Expanding Airway Education: Heart Rate Variability and the Autonomic Nervous System

by Jeffrey Hindin, DDS
The future of dentistry lies in recognizing the dentist’s role in understanding and improving patient physiology. Monitoring and assessment of heart rate variability (HRV) and the autonomic nervous system (ANS) will be key tools to understanding the physiological basis for the inextricable relationship among dentistry, medicine and other health care practices. “HRV is a useful method to assess cardiac autonomic modulation in patients undergoing dental procedures, because knowledge of physiological conditions provides greater security to the professional as well as the possibility of a better plan treatment to patient benefit.” (M. Santana, et. al. 2013)
The autonomic nervous system (ANS), composed of the sympathetic nervous and parasympathetic nervous systems, controls the cardiovascular system, in part, by releasing neurotransmitters that increase or decrease heart rate (HR), respectively. The periodic oscillations in HR and RR intervals of consecutive heartbeats, modulated by the activity of ANS on the heart is known as heart rate variability.^1-5 The SNS increases heart rate and respiration rate. Increases in sympathetic outflow decrease HRV.
A high HRV is a sign of health, depicting the body’s balance and shifting between sympathetic and parasympathetic pathways.  Lowered HRV is associated with disease states and poor adaptation to stress, and physiologic dysfunction.⁴
In dentistry, malocclusion, TMD, and surgical dental procedures have shown to lower HRV.⁶ Maixner et al. (2011) investigated the association between autonomic variables and temporomandibular disorder (TMD), testing the hypothesis that dysregulation of the autonomic nervous system contributes to the onset and persistence of TMD. The authors found that patients with TMD at rest showed reduced HRV compared with the control group. Several articles have shown that HRV changes with jaw position. Relating to sleep, patients with OSA have lowered daytime HRV, even in the absence of hypertension, heart failure, or other disease states.⁷
HindexRV^® is FDA approved instrumentation to monitor HRV and the ANS and add a new level of understanding and care for patients with airway/sleep disorders. The HindexRV^® system produces objective data on the physiological effects of jaw position, tooth positioning, appliance and treatment efficacy and other dental procedures.
Everything dentists do in their daily practice can influence the airway and physiology of the patient, whether the practitioner knows it or not. With HindexRV^® monitoring, the clinician can objectively view patient physiology, in real time, to evaluate the efficacy of treatment modalities, e.g. appliance position, and obtain the “physiological bite”.
It is accepted that HRV is an early warning system that can provide valuable information for more optimal diagnosis and treatment. In the near future, dentists will routinely monitor their patient’s physiological functions and assess the risks and benefits of their treatment. In addition, treatment specifically aimed to promote and enhance physiological function where appropriate will be provided.
For information on HindexRV^® and Physiology/HRV courses, email info@physiologicaldentistry.com.