3D影像電腦輔助設計合併兩片式手術模板正顎手術矯正治療之精準度分析－－前驅性研究

Accuracy of The Computer-Aided 3-D Virtual Planning System Combined with Double-Splint Design in The Orthognathic Surgery — A Pilot Study

目的：對於複雜的顱顏異常的手術治療，在術前模擬手術計畫中使用3D影像電腦技術已逐漸變成主流。但如何將電腦上設計之手術計畫，完美轉移到臨床手術中執行，仍困擾著許多手術醫師。我們利用錐狀射束電腦斷層攝影（Cone-beam computer tomography）、3D影像電腦輔助設計（virtual planning）、3D 列印方式輸出兩片式手術模板，轉移手術計畫於手術中執行。本研究目的乃評估此方式的精準度及其臨床可行性。材料及方法：本實驗分析五位嚴重骨骼性異常咬合的患者，其接受上、下顎正顎手術治療，並以兩片式手術模板轉移手術計畫。將患者術前及術後電腦斷層掃描作立體重疊（super-imposition），分析術前手術設計及術後成果差異。評估技術精準度標準為下：術前設計及術後成果線性差異小於2mm、角度差異小於4度。結果：由術前電腦模擬手術及實際手術成果的三維線性差異中，平均差異值皆小於2mm。上顎咬合平面角度差異中，在三維平面的平均差異皆小於1.5度，遠小於預設4度誤差標準。結論：此初步研究證明，利用3D影像電腦輔助手術設計及兩片式手術模板（double-occlusal splint）方式，可以準確轉移術前設計於手術中執行。

Purpose: The application of 3D virtual planning has been playing an increasingly important role in complicated craniomaxillofacial surgery. It remains a challenge, however, how to precisely transfer the virtual planning to the actual clinical outcome. Cone-beam CT scan, Simplant O&O virtual plan system with 3D printed splints were applied to the patients in our center with dentofacial deformities. This study is to evaluate the accuracy of the virtual plan system and the reliability of the clinical outcomes. Material and Method: Five patients with severe skeletal discrepancies between the upper and lower jaws were included in the study. All of them received double jaw surgeries. The actual post-operative digital CT models were super-imposed with the virtual planned CT models and the discrepancy between those two models was measured. The criteria of accuracy used by most studied were set at distance discrepancy less than 2.0 mm and angulation discrepancy less than 4 degrees. Outcome: The average distance difference between the planned and actual outcomes were less than 2.0 mm. The occlusal plane angle discrepancy between the planned and actual outcomes were less than 1.5 degrees, which was far less than the success criteria-4.0 degree. Conclusion: In this preliminary study, it can be concluded that virtual planned models using Cone-beam CT and Simplant O&O planning system can be accurately transferred to the actual surgical outcomes.