改良式Wunderer’s前上顎根尖下截骨術術後軟組織之對應變化

正顎手術在上一個世紀的發展輝煌騰達，造福了很多病人。但是關於預測術後軟組織對應變化的預測術研究卻還是有限；而且大部分的文獻資料對於硬組織的術前與術後的方位改變都交代不清，軟組織的術後方位改變也大都以角度來表達，造成臨床上應用的困難與困擾。因此本研究擬以改良式Wunderer’s前上顎根尖下截骨術為基礎，建立一套準確度較高，臨床上容易應用的術後軟組織方位改變的預測術。本研究收集以改良式Wunderer’s前上顎根尖下截骨術矯治雙顎前突或上顎生長過度的病例共40位，皆為女性，平均年齡25.9歲，術後追蹤半年以上；分別研究術前與立即術後，立即術後與術後三個月，以及術前與術後六個月的硬組織方位改變，鼻唇區域軟組織的方位改變，以及硬組織與軟組織間方位改變的對應關係。研究結果顯示術後前上顎骨段以及鼻唇區軟組織都有明顯的改變，而且兩者之間也有明確的對應關係。前上顎骨段立即術後相對術前的方位改變為：ANS平均後移2.61mm，上移1.38mm；Is平均後移7.49mm，上移1.06mm；呈現出整個前上顎骨段後退併有順時鐘旋轉的位移。鼻唇區軟組織術後六個月與術前的方位改變為：Prn後移0.98mm、下移0.55mm；Sn後移2.33mm、下移0.28 mm；LS後移5.36mm、下移0.71mm；ULS後移5.95mm、下移0.90mm；鼻唇角平均增加了6.92度；上唇平均增長0.62mm、增厚0.38 mm；鼻孔仰度平均減少4.35度；鼻子相對高度平均增加2.86 mm。關於硬組織與軟組織間方位改變的對應關係，研究結果發現兩者在水平方向具有顯著的相關性，鼻區：Prn對應ANS的後移會有36%的後移變化，Sn會有71%的後移變化；上唇區：LS對應Is的後移會有73%的後移變化，ULS會有81%的後移變化。由Prn的位移顯示術後鼻尖有些微變圓、後縮的情形，此變化適合於大部份東方人平直或甚至有一點凹陷的鼻樑型態，加上鼻孔仰度變小以及鼻子高度的增加，患者在術後可以獲得一個比較完美的鼻部輪廓。由於Sn對應有71%的位移變化，因此可藉由ANS的後退量來掌控術後鼻唇角的大小及鼻孔的仰度。LS的後退不止改善上唇暴突的狀態，也同時增加鼻子的相對高度。然而LS對應Is的後退量在本研究及所有文獻中都呈現個體之間有明顯差異，應與許多因素有關，其中本研究發現上唇短者因為術後進行閉唇訓練而變長同時變薄，會有較大的後退量。由研究結果可知本改良式Wunderer’s method確實適合於鼻孔較仰、鼻唇角較大，以及上唇需要大量後退的病例；此外本研究清楚的得到鼻唇區域軟組織與前上顎骨段之間的對應位移關係，臨床上只要有清楚的硬組織位移，便可以很簡單的應用本預測術預測出術後軟組織輪廓，藉此較易得到正確同時適合各個病人的治療計畫，也提升醫師與病人之間的溝通效果與效率。

關鍵字

雙顎前突；上顎生長過度；前上顎根尖下截骨術；預測術；軟組織變化

並列摘要

Patients have had the great benefit for the marvelous development in orthognathic surgery in the last century. Nevertheless we know little about the predictions of postoperative soft tissue. Changes of hard tissues in directions and in positions are not clearly stated in the majority of literature. It is also perplexing to understand the indistinct data shown in angle for the changes of soft tissue in directions and in position. Hence the data shown in angle is difficult for clinical application. In this study we made an effort to establish accurate and easy-applied soft tissue prediction ratios for clinical use on the basis of modified Wunderer technique. The study sample was composed of 40 female patients with maxillary excess or bimaxillary protrusion. The mean age of patient was 25.9. All patients had undergone the modified Wunderer technique for anterior subapical osteotomy. The postoperative follow-ups were all over 6 months. We studied the relationship between movement of anterior maxillary segment and soft tissue changes over nose and lip areas by the statistics in the hard tissue displacement and soft tissue changes 3 and 6 months postoperatively. Results of analyses revealed significant changes in the hard and soft tissue parameters and definite relation between each other. Displacement of the anterior segment immediately after operation is following: ANS was averagely displaced 2.61mm backward and 1.38mm upward; Is was averagely displaced 7.49mm backward and 1.06mm upward. The whole anterior segment of maxilla was found with setback and clockwise rotation. As for the soft tissue changes in the nose and lip areas in 6 months postoperatively, Prn was displaced 0.98mm backward and 0.55mm downward. Sn was displaced 2.33mm backward and 0.28mm downward. LS was displaced 5.36mm backward and 0.71mm downward. ULS was displaced 5.95mm backward and 0.90mm downward. Besides NLA increased by 6.92°, upper lip lengthened by 0.62mm and thickened by 0.38mm averagely; nose prominence increased by 2.86mm and inclination of nostril decreased by 4.35°averagely. The relationship between “movement of anterior segment” to “nose and lip soft tissue changes” in horizontal axis were all statistically significant. The mean ratio of shift-Prn/shift-ANS was 0.36; shift-Sn to shift-ANS was 0.71; shift-LS/shift-Is was 0.73; shift-ULS/shift-Is was 0.81. Changes of Prn showed that the nose tip was somewhat rounded and moved backward. This alteration was very suitable for most Orientals with typical depressed nasal bridge. Furthermore, the postoperative nose morphology tended toward perfection with the decreased nostril inclination and the increased nose prominence. We can determine postoperative NLA and nostril inclination for that Sn moved posteriorly in the 71% dimension of ANS setback. The great extent of LS setback contributed not only to great improvement for upper lip protrusions and markedly convex profile but also to the increase of nose prominence. The magnitude of LS setback, however, showed variance individually both in reviewed articles and in our study. There may be several factors for the variation, and those patients with “short lip” who did closing mouth exercise postoperatively was noted to be with a longer but thinner upper lip, and hence the LS moved more posteriorly. From the above we know that the modified Wunderer’s technique is applicable for those patients with high nostril inclination, with obtuse NAL, and with protrusive lip requiring setback in great quantity. Furthermore, it is easy to predict the postoperative soft tissue profile with application of the ratios calculated, and then achieve an appropriate treatment plan for individual patient. This study also works to promote an excellent communication between doctors and patients.