Sleep apnea is a potentially serious and deleterious sleep disorder in which a patient’s breathing is exceptionally shallow or repeatedly interrupted during sleep (MAYO CLINC STAFF, 2018). Each pause of breathing can last anywhere from a few seconds to several minutes and commonly results in loud choking and/or snorting sounds as breathing resumes (MAYO CLINC STAFF, 2018). There are three recognized forms of sleep apnea which include: obstructive sleep apnea, central sleep apnea, and a combination of the two known as mixed or complex sleep apnea (MAYO CLINC STAFF, 2018).
Obstructive sleep apnea is by far the most common manifestation of this sleep disorder and is caused by a complete or partial obstruction of the upper airway (MAYO CLINC STAFF, 2018). Obstructive sleep apnea is typically associated with decreased muscle tone of the pharynx, increased presence of soft tissue around the airway (often correlated with obesity), old age, and other structural abnormalities that result in a narrowing of the pharyngeal airway (MAYO CLINC STAFF, 2018). Central sleep apnea on the other hand is associated with diminished respiratory feedback mechanisms in the central nervous system (Sleep Apnea, 2018). Ultimately, this diminished respiratory feedback pathology results from malfunctions in the brain’s respiratory control centers. Specifically, the Pre-Bötzinger complex, responsible for generating respiratory rhythm, is often imbalanced and leads to a failure in the initiation of inhalation in patients with central sleep apnea (Sleep Apnea, 2018).
All forms of the disorder are not only inconvenient and disruptive, but also present serious physiological symptoms such as reduced blood oxygen saturation, excessive blood carbon dioxide levels, increased restlessness, depression, and decreased executive function from a lack of sufficient sleep (Sleep Apnea, 2018). Decreases in oxygen saturation and increased carbon dioxide levels in the blood are particularly dangerous and may also cause an increased susceptibility to strokes and heart attacks in these patients (Sleep Apnea, 2018). Patients afflicted with sleep apnea are typically treated using a continuous positive airway pressure (CPAP) machine which forces the airway open by applying constant positive pressure to the nasopharynx by utilizing a large plastic face mask which is placed over the nose (Sleep Apnea, 2018). Although effective, these masks can be incredibly burdensome and uncomfortable to patients who often experience chest discomfort, skin and nose inflammation, nosebleeds, and sore gums among various other symptoms and complications (Sleep Apnea, 2018).
Fortunately, there have been extremely clever and innovative dental applications which have been developed in an effort to circumvent the use of CPAP machines in the treatment of obstructive sleep apnea (Clark & Masanori, 2015). These oral applications, or dental orthosis, are designed to increase the area of the upper airway by advancing the orientation of the mandible noninvasively (Clark & Masanori, 2015). These dental orthoses are synthesized using acrylic polymers and the patient’s dental impressions. This allows for the brace to be custom fitted to a particular patient’s oral cavity in order to maximize comfort and the effectiveness of the device. Mandibular applications are designed to attach securely to the upper teeth and advance the upper jaw by exploiting a projection in the orthosis which engages the mandibular incisors when the teeth are approximated (Clark & Masanori, 2015). The result is the development of an orifice within this projected region in which oral airflow is permitted and any obstructions of the nasopharynx are resolved or mitigated (Clark & Masanori, 2015).
The results of testing these removable anterior mandibular positioning (AMP) devices compared to the more conventional CPAP machine treatments yielded some astonishing results. In a study conducted with 23 male subjects who were all clinically confirmed to experience sleep apnea the apnea-hypopnea index (AHI), which is a measure of the severity of sleep apnea represented by the number of apnea and hypopnea events per hour of sleep, were tabulated using both CPAP and AMP treatments (Clark, 1996). Before either treatment was implemented, the subjects exhibited a mean AHI value which ranged from 33.86 ± 14.30. When using CPAP machines the mean AHI value decreased to 59.50% of the original value (Clark, 1996). Patients who were given the AMP treatment in this study also showed a markedly improved AHI value with decreases of 38.91% the control value (Clark, 1996). Similarly, oxygen saturation levels were measured in the control and both treatment methods. Untreated subjects experienced a mean oxygen saturation level of 84.30. Both CPAP and AMP treatments show significant improvements to oxygen saturation levels with the value advancing to 91.10 and 90.20 respectably (Clark, 1996). Based on these results, the researchers were able to conclude that both CPAP and AMP devices dramatically decreased apnea related episodes and also improved oxygen saturation levels (Clark, 1996). Interestingly enough, although the CPAP machine was able to provide superior physiological relief of patients’ symptoms the majority strongly preferred utilizing AMP devices (Clark, 1996). This phenomena likely results from the fact that the CPAP machine is very cumbersome and most patients experience great discomfort when using these devices. Ultimately, this study was able to conclude that AMP applications are indeed an effective, and seemingly preferred, treatment in patients with mild to moderate obstructive sleep apnea. However, the researchers acknowledged that CPAP machines may be currently indispensable in the treatment of severe recalcitrant cases of the disorder (Clark, 1996).
Advances in the field of dental research are of invaluable importance to practicing dentists as well as the healthcare sector at large. Continued research is ultimately at the heart of all scientific improvement and advances which equip healthcare professionals with the best tools to alieve patient’s symptoms while simultaneously maximizing their quality of life. Through the exploration of seemingly unconventional treatments for sleep apnea, and utilizing advances in dentistry, dental applications and oral orthoses may completely supplement uncomfortable CPAP machines in the near future. Although current AMP devices exist which can significantly mitigate the physiological symptoms of obstructive sleep apnea, further research will be needed to improve these devices in an effort to infallibly treat this disorder and completely supplant the conventional CPAP machines used today.
Clark, Glenn T, and Masanori Nakano. “Dental Appliances for the Treatment of Obstructive Sleep Apnea.” The Journal of the American Dental Association, Elsevier, 13 Jan. 2015, www.sciencedirect.com/science/article/pii/S000281778985024X.
Clark, Glenn T, et al. “A Crossover Study Comparing the Efficacy of Continuous Positive Airway Pressure With Anterior Mandibular Positioning Devices on Patients With Obstructive Sleep Apnea.” Http://Journal.chestnet.org, OFFICIAL PUBLICATION OF THE AMERICAN COLLEGE OF CHEST PHYSICIANS, 1996, journal.chestnet.org/article/S0012-3692(15)46230-0/abstract.
MAYO CLINC STAFF. “Sleep Apnea.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 9 Mar. 2018, www.mayoclinic.org/diseases-conditions/sleep-apnea/symptoms-causes/syc-20377631