Occlusal Scheme and Temporomandibular Disorders (TMD)

Objectives: To study relationship between occlusal schemes and Temporomandibular disorders in a group of Thais patients. Methods: The patients attending at Masticatory Science clinic, Faculty of Dentistry, Mahidol University were examined for occlusal schemes on the left and the right sides and were classified according to the definition from Glossary of Prosthodontic Terms (8th edition) into group function, canine protected occlusion and combination of occlusal scheme. In addition,patients were classified into TMD and control groups. Chi-square test was used with 0.05 level of significance. Results: Total of 523 patients were included in this study: 421 TMD and 102 control patients with average age of 31.75±12.48 and 25.08±6.91 years old respectively. There was significant sex related to TMD condition (p < .001). The result showed that majority of TMD group was female (51.6%). For occlusal scheme in TMD group, 270 or 64.1 % of total TMD patients possessed group function occlusal schemes, 105 TMD patients or 24.9% possessed canine protected occlusion and 46 or 10.9 % of total patients possessed combination of both occlusal schemes. For control group, the similar distribution of occlusal scheme were found. The most common occlusal scheme was group function, canine protected occlusion and combination occlusal scheme: 71(69.6% of control), 18(17.6% of control) and 13(12.7% of control) respectively. However, no statistically significance was observed (p = .29). Conclusions: There was significant sex related to TMD patients. The majority of occlusal scheme was group function, however there was no significant occlusal scheme related to TMD condition.