Guidance of Mandibular Movements by Molar Teeth as a Possible Trigger of Chronic Condylar Dislocation Observed in One Patient

Abstract

The mechanism of condylar dislocation is not clearly understood. Temporomandibular (TMJ) surgery is a common option in the treatment of chronic condylar dislocation, but some authors have reported disappearance of its symptomatology after occlusal treatment.
A case in which condylar dislocation disappeared by changing the location of anterior guidance is presented. The patient was an 18-year-old male with an Angle class III malocclusion who had been suffering from condylar dislocation of the right TMJ upon waking up for almost one year. Clinical inspection showed that the mandibular right second molar was guiding the mandibular eccentric movements. Dislocation of the TMJ disappeared by shifting anteriorly the tooth guidance with a stabilization splint. Jaw and condyle movements were recorded by a 6-degree-of-freedom measuring device during lateral excursions with and without wearing of the splints in order to assess the influence of shifting anteriorly the location of tooth guidance on the cure of dislocation. It was found that the direction of condylar movements changed markedly during parafunctional grinding tasks. Therefore, it was concluded that