利用錐狀射束電腦斷層影像評估正顎手術後顳顎關節之位置及型態變化

Abstract

目的：本研究利用錐狀射束斷層掃描影像，觀察接受矯正配合正顎手術治療的病患，其治療前後顳顎關節的位置和表面型態變化。 材料與方法：實驗受測者共計51位接受矯正配合正顎手術治療的病患，其中34位為安格氏第三級異常咬合，17位為安格氏第二級異常咬合之病患。於矯正治療前以及所有治療結束並拆除矯正器之後，分別拍攝錐狀射束斷層掃描影像。並將治療前後的影像做全頭顱以及區域重疊後，測量其雙側顳顎關節在治療前後於軸狀、冠狀和矢狀面中的線性和角度變化。統計方面利用相依樣本t檢定觀察安格氏第三級和第二級異常咬合病患組，其各組內在治療前後的各項數值是否有差異。利用雙樣本平均數差異t檢定檢視安格氏第三級和第二級異常咬合病患組，兩組之間治療前後的變化量是否有差異。並以皮爾森相關分析衡量各組治療前後變化量和下顎的水平移動量間線性關聯性的高低程度。各項統計的顯著水準均訂為0.05，並以錯誤檢出率控制法校正。 結果與結論：治療前後下顎骨乙狀切跡最凹點位移量約在2公釐以內。軸狀下顎枝角度在治療後，在安格氏第三級異常咬合組有增加的情形，在安格氏第二級異常咬合組有減少的情形。安格氏第三級異常咬合組在矯正合併正顎手術治療後其髁頭型態無顯著變化，安格氏第二級異常咬合組在矯正合併正顎手術治療後其髁頭型態寬度與長度顯著下降。治療前後下顎骨近心段角度變化量和下顎水平移動量不相關。安格氏第三級和第二級異常咬合組的髁頭表面型態變化和下顎水平移動量均不相關。

Purpose: The aim of the present study was to use cone-beam computed tomographic images to investigate the displacement and morphological changes of temporomandibular joints in patients who received orthodontic treatment combined with orthognathic surgery. Materials and Methods: Fifty-one patients who received orthodontic treatment combined with orthognathic surgery were recruited for this study. The patients were divided in to two groups: Angle’s Class III malocclusion group (n = 34) and Angle’s Class II malocclusion group (n = 17). All patients took cone-beam computed tomography scans before and after treatments. Overall and regional superimposition of the cone-beam computed tomographic data was done. The outcome variables were the linear and angular measurement changes of temporomandibular joints in axial, coronal, and sagittal planes. Paired t-test was used to measurements within Angle’s Class III and Class II malocclusion groups. Two-sample t-test was used to measurements between Angle’s Class III and Class II malocclusion groups. Pearson's correlation coefficient was used to correlate the changes of temporomandibular joints and amount of mandibular setback or advancement. The threshold significance for data was P < 0.05, corrected using false discovery rate correction for multiple comparisons Results and Conclusions: The changes of C points (the deepest point of sigmoid notch) were within 2 mm. The axial ramal angle increased in Angle’s Class III malocclusion group, and decreased in Angle’s Class II malocclusion group. There was no significant condylar change in Angle’s Class III malocclusion group. Significant condylar changes of widths and lengths were noted in Angle’s Class II malocclusion group. There was no statistically significant correlation between the angular changes of mandibular proximal segments and the amount of mandibular setback or advancement. The linear changes of condyle in Angle’s Class III and Class II malocclusion groups had no statistically significant correlation with the amount of mandibular movement.