The aim of this study was to investigate the biomechanical relationship between the condylar and anterior guidances of patients with symptomatic temporomandibular disorders before and after orthodontic treatment. For this purpose, a four-bar link system was described for use on lateral cephalometric radiographs taken before and after treatment. A computer program was developed utilizing the lengths of the bar links of this four-bar link system on the cephalometric films. The link measurements were entered into the computer program which subsequently calculated the rotations of the mandible and the condyle during the mandibular movement. Three subjects with class II malocclusion and deep bite were selected from patients with temporomandibular pain dysfunction for this investigation. All subjects were treated by intrusion and protrusion of incisors. The rotations of mandible and condyle of these three subjects decreased and temporomandibular joint pains of the subjects were greatly diminished by treatment. In this study, it is observed that anterior guidance and condylar path are dependent on each other.

Keywords: Anterior Guidance, Condylar Guidance, Mandibular Protrusive Movement