Trigeminocardiac reflex (TCR) occurs rarely during oral and maxillofacial surgery. We report a case of sinus arrest caused by TCR during extraction of an impacted lower third molar in a 41-year-old woman referred to our department for tooth extraction. The preoperative electrocardiogram showed normal sinus rhythm. When the surgeon started luxation of the left impacted lower third molar with the patient under intravenous sedation with propofol, sinus arrest suddenly occurred. The surgery and propofol administration were discontinued immediately. The period of sinus arrest was 20 seconds, after which heart rate recovered to 70 beats per minute. The operation was resumed with the patient under propofol sedation, and no further sinus arrest occurred. It is likely that sinus arrest in this patient was caused by mechanical pressure on the inferior alveolar nerve. To prevent TCR, it is important to avoid invasive procedures and to use an appropriate local anesthetic during oral and maxillofacial surgery.
