Sant'Anna Eduardo Franzotti, Lau Geórgia W T, Marquezan Mariana, de Souza Araújo Mônica Tirre, Polley John W, Figueroa Alvaro A
Associate professor, Department of Pedodontics and Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; formerly, postdoctoral fellow, Department of Anatomy and Rush Craniofacial Center, Rush University Medical Center, Chicago, Ill.
PhD student, Department of Pedodontics and Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; formerly, postdoctoral fellow, Department of Anatomy and Rush Craniofacial Center, Rush University Medical Center, Chicago, Ill.
Am J Orthod Dentofacial Orthop. 2015 May;147(5):566-77. doi: 10.1016/j.ajodo.2014.12.027.
Hemifacial microsomia is a deformity of variable expressivity with unilateral hypoplasia of the mandible and the ear. In this study, we evaluated skeletal soft tissue changes after bimaxillary unilateral vertical distraction.
Eight patients (4 preadolescents 4 adolescents) each with a grade II mandibular deformity underwent a LeFort I osteotomy and an ipsilateral horizontal mandibular ramus osteotomy. A semiburied distraction device was placed over the ramus, and intermaxillary fixation was applied. Anteroposterior cephalometric and frontal photographic analyses were conducted before and after distraction. Statistics were used to analyze the preoperative and postoperative changes.
Cephalometrically, the nasal floor and the occlusal and gonial plane angles decreased. The ratios of affected-unaffected ramus and gonial angle heights improved by 15% and 20%, respectively. The position of menton moved toward the midline. The photographic analysis showed a decrease of the nasal and commissure plane angles, and the chin moved to the unaffected side. The parallelism between the horizontal skeletal and soft tissue planes improved, with an increase in the affected side ramus height and correction of the chin point toward the midline.
Simultaneous maxillary and mandibular distraction improved facial balance and symmetry. Patients in the permanent dentition with fixed orthodontic appliances and well-aligned dental arches responded well to this intervention.
半侧颜面短小畸形是一种表现程度各异的畸形，伴有下颌骨和耳部的单侧发育不全。在本研究中，我们评估了双侧上颌骨单侧垂直牵张术后骨骼和软组织的变化。
8例（4例青春期前儿童，4例青少年）II级下颌骨畸形患者接受了LeFort I型截骨术和同侧下颌升支水平截骨术。在升支上方放置一个半埋式牵张装置，并进行颌间固定。在牵张前后进行头影测量和正面照相分析。采用统计学方法分析术前和术后的变化。
头影测量显示，鼻底、咬合平面角和下颌角平面角减小。患侧与健侧升支高度比和下颌角高度比分别提高了15%和20%。颏点位置向中线移动。照相分析显示鼻平面角和口角平面角减小，下巴向健侧移动。水平骨骼平面与软组织平面之间的平行度提高，患侧升支高度增加，颏点向中线矫正。
上颌骨和下颌骨同时牵张可改善面部平衡和对称性。恒牙列且佩戴固定正畸矫治器、牙弓排列整齐的患者对该干预反应良好。
