Publications (2)2.76 Total impact
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ABSTRACT: Class II malocclusion is often associated with retrognathic mandible. Some of these problems require surgical correction. The purposes of this study were to investigate treatment outcomes in patients with Class II malocclusions whose treatment included mandibular advancement surgery and to identify predictors of good outcomes. Pretreatment and posttreatment cephalometric radiographs of 90 patients treated with mandibular advancement surgery by 57 consultant orthodontists in the United Kingdom before September 1998 were digitized, and cephalometric landmarks were identified. Paired samples t tests were used to compare the pretreatment and posttreatment cephalometric values for each patient. For each cephalometric variable, the proportion of patients falling within the ideal range was identified. Multiple logistic regression analysis was performed to identify predictors of achieving ideal range outcomes for the key skeletal (ANB and SNB angles), dental (overjet and overbite), and soft-tissue (Holdaway angle) measurements. An overjet within the ideal range of 1 to 4 mm was achieved in 72% of patients and was more likely with larger initial ANB angles. Horizontal correction of the incisor relationship was achieved by a combination of 75% skeletal movement and 25% dentoalveolar change. An ideal posttreatment ANB angle was achieved in 42% of patients and was more likely in females and those with larger pretreatment ANB angles. Ideal soft-tissue Holdaway angles (7 degrees to 14 degrees ) were achieved in 49% of patients and were more likely in females and those with smaller initial SNA angles. Mandibular incisor decompensation was incomplete in 28% of patients and was more likely in females and patients with greater pretreatment mandibular incisor proclination. Correction of increased overbite was generally successful, although anterior open bites were found in 16% of patients at the end of treatment. These patients were more likely to have had initial open bites. Mandibular surgery had a good success rate in normalizing the main dental and skeletal relationships. Less ideal soft-tissue profile outcomes were associated with larger pretreatment SNA-angle values, larger final mandibular incisor inclinations, and smaller final maxillary incisor inclinations. The use of mandibular surgery to correct anterior open bite was associated with poor outcomes.
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ABSTRACT: 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.