Dental Angle class asymmetry and temporomandibular disorders

The aim of this study was to determine whether there is an association between the presence of asymmetric molar or canine Angle classes on the two sides and the presence of temporomandibular joint dysfunction (TMD).

Participants to the study were divided into two groups: TMD group (90 patients) or a control group (58 patients). In the TMD group, clinical assessment for TMD was performed according to the Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) guidelines by the same two trained examiners. In both groups, all subjects underwent an assessment of dental occlusion, focusing on the assessment of bilateral canine and molar Angle class relationship. The study protocol was reviewed and approved by the Institutional Review Board of the University of Padova, and each participant gave written consent to take part in the investigation.

TMJ pain was diagnosed in 58, disk displacement in 96, arthrosis in 17, and muscle pain in 46 individuals. Molar Angle class was symmetrical in 86 individuals and asymmetrical in 62 subjects. Molar Angle class was not correlated with any of the TMD diagnoses. Canine Angle class was correlated with TMJ arthrosis. Correlation values with the other TMD diagnoses were low and were not significant.

It can be suggested that an association between dental Angle class asymmetry and TMDs does not exist and that the role of dental asymmetries as a factor correlated with the presence of TMD signs and symptoms is minimal.