Trigeminocardiac reflex during Le Fort I osteotomy: a case-crossover study Behnam Bohluli, DDS, MS, a Mohammad Bayat, DMD, MS, b Farzin Sarkarat, DDS, MS, a Behnaz Moradi, DDS, c Mohammad-Hassan Seif Tabrizi, DDS, d and Pooyan Sadr-Eshkevari, DDS, c Tehran, Iran, and Malaya, Malaysia AZAD UNIVERSITY OF TEHRAN, TEHRAN UNIVERSITY OF MEDICAL SCIENCES, PRIVATE PRACTICE, AND UNIVERSITY OF MALAYA Objective. The present study aimed to assess the occurrence of trigeminocardiac reflex (TCR) during Le Fort I osteotomies. Study design. This case-crossover study included 25 Le Fort I osteotomy candidates without systemically compromising conditions. Mean arterial blood pressure and pulse rate values were recorded before downfracture (DF) (MABP1, PR1), during DF (MABP2, PR2), and after DF (MABP3, PR3). The data were analyzed using repeated measure ANOVA tests (= 0.05). Results. PR1 and PR3 were significantly higher than PR2 (P  .001). MABP2 value was significantly lower compared with MABP1 and MABP3 values (P  .001). PR2 and MABP2 showed a mean decrease of 6.5% and 9.7% compared with PR1 and MABP1, respectively. Conclusion. Different values have been suggested for TCR. Considering the limitations, the present study may suggest a revision of the values or descriptions for TCR, at least in maxillofacial Le Fort I osteotomy. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:178-181) Trigeminocardiac reflex (TCR), a sudden decrease in pulse rate (PR) and mean arterial blood pressure (MABP) that may consequently develop asystole and even cardiac arrest, is of high importance to oral and maxillofacial surgeons. This is especially true during the course of Le Fort and mandibular osteotomies. This abrupt event is reported more than 20 times through the oral and maxillofacial surgery literature. TCR is re- ported during the corrective surgery of nasal fracture and midface fracture reduction, tuberosity osteotomy, Le Fort I osteotomy, sagittal-split osteotomy of rami, reduction of fractured zygomas, and even arthroscopic surgeries of temporomandibular joint (TMJ). 1 The prevalence of TCR has been reported to be 1.6% during maxillofacial, temporomandibular, and orthognathic surgeries. Also, there have been reports of sudden MABP or PR decrease in the course of intraoral sur- geries and extractions. 2 Different theories have been suggested to describe TCR. The mechanism of action of TCR, however, remains unclear. Some authors suggest anxiety as a contributing factor. Some others have discussed the type of anesthetic agents as an influential factor. 3,4 A third theory introduces the stimulation of lingual and palatal branches of the trigeminal nerve as the trigger- ing factor. 5 Because the occurrence of this reflex may be associated with threatening consequences without any significant signs, its prevention and management are crucial to the surgeon and anesthesiologist. 1 Authors have suggested the intravenous administration of anticolinergics for prevention of TCR. Others believe that the only proper strategy is to stop the stimulating action until MABP and PR reach the baseline. 6 Failure to manage this event may result in asystole, and even cardiac arrest in some cases. 1,7 Though oculocardiac re- flex (OCR), a subtype of TCR, has been thoroughly stud- ied through the ophthalmology literature, TCR has not yet been sufficiently discussed among oral and maxillofacial surgeons. 1,3 Because the maxillofacial literature on TCR is limited to case reports and a literature review by the authors, 1 it was decided to further assess the occurrence of TCR during Le Fort I osteotomies. MATERIALS AND METHODS Overview This case-crossover study was peer reviewed and approved by local board of ethics. Informed consents a Assistant Professor, Department of Oral and Maxillofacial Surgery, School of Dental Medicine, Azad University of Tehran, Tehran, Iran. b Assistant Professor, Department of Oral and Maxillofacial Surgery, School of Dental Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran. c Private Practice, Tehran, Iran. d Resident of Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial Surgery, University of Malaya, Malaya, Malaysia. Received for publication Sep 15, 2009; returned for revision Dec 12, 2009; accepted for publication Dec 28, 2009. 1079-2104/$ - see front matter © 2010 Mosby, Inc. All rights reserved. doi:10.1016/j.tripleo.2009.12.054 178