title: Trigeminocardiac reflex, bilateral sagittal split ramus osteotomy, Gow-Gates block: a randomized controlled clinical trial.
abstract: OBJECTIVE
  The behavior of trigeminocardiac reflex (TCR) during maxillofacial surgeries has not yet been sufficiently studied and knowledge of its behavior is limited to some case reports. The present study aimed to assess the occurrence of TCR in bilateral sagittal split ramus osteotomy and to determine the possible effect of Gow-Gates block on its incidence.
  
  
  METHODS
  Twenty candidates for bilateral sagittal split ramus osteotomy (included were American Society of Anesthesiologists I Class III patients with a prognathism of 3 to 5 mm) were given routine general anesthesia after at least 12 hours of fasting. All patients received Gow-Gates mandibular nerve block on 1 random side (case ramus; the other side was used as the control) after induction of general anesthesia before surgery. Pulse rate was recorded at baseline, soft tissue cutting, bone cutting, sagittal splitting, setback manipulation, and recovery. Mean pulse rate values were compared statistically using t test for the 2 sides in patients.
  
  
  RESULTS
  No statistically significant differences were found between the blocked and control sides except during ramus sagittal splitting and setback manipulation (P < .0001), when a significantly decreased pulse rate was recorded for the control ramus compared with the blocked ramus.
  
  
  CONCLUSIONS
  The present study provides further evidence for the complex neurophysiologic mechanism and probable prevention of peripheral TCR. The results of the present study should be further validated through future studies but already provide strong evidence that peripheral and central TCR may act differently based on slightly different pathways.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dental Medicine, Azad University of Tehran, Tehran, Iran.
authors.forename: Behnam
authors.initials: B
authors.lastname: Bohluli
authors.forename: Bernhard J
authors.initials: BJ
authors.lastname: Schaller
authors.forename: Reza
authors.initials: R
authors.lastname: Khorshidi-Khiavi
authors.forename: Mohsen
authors.initials: M
authors.lastname: Dalband
authors.forename: Pooyan
authors.initials: P
authors.lastname: Sadr-Eshkevari
authors.forename: Peter
authors.initials: P
authors.lastname: Maurer
mesh_terms: D000328:Adult; D000768:Anesthesia, General; D000779:Anesthetics, Local / Q000008:administration & dosage; D001919:Bradycardia / Q000209:etiology* / Q000517:prevention & control*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008334:Mandible / Q000601:surgery*; D008340:Mandibular Nerve / Q000187:drug effects; D016343:Monitoring, Intraoperative; D009407:Nerve Block / Q000379:methods*; D056948:Orthognathic Surgical Procedures / Q000009:adverse effects*; D010027:Osteotomy / Q000009:adverse effects; D011446:Prospective Studies; D012018:Reflex; D014276:Trigeminal Nerve / Q000502:physiology; D014630:Vagus Nerve / Q000502:physiology; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine