Precision Oral Appliance Therapy

The New Paradigm in Physician Acceptance of Oral Appliance Therapy in the Treatment of Obstruction Sleep Apnea

by Edward T. Sall, MD, DDS, MBA

In 1981, a landmark paper by Sullivan et al. reported on 5 patients treated with a nasal mask that eliminated their obstructive sleep apnea. Since that time, multiple mask interfaces have been introduced in an attempt to allow physicians to customize the mask interface to the patient’s anatomy and improve patient compliance or adherence. CPAP, stamped and branded as the “gold standard” in the treatment of Obstructive Sleep Apnea, remains the bar by which all of the other treatments are compared.

Although the standard of care for the treatment of OSA is the highly efficacious CPAP, the real-world long-term health effects of CPAP are compromised by low compliance and suboptimal hours of treatment.  Compliance has been defined as greater than 4 hours of use of CPAP over 7-10 days. This arbitrary definition is not evidence based and fails to take into account the sleep time off treatment. In fact, according to this definition, a patient only has to use CPAP 86/hrs. per month or 35% of the total sleep time to be considered adherent. Weaver et al. (2007) showed that normalization of subjective sleepiness (ESS), objective sleepiness (as tested by the MSLT), and disease specific functional status (as measured by the functional outcomes of sleep questionnaire [FOSQ]) requires 4, 6, and 7.5 hours, respectively, of nightly CPAP usage.

Sleep physicians often continue to recommend CPAP over Oral Appliance Therapy for all levels of severity of OSA because of the highly efficacious nature of CPAP without critically accounting for the poor compliance. Sutherland K. et al. (2015) have stressed that “Efficacy” must be differentiated from ”Effectiveness” and introduced the term Sleep Adjusted Residual AHI (Sarah Index) to critically assess the “effectiveness” of treatment as it properly accounts for compliance. That being said, Oral Appliance Therapy may be as equally effective as CPAP when compliance is factored into the equation. Boyd et al. (2016) introduced the term Effective AHI as a new measure of the effectiveness of PAP therapy as it accounts for sleep disordered- breathing events during the time PAP is (PAP on) and is not (PAP off) being used.

Rotenberg et al. (2016) reported that there was no clinical improvement in CPAP adherence in recent years despite efforts toward behavioral intervention and patient coaching. He concluded that these findings (20 years of data collection) calls into question the concept of CPAP as the “gold standard” of therapy for OSA. Despite these findings, sleep physicians still have reservations about referring patients for Oral Appliance Therapy. An online survey of sleep physicians was reported in Sleep Review in 2016 to poll the participants as to the top reasons for not referring patients to a dentist for OAT. They were as follows:

1. “I want to try other strategies to get the patient CPAP adherent.”
2. “The patient won’t be able to afford an appliance.”
3. “The oral appliance may not be effi”
4. “The oral appliance won’t record the patient’s adherence with the therapy.”
5. “The patient may develop side effects from using the oral appliance.”
6. “I worry dentists are acting outside the scope of practice in all or part when treating OSA.”
7. “Patients disappear when I refer them to a dentist.”
8. “I don’t know a local dentist who I trust with my patients.”

The fundamental issue that all dentists delivering Oral Appliance Therapy for the treatment of patients with OSA is how to move the needle for more physician acceptance of that paradigm. Clearly, physicians have reservations about the efficacy, predictability, adherence monitoring, and side effects of OAT which prevents them from embracing this form of treatment. By addressing the primary concerns of physicians, we should be able to dramatically increase acceptance of Oral Appliance Therapy.

In the field of Dental Sleep Medicine, before the advent of precision medical devices for the treatment of OSA, most of the available custom oral appliances had similar efficacy. It was often reported, in general terms, that over a third of patients will show a complete response to oral appliance therapy with a reduction in AHI to <5/hr (or no OSA).  Another third will have a clinically important response showing >50% reduction in AHI, although AHI remains >5/hr, and a third will not achieve >50% reduction in AHI. These traditional results have made physicians reluctant to refer patients for OAT because they feel it is too difficult to predict how one will respond to this treatment. The irony of this resistance is that sleep physicians often neglect concepts of the SARAH Index and Effective AHI in prescribing the “gold standard” of CPAP. Additionally, the FDA approved implantation of the neurostimulation devices (Inspire) with “the surgical success” criteria of <50% reduction of the AHI and an AHI <20/hr. When viewed in this context, OAT may be more effective than the Inspire at a fraction of the cost.

For many years, oral appliance design and performance have remained stagnant. At that time, choosing a device was far more about patient preference, comfort, ease of delivery and use. The initial price of the device along with the full cost of repair, remakes, and chair time influenced the selection of the appliance by the sleep dentist. While these factors may have been important in the economics of a sleep dentistry practice, they are not the concerns of the sleep physicians. The sleep physicians remain concerned about efficacy, predictability, adherence, and absence of side effects.

The root cause issue is that traditional oral appliances are not particularly consistent at satisfying their stated mechanisms of action.  Medical guidelines (AASM and AADSM) have established that the mechanisms of action of oral appliances are to reposition and stabilize the mandible to achieve and maintain airway patency. Laboratory testing has demonstrated that traditional oral appliances can express up to 6mm of variance to the prescribed mandibular position. Furthermore, engineering testing has demonstrated that traditional or ”legacy” oral appliance designs feature titration mechanisms like straps, hinges, herbst attachment arms, and angled posts that can express up to 5mm of additional variance when attempting to stabilize the mandible. Clearly, inconsistent efficacy is the consequence of these variances, among other factors including compliance, side effects, and durability.

AI design and robotic manufacturing have created a new class of Oral Appliances. They have resulted in Precision Oral Appliances (ProSomnus Sleep Technologies, Inc.) that offer 26% better efficacy than the older “legacy oral appliances” and have been found to have an objectively measured adherence (via compliance monitoring) of 90%. The accuracy of bite transfer, smaller profile (allowing for more space for the tongue), the minimization of side effects, the ability to maintain the prescribed bite position, and lack of biogunk have all contributed to this increased efficacy and objectively measured adherence. Taking all this into account, Precision Oral Appliance Therapy may be comparable or better than CPAP or Hypoglossal Nerve Stimulation in effectiveness for patients with mild, moderate, and even severe OSA.

Obstructive Sleep Apnea is a global epidemic, and in 2019 in the Lancent article, the WHO and ATS estimated the global prevalence of OSA at 1 billion people. As we know, 80-85% of the people remain undiagnosed of their disease. While OSA has multiple phenotypes, it should be clear that there is poor support of the notion that CPAP is the “gold standard” for therapy. Moving the needle for physician acceptance of Oral Appliances for the treatment of OSA requires an individualized approach to therapy. Utilizing Precision Oral Appliance Therapy (ultimately with compliance monitoring) will become the new paradigm for physician acceptance. It is in the best interest of their patients that dental sleep specialists choose the most precise and most researched appliance available. Increasing the predictability of the results, minimizing the incidence of side effects, and monitoring adherence will increase the acceptance by your referring physicians.

Inspire spent over 100 million dollars in marketing for HNS in 2022 and plans to increase that to 200 million in 2023. That amount of marketing dollars has created unprecedented awareness of an alternative treatment to CPAP. That being said, roughly only 10% of those patients that seek a consultation for HNS actually have the surgery.  The message is very clear; patients want alternatives to CPAP because it isn’t the “gold standard”. Oral Appliance Therapy suffers from an awareness issue as many patients simply don’t know the option exists. The introduction of this new class of Oral Appliances has the potential to change the perception and acceptance of Oral Appliances as the preferred form of therapy for the majority of patients with OSA.