CBCT Research On The Morphology Of Root And Root Canal Of The Maxillary Second Molars In Qingdao District

Objective: To investigate the anatomic structure,morphology of root and root canal system of maxillary second permanent molars in Qingdao district by CBCT.So as to provide the reference for clinical treatment.Methods: All patients who accepted the CBCT check in the Department of Stomatology of the Affiliated Hospital of Qingdao University from January 2018 to April 2018 were included in the study,and the patients' regions,names,gender,age were recorded,and the following contents were researched:(1)Tooth position;(2)Number and morphology of root;(3)Number and configuration of root canal;(4)The distance of root canal orifice and pulp chamber;(5)The position of MB2;(6)The symmetry in homonym teeth.The correlation between the above measurement indexes and age and gender was analyzed.Software KaVo i-CAT Vision and KaVo Invivo 5 were used to scan and measure the images.Statistical analysis was performed by SPSS 20.0.Results: The root type of the 1174 maxillary second permanent molars was mainly type I,59.70% for males and 50.47% for females;The type of three roots was the main form of root including 73.88% for males and 61.64% for females respectively;The main type of root canals was three root canals,80.22% for males and 77.43% for females included;The percentage of fused roots was 25.37% for males and 30.72% for females;The detective rate of MB2 was 13.06% in males and 10.34% in females;The main classification of the buccal root canal was type I(68.83%),and the main classification of the mesial-buccal root canal was type ?(63.24%)while MB2 exists;The height of pulp chamber decreased with the increase of age,showing statistical difference(p < 0.05).There was a significant difference in the distance of root canal orifice between different gender and ages(p < 0 05);The position of MB2 was more constant.The symmetry of number and morphology of root,number and configuration of root canal in different roots number had statistical difference(p < 0.05).Conclusion: The roots and root canal systems of maxillary second permanent molars are all complex and changeable in Qingdao district.The shape of root and root canal is the most common in three roots and three canals.The tendency of root fusion in women is larger than that in men.The height of pulp chamber decreases with the increase of age.The distance of root canal orifice in man is higher than that in women.The anatomic position of MB2 is relatively constant relative to the mesial-buccal root canal.CBCT increases the understanding of root and root canal anatomy and improves the curative effect of root canal therapy.