安格氏三級咬合病例以犬齒取代側門齒合併正顎手術治療之病例報告

Surgical-orthodontic Treatment of A Skeletal Class III Malocclusion with Canine Substitution for Peg Lateral Incisors - Case Report

上顎錐形側門齒在蒙古人種的發生率為3.1%，高於其他人種1 ，所造成的美觀問題，常常令臨床醫師感到棘手。本病例二十歲男性為骨性上顎輕微後縮合併骨性下顎前突、前牙錯咬、上顎雙側錐形側門齒、上顎齒列擁擠的安格氏三級異常咬合病例。經評估後決定拔除上顎錐形側門齒，犬齒取代，關閉空間來解決上顎擁擠，達到手術前的齒性去代償，再進行正顎手術解決骨性下顎前突問題。最後的治療結果不僅外觀改善，也達到理想的咬合關係。

The overall prevalence of peg-shaped maxillary permanent lateral incisors was 1.8%. The occurrence rates were higher in Mongoloid (3.1%) than in black (1.5%) and white (1.3%) patients. The presence of peg lateral incisors was also a complicated esthetic issue for orthodontist. This case is a skeletal Class III malocclusion 20-years-old male. His problems were mild maxillary skeletal retrognathism combined with mandibular prognathism, anterior crossbite, peg lateral incisors, and upper arch crowding. Treatment involved extraction of two maxillary lateral incisors. Maxillary canine substituted for lateral incisors. Before orthognathic surgery, the extraction spaces were closed for crowding relief of upper arch and dental decompensate was also achieved. Finally, the orthognathic surgery was performed to correct the problem of severe skeletal Class III. After 30 months of treatment, the facial profile was improved and ideal occlusal relationship was achieved.