山东地区不同垂直骨面型成人Ⅱ类患者(牙合)平面倾斜度的锥形束CT转化分析

Cone-beam CT analysis of occlusal planes between different vertical skeletal types of adult classⅡmalocclusions in Shandong province

目的应用锥形束CT(CBCT)转化侧位片探究山东地区不同垂直骨面型成人安氏Ⅱ类错(牙合)患者的前牙、后牙及上颌(牙合)平面倾斜度特点,比较其与正常(牙合)患者的差异,为矫正安氏Ⅱ类错(牙合)提供治疗思路和策略依据。方法选取2017年12月~2020年6月青岛大学附属医院口腔正畸科收治的123例正畸患者CBCT头颅造影(CCB)为研究对象,其中89例成年安氏Ⅱ类患者作为实验组,34例为对照组,利用CBCT三维影像转化得到矫正前的头颅侧位片并进行测量,根据FH平面与下颌平面之间的夹角(FH-MP)及SN平面与下颌平面之间的夹角(SN-MP),将患者分为3个不同垂直骨面型的实验组。选取34例安氏Ⅰ类均角患者作为对照组。将实验组测量结果与对照组测量结果进行对比,分析各测量指标的数据差异。结果Ⅱ类高角组前牙(牙合)平面倾斜度为(14.73±3.76)°,后牙(牙合)平面倾斜度为(21.42±5.77)°,两者均较Ⅱ类均角组及低角组更大(P<0.05),与对照组前牙及后牙(牙合)平面之间同样有明显差异(P<0.05)。上颌第二磨牙的高度从低角组到高角组依次减小,各组间差异显著(P<0.01)。结论不同垂直骨面型的安氏Ⅱ类错(牙合)具有不同的平面倾斜度特征。Ⅱ类高角组前牙及后牙(牙合)平面较均角组、低角组及对照组陡。其中后牙(牙合)平面倾斜度的差异主要由上颌第二磨牙的垂直高度不同造成。

Objective To investigate the cant of the occlusal planes in Chinese adult classⅡmalocclusions with hypodivergent,normodivergent,and hyperdivergent facial vertical patterns using cone-beam CT.Methods The descriptive,cross-sectional study evaluated 123 cephalogram from CBCT(CCB)of patients in Department of Orthodontics,the Affiliated Hospital of Qingdao University.According to cephalometric analysis,89 Chinese adult classⅡpatients were divided into three groups according to the angle between FH-MP and the angle between SN-MP.In comparison,34 ClassⅠnormodivergent malocclusions individuals were selected as the control group.Comparing the cephalometric result between 4 groups.Results As expected,the hyperdivergent group had steeper anterior occlusal planes(14.73±3.76)°and posterior occlusal planes(21.42±5.77)°,there was a significant statistical difference between the hyperdivergent group and other 2 groups in classⅡpatients(P<0.05).The height of maxillary second molar increased from high angle group to low angle group(P<0.01).Conclusion There are different characters of the occlusal planes in varied vertical facial pattern.The inclinations of anterior and posterior occlusal planes in Chinese classⅡhyperdivergent group were steeper than other 3 groups.The difference of posterior occlusal plane inclination is mainly caused by the height of maxillary second molar.