title: Four osteotomy methods with piezosurgery to remove complicated mandibular third molars: a retrospective study.
abstract: OBJECTIVE
  Piezosurgery has been used widely in oral and maxillofacial surgery, but there has been no report systematically describing an osteotomy method with piezosurgery for complicated mandibular third molar removal. The aim of this study was to introduce 4 osteotomy methods using piezosurgery and evaluate their effects.
  
  
  METHODS
  A retrospective study was conducted of patients with a complicated impacted mandibular third molar requiring extraction. The predictor variable was the extraction technique. Four osteotomy methods using piezosurgery were tested according to different impaction types: method 1 involved complete bone removal; method 2 involved segmental bone removal; method 3 involved bone removal combined with tooth splitting; and method 4 involved block bone removal. Outcome variables were success rate, operative time, major complications (including nerve injury, mandible fracture, severe hematoma, or severe edema), and serious pyogenic infection. Data were analyzed using descriptive statistics.
  
  
  RESULTS
  The study was composed of 55 patients with 74 complicated impacted mandibular third molars. All impacted mandibular third molars were removed successfully. The average surgical time was 15 minutes (range, 8 to 26 minutes). Thirty-eight molars (51.4%) were extracted by method 1, 18 molars (24.3%) by method 2, 12 molars (16.2%) by method 3, and 6 molars (8.1%) by method 4. Two cases (2.7%) developed postoperative infections and recovered within 1 week using drainage and antibiotic administration.
  
  
  CONCLUSIONS
  The 4 osteotomy methods with piezosurgery provide effective ways of removing complicated impacted mandibular third molars.
authors.affiliation: PhD Student, Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Ge
authors.affiliation: Full Professor, Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. Electronic address: yangchi63@hotmail.com.
authors.forename: Chi
authors.initials: C
authors.lastname: Yang
authors.affiliation: Full Professor, Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Jia-Wei
authors.initials: JW
authors.lastname: Zheng
authors.affiliation: Full Professor, Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: He
authors.affiliation: Associate Professor, Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Ling-Yan
authors.initials: LY
authors.lastname: Zheng
authors.affiliation: Master's student, Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Ying-Kai
authors.initials: YK
authors.lastname: Hu
mesh_terms: D006801:Humans; D008334:Mandible / Q000601:surgery*; D008964:Molar, Third / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D012189:Retrospective Studies