基于CBCT成人下颌后牙区种植相关解剖结构的检测分析

Measurement and analysis of implant-related anatomical structure in the adult mandibular posterior tooth area based on CBCT

目的利用锥形束CT(CBCT)对成人下颌后牙区颏孔、颏管、下颌下腺窝等种植相关解剖结构的位置、形态进行测量,分析种植位点牙槽骨颊舌向生理斜度与各解剖结构之间的关系,为种植体植入方向的确定提供依据。方法选取181例行CBCT检查的患者影像资料,其中牙列缺损患者109例,男59例,女50例;非牙列缺损患者72例,男36例,女36例,对其下颌后牙区各解剖标志进行测量分析。结果左右侧牙槽骨倾斜角度颏孔区分别为(5.08±3.86)°和(3.07±5.20)°,下颌第一磨牙处为(8.57±5.03)°和(9.54±5.19)°,下颌第二磨牙处为(15.48±5.23)°和(14.21±6.67)°,左右侧颏管斜度为(41.81±10.07)°和(44.77±8.96)°。颏孔上缘至牙槽嵴顶(12.35±2.38)mm,颏孔上缘内侧1.5 mm处颏管上缘至牙槽嵴顶(14.14±2.46)mm。第一、二磨牙处下颌下腺窝深度为(0.80±0.56)mm和(1.00±0.50)mm,最凹点至牙槽嵴顶距离为(14.15±5.95)mm和(14.52±3.55)mm,冠方最凸点至牙槽嵴顶距离为(10.71±4.72)mm和(9.25±2.81)mm,下颌管上缘至牙槽嵴顶距离为(15.52±3.48)mm和(13.83±2.76)mm。结论下颌牙槽骨自前磨牙区至磨牙区颊舌向倾斜呈现由颊侧逐渐向舌侧倾斜趋势,且第二磨牙区牙槽骨舌向倾斜最为明显;下颌颏孔区种植修复时可使种植体尖端止于颏孔上缘水平,以获取更佳的初期稳定性;下颌下腺窝的存在一定程度上限制了种植体的植入深度及方向,术前利用CBCT对此部位进行精准测量分析必不可少,以免出现下颌舌侧穿孔等并发症,提高种植修复成功率。

Objective To measure and analyze the position and shape of implant-related anatomical structure such as mental foramen,mental canal and the submandibular fossa in the adult mandibular posterior tooth area based on Cone Beam Computed Tomography(CBCT)images,and to detect the relationship between anatomical structures and the anatomice buccalingual angulation at implant site in order to help determine the implant angulation at the implant treatment-planning phase.Methods Random samples of 181 CBCT images were selected and analyzed,including 109 patients with dentition defect:59 males and 50 females,and 72 patients with non dentition defect:36 males and 36 females.The anatomic marks and alveolar bone inclination of mandibular posterior tooth area were measured respectively,and the results were statistically analyzed.Results The inclination angles of alveolar bonewere(5.08±3.86)on the left and(3.07±5.20)on the right of the mental foramen area,(8.57±5.03)and(9.54±5.19)on the first mandibular molar,(15.48±5.23)and(14.21±6.67)on the second mandibular molar,and the inclination angles of the left and right mental canal were(41.81±10.07)and(44.77±8.96)respectively.The distance from the upper edge of the mental foramen to the top of the alveolar ridge was(12.35±2.38)mm,and the distance between the mental canal at 1.5 mm inside the mental foramen and the top of the alveolar ridge was(14.14±2.46)mm.The depth of the submandibular gland fossa in the first and second molars were(0.80±0.56)mm and(1.00±0.50)mm,the distance from the most concave point to the alveolar crest top were(14.15±5.95)mm and(14.52±3.55)mm,the distance from the most convex point of the crown to the alveolar crest top were(10.71±4.72)mm and(9.25±2.81)mm,and the distance from the upper edge of the mandibular canal to the alveolar crest top were(15.52±3.48)mm and(13.83±2.76)mm.Conclusion The buccallingual inclination of mandibular alveolar bone is gradually inclined from buccal side to lingual side from premolar area to molar area,and the lingual inclination in the second molar area is the most obvious;The implant tip can stop at the upper edge of the mental foramen to obtain better initial stability;The existence of submandibular fossa limits the depth and direction of implant implantation to a certain extent.It is necessary to accurately measure and analyze this part with CBCT before operation to avoid complications such as mandibular lingual perforation and improve the success rate of implant repair.