepatitis infection and adiposity measures, higher concentrations of CRP, IL-6, C-peptide and non-HMW adiponectin were associated with higher risk of HCC (IRR per doubling of concentrations = 1.22; 95%CI = 1.02-1.46, P=0.03; 1.90; 95%CI = 1.30-2.77, P=0.001; 2.25; 95%CI = 1.43-3.54, P=0.0005 and 2.09; 95%CI = 1.19-3.67, P=0.01, respectively). CRP was associated also with risk of GBTC (IRR = 1.22; 95%CI = 1.05-1.42, P=0.01). GLDH was associated with risks of HCC (IRR = 1.62; 95%CI = 1.25-2.11, P=0.0003) and IBD (IRR = 10.5; 95%CI = 2.20-50.90, P=0.003). The continuous net reclassification index was 0.63 for CRP, IL-6, C-peptide and non-HMW adiponectin, and 0.46 for GLDH indicating good predictive ability of these biomarkers. Conclusion: Elevated levels of biomarkers of inflammation and hyperinsulinemia are associated with a higher risk of HCC, independent of obesity and established liver cancer risk factors.

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  • 45. Aleksandrova, Krasimira
    et al.
    Pischon, Tobias
    Jenab, Mazda
    Bueno-de-Mesquita, H Bas
    Fedirko, Veronika
    Norat, Teresa
    Romaguera, Dora
    Knüppel, Sven
    Boutron-Ruault, Marie-Christine
    Dossus, Laure
    Dartois, Laureen
    Kaaks, Rudolf
    Li, Kuanrong
    Tjønneland, Anne
    Overvad, Kim
    Quirós, José Ramón
    Buckland, Genevieve
    Sánchez, María José
    Dorronsoro, Miren
    Chirlaque, Maria-Dolores
    Barricarte, Aurelio
    Khaw, Kay-Tee
    Wareham, Nicholas J
    Bradbury, Kathryn E
    Trichopoulou, Antonia
    Lagiou, Pagona
    Trichopoulos, Dimitrios
    Palli, Domenico
    Krogh, Vittorio
    Tumino, Rosario
    Naccarati, Alessio
    Panico, Salvatore
    Siersema, Peter D
    Peeters, Petra HM
    Ljuslinder, Ingrid
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology.
    Ericson, Ulrika
    Ohlsson, Bodil
    Weiderpass, Elisabete
    Skeie, Guri
    Borch, Kristin
    Rinaldi, Sabina
    Romieu, Isabelle
    Kong, Joyce
    Gunter, Marc J
    Ward, Heather A
    Riboli, Elio
    Boeing, Heiner
    Combined impact of healthy lifestyle factors on colorectal cancer: a large European cohort study2014In: BMC Medicine, E-ISSN 1741-7015, Vol. 12, no 1, p. 168-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Excess body weight, physical activity, smoking, alcohol consumption and certain dietary factors are individually related to colorectal cancer (CRC) risk; however, little is known about their joint effects. The aim of this study was to develop a healthy lifestyle index (HLI) composed of five potentially modifiable lifestyle factors - healthy weight, physical activity, non-smoking, limited alcohol consumption and a healthy diet, and to explore the association of this index with CRC incidence using data collected within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. METHODS: In the EPIC cohort, a total of 347,237 men and women, 25- to 70-years old, provided dietary and lifestyle information at study baseline (1992 to 2000). Over a median follow-up time of 12 years, 3,759 incident CRC cases were identified. The association between a HLI and CRC risk was evaluated using Cox proportional hazards regression models and population attributable risks (PARs) have been calculated. RESULTS: After accounting for study centre, age, sex and education, compared with 0 or 1 healthy lifestyle factors, the hazard ratio (HR) for CRC was 0.87 (95% confidence interval (CI): 0.44 to 0.77) for two factors, 0.79 (95% CI: 0.70 to 0.89) for three factors, 0.66 (95% CI: 0.58 to 0.75) for four factors and 0.63 (95% CI: 0.54 to 0.74) for five factors; P-trend <0.0001. The associations were present for both colon and rectal cancers, HRs, 0.61 (95% CI: 0.50 to 0.74; P for trend <0.0001) for colon cancer and 0.68 (95% CI: 0.53 to 0.88; P-trend <0.0001) for rectal cancer, respectively (P-difference by cancer sub-site = 0.10). Overall, 16% of the new CRC cases (22% in men and 11% in women) were attributable to not adhering to a combination of all five healthy lifestyle behaviours included in the index. CONCLUSIONS: Combined lifestyle factors are associated with a lower incidence of CRC in European populations characterized by western lifestyles. Prevention strategies considering complex targeting of multiple lifestyle factors may provide practical means for improved CRC prevention.

