Postoperative mandibular stability after bilateral sagittal split ramus osteotomy based on skeletal correction in patients with facial asymmetry

• Published in: Journal of oral and maxillofacial surgery, medicine, and pathology Vol. 29; no. 3; pp. 181 - 188
• Main Authors: Suzuki, Kenji, Kobayashi, Masaru, Ozawa, Shigeyuki, Kondo, Tadanori, Ikoma, Takeharu, Iwabuchi, Hiroshi, Fushima, Kenji, Kubota, Eiro
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2017
• Subjects: Computer-assisted surgery; Facial asymmetry; Sagittal split ramus osteotomy; Three-dimensional imaging; Facial asymmetry; Sagittal split ramus osteotomy; Computer-assisted surgery; Three-dimensional imaging
• ISSN: 2212-5558; 2212-5566
• DOI: 10.1016/j.ajoms.2016.10.001

The objective of this study was to examine postoperative stability of the mandible after bilateral sagittal split ramus osteotomy (BSSRO) based on skeletal correction rather than occlusal correction in patients with facial asymmetry. Eighteen patients with facial asymmetry were enrolled in this study. BSSRO was performed, and an intermaxillary mandibular repositioning splint was prepared using a newly developed surgical simulation system (Mandibular Motion Tracking System [ManMoS]). Chin deviation was evaluated by frontal cephalography immediately after surgery (T1) and after active orthodontic treatment (T2). Three-dimensional analysis was carried out by calculating the three-dimensional coordinates of the cranial and mandibular planes. The mean crista galli-anterior nasal spine-menton angle was 1.11° at T1 and 0.88° at T2. The rotational change (T2–T1) was calculated as an actual number (Roll: −0.29±1.78°, Elevation: −1.31±2.44°, Azimuth: +0.41±1.64°). Our results suggest that the spatial orientation of the mandibular body was stable after BSSRO in the horizontal and frontal planes, while forward and upward rotation of the mandible was recognized in the sagittal plane. Thus, mandibular positioning with priority given to skeletal correction using the ManMoS is an effective therapeutic method, especially in cases of facial asymmetry.