title: Bad splits in bilateral sagittal split osteotomy: systematic review of fracture patterns.
abstract: An unfavourable and unanticipated pattern of the mandibular sagittal split osteotomy is generally referred to as a 'bad split'. Few restorative techniques to manage the situation have been described. In this article, a classification of reported bad split pattern types is proposed and appropriate salvage procedures to manage the different types of undesired fracture are presented. A systematic review was undertaken, yielding a total of 33 studies published between 1971 and 2015. These reported a total of 458 cases of bad splits among 19,527 sagittal ramus osteotomies in 10,271 patients. The total reported incidence of bad split was 2.3% of sagittal splits. The most frequently encountered were buccal plate fractures of the proximal segment (types 1A-F) and lingual fractures of the distal segment (types 2A and 2B). Coronoid fractures (type 3) and condylar neck fractures (type 4) have seldom been reported. The various types of bad split may require different salvage approaches.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Academic Medical Centre (AMC), Amsterdam, Netherlands. Electronic address: s.a.steenen@amc.uva.nl.
authors.forename: S A
authors.initials: SA
authors.lastname: Steenen
authors.affiliation: Department of Oral and Maxillofacial Surgery, Spaarne Gasthuis Haarlem, Academic Medical Centre (AMC), Amsterdam, and Academic Centre for Dentistry (ACTA) in Amsterdam, Netherlands.
authors.forename: A G
authors.initials: AG
authors.lastname: Becking
mesh_terms: D006801:Humans; D008334:Mandible / Q000601:surgery*; D008337:Mandibular Fractures / Q000145:classification / Q000453:epidemiology* / Q000208:ethnology; D010027:Osteotomy / Q000009:adverse effects* / Q000379:methods; D059229:Osteotomy, Sagittal Split Ramus / Q000009:adverse effects / Q000145:classification* / Q000379:methods / Q000706:statistics & numerical data; D016879:Salvage Therapy / Q000379:methods
keywords: bad split; bilateral sagittal split osteotomy; classification; intraoperative complications; management; mandibular fracture; orthognathic surgery; sagittal ramus osteotomy