The commentary, written by Joseph Russo, Vinita Vidya, and Robert Stansbury of West Virginia University’s Division of Pulmonary, Critical Care and Sleep Medicine, responds to a growing body of evidence suggesting that oral appliance adherence is far more complicated than a single nightly usage figure can capture. The authors center their argument on a one-year longitudinal pilot study by Zhang and colleagues that tracked both objective and subjective adherence in adults using mandibular advancement devices, and their conclusion is provocative: patients and clinicians often disagree about how much the device is being used, and neither number alone tells the full story of therapeutic benefit.

Obstructive sleep apnea affects hundreds of millions of people worldwide and is driven by the repeated collapse of the upper airway during sleep, fragmenting sleep, starving the body of oxygen, and raising the long-term risk of hypertension, cardiovascular disease, stroke, and daytime cognitive impairment. Oral appliances work by holding the lower jaw, and with it the tongue and surrounding soft tissues, in a forward position, mechanically propping open the pharyngeal airway. They are recommended by clinical practice guidelines, including the American Academy of Sleep Medicine’s 2015 update, as a first-line option for patients with mild to moderate apnea and for those with severe disease who cannot tolerate or decline CPAP.

The appeal of these devices is obvious. They are small, silent, portable, and free of the pressurized airflow that drives many patients away from CPAP. But that same convenience creates a measurement problem. A CPAP machine is, in effect, its own compliance monitor, logging pressure, flow, and mask-on time every night. A mandibular advancement device is a piece of molded acrylic and hardware that sits silently in the mouth, generating no data of its own unless it is fitted with embedded sensors. Historically, clinicians have therefore relied on what patients tell them, and self-report is notoriously unreliable in sleep medicine, with patients consistently overestimating how often and how long they use their devices.

The Zhang pilot study highlighted in the commentary tackled this gap by comparing objective adherence data with subjective patient reports over a full year of therapy, an unusually long follow-up window for this kind of device monitoring. The commentary’s authors use those findings to make a broader conceptual point: adherence to oral appliance therapy is not a single number but a multidimensional behavior. It includes how many nights per week the device is worn, how many hours per night, whether it is worn consistently across the entire sleep period or removed partway through the night, and whether the device’s titration, the gradual forward adjustment of the jaw, has actually been optimized to control the patient’s apnea.

That last dimension may be the most underappreciated. A patient can wear a mandibular advancement device faithfully every night for eight hours and still have untreated, or undertreated, sleep apnea if the jaw has not been advanced far enough to keep the airway open during rapid eye movement sleep, when muscles relax most completely and airway collapse is most likely. Conversely, a patient who wears the device fewer hours but at an effective titration position may derive more genuine protection. Hours per night, in other words, is a proxy for exposure, not for efficacy, and conflating the two risks mislabeling adherent-but-undertreated patients as successfully managed.

The timing of this rethinking is significant because the therapeutic landscape of obstructive sleep apnea is changing rapidly. The field has moved decisively toward precision or endophenotype-based approaches, as reflected in a 2025 American Thoracic Society research statement on translating apnea subtyping into clinical practice. Pharmaceutical options have arrived as well: the GLP-1 receptor agonist tirzepatide demonstrated meaningful reductions in apnea severity in obese patients in a landmark 2024 New England Journal of Medicine trial, and a combination therapy of aroxybutynin and atomoxetine, known as AD109, completed a randomized phase 3 trial targeting the neural control of upper airway tone. In a world of tailored, multimodal therapy, the commentary argues, a blunt nightly-hours metric for oral appliances looks increasingly anachronistic.

Technology is also converging on the problem. Digital dentistry workflows, including intraoral scanning and computer-aided design and fabrication of custom devices, have been shown in pilot studies to produce mandibular advancement devices with comparable or improved usability compared with conventional fabrication, and they open the door to embedded sensors that log temperature, movement, and wear time objectively. The commentary situates these developments within a broader vision of combination therapy, in which oral appliances are paired with positional therapy, weight management, pharmacotherapy, or even surgically fabricated hybrid devices, each component monitored on its own terms rather than collapsed into a single adherence statistic.

