面罩治療發育中骨性三級異常咬合病患的顱顏幾何形態學分析

Morphometric Analysis of Treatment Effects of Face Mask Therapy on Skeletal Class III Malocclusion

張瑞青(Zwei-Chieng Chang)

指導教授 ： 張心涪

共同指導教授 ： 張宏博(Hong-Po Chang)

國立臺灣大學/醫學院/臨床牙醫學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.10109

摘要

黃種人孩童的三級異常咬合罹患率高於白種人，對於上顎後縮伴隨著正常或些微下顎骨前突所造成的三級異常咬合，臨床上經常採取面罩配合腭骨擴張器做早期骨性矯治治療。由於幾何形態測量學比傳統測顱分析能更有效地提供生物形態的整體與局部變化特徵及差異部位，並可以利用圖形來表示不同形態間的差異，本研究的目的是利用新式幾何形態測量法來探討使用面罩治療發育中骨性三級異常咬合病患的顱顏形態變化。
研究材料方面，樣本選自歷年來曾在台大醫院齒顎矯正科接受過面罩治療，符合選取標準且資料完整的病例，其中單獨使用面罩組病例數為15位，使用面罩合併腭骨擴張組病例數亦為15位。控制組是來自一群長期追蹤未曾接受過矯正治療的骨性三級異常咬合年輕病患，以一對一的方式從中比對選擇和治療組的年齡、性別、追蹤時程，以及顱顏形態相符合者作為控制組。研究方法整合了普氏疊合分析、薄板仿樣分析以及應變張量分析法進行治療評估，並根據主應變軸方向畫出骨骼經面罩合併或不合併腭骨擴張治療後的變化走向。
本研究以普氏疊合分析的F-檢定檢測結果發現，治療前以及治療後單獨使用面罩組和面罩合併腭骨擴張這兩組的顱顏形態變化極相似，因此把這兩個治療組合併為一個單一的治療組，病例數共計為30，來作後續的分析。經面罩治療後無論在顱底、中臉部以及下顎骨皆有明顯的整體與局部形狀變化和尺寸改變。
本研究可歸納以下結論：1. 單獨使用面罩治療組和使用面罩合併腭骨擴張治療組顱顏形態變化極為相似。2. 薄板仿樣分析法顯示面罩治療使鼻上顎複合體位置前移、長度增加，腭平面逆時針旋轉，下顎骨順時針旋轉扭曲，髁頭向前上生長，下顎聯合區及頦部受到抑制，顱底也有逆時針方向的扭曲變形。3. 利用有限元素分析法可以很明確的看出經面罩治療顱底、中臉部以及下顎骨局部形狀與尺寸的變化量。4. 單獨使用面罩治療組和使用面罩合併腭骨擴張組二者治療療效在統計學上雖然沒有顯著差異，不過合併面罩合併腭骨擴張器治療者可能在較短的時程內達到臨床上滿意的療效，牙齒的改變較少，且對顱骨形態的影響有涵誘騆

關鍵字

腭骨擴張器 ； 面罩 ； 薄板仿樣分析 ； 普氏疊合分析 ； 應變張量分析法 ； 三級異常咬合 ； 主應變軸方向

並列摘要

The prevalence of Class III malocclusion among oriental population is much higher than among Caucasians. For the growing patients who suffer from maxillary retrognathia without or with mild mandibular prognathism, face mask therapy proves to be a promising way for treatment. Newer geometric morphometric methods for shape comparisons are preferable to conventional cephalometry in that they provide explanatory visualization of shape changes and that they highlight regions of localized dissimilarity. The purpose of this study was to investigate the treatment effects of the face mask therapy by means of morphometric techniques.
Thirty children who had been treated with face masks (15 combined with palatal expanders and 15 without) at the Orthodontic Department of National Taiwan University Hospital were compared with a group of thirty sex-matched, age-matched, observation period-matched, and craniofacial configuration-matched subjects with untreated Class III malocclusions. Average geometries, scaled to an equivalent size, were generated by means of Procrustes analysis, and these configurations were statistically tested for equivalence. Graphical analysis, utilizing thin-plate spline analysis and strain tensor methods, was performed for localization of differences in shape/size changes. Maximum and minimum principal extensions were drawn to express the directions of shape change.
Residuals from the Procrustes analysis were compared by means of an F distribution. Statistically insignificant differences occurred between the two treatment groups (the face mask only group and the face mask combined with palatal expander group) at the pretreatment and the post-treatment stages. Thus the two treatment groups were combined into a single treated group with the sample size of thirty patients. Significant treatment-induced shape/size changes involved the cranial base, the midface, and the mandible.
It is concluded that: 1. the treatment-induced changes of the face mask only group and the face mask combined with palatal expander group did not differ significantly. 2. thin-plate spline analysis revealed that major treatment effects caused by face mask therapy consisted of forward displacement of the nasomaxillary complex, increase maxillary length, counter-clockwise rotation of the palatal plane, downward and backward deformation of the mandible, upward and forward direction of condylar growth, restriction in sagittal advancement of symphysis, and counter-clockwise deformation of the cranial base. 3. strain tensor analysis indicated that the face mask treatment of the Class III malocclusion induced favorable localized size and shape changes in the cranial base, the midface, and the mandible. 4. though statistically insignificant, combined face mask and palatal expansion therapy seemed to achieve satisfactory clinical results in shorter time, have less dental effects, and cause more extensive regional changes in the craniofacial configurations. 5. the use of morphometric procedures in this study not only displayed morphological differences qualitatively but also quantitatively. Though we cannot prove that the results reveal true biological response of the individuals, the morphometric procedures seem to provide a valuable supplement for conventional cephalometric analysis.

並列關鍵字

face mask ； Procrustes analysis ； thin-plate spline analysis ； palatal expander ； strain tensor analysis ； Class III malocclusion ； maximum and minimum principal extensions

參考文獻

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