上颌第一前磨牙根管形态的锥形束CT研究

Root and canal morphology of maxillary first premolars by cone-beam computed tomography

目的利用CBCT评估上颌第一前磨牙根管解剖形态。方法收集因种植手术前评估,正畸治疗前评估,复杂疑难根管治疗等原因拍摄的CBCT 710例,根据样本纳入标准得到404例双侧CBCT图像,记录患者的姓名,性别,年龄,牙位,牙根和根管数目,牙根弯曲方向和根分叉的位置。结果上颌第一前磨牙以单根牙和多根牙多见,三根牙最少见,单根牙发生率为65.1%,双根牙发生率为34.7%,三根牙发生率为0.2%,有2例左侧颊根分为两根,为三根牙。单根牙和双根牙在男女性别间的发生率无统计学差异,根管类型中14.7%有1个根管为Ⅰ(1-1)型,85.1%为复杂的两根管类型(Ⅱ型到Ⅶ型及2-1-2-1型),只有0.2%有三根管为Ⅷ型。上颌第一前磨牙牙根弯曲的发生率为38.1%。根据弯曲方向分为5种类型,颊侧弯曲22.7%,舌侧弯曲17.3%,近中弯曲11.6%,远中弯曲42.1%,S形弯曲6.2%。上颌第一前磨牙牙根分叉的发生率为34.9%,根据分叉的部位分为根冠1/3、根中1/3、根尖1/3分叉,发生率为31.6%,44.7%,23.8%。结论上颌第一前磨牙多为单根牙,而且多为单根牙双根管,单根牙的根管形态多样,牙根多向远中弯曲,牙根分叉位于牙根中段。

Objective To evaluate the external and internal anatomy of maxillary first premolars in a native Chinese population by cone-beam computed tomography. Methods A total of 404 CBCT images of maxillary first premolar teeth were obtained from 710 patients who underwent CBCT scanning as part of an oral and dental examination. The type of root and canal, the shape of root curvature, the place of the root branch and the occurrence of furcation groove of buccal root were analyzed. Results Overall, 65.1%of teeth had one root, 34.7% had two roots and the remaining had three roots. There was no statistical significance between left and right sides. The incidence of root curvature was 38.1%, buccal curvature 22.7%, lingual curvature 17.3%, mesial curvature 11.6%, distal curvature 42.1%, S-shaped curvature 6.2%. The incidence of root branch was 34.9%, 31.6% of which was divided in the crown one-third of the root,44.7% in the middle one-third of the root, and 23.8% in the apical one-third of the root. Conclusion Most maxillary first premolars have one root with two canals.The root canal is varied. Most roots are distally curved. The bifurcation of the root is located frequently in the middle third.