不同面部生长型正常少年的后牙近远中向倾斜度研究

Study on the posterior teeth mesiodistal tipping degree of normal occlusion subjects among different facial growth patterns

目的研究恒牙列初期正常少年人群的面部生长型与后牙近远中向倾斜度的关系。方法选择163例正常少年为研究对象,根据面部生长型分为垂直、平均、水平生长型3组,均拍摄X线头颅定位侧位片并进行X线头影测量分析,研究其上下颌后牙近远中向倾斜度及上下颌后牙牙体长轴交角的差异。结果垂直生长型24例,平均生长型96例,水平生长型43例。垂直生长型与水平生长型、水平生长型与平均生长型之间的上下颌第一磨牙和第一、二前磨牙牙体长轴近远中向倾斜度均存在统计学差异(P<0.05),但垂直生长型与平均生长型之间的差异无统计学意义(P>0.05)。3组的上下颌后牙牙体长轴交角的差异无统计学意义(P>0.05)。结论恒牙列初期正常人群中不同面部生长型有各自相协调的后牙近远中向倾斜度。

Objective To study the relationship between the mesiodistal tipping degree of maxillary and mandible posterior teeth and different vertical facial skeletal types of subjects with normal occlusion.Methods 163 subjects with normal occlusion were selected,lateral cephalograms were taken and divided into three different facial skeletal types.The difference of the mesiodistal tipping degrees and intersection angles of upper and lower posterior teeth between the three different facial skeletal types were analyzed.Results Among 163 subjects,vertical growth pattern,average growth pattern and horizontal growth pattern were 24,96 and 43 respectively.There were statistic differences of mesiodistal tipping degrees of the first and second maxillary and mandible premolar and the first permanent molar between vertical growth and horizontal growth pattern,horizontal growth and average growth pattern（P〈0.05）.But there were no statistically significant differences between vertical growth and average growth pattern（P〉0.05）.The differences of the maxillary and mandible posterior teeth＇s intersection angle among three vertical facial skeletal types had no statistic significance（P〉0.05）.Conclusion Different vertical facial skeletal type has its own normal and coordinated posterior teeth mesiodistal tipping degrees.