辽宁地区成人深覆(牙合)患者颌面部硬组织形态特征的CBCT研究

摘要

Objective:To evaluate the skeletal and dentoalveolar features in adults with deep bite malocclusion.Methods:CBCT data of normal(n=80) and deep bite(control group,n=80) subjects were used to reconstruct the 3D-dentoalveolar models of the subjects by Mimics 17.0 software,the related indexes were mesured on the models.Data were analyzed statistically by paired t-test.Results:In deep bite group,for the skeletal features,the indexes of mandibular plane angle,palatal-mandibular plane angle and craniomandibular triangle were decreased,while the length of the ramus,the posterior facial height,the upper facial height and the ratio of the posterior facial height to the anterior facial height were increased;the lower facial height,the ratio of the lower facial height to the anterior facial height,and to the upper facial height were decreased in the deep bite group.For the dental features,the inclination of central incisors was decreased,while the depth of the Spee curve was significantly increased.In addition,the eruption length of the maxillary central incisor was increased,while the mandibular first molar eruption length decreased.Conclusion:The counterclockwise rotation of the mandible,the increased Spee curve depth and the increased posterior facial height are the dominant features of deep bite malocclusion.%目的:探讨成人深覆患者的牙性和骨性结构特征.方法:纳入符合标准的160 份CBCT资料,其中深覆组80 例,正常对照组80 例,利用Mimics 17.0三维重建软件建模,得出点、线、面的三维数据,采用配对样本t检验进行统计分析.结果:骨性特征中,下颌平面角、上下颌聚散角和颅下颌三角,深覆组均比正常对照组降低,而下颌升支长度、后面高、上面高以及后面高与前面高的比值,深覆组比正常对照组大,下面高以及下面高分别与前面高和上面高的比值,深覆组比较小.牙性特征中,上下颌中切牙的轴倾角,深覆组比正常对照组小,而Spee曲线深度,深覆组明显增大.上颌中切牙萌出长度和下颌第一磨牙萌出长度在2 组间增减趋势相反,前者在深覆组增大,而后者在深覆组减小.结论:下颌骨的逆时针旋转以及Spee曲线的加深和后面高的增大是促使深覆形成的重要因素.