前牙开(牙合)患者颞下颌关节间隙及髁突形态的锥形束CT评价

目的应用锥形束CT(cone-beam CT,CBCT)对前牙开(牙合)患者的颞下颌关节间隙及髁突形态进行测量分析,探讨前牙开(牙合)患者与正常覆(牙合)患者的颞下颌关节的差异。方法选取2014年6月至2020年8月于南京大学医学院附属口腔医院正畸科就诊的前牙开(牙合)患者54例(前牙(牙合)开组)和正常覆(牙合)患者54例(正常覆(牙合)组),对其拍摄的颌面部CBCT图像使用多平面重建技术重建颞下颌关节矢状位及冠状位图像。使用Ka-melchuk法测量颞下颌关节上、后、前间隙,根据髁突骨质情况将髁突形态分为正常型与异常型2类,对前牙开(牙合)组和正常覆(牙合)组进行关节间隙及髁突形态的统计学分析。将前牙开(牙合)组根据开(牙合)的程度分为3个亚组:(1)Ⅰ°开(牙合)组(开(牙合)距离<3 mm);(2)Ⅱ°开(牙合)组(3 mm≤开(牙合)距离≤5 mm);(3)Ⅲ°开(牙合)组(开(牙合)距离>5 mm),比较3个亚组间关节间隙的差异。结果前牙(牙合)开组与正常覆(牙合)组相比,颞下颌关节前、上间隙差异无统计学意义(P>0.05),颞下颌关节后间隙显著增宽(P<0.01);前牙开(牙合)组髁突骨质异常占52.8%,正常覆(牙合)组骨质异常占21.3%,两组间具有显著性差异(P<0.01)。与Ⅰ°和Ⅱ°前牙开(牙合)患者相比,Ⅲ°前牙开(牙合)患者髁突在关节窝内更靠前(P<0.05)。结论前牙开(牙合)患者的髁突在关节窝内位置更加靠前、髁突骨质异常比例较高。

Evaluation of temporomandibular joint space and condylar morphology in patients with anterior open-bite based on cone-beam CT

Objective To investigate the difference of the temporomandibular joint between patients with anterior open-bite and normal overbite with cone beam CT(CBCT).Methods Fifty-four patients with anterior open bites and 54 patients with normal overbites were selected from the Department of Orthodontics,Nanjing Stomatological Hospital,Medical School of Nanjing University from June 2014 to August 2020.Sagittal and coronal images of the temporomandibular joint were reconstructed with multiplanar reconstruction techique.The Kamelchuk method was used to measure the superior,posterior and anterior space of the temporomandibular joint,and the condylar morphology was divided into two types:normal and abnormal.The joint space and condylar morphology of the anterior open-bite group and the normal overbite group were statistically analyzed.The anterior open-bite group was divided into 3 subgroups:①Ⅰ°openbite(open bite distance<3 mm),②Ⅱ°open-bite(open bite distance≥3 mm and≤5 mm)and③Ⅲ°open-bite(open bite distance>5 mm).The difference of overbite spaces of the temporomandibular joint was compared among these three subgroups.Results Compared to the normal group,no significant differences were found for the anterior and superior space of the temporomandibular joint in the anterior open-bite group(P>0.05),but the posterior space increased significantly(P<0.01).A total of 52.8%of patients in the anterior open-bite group had abnormal condyles,whereas 21.3%of patients in the normal group,overbite significant differences was found between the two groups(P<0.01).Compared with patients withⅠ°andⅡ°openbite,the condyle of patients with III°open bites was more forward in the fossa(P<0.05).Conclusion The position of the condyle in the fossa of patients with anterior open bites is more forward,and abnormal condylar bone is more common found.