Occlusal Riskfactors in Subjects with Temporomandibular Dysfunction

MATERIALS AND METHOD: 197 subjects between 18 and 65 years old (mean: 32.07, SD: 10.83) were randomly selected in urban (Mashhad) and rural (Zoshk) area. All Subjects were physically examined according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/ TMD). Subsequently diagnoses of myofacial pain (MP), disc displacement (DD), condylar deformity (CD) or no diagnosis according to RDC/TMD was made. Possible risk factors such as missing anterior or posterior contacts, wear facets, major discrepancies between centric relation and centric occlusion (CO) and impressions on the cheek or tongue were documented. Nightly and or daily teeth grinding was assesed by using a questionnaire. Using a logistic regression model a statistical analysis of risk factors for different subgroups of TMD diagnoses was performed.

RESULTS: The prevalence of MP was 9.9%, DD 10 % and condylar deformity 12.8%. Risk factors for MP were a high number of anterior teeth (p=0.01, OR=0,244) and a low number of posterior teeth (p=0.05, OR=3,088) in statistic occlusion. Wear facets (p=0.04, OR=0,227) had a risk reducing effect according to disc displacement. The age however increased the risk (p=0.004, OR=1,068).

CONCLUSION: Specific occlusal factors seem to have different effects in specific subgroups of TMD.