Stability and outcome of surgical-orthodontic treatment in patients of Class III deformity with and without a history of orthodontic treatment

BACKGROUND/PURPOSE: Many adult patients seeking surgical-orthodontic treatment have previously undergone orthodontic treatment during their youth. This study aimed to compare the stability and outcome of surgical-orthodontic treatment between Class III patients who had undergone previous orthodontic treatment and those who had not.

MATERIALS AND METHODS: 82 adult Class III patients who consecutively received surgery-first bimaxillary surgery were included, 30 who had not undergone orthodontic treatment (NFO group), 25 who had undergone orthodontic treatment with premolar extraction (FO-E group), and 27 who had undergone orthodontic treatment without premolar extraction (FO-NE group). Cone-beam computed tomography were obtained pre-surgery (T0), 1 week after surgery (T1) and after debonding (T2) to determine skeletal stability and treatment outcome of skeletal, dental and soft tissue structures. Self-report questionnaires including satisfaction with facial appearance and quality of life were also evaluated.

RESULTS: Treatment outcome, satisfaction and quality of life did not differ significantly among the three groups except the mandibular alveolar thickness (6.3 ± 1.9 mm vs 5.3 ± 1.3 mm vs 5.4 ± 1.5 mm, respectively for the NFO, FO-E and FO-NE groups). Neither group exhibited a significant difference in skeletal stability except in the anterior maxilla (ANS, 1.0 ± 1.2 mm vs 0.3 ± 0.7 mm vs 0.5 ± 0.8 mm, respectively for the NFO, FO-E and FO-NE groups). Mean relapse was ≤1 mm at the maxilla and <2 mm at the mandible within each group.

CONCLUSION: A history of orthodontic treatment in patients of Class III deformity with mandibular prognathism has limited effects on the final surgical-orthodontic correction outcome.