锥形束CT对下颌神经管走向的测量分析

目的 通过锥形束CT(CBCT)测量下颌神经管在下颌后牙区颌骨内的走行,为下颌后牙区种植术前评估提供理论支持.方法 收集65例患者的下颌骨CBCT数据,测量后牙区下颌神经管距离四周骨壁的距离,并对比分析男女之间、左右侧之间的差异.结果 下颌神经管外缘至颊侧骨板的平均距离由前向后逐渐增大,在颏孔区处最小,在颏孔后18 mm处最大.下颌神经管内缘至舌侧骨板的平均距离由前向后逐渐减小,在颏孔区处最大,在颏孔后18 mm处最小.下颌神经管上缘至牙槽嵴顶的平均距离由前向后逐渐减小,在颏孔区处最大,在颏孔后18 mm处最小.下颌神经管下缘至下颌骨下缘的平均距离由前向后先缩小,再增大,在颏孔后6 mm处最小,在颏孔后18 mm处最大.结果显示男女之间、左右侧之间差异均无统计学意义.结论 下颌神经管从前向后,在垂直向上先向下,在约第一磨牙近中部位再折返向上走行,在颊舌向上由颊侧向舌侧走行,对下颌后牙区种植术前评估有重要意义.

Measurement and analysis of mandibular canal course by cone-beam computed tomography

Objective To measure the course of the mandibular canal in mandibula posterior area by cone-beam computed tomography ( CBCT ) , to provide a theoretical support for implant preoperative assessment. Methods Mandibular data of 65 people measured by CBCT were collected, measured the distance between mandibular canal around the bone wall and analyzed the differences by gender and the differences between the left and the right. Results The average distance of mandibular canal outer edge to the buccal bone plate by former backward in-creased gradually,at least in the area of the mental formen, at largest in the area of the mental foramen after 18 mm. The average distance between mandibular canal inner edge to lingual bone plate by former backward reduced gradually, at largest in the area of the mental foramen,at least in the area of the mental foramen after 18 mm. The average distance between mandibular canal upper edge to alveolar crest by former backward reduced gradually,at largest in the area of the mental foramen, at least in the area of the mental foramen after 18 mm. The average dis-tance between the edge of mandibular canal to the edge of mandible by former backward reduced previous,then in-creased, at least in the area of the mental foramen after 6 mm, at largest in the area of the mental foramen after 18 mm. All the results had no significant statistical differences between the male and the female, and had no significant statistical differences between the left and the right. Conclusion The trajectory of the mandibular canal from front to back is downward first, then upward in the mesial of the first molar in the vertical, and whose from the buccal side to the lingual side. That has significance for assessment before implant in mandibular posterior area.