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BioMed Research International
Volume 2016, Article ID 7046361, 5 pages
Research Article

Relationship between Frontal Gap and Postoperative Stability in the Treatment of Mandibular Prognathism

1Department of Orthodontics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
2Graduate Institute of Dental Sciences, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
3Department of Family Dentistry, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
4Department of Oral Hygiene, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
5Department of Oral and Maxillofacial Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan

Received 10 April 2016; Revised 28 August 2016; Accepted 8 September 2016

Academic Editor: Li Wu Zheng

Copyright © 2016 Yu-Chuan Tseng et al. This 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.


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  mm. Vertically, the mean downward Me movement was  mm. The mean frontal gaps were  mm and  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 (, ) 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.