Kwon Sun Mi, Baik Hyoung-Seon, Jung Hwi-Dong, Jang Woowon, Choi Yoon Jeong
Fellow, Department of Orthodontics, Institute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
Professor Emeritus, Department of Orthodontics, Institute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
J Oral Maxillofac Surg. 2019 Jun;77(6):1261-1275. doi: 10.1016/j.joms.2019.01.028. Epub 2019 Jan 29.
Morphologic differences and surgical outcomes were compared between the ipsilateral type of facial asymmetry, in which the menton deviates to the side of the upward frontal occlusal plane (FOP) cant (FOP), and the contralateral type, in which the menton deviates to the side of the downward FOP cant (FOP), by using cone beam computed tomography (CBCT) images.
This retrospective study included consecutive patients with skeletal Class III malocclusion and facial asymmetry who had undergone bimaxillary orthognathic surgery and serial CBCT before, 1 month after, and 1 year after surgery. CBCT images were reconstructed and analyzed for predictor (group and timing) and outcome (CBCT measurements over time) variables. The data were analyzed using independent t tests and paired t tests.
The contralateral group (n = 12) was selected first; the ipsilateral group (n = 12) was selected by matching age, gender, and degree of FOP cant with those of the contralateral group. Before surgery, in the ipsilateral group, the ramal length was longer on the nondeviated (N-Dev) side than on the deviated (Dev) side (P < .05) whereas the mandibular body length showed no significant difference (P > .05). In the contralateral group, the ramal length was longer on the Dev side (P < .05) whereas the mandibular body length was longer on the N-Dev side (P < .01). One year after surgery, most measurements were corrected symmetrically in both groups (P > .05); however, the hemi-lower facial area remained asymmetrical in the contralateral group (P < .05).
Differences in ramal lengths in the ipsilateral group and mandibular body lengths in the contralateral group between the Dev and N-Dev sides seemed to be the main cause of facial asymmetry. Although facial asymmetry improved after surgery in both groups, asymmetry in the soft tissue remained in the contralateral group 1 year after surgery.
通过锥形束计算机断层扫描（CBCT）图像，比较颏点偏向额平面（FOP）向上倾斜侧的同侧型面部不对称与颏点偏向FOP向下倾斜侧的对侧型面部不对称之间的形态学差异和手术效果。
这项回顾性研究纳入了连续的接受双颌正颌手术且术前、术后1个月及术后1年均进行了系列CBCT检查的骨性III类错牙合畸形和面部不对称患者。对CBCT图像进行重建，并分析预测变量（分组和时间）和结果变量（随时间的CBCT测量值）。使用独立t检验和配对t检验对数据进行分析。
首先选择对侧组（n = 12）；通过年龄、性别和FOP倾斜度与对侧组匹配，选择同侧组（n = 12）。术前，同侧组中，未偏斜（N-Dev）侧的升支长度比偏斜（Dev）侧长（P <.05），而下颌体长无显著差异（P >.05）。在对侧组中，Dev侧的升支长度更长（P <.05），而N-Dev侧的下颌体长更长（P <.01）。术后1年，两组的大多数测量值均对称矫正（P >.05）；然而，对侧组的半侧下面部面积仍不对称（P <.05）。
同侧组Dev侧与N-Dev侧升支长度的差异以及对侧组下颌体长的差异似乎是面部不对称的主要原因。尽管两组术后面部不对称均有所改善，但对侧组术后1年软组织仍存在不对称。
