不同垂直骨面型成人下颌骨皮质厚度的锥形束CT研究

A study on the thickness of buccal bone in the mandible of different vertical facial type in adults using cone-beam CT

目的:通过测量分析不同垂直骨面型的成人下颌后牙区颊侧骨皮质厚度,为正畸临床治疗中不同骨面型患者种植支抗类型的选用和植入部位的确定提供参考。方法:在成年正畸患者中,按照下颌平面角测量值及纳入标准选择45例病例,均分为高角、均角和低角3组。利用CBCT采集患者颅面部数据并进行三维重建,对下颌后牙区颊侧不同高度(距牙槽嵴顶4、6、8mm处)的骨皮质厚度进行测量,应用SPSS11.0软件包对数据进行方差分析和LSD检验。结果:3组在下颌后牙区骨皮质厚度为高角组<均角组<低角组,同组内厚度4 mm组<6 mm组<8 mm组,有显著差异(P<0.05)。结论:下颌颊侧4 mm处即可进行种植支抗植入,而低角组的骨皮质厚度较高,最好选用助攻法。

PURPOSE： To provide some references of using micro-implant anchorage in clinical orthodontic treatment, the thickness of buccal bone of mandible of different vertical facial type in adults with cone-beam CT （CBCT） were measured. METHODS： Initial 3-dimensional images of 45 adult patients （15 men, 30 women）were reoriented by using a standardized protocol, and divided into 3 groups by angle of mandibular plane （GI： high angle, 15 patients; G2： average angle, 15 patients; G3： low angle, 15 patients）. After signing the informed consent form, three measurement points were defined at 4, 6, and 8mm from the alveolar crest in each measurement area. Statistical analysis was performed with SPSS11.0 software package. RESULTS： The thickness of buccal bone in mandible was thinner in G1 than in G2, and was thinnest in G3. The cortical bone thickness was thickest at the 8 mm level and thinnest at the 4mm level. CONCLUSIONS： The study suggested that the cortical bone thickness at 4mm level from the alveolar crest was safe for implantation. It is more stable when the distance of implants was more away from the alveolar crest. Patients with low mandibular plane angle should use self-tapping micro-implant anchorage.