- 期刊
顎間水平關係異常成年矯正患者之齒顎顱顏形態分析
Analysis of Craniofacial and Dentoalveolar Morphology in Adult Orthodontic Patients with Sagittal Jaw Discrepancy
摘要
本研究主要目的為探討國人骨骼性顎間水平關係異常伴隨的齒顎顱顏特徵及齒列代償機制。此hospital-based study是經由立意抽樣法(purposive sampling)選取樣本，樣本來自台大醫院齒顎矯正科門診病人的檔案，選取270名成人病患之側面測顱X光片，包含骨性一級、二級、三級顎間關係之狹角群、均角群以及廣角群共九種顱顏顎間型態，每組各30名，其中男女各半，統計分析呈現單一、分布均勻對稱的群體，故可使用ANOVA (analysis of variance)加以檢定，而本文主要探討骨性顎間水平關係異常的顱顏特徵及齒列代償現象。綜合本研究分析結果得知：水平顎間關係異常主要導因於下顎長度、形態、空間位置異常，二級異常者其下顎長度及下顎枝高度皆短、角點角較小、下顎枝往後傾斜，所以下顎明顯地後縮，齒列代償結果表現出上顎門齒往舌側傾斜且齒槽高度較長、下顎門齒往唇側傾斜、咬合平面傾斜度大：而三級異常者則呈現相反的特徵，且其前後顱底及上顎有效長度較短。
並列摘要
The aim of this study was to investigate the morphological characteristics of cranio-dento-facial complex and dental compensation among Taiwanese adults associated with sagittal skeletal malocclusions. The classification of antero-posterior skeletal types was based on the judgment off our experienced faculties in orthodontic department. The types were determined with presence of full sets of orthodontic records including clinical examination, photograph, study models, panoradiograph, and lateral cephalometric analysis. The vertical relation ships were categorized according to the mandibular plane angle as low(＜28°), average (28~38°), and high (＞38°), i.e., the hypodivergent, orthodivergent, and hyper divergent groups, respectively. This study was a hospital-based study and the purposive sampling method was used. Lateral cephalometric roentgenograms of 270 Chinese adults were selected from database of Orthodontic Department of National Taiwan University Hospital. All the patients were equally distributed in three subgroups with different anteroposterior skeletal types, in which different extent offacial divergency was included. After testing the distribution of different variables, ANOVA, a robust analysis, was used to analyze this homogenous population because of normal distribution and the equal sample size in each subgroup. The sagittal jaw discrepancy mainly resulted from the length, morphology, and position of the mandible. In Class Ⅱ jaw relationship, shorter mandibular length and ramusheight, lower gonial angle and more backward rotation of the ramusresulted in retrognathic mandible. Dental compensation in this group included reduced upper incisor inclination and elongation of upper anterior dento-alveolar height, increased lower incisor labial tipping, and steeper occlusal plane. While in the Class Ⅲ jaw relationship, the opposite results for all the dimensions mentioned above were noticed. Also shorter cranial base and maxillary length were found in Class Ⅲ jaw relationship.