新疆地区人群上颌第二磨牙牙根和根管形态的CBCT研究

目的 采用锥形束CT研究新疆地区人群上颌第二磨牙的牙根和根管形态，为本地区口腔临床诊疗提供参考依据。方法 对纳入研究的539例新疆地区人群的上颌第二磨牙，利用CBCT对其牙根形态、数目，根管形态、数目和弯曲度，牙冠颊舌径和近远中径以及对称性进行观察、分析和统计。结果 在1017颗上颌第二磨牙中，三根牙的检出率最高为85.2%，四根牙检出率最低为3.2%，不同牙位和性别在牙根形态上的分布存在统计学差异；MB2的检出率与年龄无统计学差异；56岁及以上年龄组的四根牙检出率最高。颊舌径、近远中径的平均测量值越大，其对应的根管数目越多。上颌第二磨牙的牙根数目和形态对称、根管形态及四种特征均对称方面较高，上颌第二磨牙近颊根管和远颊根管68%为重度弯曲，弯曲位于根中1/3较多。结论 新疆地区人群上颌第二磨牙以三根牙为主，对称率较高，弯曲程度大，但存在一些牙根和根管的变异，临床上可以运用CBCT来指导诊疗。

A CBCT study on root and canal morphology of maxillary second molars in Xinjiang region

Objective To study the root and root canal morphology of maxillary second molars in China''s Xinjiang using conical beam CT(CBCT), and to provide a reference for the clinical diagnosis and treatment of dentistry in the region.Methods In 539 cases of maxillary second molars from Xinjiang region, the morphology,number, shape, number and curvature of root canal, crown buccal diameter, proximal distal diameter and symmetry of tooth were observed, quantified, and analyzed by CBCT.Results Among 1017 maxillary second molars, the highest detection rate of three roots was 85.2%, while the lowest detection rate of four roots was 3.2%. There were statistical differences in the distribution of root morphology among different tooth positions and genders. There was no statistical difference between the detection rate of MB2 with respect to age. The age group 56 years and above had the highest detection rate of four roots. The larger the average measurement value of buccal lingual diameter and proximal distal diameter, the corresponding numbers of root canals were increased. The maxillary second molar had a high degree of symmetry in terms of root number and morphology, root canal morphology and symmetry in all four features. The proximal and distal buccal root canals of maxillary second molars were severely curved in 68%, and the curvature was more in 1/3 of the roots.Conclusion The maxillary second molar of the population in Xinjiang region, is predominantly a three-rooted tooth with a high rate of symmetry and a large degree of curvature. There are some root and root canal variations, and CBCT can be used to guide the diagnosis and treatment in clinical treatment.