下颌下窝的锥形束CT影像分析

Evaluating of the submandibular fossa by cone beam CT

目的通过锥形束CT(CBCT)测量分析下颌骨下颌下窝的形态,为牙种植术提供一定的参考。方法对100例CBCT影像中下颌下窝骨倒凹的分布规律进行观察分析,测量下颌下窝深度、骨倒凹最深点至牙槽嵴顶和颊侧骨壁的距离,分析其与下颌管的毗邻关系。结果下颌下窝位于下颌磨牙区,大部分下颌下窝骨倒凹最深点低于下颌管上缘;第一磨牙区下颌下窝骨倒凹深度为(1.2±0.73)mm,第二磨牙区为(1.7±0.54)mm,性别、左右及是否有牙的差异无统计学意义。第一磨牙区下颌下窝最深点至牙槽嵴顶的垂直距离在有牙和无牙时分别为(17.2±2.16)mm和(13.1±2.71)mm,至颊侧骨壁的水平距离为(10.1±2.07)mm,第二磨牙区下颌下窝最深点至牙槽嵴顶的垂直距离在有牙和无牙时分别为(15.3±2.43)mm和(9.6±2.56)mm,至颊侧骨壁的水平距离为(11.3±1.53)mm。结论在下颌磨牙区行种植手术时,应综合考虑下颌下窝和下颌管对手术的影响,CBCT可以实现对下颌下窝的精确测量,能够清晰显示下颌下窝与下颌管的位置关系,为下颌磨牙区种植手术提供重要信息。

Objective The aim of this study was to measure and evaluate the bone anatomy morphology of submandibular fossa by cone-beam CT (CBCT). Methods The CBCT images of 100 patients were retrospectively studied. The depth of the submandibular fossa, the adjacency of mandibular canal, and submandibular fossa were observed and measured. Results The deepest point of the submandibular fossa was lower than that of the upper edge of the mandibular canal. The average depth of submandibular fossa in the 1st molar region was (1.2±0.73) mm, and that in the 2nd molar region was (1.7±0.54) mm. The average distances from the deepest point of the submandibular fossa to the alveolar crest in the 1st molar were (17.2±2.16) mm and (13.1±2.71) mm (tooth missing), and those in the 2st molar were (15.3±2.43) mm and (9.6±2.56) mm (tooth missing). The horizontal distance from the depth of submandibular fossa to buccal bone wall in the 1st molar was (10.1±2.07) mm and that in the 2st molar was (11.3±1.53) mm. Conclusion CBCT clearly showed the relationship between the submandibular fossa and the mandibular canal.