前牙開咬之齒顎形態測量學的探討

The Dentofacial Morphometry of Anterior Open-Bite

陳昱杰(Yu-Chieh Chen) ； 張宏博(Hong-Po Chang)

《中華民國齒顎矯正學雜誌》 19卷1期 (2007/03) Pp. 14-22

https://doi.org/10.30036/TJO.200703.0003

摘要

本研究主要目的為探討國人開咬異常咬合所具有的齒顎顱顔特徵及齒列代償機制。樣本來自高雄醫學大學齒顎矯正科門診與矯正專科診所檔案，選取共160名未經矯治病患之側面測顱X光片，包含有正常咬合群與前牙開咬群，每組80名，其男女各半，統計方面則使用t檢定。綜合本研究分析結果得知，開咬者其垂直顎間關係在統計上具有顯著意義，其中顔面開展度、前下顔面高度、下顎平面角、角點角與牙齒齒槽高度在開咬群都顯著較大；後顔面與前顔面的比值與下顎枝長度則顯著較小。其他諸如顱底形態、水平顎間關係均無顯著差異。開咬群齒列方面則上下後牙與前牙區呈現過度萌發，且牙齒長軸皆向近心傾斜。

關鍵字

前牙開咬 ； 顱顔特徵 ； 測顱分析

並列摘要

The purpose of this study was to investigate the morphological characteristics of the craniofacial structures in people with open-bite malocclusion.
Lateral cephalograms of untreated 80 patients with open-bite were compared with 80 people with normal occlusion. Thirty-three landmarks were traced, identified and digitized. Cephalometric analysis utilizing 23 linear, 24 angular measurements and 4 ratios were undertaken. The Student's t-test was used for statistical analysis.
The results are as follows: the main differences between the open-bite combined skeletal Class Ⅰ, Ⅱ or Ⅲ exist almost in horizontal relation, but are similar in vertical relation. There is no significant difference in the angular or linear measurements of cranial base between the open-bite and the normal groups. The angular measurements of the facial pattern and the PFH/AFH ratio of the open-bite group are statistically significant compared with the normal. The average of ATFH of the open-bite group is more than the average of ATFH in the other group, most of the increased 6 amount rising from the ALFH. The mandibular plane angle, whether compared with SN, FH and PP, is significantly increased statistically, possibly resulting from the clockwise rotation of the mandible. The shorter ramal length and obtuse gonial angle are shown in the open-bite group. The vertical heights of both anterior and posterior teeth in open-bite group are increased significantly. The long axis of posterior teeth tilts toward mesially, but there is no difference in the anteriors. In this study, almost all teeth positon more anteriorly in the open-bite group.

並列關鍵字

open-bite ； malocclusion ； dentofacial morphometry ； cephalometric analysis