Association Between Lingual Retraction and Hemodynamic Changes in Patients Receiving Dental Treatment Under General Anesthesia

Overview

This study aims to investigate the association between sudden decreases in heart rate and blood pressure during dental procedures requiring lingual retraction-such as fillings, root canal treatments, tooth extractions, and cyst surgeries-under general anesthesia. Patients will be routinely monitored for vital parameters during anesthesia. Sudden drops in heart rate and blood pressure (10-20% decrease) will be recorded as lingual retraction-related trigeminocardiac reflex (TCR) events, along with the type of lingual retraction, dental procedure, and tooth location at the time of occurrence. Additionally, the results will be analyzed in relation to patient age, sex, and tongue size.

Stimulation of both the central and peripheral branches of the trigeminal nerve can lead to clinically significant hemodynamic changes. The trigeminocardiac reflex (TCR), a brainstem-mediated reflex mechanism triggered by such stimulations, causes sudden and marked decreases in heart rate and arterial blood pressure. This reflex may result in hemodynamic instability during surgical interventions and, in rare cases, can precipitate severe cardiac complications including cardiac arrest. While TCR is more commonly observed during ophthalmic, craniofacial, and skull base surgeries, it may also occur during dental procedures. Stimulation of the peripheral branches of the lingual nerve, such as during lingual retraction, has been associated with cardiovascular side effects like bradycardia. This phenomenon reflects systemic hemodynamic responses resulting from trigeminal nerve stimulation. The literature reports significant drops in heart rate and arterial pressure due to TCR during common dental procedures such as tooth extraction and implant surgery. Notably, sudden decreases of 10-20% in blood pressure are considered clinically relevant indicators of TCR. Additionally, hemodynamic changes potentially related to this reflex have been documented during endodontic treatments, particularly in cases of irreversible pulpitis. Thus, stimulation of the dental branches of the trigeminal nerve may trigger TCR during dental procedures, leading to systemic hypotension. In conclusion, TCR triggered by trigeminal nerve stimulation is an important hemodynamic reflex encountered during surgical and dental interventions. Early recognition and appropriate preventive measures are critical to mitigating potential cardiac risks. Clinical procedures should consider patients' susceptibility to such reflexes in planning and management. This study aims to investigate the incidence of trigeminocardiac reflex triggered primarily by lingual retraction, and secondarily by dental procedure type, tooth location, patient age, and duration of general anesthesia in adult and pediatric patients undergoing dental surgeries under general anesthesia. Conducted at the operating rooms of Kırıkkale University Faculty of Dentistry, this prospective observational study will record TCR events using a specially designed patient monitoring form, correlating these events with various clinical factors.