以側面輪廓角定義成人軟組織下頦之位置

Profile Angle Defines Soft Tissue Chin Position in Adults

目的：定義軟組織下頦相對於法蘭克福水平面與鼻樑交錯的上顏面之位置關係，進而發展出一種能適用於不同種族之矯正治療計劃制定時的測量值。材料與方法：選取48位臺灣成人病患（男性：23位，女性：25位），選取標準包括適當標準的齒列咬合，骨性第一級關係，嘴唇閉合正常，和符合美觀線（ E-line）的標準值。將這些病患的資料進行軟組織分析並與相對應的白種人標準值比較。結果：分析結果顯示臺灣人的鼻子比白種人短，上唇和下頦比白種人厚，但是儘管對臺灣人有以上較不利的測量值，所有選取的臺灣病患仍然均符合美觀線的標準值，顯示下顎下頦的位置是重要的關鍵。於是我們將側面輪廓線（由法蘭克福水平面與鼻樑的交點相切於軟組織下頦）與法蘭克福水平面所形成的交角作測量，結果發現不分男女，均可得至約84度的一致測量值。結論：測量側面輪廓角能定位下頦的位置，儘管不同種族間鼻子的長度，嘴唇和下頦的厚度有差異，下顎下頦前後的位置可以在不同種族間提供側面顏面美觀的重要依據。

Objectives: To identify the soft tissue chin position relative to the upper part of the face wherein the Frankfort horizontal (FH) plane intersects the nasal bridge and to define a specific measurement that might benefit different racial groups and their treatment goals. Materials and Methods: Forty-eight Taiwanese adults (23 males and 25 females), selected based on criteria consisting of proper occlusion, skeletal Class I pattern, lip competence in repose, and within the Esthetic (E) line confined standard, were subjected to standard soft tissue facial analyses. The results were used to compare with those of the White norm. Results: Analyses revealed that the means of the nose of our sample were shorter than those of the White, but those of the upper lip and chin were thicker. Despite the measured counter or unfavorable differences, all samples still abide E line criteria, suggesting that chin position in mandible must justify the harmonious facial profile. Moreover, a facial angle was constructed between the FH plane and a profile line drawn from a point where the FH plane meets the nasal outline tangentially to soft-tissue chin. A consistent value of 84 degrees was obtained in both male and female. Conclusion: The measurement of the profile angle can identify and localize the chin point. Even though the length of the nose and the thickness of the lips and chin may vary, the proper chin position may eventually justify a pleasing facial profile among different ethnic origins.