不同垂直面型AngleⅡ^1错切牙区颌骨形态结构比较研究

A comparative study of jaw bone morphological structure at incisor area in class Ⅱ division 1 malocclusion among different vertical facial skeletal types

目的比较研究不同垂直面型AngleⅡ1错切牙区颌骨形态结构特征。方法随机选择2009年1月至2011年1月本院正畸科收治的恒牙初期AngleⅡ1错患者121例,测量比较不同垂直面型组治疗前的头颅定位侧位片,包括线距、角度、面积、比值等。结果 (1)线距:低角者前牙区牙槽骨与基骨厚、颌骨高度低,中切牙根尖点到唇舌(腭)侧骨皮质板的距离较远;高角则相反。(2)角度:上颌相对于前颅底平面及腭平面、下颌相对于下颌平面,低角者前牙区牙槽骨及切牙比高角者更唇倾。(3)面积:不同垂直面型,上下颌切牙区颌骨面积比较差异无统计学意义。(4)比值:某一垂直面型上下颌切牙区颌骨高度的代偿方向一致,但代偿量不同,上颌大于下颌。结论不同垂直面型颌骨形态结构不同,治疗方法、预后及注意事项也有所不同。

Objective To analyze and compare the anterior alveolus morphology of jaw bone of class Ⅱ division 1 malocclusion among different vertical skeletal facial types.Methods 121 cases of class Ⅱ division 1 malocclusion in early permanent dentition were randomly selected from the patients in the orthodontic department of our hospital from January 2009 to January 2011.The lateral cephalometric X-ray films before treatment in different vertical facial skeletal types were measured and compared,including lingers,angles,areas and rates.Results（1）Lingers：low angle individuals presented a thick incisor alveolar and basal bone,the distance from the root apex of upper and lower central incisors were far away from the palatal,lingual or labial cortex in low angle.High angle individuals were opposite.（2）Angles：the inclination relating to SN plane,GoGn plane,the incisors and alveolar bone of maxillary and mandibular incisor jaws showed more labially in low angle than high angle individuals of class Ⅱ division 1 malocclusion.（3）Areas：the areas of maxillary and mandibular basal bones showed no statistical difference.（4）Rates：among different vertical facial types of class Ⅱdivison 1 malocclusion,the ability of compensation of height may be stronger in maxillary jaw at incisor area than mandibular jaw at the incisor area.Conclusion The morphological structure of jaw bone among different vertical facial types is different.Therefore,the treatment methods,prognosis and precautions also are different.