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  • 46.
    Al-Faisal, Hanien
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Alkheder, Bayan
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    The Acute Maxillofacial Infection- a retrospective medical journals analysis of patients in inpatient care2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Introduction: An absolute majority of dental infections are treated without major complications. In exceptional situations dental infections can spread to surrounding structures such as the airways or even the brain leading to a life-threatening condition that requires hospitalization. According to literature, some qualified risk factors appear to be common in hospitalized patients.

    Aim: To outline factors typically seen in patients with acute maxillofacial infections with dental origin at Norrland University Hospital (NUS) and find possible association between these factors and the length of hospital stay. 

    Methods: A literature review using keywords associated with dental infections and acute throat and head infections was performed. Retrospective structured medical journal reviews of 58 patients suffering from acute maxillofacial infections which required hospitalization at NUS were analyzed. The results were analyzed using IBM SPSS Statistics software and Microsoft Office Excel.

    Results: The results indicated that overweight/obese people (Body Mass Index ⊵25) require longer care at the hospital due to their infection. Every other of the hospitalized patients had received dental treatment within 14 days prior to hospitalization. 

    Conclusions: In situations with acute maxillofacial infections of dental origin requiring hospitalization, BMI ⊵25 is eventually a risk factor. A group of patients received dental treatment for their infection, but the infection still exacerbated. How come? This requires deeper analysis with further studies.

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  • 47.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Lorentzon, Mattias
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Bäckman, Stina
    Umeå University, Faculty of Medicine, Department of Odontology, Oral Cell Biology.
    Bäckman, Assar
    Umeå University, Faculty of Medicine, Department of Odontology, Oral Cell Biology.
    Lerner, Ulf H
    Umeå University, Faculty of Medicine, Department of Odontology, Oral Cell Biology.
    cDNA-arrays and real-time quantitative PCR techniques in the investigation of chronic Achilles tendinosis.2003In: Journal of Orthopaedic Research, ISSN 0736-0266, E-ISSN 1554-527X, Vol. 21, no 6, p. 970-975Article in journal (Refereed)
    Abstract [en]

    The aetiology and pathogenesis of chronic painful Achilles tendinosis are unknown. This investigation aimed to use cDNA arrays and real-time quantitative polymerase chain reaction (real-time PCR) technique to study tendinosis and control tissue samples. Five patients (females mean age 57.1+/-4.3 (years+/-SD)) with chronic painful Achilles tendinosis were included. From all patients, one biopsy was taken from the area with tendinosis and one from a clinically normal area (control) of the tendon. The tissue samples were immediately immersed in RNAlater and frozen at -80 degrees C until RNA extraction. Portions of pooled RNA from control and tendinosis sites, respectively, were transcribed to cDNA, radioactively labelled (32P), hybridized to cDNA expression arrays, and exposed to phosphoimager screens over night. Expressions of specific genes, shown to be regulated in the cDNA array analysis, were analyzed in the individual samples using real-time PCR. cDNA arrays showed that gene expressions for matrix-metalloproteinase-2 (MMP-2), fibronectin subunit B (FNRB), vascular endothelial growth factor (VEGF), and mitogen-activated protein kinase p38 (MAPKp38) were up-regulated, while matrix-metalloproteinase-3 (MMP-3) and decorin were down-regulated, in tendinosis tissue compared with control tissue. Using real-time PCR, 4/5 and 3/5 patients showed up-regulation of MMP-2 and FNRB mRNA, respectively. For decorin, VEGF, and MAPKp38, real-time PCR revealed a great variability among patients. Interestingly, the mRNAs for several cytokines and cytokine receptors were not regulated, indicating the absence of an inflammatory process in chronic painful Achilles tendinosis. In conclusion, cDNA-arrays and real-time PCR can be used to study differences in gene expression levels between tendinosis and control tendon tissue.

