切牙管与上颌中切牙位置关系的定量研究

Quantitative study of the relationship between the incisive canal and maxillary central incisors

目的本研究旨在通过研究切牙管与上颌中切牙之间的位置关系,以期为临床治疗及后续研究提供借鉴和参考。方法选取76例正在进行正畸治疗的成人患者,以PP平面为参考平面,在正中矢状面上定义以下三个测量水平,此三个水平均与PP平面平行。N水平:鼻腭孔高度水平;R水平:上颌中切牙牙根根尖高度水平;I水平:切牙孔高度水平。定义以下测量项目:N水平切牙管唇侧牙槽骨板厚度(NT);R水平切牙管唇侧牙槽骨板厚度(RT);I水平切牙管唇侧牙槽骨板厚度(IT)。N水平切牙管宽度(NW);R水平切牙管宽度(RW);I水平切牙管宽度(IW);上颌中切牙根尖距离(R-R);R水平UR1到切牙管距离(RRD);R水平UL1到切牙管距离(RLD);I水平UR1到切牙管距离(IRD);I水平UL1到切牙管距离(ILD)。在CBCT图像上对以上指标进行测量,并对结果进行统计学分析。结果 RRD大于IRD;RLD大于ILD,有统计学差异(P<0.05)。RRD与RLD;IRD与ILD,无统计学差异(P>0.05)。NW小于RW;RW小于IW,有统计学差异(P<0.05)。NT大于RT,有统计学差异(P<0.05);NT与IT之间无显著性差异(P>0.05);RT与IT之间无显著性差异(P>0.05)。结论 U1根尖至切牙管平均距离仅为3.5 mm;U1在I水平牙根至切牙管平均距离仅为2.4 mm,应注意在上颌前牙内收时有可能导致牙根根尖及牙根舌侧面的吸收。并且当上颌前牙内收尤其配合压低移动时,应注意有可能造成牙根近中邻面的吸收。

Objective To study the positional relationship between the incisive canal and the maxillary central incisors,in order to provide reference for clinical treatment and subsequent research.Methods Seventy-six adults undergoing orthodontic treatment were selected.Three measurement levels were defined on the CBCT image,and the measurement level paralleling to PP plane included:nasopalatine foramen level(N),root tip level(R),incisive foramen level(I).The following measuring projects were defined,the N level incisive canal lip side alveolar bone plate thickness(NT),R level incisive canal lip side alveolar bone plate thickness(RT),I level incisive canal lip side alveolar bone plate thickness(IT),N level incisive canal width(NW),R level incisive canal width(RW),I level incisive canal width(IW),the maxillary central incisor apex distance(R-R),R level UR1 to incisive canal distance(RRD),R level UL1 to incisive canal distance RLD,I level UR1 to incisive canal distance(IRD),I level UL1 to incisive canal distance(ILD).The above projects were measured on CBCT images and the results were statistically analyzed.Results RRD was greater than IRD,RLD was greater than ILD,and the difference was statistically significant(P<0.05).There was no significant difference between RRD and RLD,IRD and ILD(P>0.05).NW was less than RW;RW was less than IW,and there was a statistical difference(P<0.05).NT was greater than RT,with a statistical difference(P<0.05).There was no significant difference between NT and IT(P>0.05).There was no significant difference between RT and IT(P>0.05).Conclusion The average distance from the root tip of U1 to the incisive canal is only 3.5 mm,while the I-level average distance from the root of the U1 to the incisive canal is only 2.4 mm.It should be noted that the retraction of the maxillary anterior teeth may lead to the absorption of the root apex and the lateral side of the root.When the retraction of the maxillary anterior teeth is especially matched with the intrusion movement,attention should be paid to the possibility of the absorption of the mesial surface of the roots.