前牙開咬暨骨性三級異常咬合患者之手術矯正治療－－病例報告

Surgical Orthodontic Correction of Class III Maloccusion with Anterior Openbite–A Case Report

骨性三級異常咬合的成因可能與下顎過度生長、上顎生長發育不足或兩者皆有關。而顏面骨骼形態、牙齒咬合異常、不良的習慣或是功能性問題則可能導致前牙開咬。骨釘錨定常被用來壓入上顎後牙，藉由下顎的逆時針旋轉關閉前牙開咬。對於骨性三級異常咬合的患者，上述治療方法雖然可改善前牙開咬，卻無法使患者的外觀得到改善，因此常會需要配合正顎手術達成較理想之治療結果，在骨性三級異常並非極端嚴重的某些特定患者，手術治療可選擇單顎或雙顎手術。本報告病例為骨性三級異常咬合合併前牙開咬之患者，本案例基於經濟考量選擇單顎手術，我們利用迷你骨釘將上顎後牙壓入，並配合單顎正顎手術改善下顎前突之問題，並在治療過程中提醒患者自我訓練改善舌頭前吐的習慣。患者在正顎手術合併全口齒列矯正治療後，顏面美觀及咬合功能皆有大幅度改善。

The etiologies of skeletal Class III malocclusion include excessive growth of mandible, deficient growth of maxilla, and the combination of both. Anterior openbite may be due to skeletal, dental, habitual, or functional problems. Mini-implant can be a reliable anchorage for maxillary molar intrusion, which facilitate anterior openbite closure by counterclockwise rotation of the mandible. However, the mandibular counterclockwise rotation may increase antero-posterior jaw discrepancy in Class III malocclusion. Therefore, surgical orthodontics is often required in the treatment of Class III malocclusion with anterior openbite. In this report, we present the treatment of an adult Class III patient with mandibular prognathism, excessive maxillary dentoalveolar growth, and anterior open bite. Due to financial consideration, the patient preferred to have onejaw surgery instead of two-jaw surgery. Two mini-screws were installed on bilateral infrazygomatic crest of the maxilla to correct anterior open bite by maxillary molar intrusion. Then mandibular surgery was done to setback the mandible. During the post-surgery orthodontic treatment period, the tongue-thrusting habit was progressively eliminated with the tongue training exercise. At the end of treatment, the facial esthetics was significantly improved and stable occlusal relationship was established.