人下颌恒切牙管间峡区解剖的显微CT研究
发表时间：2014-05-19 浏览次数：866次
刘成霞，李文， 郑庆华等、人下颌恒切牙管间峡区解剖的显微CT研究、[J].华西口腔医学杂志,2010,7(2):
根管解剖； 下颌切牙； 管间峡区； 根管壁厚度
刘成霞1 李文2 郑庆华1 耿宁1 孙拓祺1 黄定明2
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 610
2010
知网
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6 mm以内的牙根组织进行显微CT扫描。扫描层厚20 μm，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、6 mm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6 mm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1~6 mm处管间峡区出现率的差异有统计学意义（P=0.001）。距根尖3~6 mm处管间峡区出现率较高，以5 mm处最高，为85.5%。距根尖6 mm以内的根管壁最小厚度均小于0.5 mm。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 ra-diograph 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 num-bers 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 inci-dence 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.
