上颌第一恒磨牙近中颊根尖部根管峡区的研究

Research of Root Canal Isthmuses in Apex Part of Mesiobuccal Root of Maxillary First Molars

目的:通过显微CT技术研究上颌第一恒磨牙近中颊根尖部根管峡区的三维形态特征。方法:收集173颗上颌第一恒磨牙,显微CT扫描及三维重建后,观察近中颊根尖部根管峡区的发生率及其形态特点。结果:173颗上颌第一恒磨牙中128颗牙的近中颊根尖部根管出现峡区,发生率为73.99%;近中颊根距根尖5mm～区段峡区发生率最高,为68.21%;三维重建结果显示,混合型根管峡区所占构成比最高,达60.94%。结论:上颌第一恒磨牙近中颊根尖部根管峡区发生率较高,加强峡区的清理对提高根管治疗成功率具有重要意义。

Objective： To investigate the three dimensional morphology of root canal isthmuses in apex part of me- siobuccal root of maxillary first molars. Methods： 173 intact maxillary first molars were scanned by μCT--50. Af- ter reconstruction, the incidence of root canal isthmuses in the apical part of mesiobuccal root were analyzed and the three dimensional configuration of root canal isthmuses were classified according to Fan＇s classification. Results： The incidence of root canal isthmuses in the apical part of mesiobuccal root of maxillary first molars was 73.99%. The incidence of root canal isthmus in the apical 5 mm- region （68. 21%） was significantly higher than other groups. The constituent ratio of mixed isthmuses （60.94%） was the highest. Conclusion.. In the apical part of the mesiobuecal root, maxillary first molars had a high incidence of root canal isthmuses.