Class III surgical-orthodontic treatment: a cephalometric study

In this retrospective study, we investigated treatment outcomes in Class III surgical-orthodontic patients.

Records of 151 consecutively completed Class III surgical-orthodontic patients (overjet, 0 mm or less) were obtained from 87 consultant orthodontists in the United Kingdom. Pretreatment and posttreatment cephalometric radiographs were analyzed.

Bimaxillary surgical patients (75%) had more negative initial ANB-angle values and smaller initial SNA-angle values than those treated with single-jaw mandibular surgery. Mandibular surgery patients (15%) had greater pretreatment mandibular prominence (SNB angle) than maxillary patients. Maxilla-only patients (10%) had lower negative initial overjet values than bimaxillary patients. An overjet within the ideal range of 1 to 4 mm was achieved in 83% of the patients. Logistic regression identified no predictors of ideal overjet outcome. SNB angle was corrected to within the ideal range of 75 degrees to 81 degrees in 44% of the patients. This was less likely in those treated with maxillary surgery only and larger initial SNB-angle values. An ideal posttreatment ANB angle (1 degrees to 5 degrees) was achieved in 40% of the patients and was more likely in those with bimaxillary surgery, lower negative pretreatment ANB angles, and presurgical orthodontic extractions in the maxillary arch. Ideal posttreatment unadjusted Holdaway angles (7 degrees to 14 degrees) were achieved in 59% of the patients and were more likely when single-jaw mandibular surgery was used. Incisor decompensation was incomplete in 46% of the patients and was associated with mandibular arch extractions.

Surgical-orthodontic treatment had a high success rate in normalizing the overjet and soft-tissue profile to within ideal ranges in Class III patients. Bimaxillary surgery was the most frequently used procedure and was associated with an increased likelihood of an ideal correction of the anteroposterior skeletal discrepancy.