OBJECTIVETo investigate effects of non-surgical treatment on temporal mandibular joint(TMJ) of adult low-angle subjects with severe skeletal Class III deformity.

METHODSThirteen low-angle patients with severe skeletal Class III malocclusion (male 5, female 8) were included in the study. The average age was 21.3 years old. They were treated with OPA-K straight wire technique. Helkimo index evaluation was made before and after treatment. Lateral cephalometric films and corrected TMJ lateral cephalometric radiograghs were taken before and after treatment, and linear and area measurement were observed. All data were analyzed with SPSS 12.0 software.

RESULTSAfter non-surgical treatment, Helkimo indexes of all patients redistributed. The line distance and area of anterior space in TMJ increased while the posterior space decreased. Linear percent decreased from 20.81% to 8.04%, and area proportion decreased from 1.62 to 1.01. Anterior space was the same as the posterior. Condyles and mandibles were retruded.

CONCLUSIONAfter non-surgical therapy in adult low-angle subjects with severe skeletal Class III malocclusion, condyles remove posteriorly from more anterior position to normal concentric position, and temporo-mandibular disorders symptom is relieved and cured effectively.