The clinical implications are concrete. If adherence is multidimensional, then follow-up visits should ask not only how often the device is in the mouth but whether the patient wakes refreshed, whether a bed partner still hears snoring, and whether objective testing shows the apnea hypopnea index actually falling into the treated range. Sleep physicians and dentists, who jointly manage most oral appliance patients, need shared frameworks for distinguishing a device that is worn but ineffective from one that is effective but inconsistently worn, because the interventions differ completely: the first calls for retitration or combination therapy, the second for adherence support and troubleshooting discomfort, dry mouth, dental changes, or temporomandibular symptoms that drive patients to quietly abandon the device.

What makes the commentary resonate beyond the sleep clinic is its challenge to a habit of measurement that extends across medicine. Adherence metrics are convenient because they are countable, but countable is not the same as meaningful. For the millions of patients who choose a mouthguard over a mask, the question that ultimately matters is not how many hours the device spent in the mouth but whether the airway stayed open, the oxygen stayed up, and the long-term health risks of untreated apnea actually receded. Reframing adherence around those outcomes, the authors suggest, is the necessary next step for a therapy whose popularity continues to grow while the way it is judged has barely evolved since the first practice parameters were written three decades ago.

Subject of Research: Redefining adherence measurement for oral appliance therapy in obstructive sleep apnea

Article Title: Beyond hours per night: rethinking oral appliance adherence in OSA

Article References: Russo, J., Vidya, V., & Stansbury, R. (2026). Beyond hours per night: rethinking oral appliance adherence in OSA. Journal of Clinical Sleep Medicine, 22(1), Article 196. https://doi.org/10.1007/s44470-026-00207-3

Image Credits: AI Generated

DOI: 10.1007/s44470-026-00207-3

Keywords: obstructive sleep apnea, oral appliance therapy, mandibular advancement device, adherence, CPAP, sleep medicine, titration, digital dentistry, tirzepatide, precision medicine, Journal of Clinical Sleep Medicine, Beyond

The clinical stakes are considerable. Obstructive sleep apnea affects hundreds of millions of people worldwide and is linked through sleep fragmentation and repeated drops in blood oxygen to cardiovascular disease, metabolic dysfunction, and daytime impairment. Continuous positive airway pressure, or CPAP, remains the gold standard treatment, but between 46 and 83 percent of patients fail to meet the conventional adherence benchmark of more than four hours of use per night. Oral appliances, particularly mandibular advancement devices, are recommended as a first-line option for mild to moderate disease and as an alternative for patients who cannot tolerate CPAP. Earlier studies suggested that patients wear these appliances roughly an hour longer per night than they use CPAP, but much of that evidence rested on self-reports, which are notoriously prone to overestimation.

The study’s technical approach was elegantly simple. The TheraMon sensor, embedded in the posterior buccal side of the mandibular arch tray, was programmed to log temperature readings between 33.5 and 39.5 degrees Celsius. Because the oral cavity sits within that range and room temperature does not, continuous readings within the window were interpreted as periods of actual device use. Participants were not explicitly told that nightly appliance use was being objectively monitored, nor were they informed of the details of the one-year follow-up plan, a deliberate design choice intended to preserve natural patterns of use. At baseline, each participant underwent overnight polysomnography, sleep questionnaires including the Epworth Sleepiness Scale and the Pittsburgh Sleep Quality Index, a five-factor personality assessment, and cone-beam computed tomography to characterize craniofacial morphology.

The therapy itself worked well when the device was actually worn. Mandibular advancement was initially set at 70 percent of each patient’s maximum protrusion and titrated in half-millimeter increments when needed, and the mean apnea-hypopnea index fell from 16.6 events per hour at baseline to 4.16 events per hour with the appliance in place. But the adherence data told a more complicated story. During the first three months, the median nightly use across all nights was just 3.85 hours, below the four-hour threshold used to define adequate adherence. When patients did wear the device, they wore it for a median of 7.05 hours, a full night of sleep. The problem was frequency: patients used the appliance on a median of only 3.7 days per week, and only 55.7 percent of nights met or exceeded the four-hour mark.

The comparison between objective and subjective measures revealed a specific and revealing pattern of bias. Participants were statistically accurate when reporting how long they wore the device on nights they used it, reporting a median of 7.0 hours against an objective 7.05 hours. But they significantly overestimated how often they used it, claiming a median of five days per week when sensors recorded 3.7 days, a difference that was highly significant. Bland-Altman analysis showed that self-reported nightly use across all nights exceeded objective values by a mean of 0.92 hours, and self-reported usage days exceeded objective records by an average of 1.41 days per week. The researchers attribute this to a combination of recall bias and what they describe as white coat adherence: a temporary uptick in device use shortly before scheduled clinic visits, which then dominated patients’ memories of their own behavior.

