华东地区中国人下颌第一恒磨牙根管形态的锥形束CT分析

Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular first molars in Chinese individuals

目的:通过锥形束CT(cone-beam computed tomography,CBCT)分析华东地区下颌第一恒磨牙不同根管形态及其发生率,以期为临床诊疗提供参考。方法:随机抽取在南京医科大学附属口腔医院放射科行CBCT检查的患者图像资料,参照Vertucci分类法统计分析健康、未经治疗、发育完全的下颌第一恒磨牙的根管形态。结果:共获取766例患者(137例患者单侧下颌第一恒磨牙缺失)的1 395颗下颌第一恒磨牙的CBCT图像数据。下颌第一恒磨牙双根的发生率大约为68.5%,3根的发生率为31.4%;3根管的发生率为57.9%,4根管的发生率为38.5%。近中根大多拥有2个根管。大部分的远中根均为Vertucci I型,近中牙根的根管形态比较复杂,下颌第一磨牙拥有6种不同的根管形态。下颌第一恒磨牙远中舌根的个体发生率为35.3%。男女性别间发生率无统计学差异(P>0.05)。下颌第一恒磨牙远舌根双侧对称性的发生率为60%,且右侧大于左侧,差异有统计学意义(P<0.05)。结论:下颌第一恒磨牙根管形态及数目具有多样性,CBCT是一个非常有效的工具来辨别分析下颌磨牙的根管形态,为根管治疗提供参考依据。

Objective：To evaluate the root and canal morphology of mandibular first molars in Chinese individuals using cone-beam computed tomography （CBCT）. Methods：A total of 766 patients of Chinese descent with healthy,well-developed mandibular first molars were included. These patients went to the Stomatological Hospital Affiliated of Nanjing Medical University and underwent radiographic examination by CBCT as part of their routine examination,diagnosis and treatment planning. The root canal configurations were classified according to the method of Vertucci. Results ： CBCT image data of 1,395 mandibular first molars from 766 patients （137 patients without unilateral mandibular first molars） were obtained. The prevalence of mandibular first molars with two separate roots was 68.5%, however, three roots were identified in 31.4% of mandibular first molars. Three canals were found in 57.9% of mandibular first molars and 38.5% had four canals. 93.1% mesial roots contained two canals, most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems. The incidence of permanent three-rooted mandibular first molars was 35.3% ,the incidence had no significantly difference between male and female （P 〉 0.05）. Of all the patients with 3- rooted mandibular first permanent molars,60% occurred bilaterally. There was a significantly higher incidence of three-rooted mandibular first permanent molars on the right side than on the left （P 〉 0.05）. Conclusion：Three-rooted mandibular first molars occurred frequently in this Chinese population. CBCT is an effective tool for the detection of additional distolingual roots and it is a valuable aid for dentists providing root canal treatment.