evaluation of trigeminocardiac reflex during le fort i and sagittal split ramus osteotomies

Introduction: the trigeminocardiac reflex (tcr) refers to the sudden development of bradycardia as well as asystole along with arterial hypotension associated with any manipulation of sensory branches of the trigeminal nerve. clinically, the tcr has been reported to occur during craniofacial surgery. it is crucial to learn about this sudden physiological response during maxillofacial surgery that is likely to happen with any craniofacial surgical procedures. materials and methods: in this clinical study 44 volunteers without any systemically compromising conditions were divided into 2 groups. the first group underwent le fort i osteotomy and the second mandibular osteotomy. mean arterial blood pressure and pulse rate (mabp1, pr1) values were recorded before down fracture (df) of maxilla and sagittal splitting (ss) of mandible, during df and ss (mabp2, pr2), and after df and ss (mabp3, pr3). the data were analyzed using repeated measure anova tests (p = 0.05). result: in le fort i group, pr1 and pr3 were significantly higher than pr2 (p< .001). mabp2 was significantly lower compared with mabp1 and mabp3 (p < .001). pr2 and mabp2 showed a mean decrease of 7.4% and 8.9% compared with pr1 and mabp1, respectively. in second group differences on mabp and pr was not statistically significant. conclusion: it is concluded that tcr is triggered by the stimulation of v2 but v3 branch stimulation does not cause such reflex.