Skeletal, dental and soft tissue changes in Class III patients treated with fixed appliances and lower premolar extractions.

Background: Mild Class III malocciusions can be treated by upper incisor proclination and lower incisor retroclination following extraction of the lower first premolars.

Aims: To compare the skeletal, dental and soft tissue changes in Class III patients treated with fixed appliances, Class III traction and lower first premolar extractions with the changes in a group of untreated Class III patients.

Methods: The Treatment group consisted of 30 Class III patients (Mean age 13.69 +/- 1.48 years) who were treated by upper and lower fixed appliances, Class III intermaxillary traction and lower first premolar extractions for 2.88 +/- 1.12 years. The Control group consisted of 20 untreated Class III patients (Mean age 13.51 +/- 0.95) matched for age and gender. The T1 to T2 changes in the treated and untreated groups were compared using a paired t-test while differences between the two groups were compared with an independent t-test.

Results: During treatment, the upper incisors were proclined about 1 degree and the lower incisors were retroclined 8 degrees. Small, but statistically significant changes in SNB, Wits and the overlying soft tissues accompanied the changes in incisor inclination. At the end of treatment a positive overbite and overjet were achieved. The increase in lower facial height in the Treatment group was comparable with the change in the Control group.

Conclusions: A range of mild to moderate Class III malocclusions can be treated by dentoalveolar compensation.