【摘要】 目的:分析下颌第三磨牙倾斜度、磨牙后间隙与骨性Ⅲ类错畸形的关联性。方法:研究主要包括60例受试者,骨性Ⅰ类、骨性Ⅲ类错畸形各30例,分别拍摄并测量全颌曲面断层片和头颅定位侧位片的常见指标。分析两组下颌第三磨牙的倾斜角度及磨牙后间隙大小方向差异,并探讨下颌第三磨牙与骨性Ⅲ类错畸形的关系。结果:两组间性别分布有差异,年龄分布、Go-Co、SN-MP均无差异。独立样本t检验结果显示骨性Ⅲ类组中SNA和第三磨牙倾斜角均显著小于骨性Ⅰ类组(P<0.05),骨性Ⅲ类组中SNB、Go-Pog、磨牙后间隙均显著大于骨性Ⅰ类组(P<0.05)。二元逻辑回归显示磨牙后间隙是骨性Ⅲ类的危险因素,第三磨牙倾斜角是骨性Ⅲ类的保护因素。结论:第三磨牙的磨牙后间隙、倾斜角与骨性Ⅲ类错的发生存在相关性。更多还原

【Abstract】 Objective: To analyze the relationship between the angulation and the retromolar space of the third molar and skeletal class Ⅲ malocclusion. Methods: A total of 60 orthodontic patients were investigated from dental pantomograms( DPTs) and lateral cephalograms( LC). The subjects were divided into two groups according to their ANB angle,that skeletal class I and skeletal class Ⅲ. Values of DPT and LC were traced and the following variables were measured that were SNA angle,SNB angle,retromolar space width,third molar angulation,Go-Co length,Go-Pog length and SN-MP angel. Results:There was a difference in gender distribution between the two groups( P < 0. 05). There was no difference in age distribution,Go-Co,and SN-MP( P > 0. 05) respectively. The angle of SNA and angulation of third molar in skeletal class Ⅲ subjects were smaller than those in skeletal class I subjects( P < 0. 05) respectively. The angle of SNB,Go-Pog length and the retromolar space in skeletal class Ⅲ subjects were larger than in the skeletal class I subjects( P < 0. 05) respectively. Binary logistic regression showed that the retromolar space was a risk factor and the angulation of third molar was a protective factor. Conclusion:There is a relationship between the angulation of the third molar and the retromolar space and the occurrence of skeletal class Ⅲmalocclusion.更多还原