title: Comparison of lower lip hypoesthesia between hybrid fixation and conventional fixation following sagittal split ramus osteotomy.
abstract: OBJECTIVE
  The purpose of this study was to compare the recovery period of lower lip hypoesthesia between hybrid fixation and conventional fixation using absorbable plates and screw systems following sagittal split ramus osteotomy (SSRO).
  
  
  METHODS
  The subjects were 66 patients (132 sides) who underwent bilateral SSRO setback surgery. They were divided into a hybrid fixation group (66 sides, 1 u-HA/PLLA plate and 4 mono-cortical screws and a bi-cortical screw in each side) and a conventional fixation group (66 sides, 1 u-HA/PLLA plate and 4 mono-cortical screws in each side). Trigeminal nerve hypoesthesia at the region of the lower lip was assessed bilaterally by the trigeminal somatosensory-evoked potential (TSEP) method.
  
  
  RESULTS
  The mean measurable periods were 8.1 ± 10.4 weeks in the hybrid fixation group, 5.1 ± 11.5 weeks in the conventional group with no significant difference. However, the maximum in the hybrid fixation group was 27 sides at 4 weeks postoperative and in the conventional fixation group was 37 sides at 1 week postoperative, and there was significant difference in the distribution of the measurable period (P < 0.0001).
  
  
  CONCLUSIONS
  This study suggested that additional bi-cortical screws could affect the recovery of lower lip hypoesthesia after SSRO with bent absorbable plate fixation.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan. Electronic address: kueki@yamanashi.ac.jp.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Ueki
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Moroi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Ishihara
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Sotobori
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Ran
authors.initials: R
authors.lastname: Iguchi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kosaka
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Hiroumi
authors.initials: H
authors.lastname: Ikawa
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Marukawa
mesh_terms: D020341:Absorbable Implants; D000293:Adolescent; D000328:Adult; D001672:Biocompatible Materials / Q000737:chemistry; D001860:Bone Plates; D001863:Bone Screws; D017886:Durapatite / Q000737:chemistry; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006987:Hypesthesia / Q000209:etiology*; D008046:Lip / Q000294:innervation; D008047:Lip Diseases / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D059229:Osteotomy, Sagittal Split Ramus / Q000295:instrumentation*; D011091:Polyesters / Q000737:chemistry; D011378:Prognathism / Q000601:surgery; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology; D020433:Trigeminal Nerve Diseases / Q000209:etiology; D055815:Young Adult
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; C499699:hydroxyapatite-polylactide; D017886:Durapatite
keywords: Absorbable plate; Hybrid fixation; Sagittal split ramus osteotomy (SSRO); Trigeminal somatosensory-evoked potential (TSEP)