title: Relationship between Frontal Gap and Postoperative Stability in the Treatment of Mandibular Prognathism.
abstract: Objectives. To investigate the correlation between frontal gaps and skeletal stability after intraoral vertical ramus osteotomy (IVRO) for correction of mandibular prognathism.Materials and Methods. Thirty-three patients with frontal gaps after IVRO-based mandibular prognathism correction were included. Three lateral and frontal cephalometric radiographs were obtained: preoperatively (T1), immediately postoperatively (T2), and 2 years postoperatively (T3). Two linear measurements (menton [Me] and frontal gap) were compared from T1 to T3 (T21: immediate surgical changes; T32: postoperative stability; T31: 2-year surgical change). Data were analyzed using Pearson's correlation coefficient and multiple linear regression.Results. The T21 mean surgical horizontal change in the Me position was 12.4 ± 4.23 mm. Vertically, the mean downward Me movement was 0.6 ± 1.73 mm. The mean frontal gaps were 4.7 ± 2.68 mm and 4 ± 2.48 mm in the right and left gonial regions, respectively. Postoperative stability (T32) significantly correlated with the amount of setback. Frontal gaps did not have a significant effect on postoperative stability. However, multiple regression model (R2= 0.341,P= 0.017) showed value predictability, especially in the amount of setback.Conclusion. Frontal gaps occur after IVRO but have no significant effect on long-term postoperative skeletal stability. The primary risk factor for postoperative relapse remains the amount of mandibular setback.
authors: Department of Orthodontics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Graduate Institute of Dental Sciences, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Yu-Chuan
authors: YC
authors: Tseng
authors: Department of Family Dentistry, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Kun-Jung
authors: KJ
authors: Hsu
authors: Graduate Institute of Dental Sciences, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Ker-Kong
authors: 0000-0001-6474-0372
authors: KK
authors: Chen
authors: Department of Oral Hygiene, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Ju-Hui
authors: JH
authors: Wu
authors: Graduate Institute of Dental Sciences, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Oral and Maxillofacial Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors: Chun-Ming
authors: 0000-0002-7993-9760
authors: CM
authors: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D011182:Postoperative Care; D012044:Regression Analysis; D055815:Young Adult