Research Article Comparisons of Jaw Line and Face Line after Mandibular Setback: Intraoral Vertical Ramus versus Sagittal Split Ramus Osteotomies Chun-Ming Chen , 1,2 Yu-Chuan Tseng , 2,3 Edward Chengchuan Ko, 1,2 Michael Yuan-Chien Chen, 4,5 Kwei-Jing Chen, 4,5 and Jung-Hsuan Cheng 3 1 Department of Oral and Maxillofacial Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan 2 School of Dentistry, College of Oral Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan 3 Department of Orthodontics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan 4 School of Dentistry, College of Medicine, China Medical University, Taichung, Taiwan 5 Department of Dentistry, China Medical University Hospital, China Medical University, Taichung, Taiwan Correspondence should be addressed to Jung-Hsuan Cheng; zinglontion@hotmail.com Received 17 August 2018; Accepted 3 December 2018; Published 18 December 2018 Academic Editor: Mar´ ılia G. de Oliveira Copyright © 2018 Chun-Ming Chen et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Tis study investigates the diferences in the lateral profle and frontal appearance afer sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) procedures for the correction of mandibular prognathism. Methods. Sixty patients (30 SSRO and 30 IVRO) underwent mandibular setback surgery. Serial cephalograms were obtained: (1) T1: approximately 1 month before surgery; (2) T2: at least 6 months afer surgery for SSRO and at least 1 year afer surgery for IVRO. Te landmarks, linear distances, and related angles were measured. Te t-test was applied to the intragroup and intergroup comparisons. Te null hypothesis was that SSRO and IVRO made no diference in the facial appearance. Results. In the IVRO group, the ramus and gonial widths signifcantly decreased by 3.9 mm and 5.8 mm, respectively. SSRO signifcantly reduced the gonial angle by 2.6 ∘ , and IVRO increased it signifcantly by 5.3 ∘ . Te postoperative increases at frontal bone levels 0 and 1 afer IVRO were signifcantly larger than those afer SSRO, but, at level 3, the increases afer SSRO were larger than those afer IVRO. In the frontal muscular and facial planes, SSRO and IVRO presented no diference. Te frontal jaw angle and face angle were signifcantly larger with IVRO than with SSRO. Terefore, the null hypothesis was rejected. Conclusions. Te ramus width and gonial width were signifcantly decreased in IVRO compared to SSRO. IVRO increased angles in the lateral profle (gonial angle and mandibular plane angle) and frontal appearance (jaw angle and face angle) more than SSRO did. 1. Introduction Facial aesthetics is an essential factor that determines inter- personal relationships, afects social and psychological devel- opment, and plays an important role in a person’s employ- ment and social status. Mandibular prognathism is an Angle’s Class III malocclusion commonly characterized by a concave facial shape. In addition to abnormalities in the growth between the maxilla and the mandible, patients with Angle’s Class III malocclusion have a shorter anterior cranial base, an acute cranial base angle, and a more obtuse gonial angle [1, 2]. Moreover, patients with mandibular prognathism present with anterior crossbite leading to difculty in mastication. Tis further results in problems with malnutrition and vocal- ization. Te unaesthetic profle and malocclusion ofen lead to social dysfunction and psychological disorders. However, the etiology of mandibular prognathism is still uncertain. It has been thought that environmental and genetic factors are involved in the growth and development of mandibular prognathism [1]. Treatment for patients with mandibular prognathism not only requires mandibular setback to correct the malocclusion Hindawi BioMed Research International Volume 2018, Article ID 1375085, 7 pages https://doi.org/10.1155/2018/1375085