title: Skeletal stability after mandibular setback surgery: comparison between the hybrid technique for fixation and the conventional plate fixation using an absorbable plate and screws.
abstract: OBJECTIVE
  The purpose of this study was to compare the temporal changes in condylar long axis and skeletal stability after sagittal split ramus osteotomy (SSRO) with the hybrid fixation technique and the conventional plate fixation.
  
  
  METHODS
  Of 44 Japanese patients diagnosed with mandibular prognathism, 22 underwent SSRO with the conventional plate fixation (1 u-HA/PLLA plate and 4 monocortical screws in each side) and 22 underwent SSRO with a hybrid fixation technique (1 u-HA/PLLA plate and 4 monocortical screws and bicortical screw in each side). The temporal changes in condylar long axis and skeletal stability were assessed by axial, frontal, and lateral cephalograms. After surgery, breakage of the plate and screws was checked by 3-dimensional computed tomography (3DCT).
  
  
  RESULTS
  Although there was a significant difference between the groups regarding Me-Ag in T1 (P = 0.0138), there were no significant differences between the groups for the other measurements in lateral, frontal and axial cephalometric analysis in each time interval. In two cases, 4 sides in the conventional plate fixation group, failure of the absorbable plate was found by 3DCT. However, there was no breakage in the hybrid fixation group.
  
  
  CONCLUSIONS
  This study suggested that there were no significant differences in the postoperative temporal changes between the two groups in mandibular setback surgery.
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. K. Ueki), Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi 409-3898, Japan. Electronic address: kueki@yamanashi.ac.jp.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Ueki
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, 13-1 Takaramachi, Kanazawa 920-8641, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Okabe
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, 13-1 Takaramachi, Kanazawa 920-8641, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Marukawa
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, 13-1 Takaramachi, Kanazawa 920-8641, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Mukozawa
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. K. Ueki), Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi 409-3898, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Moroi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, 13-1 Takaramachi, Kanazawa 920-8641, Japan.
authors.forename: Mao
authors.initials: M
authors.lastname: Miyazaki
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. K. Ueki), Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi 409-3898, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Sotobori
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. K. Ueki), Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi 409-3898, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Ishihara
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, 13-1 Takaramachi, Kanazawa 920-8641, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, 13-1 Takaramachi, Kanazawa 920-8641, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ooi
mesh_terms: D020341:Absorbable Implants; D000293:Adolescent; D000328:Adult; D059925:Anatomic Landmarks / Q000473:pathology; D001860:Bone Plates; D001863:Bone Screws; D002508:Cephalometry / Q000379:methods; D017886:Durapatite / Q000737:chemistry; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008334:Mandible / Q000473:pathology / Q000601:surgery*; D008335:Mandibular Condyle / Q000473:pathology; D008437:Maxilla / Q000473:pathology; D008875:Middle Aged; D009295:Nasal Bone / Q000473:pathology; D059229:Osteotomy, Sagittal Split Ramus / Q000295:instrumentation / Q000379:methods*; D011091:Polyesters / Q000737:chemistry; D011378:Prognathism / Q000601:surgery; D012658:Sella Turcica / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult
chemical_list: D011091:Polyesters; C499699:hydroxyapatite-polylactide; D017886:Durapatite
keywords: Hybrid fixation; Sagittal split ramus osteotomy; Stability; Unsintered hydroxyapatite (u-HA)/poly-l-lactic acid (PLLA) plate