成年骨性Ⅱ类错[牙合]患者上颌中切牙牙根与切牙管的位置关系研究

Study on the relationship between the roots of maxillary central incisors and the incisive canal in skeletal Ⅱ adults

目的:研究成年骨性Ⅱ类错[牙合]畸形患者上颌中切牙牙根与切牙管的位置关系,进一步探讨上中切牙唇倾度对其位置关系的影响。方法:选取67例安氏Ⅱ类且骨性Ⅱ类错[牙合]的成年患者,通过锥形束CT和Dolphin11.9软件在切牙管腭侧开口平面(F1)和根尖平面(F2)上分别测量切牙管到上颌中切牙之间的相关数据,根据∠U1-PP角度分为上颌中切牙唇倾组、直立组、舌倾组,采用单因素方差分析和秩和检验对测量结果进行统计分析。结果:腭侧开口平面和根尖平面上,上中切牙近中缘至切牙管的距离(Lml)分别为(3.27±1.02)mm、(3.07±1.35)mm。腭侧开口平面上,3组切牙管侧缘到同侧上中切牙的距离(Lc)差异有统计学意义,唇倾组明显小于直立组和舌倾组;根尖平面上,3组Lml的差异有统计学意义,舌倾组明显大于唇倾组和直立组。结论:成年骨性Ⅱ类错[牙合]患者上前牙内收是有限度的,唇倾组的上中切牙牙根更接近切牙管,舌倾组牙根更远离切牙管。

Objective:To study the distance between the upper central incisors and the incisive canal,and further discuss the effect of inclination of upper central incisors on the distance. Methods:A total of 67 adult skeletal Ⅱ and angle Ⅱ orthodontic patients were included in this study. CBCT and Dolphin11.9 software were used to measure the distance between the incisive canal and upper central incisor roots at two planes:the palatal opening level(F1),and the root apex level of the maxillary central incisors(F2). Then,all patients were divided into three groups(procline,upright,and recline)according to ∠U1-PP. One-way ANOVA or rank sum test was performed for statistical analysis. Results:At F1 and F2 planes,the anteroposterior distance between upper incisor roots and the anterior line of incisive canal(Lml)was(3.27±1.02)mm and(3.07±1.35)mm,respectively. As for three groups,Lc of procline group was significantly lower than upright group and recline group at F1 plane;while Lml of recline group was significantly larger than the other two groups at F2 plane. Conclusion:There is strict limit in tooth movement during retraction of the maxillary incisors in adult skeletal Ⅱ orthodontic patients. The upper incisor roots of procline group were much closer to the incisive canal,while the upper incisor roots of recline group were much far away from the incisive canal.