Seo Seung-Won, Jung Young-Soo, Baik Hyoung-Seon
*Resident, Department of Orthodontics, The Institute of Cranio-Facial Deformity †Professor, Department of Oral & Maxillofacial Surgery, College of Dentistry ‡Professor, Department of Orthodontics, The Institute of Cranio-Facial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
J Craniofac Surg. 2017 Oct;28(7):1789-1796. doi: 10.1097/SCS.0000000000003754.
This study investigated the correlation between the 3-dimensional changes in midfacial soft tissues, including the parasagittal area and maxilla-mandible complex, after Le Fort I maxillary posterior impaction and bilateral intraoral vertical ramus osteotomy (B-IVRO), using cone-beam computed tomography (CBCT). This retrospective study included 22 skeletal Class III patients (6 men and 16 women; mean age 21.6 years) who underwent orthognathic surgery. Three-dimensional CBCT images taken before and 1 year after surgery were superimposed based on the cranial base. Midfacial soft tissues, including those in the parasagittal area (paranasal area, anterior cheek area, lateral cheek area) and midsagittal areas of the face, were evaluated using reconstructed CBCT images. Correlations and the ratios between soft tissue and hard tissue movement were calculated. After surgery, both paranasal areas showed significant forward movement (about 2.0 mm) and the largest upward movement (about 0.15 mm) among the 3 areas. The paranasal areas moved forward with a ratio of 0.5, according to vertical movement of B. Orthognathic surgery using Le Fort I maxillary posterior impaction with B-IVRO mandibular setback results in forward movement of midfacial soft tissues, even though sagittal movement of the maxilla is limited because facial muscles and retaining ligaments pull the redundant soft tissues, which are caused by vertical movement of the maxilla-mandible. This midfacial soft tissue change with maxillary posterior impaction could be advantageous to patients who have paranasal depression and protrusion of the upper lip owing to proclined upper incisors, which are prevalent among Asian Class III patients.
本研究采用锥形束计算机断层扫描（CBCT），调查了Le Fort I型上颌后份骨切开术和双侧口内垂直升支骨切开术（B-IVRO）后，面中部软组织（包括矢状旁区域和上颌-下颌复合体）的三维变化之间的相关性。这项回顾性研究纳入了22例接受正颌手术的骨骼III类患者（6名男性和16名女性；平均年龄21.6岁）。术前和术后1年拍摄的三维CBCT图像基于颅底进行叠加。使用重建的CBCT图像对面中部软组织进行评估，包括矢状旁区域（鼻旁区域、前颊区域、外侧颊区域）和面部矢状中线区域的软组织。计算软组织和硬组织移动之间的相关性及比率。术后，两个鼻旁区域均显示出显著的向前移动（约2.0毫米），且在三个区域中向上移动最大（约0.15毫米）。根据B的垂直移动，鼻旁区域向前移动的比率为0.5。使用Le Fort I型上颌后份骨切开术联合B-IVRO下颌后缩进行正颌手术，即使上颌的矢状移动受限，但由于面部肌肉和保留韧带牵拉上颌-下颌垂直移动所导致的多余软组织，仍会导致面中部软组织向前移动。这种上颌后份骨切开术引起的面中部软组织变化，对于因上前牙前倾而出现鼻旁凹陷和上唇前突的患者可能是有利的，这种情况在亚洲III类患者中很常见。
