不同矢状骨面型成年患者磨牙后三角及下颌升支前缘骨骼特征的CBCT分析

CBCT analysis of bone characteristics of mandibular retromolar trigone and anterior ramus region in adults with different sagittal skeletal patterns

目的通过CBCT评估不同矢状骨面型成年患者磨牙后三角及下颌升支前缘骨骼特征,并分析微种植体的植入风险。方法选取2016—2020年就诊于南京医科大学附属口腔医院正畸科的150例成年患者,按照矢状骨面型分为三类。在矢状面上高于(牙合)平面2 mm及4 mm处绘制与(牙合)平面平行和成45°的参考线,测量参考线上的有效骨量和骨皮质厚度。结果所有测量的植入部位平均有效骨量超过10 mm,平均骨皮质厚度1.7~2.4 mm;与(牙合)平面平行处测得的有效骨量和骨皮质厚度的平均值大于与(牙合)平面成45°处测得的有效骨量和骨皮质厚度的平均值,差异具有统计学意义(P<0.05);骨性Ⅲ类患者有效骨量最小,骨性Ⅱ患者有效骨量最大,差异具有统计学意义(P<0.05)。结论不同矢状骨面型成年患者磨牙后三角及下颌升支前缘具有足够的有效骨量和骨皮质厚度,可以安全地植入微种植体。

Objective To evaluate bone characteristics of the mandibular retromolar trigone and anterior ramus region to analyze the risks for miniscrew insertion in adults with different sagittal skeletal patterns. Methods The sample consisted of 150 adult patients with different sagittal skeletal patterns who visited Affiliated Stomatological Hospital of Nanjing Medical University from 2016 to 2020. On sagittal scan views, bone depth and cortical bone thickness were evaluated on specific lines parallel and at a 45° angle to the occlusal plane, and at 2 mm and at 4 mm distance from it. Results All of the considered insertion sites showed on average more than 10 mm of bone depth. Cortical bone thickness showed average values varying from 1.7 mm to 2.4 mm. Inferential statistics showed significantly(P<0.05) greater bone depth and cortical bone thickness in cross-sectional scans parallel to the occlusal plane compared with those at a 45° angle to it. The Class Ⅲ patients have the smallest bone depth while the Class Ⅱ patients have the biggest(P<0.05). Conclusion The retromolar trigone and anterior ramus region shows enough bone depth and cortical bone thickness for safe miniscrew insertion in adults with different sagittal skeletal patterns.