Is malocclusion associated with temporomandibular disorders?

Rationale and aim of the study. The role of malocclusion in temporomandibular joint disorders is controversial in the literature. The aim of this study was to evaluate the frequency of temporomandibular joint (TMJ) disorders and their association with malocclusion. Material and the methods. 50 patients who experienced TMJ disorders were examined in the department of Maxillo-facial surgery and the department of Orthodontics at Lithuanian University of Health Sciences. The examination consisted of three parts: first - extraoral examination which included investigation of the muscles, TMJ and lower jaw movements, the second - intraoral examiation- evaluation of occlusion, and the last one – the TMJ symptom questionnaire. Results. The most prevalent diagnosis of TMJ disorders was disk displacement with reduction without intermittent locking (44%). Pain - related TMD was found in 62%. 96% of patients had malocclusion in sagittal, transversal and/or vertical planes. The most prevalent sagittal malocclusion was Angle class II. One third of patiets had crossbite. All patients with crossbite had deviation or deflection of the lower jaw. Deep bite was found in 30% of patients. Deep bite was significantly associated with reduced anterior movement. Conclusions. The most prevalent TMJ disorder was disk displacement with reduction, which was found in about half of included patients. Nearly all of included patients had malocclusion. The most prevalent malocclusion – Angle class II, cross bite and deep bite. Based on the results of the present study, malocclusion is associated with temporomandibular joint disorders