title: Recovery of inferior alveolar nerve injury after bilateral sagittal split ramus osteotomy (BSSRO): a retrospective study.
abstract: BACKGROUND
  Bilateral sagittal split ramus osteotomy (BSSRO) is the most widely used mandibular surgical technique in orthognathic surgery and is easy to relocate the distal segments, accelerating bone repair by the large surface of bone contact. However, it can cause neurosensory dysfunction (NSD) or sensory loss by injury of the inferior alveolar nerve. The purpose of the present study was to evaluate NSD after BSSRO and modifiers at NSD recovery.
  
  
  METHODS
  In this study, NSD characteristics after BSSRO from 2009 to 2014 at the Kyung Hee University Dental Hospital were evaluated. The pattern of sensory recovery over time was also evaluated based on factors such as field of sensory dysfunction, surgical procedure, presence of pre-operative facial asymmetry, and postoperative medications.
  
  
  RESULTS
  Most of the patients had shown NSD immediately after orthognathic surgery. Among the 1192 sides of 596 patients, NSD was observed in 953 sides and 544 patients. Sexual predilection was shown in males (pvalue = 0.0062). In the asymmetric group of 132 patients, NSD was observed in 128 patients (96.97 %). In the symmetric group of 464 patients, NSD was observed in 416 patients (89.45 %); on the other hand, NSD was observed significantly higher in the asymmetric group (p= 0.025). NSD-associated factors were analyzed, and vitamin B12 may be beneficial for NSD recovery.
  
  
  CONCLUSIONS
  There was a difference between the symmetric group and the asymmetric group in NSD recovery. Vitamin B12 can be regarded as an effective method to nerve recovery. However, a further prospective study is needed.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Chi-Heun
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Baek-Soo
authors.initials: BS
authors.lastname: Lee
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Byung-Joon
authors.initials: BJ
authors.lastname: Choi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Jung-Woo
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Joo-Young
authors.initials: JY
authors.lastname: Ohe
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Hee-Young
authors.initials: HY
authors.lastname: Yoo
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Yong-Dae
authors.initials: YD
authors.lastname: Kwon
keywords: Neurosensory dysfunction; Orthognathic surgery; Vitamin B12