锥形束CT应用于恒前牙复杂根管系统的研究

Root canal system in permanent anterior teeth studied by cone beam computed tomography

目的:运用锥形束CT(cone-beam computed tomography,CBCT)研究上下颌前牙根管构型等特征。方法:纳入1103例患者12858颗前牙,以40岁为界分A组(≤40岁)和B组(>40岁),上前牙6404颗,下前牙6454颗,分析其牙根及根管数目、冠根长度、根管构型、左右同名牙双根管的对称性及与年龄、性别的关系,比较下前牙间双根管检出的两两相关性。结果:上前牙及下切牙均为单根,下尖牙双根检出率为1.66%。上、下前牙双根管检出率分别为0.03%和11.25%,其中下侧切牙检出率最高(17.40%)。上下前牙根管构型以Ⅰ型为主,下前牙双根管构型以Ⅲ型为主(7.07%)。下前牙左右同名牙双根管检出呈对称性。上下前牙冠根长度无年龄差异(P>0.05)。18~50岁下前牙双根管检出率逐渐增加,50岁之后逐渐降低。男性下前牙双根管检出率(13.12%)高于女性(9.93%)(P<0.05)。下中切牙、下侧切牙及下尖牙两两间的双根管检出均呈正相关关系(P<0.05)。结论:下前牙根管形态复杂多变。双根管具有左右对称性、年龄及性别差异。

Objective： To study the root canal system in permanent anterior teeth by cone-beam computer tomography（CBCT）. Methods： 12 858 anterior teeth in 1 103 patients were divided into group A（ ≤40 years） and group B（ 〉40 years）. The CBCT images of 6 404 maxillary anterior teeth and 6 454 mandibular anterior teeth were collected. The number of roots and root canals, crown-root length, the types of root canal configurations, symmetry, agerelated changes and gender differences were analyzed statistically. The correlation of double root canals system in mandibular anterior teeth were compared. Results： All of the maxillary anterior teeth and mandibular incisors had only one root while 1.66% double roots were found in canines. The prevalence of double root canals in maxillary and mandibular anterior teeth were 0.03% and 11.25% respectively, that of the lateral incisors was the highest（ 17.40% ）. Type I was the most frequent type （88.75 % ） in permanent anterior teeth followed by Type III （7.07 % ）. There was symmetrical distribution of the bilateral root canals of anterior teeth. There was no statistical significance of crown-root length among different age groups in permanent teeth （ P 〉 0.05 ）. The variation of the root canal rate increased gradually at the age of 18 - 50 years, decreased gradually after the age of 50. The incidence of double root canals was higher in males （13. !2% ）than in females （9, 93 % ） in mandibular anterior teeth. The incidence of double root canals of mandibular central incisors was positively correlated with lateral incisors and canines respectively （ P 〈 0.05）. Conclusion： The root canal morphology of mandibular anterior teeth is complicated. The prevalence of double root canals is symmetic, age-related andgender difference.