人下颌恒切牙管间峡区解剖的显微CT研究  

Anatomic study of canal isthmuses of mandibular permanent incisors by Micro-CT

作　　者：刘成霞[1] 李文[2] 郑庆华[1] 耿宁[1] 孙拓祺[1] 黄定明[2] 

机构地区：[1]口腔疾病研究国家重点实验室,四川大学 [2]四川大学华西口腔医院牙体牙髓病科,四川成都610041

出　　处：《华西口腔医学杂志》2010年第2期177-180,共4页West China Journal of Stomatology

基　　金：国家"十五"科技攻关计划资助项目(2004BA720A23)

摘　　要：目的研究人离体下颌恒切牙管间峡区的解剖学特点。方法选择离体下颌恒切牙拍摄近远中向X线片,选出双根管牙33颗,对距根尖6mm以内的牙根组织进行显微CT扫描。扫描层厚20μm,每颗牙齿获得扫描截面300个。通过三维重建观察牙根管间峡区的解剖形态。记录距根尖1、2、3、4、5、6mm处各截面根管数目及管间峡区的出现情况,并测量根管壁的最小厚度。结果所有双根管下颌恒切牙都存在管间峡区,完全峡区占49.7%,部分峡区占4.5%。距根尖6mm内各截面管间峡区的出现率为10.0%~85.5%,卡方检验显示距根尖1~6mm处管间峡区出现率的差异有统计学意义（P=0.001）。距根尖3~6mm处管间峡区出现率较高,以5mm处最高,为85.5%。距根尖6mm以内的根管壁最小厚度均小于0.5mm。结论下颌恒切牙管间峡区的出现率较高,根管壁最小厚度位于峡部,在临床进行根管治疗和牙髓外科手术时应引起重视。Objective To investigate the anatomic feature of the canal isthmus of mandibular permanent incisors by Micro-CT. Methods Thirty-three mandibular permanent incisors with two canals were selected through the radiograph in proximal view. These teeth were then scanned using Micro-CT and reconstructed. The scanning layer thickness was 20 μm. We observed the apical 6 mm of the 33 roots, and 300 sections were gained each tooth, giving a total of 9 900 sections. The numbers of canals at each level in the apical 6 mm were recorded. The numbers of sections showing isthmuses at each level of the root canals were recorded too. Data were analyzed using the Chi-square statistic to test the null hypothesis that location of the sections in each of the apical 6 mm and presence of the isthmus were independent. The minimum root canal wall thickness was measured in each of the apical 6 mm of the roots. Results Isthmuses were found to be present at all levels with prevalence from 10.0% to 85.5%. The Chi-square test indicated a significant difference in the distribution of isthmuses with section（P=0.001）. The incidence of isthmuses was higher at the apical 3-6 mm level, and the highest incidence（85.5%） was at 5 mm level. There were many more sections containing complete isthmuses（49.7%） than those containing partial isthmuses（4.5%）. The thickness of the minimum root canal was less than 0.5 mm. Conclusion The mandibular incisors have a high incidence of isthmus and are narrow in proximal direction. Debridement of the isthmus is a major challenge during surgical and nonsurgical root canal treatment.

关 键 词：根管解剖 下颌切牙 管间峡区 根管壁厚度 

分 类 号：R816.98[医药卫生—放射医学]