title: Effect of self-setting α-tricalcium phosphate between segments for bone healing and hypoaesthesia in lower lip after sagittal split ramus osteotomy.
abstract: OBJECTIVE
  The aim of this study was to evaluate hypoaesthesia of the lower lip and bone formation using self-setting α-tricalcium phosphate (Biopex(®)) between the proximal and distal segments following sagittal split ramus osteotomy (SSRO) with bent absorbable plate fixation.
  
  
  METHODS
  The subjects were 40 patients (80 sides) who underwent bilateral SSRO setback surgery. They were divided into a Biopex(®) group (40 sides) and a control group (40 sides). The Biopex(®) was inserted into the anterior part of the gap between the segments in the Biopex(®) group. Trigeminal nerve hypoaesthesia in the region of the lower lip was assessed bilaterally using the trigeminal somatosensory-evoked potential (TSEP) method. Ramus square, ramus length, and ramus width, the square of the Biopex(®) at the horizontal plane under the mandibular foramen were assessed preoperatively, immediately after surgery, and 1year postoperatively by computed tomography (CT).
  
  
  RESULTS
  The mean measurable period and standard deviation were 9.3±15.7weeks in the control group, 5.3±8.3weeks in the Biopex(®) group, and there was no significant difference. Ramus square after 1year was significantly larger than that prior to surgery and new bone formation was found between the segments in both groups (P<0.05). In the Biopex(®) group, the square of the Biopex(®) after 1year was significantly smaller than that immediately after surgery (P<0.05).
  
  
  CONCLUSIONS
  This study suggested that inserting Biopex(®) in the gap between the proximal and distal segments was useful for new bone formation and it did not prevent the recovery of lower lip hypoaesthesia after SSRO with bent absorbable plate fixation.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Kanazawa University, Kanazawa, Japan. kueki@med.kanazawa-u.ac.jp
authors.forename: Koichiro
authors.initials: K
authors.lastname: Ueki
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Okabe
authors.forename: Kohei
authors.initials: K
authors.lastname: Marukawa
authors.forename: Aya
authors.initials: A
authors.lastname: Mukozawa
authors.forename: Akinori
authors.initials: A
authors.lastname: Moroi
authors.forename: Mao
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Kiyomasa
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Etsuhide
authors.initials: E
authors.lastname: Yamamoto
mesh_terms: D020341:Absorbable Implants; D000293:Adolescent; D000328:Adult; D001672:Biocompatible Materials / Q000627:therapeutic use*; D001860:Bone Plates; D018786:Bone Substitutes / Q000627:therapeutic use*; D002130:Calcium Phosphates / Q000627:therapeutic use*; D002508:Cephalometry / Q000379:methods; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006987:Hypesthesia / Q000209:etiology*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008046:Lip / Q000294:innervation; D008047:Lip Diseases / Q000209:etiology*; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging; D008875:Middle Aged; D056948:Orthognathic Surgical Procedures / Q000379:methods; D010012:Osteogenesis / Q000187:drug effects*; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods*; D011930:Reaction Time / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D014057:Tomography, X-Ray Computed / Q000379:methods; D020433:Trigeminal Nerve Diseases / Q000209:etiology; D055815:Young Adult
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate