The study of the root and root canal system of mandibular third molars by CBCT
DONG Hong-yu;LIU Qing-mei;Shanxi Medical University School and Hospital of Stomatology;Shanxi Dayi Hospital Affiliated to Shanxi Medical University;Depantment of Stomatology,Shanxi Medical University;
Objective: To observe the root morphology of the mandibular third molar and the anatomical morphology of the root canal system were by cone-beam CT( CBCT). Methods: The CBCT images of 160 mandibular third molars were randomly selected to analyze the number of roots,number of root canals and the anatomical morphology of the root canal system.Results: Among the 160 mandibular third molars,87 cases( 54. 38%) had two root teeth,single tooth in 65 cases( 40. 63%).Statistics of the number of root canals indicated 112 cases( 70. 00%) of both root canals in the near and far.There were 29 cases( 18. 13%) have single root canal,17 cases( 10. 63%) have three root canals and 2 cases( 1. 25%) have four root canals.According to the Vertucci classification,single tooth was given priority to with Ⅳ type.Four pairs of tooth root,three teeth and tooth root canal was given priority to withⅠtype.Conclusion: Mandibular third molar root morphology and anatomy of root canal system structure classification is diversiform,but root for single,double,and root canal morphologyⅠ,Ⅳ type.