Abstract: Objective: To measure and evaluate the morphologic character of mandible alveolar bone in mental foramen area. Methods: 150 patients' bilateral 300 CBCT images of mental foramen area were subjected in this study. Tomography was carried out using Planmeca ProMax 3D volume scanner. The heights of alveolar bone in mental foramen area were measured along an axial plane from a CBCT image. The digits were analyzed by using group t test with SPSS 16.0 software package.  Results: In the buccal aspect, average distance from the mental foramen to the alveolar crest was 11.87 mm. The average distance from the upper roof of mental canal in the same axial plane to the alveolar crest was 16.45 mm. The difference was 4.58 mm. At the level of 2 mm below the upper margin of the mental foreman, the average width from the mental canal to the lingual margin is 11.53 mm.  Conclusion:  The distance from the buccal margin of mental foramen to the alveolar crest measured by CBCT images showed differences as compared with the two-dimensional X-ray (such as oral panoramic) measurement. The mean difference was 4.58mm. The implant treatment design in this area should not be based on the panoramic measurement, but on the basis of CBCT examination. The so-called " 2 mm safe distance" from the tip of implant to the mental foreman based on panoramic should be re-evaluated.

摘要： 目的：通过应用锥形束CT（cone-beam computed tomography, CBCT）观察、测量和评价下颌颏孔区牙槽骨的形态，为种植手术设计提供参考。方法：选取150例患者双侧CBCT图像，观察、测量和分析下颌颏孔区牙槽骨的解剖形态，测量此区骨高度和骨宽度，用SPSS16.0软件包对测量结果进行分析。结果：颏孔上缘到牙槽嵴顶的平均距离为11.87 mm；颏孔截面下颌神经管上缘到牙槽嵴顶的平均距离为16.45 mm；两者的差值为4.58 mm；颏孔上缘下2 mm处颏管至舌侧骨边缘的平均宽度为11.53 mm。结论：在二维平片（如口腔全景片）上观察到的颏孔到牙槽嵴顶的距离，和CBCT同一截面下颌神经管上缘到牙槽嵴顶的距离存在着较大的差距，平均差距大于4 mm。因此在此区域的种植体设计不应以平片为依据，而应进行CBCT检查。颏孔区种植体尖端到颏孔的安全距离也应进行重新评估。

关键词: 下颌骨,  ,  , 颏孔,  ,  , 锥形束CT

CLC Number: 

• R782.13