  • 48. Alghadir, A. H.
    et al.
    Anwer, S.
    Zafar, Hamayun
    Umeå University, Faculty of Medicine, Department of Odontology. Rehabilitation Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia ; Department of Rehabilitation Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
    Al-Eisa, E. S.
    Effect of quadriceps and hamstrings muscle cooling on standing balance in healthy young men2017In: Journal of Musculoskeletal and Neuronal Interactions - JMNI, ISSN 1108-7161, Vol. 17, no 3, p. 176-182Article in journal (Refereed)
    Abstract [en]

    Objective: The present study compared the effect of quadriceps and hamstring muscle cooling on standing balance in healthy young men.

    Methods: Thirty healthy young men (18-30 years) participated in the study. The participants were randomly assigned to three groups (n=10 each): quadriceps cooling (QC), hamstring cooling (HC), or control group (no cooling). Participants in the QC and HC groups received 20 minutes of cooling using a cold pack (gel pack), placed on the anterior thigh (from the apex of the patella to the mid-thigh) and the posterior thigh (from the base of the popliteal fossa to the mid-thigh), respectively. Balance score including unilateral stance was measured at baseline and immediately after the application of the cold pack.

    Results: No significant difference in the balance score was noted in any group after the application of the cold pack (p>0.05). Similarly, no significant differences in post-test balance score were noted among the three groups (p>0.05).

    Conclusions: Cooling of the quadriceps and hamstring muscles has no immediate effect on standing balance in healthy young men. However, longitudinal studies are warranted to investigate the long-term effects of cooling these muscles on standing balance.

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  • 49. Alghadir, A. H.
    et al.
    Anwer, S.
    Zafar, Hamayun
    Umeå University, Faculty of Medicine, Department of Odontology. Rehabilitation Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
    Iqbal, Z. A.
    Effect of localised vibration on muscle strength in healthy adults: a systematic review2018In: Physiotherapy, ISSN 0031-9406, E-ISSN 1873-1465, Vol. 104, no 1, p. 18-24Article, review/survey (Refereed)
    Abstract [en]

    Objective To investigate the effects of local vibration on muscle strength in healthy adults.

    Data sources The electronic databases PubMed, CINAHL, Scopus and Web of Science were searched using a combination of the following keywords: vibration, vibration therapy, power, maximal voluntary contraction, performance, rate of force development and vibratory exercise. In addition, the Medical Subject Headings 'vibration', 'strength' and 'exercise' were used. The bibliographical search was limited to articles published in English.

    Study selection Trials that evaluated the effect of localised vibration on muscle strength in healthy humans were included.

    Data extraction Two independent evaluators verified the quality of the selected studies using the PEDro Scale and the Cochrane Collaboration's tool for assessing the risk of bias. Muscle strength was calculated for each intervention.

    Results In total, 29 full-text studies were assessed for eligibility. Eighteen studies did not match the inclusion criteria, and were excluded. The 11 studies included in this review had an average PEDro score of 5.36/10. Most of the studies reported significant improvements in muscle strength after the application of local vibration. There was considerable variation in the vibration training parameters and target muscle location.

    Conclusions The use of local vibration on the target muscle can enhance muscle strength in healthy adults. Further well-designed controlled studies are required to confirm the effect of local vibration training on muscle strength. 

  • 50. Alghadir, Ahmad
    et al.
    Aly, Farag
    Zafar, Hamayun
    Umeå University, Faculty of Medicine, Department of Odontology, Clinical Oral Physiology.
    Effect of face veil on ventilatory function among Saudi adult females2012In: Pakistan journal of medical sciences print, ISSN 1682-024X, E-ISSN 1681-715X, Vol. 28, no 1, p. 71-74Article in journal (Refereed)
    Abstract [en]

    Objective: The use of face veil called "niqab" by women to cover their faces at public places is a common practice in some Muslim communities. The long-term effect of niqab use on ventilatory function (VF) has not previously been reported. The aim of this cross-sectional study was to compare VF between niqab wearing and non-niqab wearing healthy Saudi females. Methodology: Thirty eight healthy adult Saudi females participated in this study. Nineteen subjects were regular niqab users and the other nineteen were either not using niqab at all or used it for less than one hour per day. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC (%), and maximal voluntary ventilation (MVV) were recorded using a digital spirometer. Results: Mean values of FVC, FEV1, FEV1/FVC (%) and MVV for niqab wearers were significantly lower than the corresponding values for non-niqab wearers. Significant negative correlation was found between the FVC and FEV1 values and the number of hours of the use of face veil per day. Conclusions: Long-term use of traditional niqab use can affect VF.

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