第三磨牙先天缺失与颅面矢状向发育关系临床研究

Clinical study on the relationship between the congenital missing of the third molars and the craniofacial saggital development in northeast of China

目的通过对第三磨牙先天缺失情况、缺失数目及缺失位置的研究,分析第三磨牙先天缺失与颅面矢状向发育之间的关系。方法研究组227例为2007—2015年中国医科大学附属口腔医院正畸科就诊的错畸形患者,每例至少有1颗第三磨牙先天缺失,对照组227例为同期就诊4颗第三磨牙均存在的错畸形患者。采用winceph8.0软件对所有研究对象的曲面平展片及头颅侧位片进行测量,并进行相关统计学分析。结果研究组第三磨牙先天缺失个数间差异有统计学意义,最多见缺失数目为2颗(92例),其次为1颗(61例)、4颗(46例)和3颗(28列);第三磨牙先天缺失位置间差异有统计学意义,最常见缺失发生于上颌,其次为双颌和下颌。研究组和对照组男性ANS-PNS、Go-Po长度均大于女性且差异有统计学意义,其余测量指标差异均无统计学意义。研究组仅Go-Po长度大于对照组且差异有统计学意义。第三磨牙先天缺失及其缺失位置与颅面骨性分类间差异均无统计学意义。结论研究组和对照组男性上、下颌体长度均大于女性;第三磨牙先天缺失取决于下颌体长度而非上颌体长度;第三磨牙先天缺失及其缺失位置与颅面矢状向发育无明显联系。

Objective Based on the research of the missing of the third molar,the missing numbers and the missing positions,to analyze the relationship between the missing of the third molar and the craniofacial saggital development. Methods This study included the patients who vesited Stomalogoy Hospital of China Medical University from 2007 to 2015：select 227 patients who had at least one of the third molars missing as the study group;select 227 patients who had four third molar present as control group. Use winceph 8.0 software to measure all the lateral cephalograms of the research objects. Use correlation statistical method to perform statistical analysis. Results There was significant difference in the congenital missing number of third molar and the missing sequence was 2,1,4,3;there was statistical difference in the positions of congenital missing of third molars;the most common position was in the maxilla,followed by double jaws,then the mandible. Both in the study group and the control group,the length of ANS-PNS and Go-Po in male was greater than that of female,and there was statistical difference between the two groups;however,other measurments were not statistically different. The Go-Po length in the study group was greater than that in the control group,and there was a significant difference. There was no statistical difference between the third molar congenital agenesis or the agenesis position and the craniofacial skeletal classification. Conclusion There is no obvious relationship between the congenital missing of the third molar or the missing position and craniofacial saggital development. Both in the study group and the control group,the length of maxlli and mandible in male is greater than that of female. Agenesis of third molar does not depend on anteroposterior dimensions of the maxilla but depends on anteroposterior dimensions of the mandible.