The effect of parafunction on condylar asymmetry in patients with temporomandibular disorders.

This study was undertaken to examine the relationship between condylar asymmetry and parafunction in patients with temporomandibular disorders (TMD). Twenty-eight patients with TMD and parafunction and 30 patients with TMD but no parafunction were examined. A panoramic radiograph was obtained for each patient and from this the condylar asymmetry determined. The group with parafunction showed a significantly (P < 0.005) higher asymmetry index than did the group with no noticeable parafunction. Patients were grouped into the following age ranges: 10-19 years, 20-29 years, 30-39 years, and 40 + years. The mean asymmetry index was determined for each age range for both groups of patients. The group of patients with TMD and parafunction had a higher mean asymmetry index in all the age ranges studied. This suggests that muscle hyperactivity may be a factor in the increased asymmetry found in patients with TMD.