title: Nerve injury associated with orthognathic surgery. Part 2: inferior alveolar nerve.
abstract: The inferior alveolar nerve (IAN) is the most commonly injured structure during mandibular osteotomies. The prevalence of temporary injury has been reported as 70/100 patients (95% CI 67 to 73/100) or 56/100 nerves (95% CI 46 to 65/100), and the prevalence of permanent alteration in sensation was 33/100 patients (95% CI 30 to 35/100) or 20/100 nerves (95% CI 18 to 21/100) when assessed subjectively. The prevalence varied significantly between different operations (p<0.0001). It was significantly higher for sagittal split osteotomy (SSO) combined with genioplasty than for SSO alone (p<0.0001) or vertical ramus osteotomy (VRO) (p<0.0001). Injury may result from traction during stripping or manipulation of the distal fragment, incorrect placement of the cuts, or misjudged placement of fixation in ramus ostotomy. During SSO, they can occur during retraction to make cuts in the medial ramus, when the bone is cut or split, and on fixation. The impact of injury is generally said to be low as it does not seem to affect patients' opinions about the operation.
authors.affiliation: Department of Oral & Maxillofacial Surgeon, Oxford University Hositals NHS Trust, Headley Way, Oxford OX3 9DU. Electronic address: niall_mcleod@yahoo.co.uk.
authors.forename: N M H
authors.initials: NM
authors.lastname: McLeod
authors.affiliation: Department of Orthodontics, Worcester Royal Hospital, Charles Hasting Way, Worcester WR5 1DD.
authors.forename: D C
authors.initials: DC
authors.lastname: Bowe
mesh_terms: D006801:Humans; D008334:Mandible; D008340:Mandibular Nerve; D056948:Orthognathic Surgical Procedures / Q000009:adverse effects*; D010027:Osteotomy; D059229:Osteotomy, Sagittal Split Ramus; D061221:Trigeminal Nerve Injuries / Q000209:etiology*
keywords: Inferior Alveolar Nerve; Nerve Injury; Orthognathic Surgery