Even more striking was the divergence in trajectories between adherent and non-adherent users. Of the forty-three participants who completed the three-month follow-up, twenty-one, or 48.8 percent, met the adherence criterion. The adherent group wore the device a median of 6.23 hours per night across all nights and used it on roughly six days per week, with stable, sustained use throughout the observation period. Non-adherent users averaged just 2.38 hours per night on 2.32 days per week, and their weekly use fluctuated, declining when unsupervised and spiking before appointments. Notably, on the nights when both groups actually wore the appliance, the duration of use was statistically indistinguishable, at roughly seven hours. The difference between success and failure was not how long patients slept with the device, but whether they chose to put it in at all.

By the twelve-month follow-up, conducted by telephone with all forty-three completers, the split had hardened. Nineteen participants, or 44.2 percent, remained adherent, and their habits had become exemplary: a median of seven hours per night on seven nights per week. Most non-adherent users, by contrast, had effectively discontinued therapy, with median use of zero hours and zero days per week. Multivariate logistic regression identified two independent predictors of twelve-month adherence: older age, with each additional year raising the odds by about 7 percent, and a smaller mandibular plane angle measured relative to the Frankfort horizontal plane. Patients with hyperdivergent, steeply angled facial skeletons, a craniofacial type already known to be a risk factor for sleep apnea and to require greater mandibular advancement for efficacy, were significantly less likely to keep using the device.

The three-month picture had its own predictors. Older age again emerged as protective, alongside lower baseline Epworth Sleepiness Scale scores, with each point of sleepiness reducing the odds of adherence by roughly 26 percent. Spearman correlations showed that sleepiness scores were negatively associated with every objective adherence measure, including nightly use, weekly frequency, and the percentage of nights exceeding four hours. The authors speculate that patients with excessive daytime sleepiness may initially experience limited symptomatic improvement, only encountering positive feedback later as accumulated use eases their symptoms, and they suggest that greater mandibular advancement combined with enhanced early support might help this subgroup. Personality traits measured by the NEO-FFI, including conscientiousness and neuroticism, showed no significant association with adherence, indicating that behavior was shaped more by clinical and anatomical factors than by stable psychological disposition.

Several caveats frame the findings. Objective sensor data were collected only during the first three months, so the twelve-month comparison relied on self-report, the very measure shown to be unreliable. Side effects and discomfort were not systematically recorded, sleep diaries were not used, and the cohort consisted exclusively of Chinese patients with a mean age of about thirty-nine, limiting generalizability to other populations and to the very elderly. The authors also note that generally shorter sleep duration in the Chinese population may partly explain the relatively low nightly wear time, and that adherence to this particular appliance design should not be assumed to generalize to all oral appliances.

Even so, the study carries a clear practical message. Adherence behavior in oral appliance therapy, as in CPAP therapy, appears to be established early: patients who went on to succeed had already formed stable wearing habits within the first week of treatment. Because the low overall adherence in this cohort was driven primarily by infrequent use rather than short wear sessions, the authors recommend embedding reminders, whether through alarms, mobile applications, or email, into routine care, citing prior evidence that app-based monitoring significantly increases wearing days. They argue for long-term, objective, and individualized adherence monitoring as a standard component of oral appliance management, particularly if these devices are to deliver the cardiovascular benefits that have proven elusive in CPAP trials. For clinicians, the takeaway is that the first three months, and perhaps the first few weeks, offer a critical window to identify struggling patients and intervene before quiet abandonment of therapy becomes permanent.

Subject of Research: Objective versus subjective adherence to oral appliance therapy in adults with obstructive sleep apnea

Article Title: Objective and subjective adherence to oral appliance therapy in adults with obstructive sleep apnea: pilot data from a one-year longitudinal study

Article References: Zhang, W., Yu, M., Gong, X., Dang, W., & Gao, X. (2026). Objective and subjective adherence to oral appliance therapy in adults with obstructive sleep apnea: pilot data from a one-year longitudinal study. Journal of Clinical Sleep Medicine, 22(1), Article 115. https://doi.org/10.1007/s44470-026-00123-6

Image Credits: AI Generated

DOI: 10.1007/s44470-026-00123-6

Keywords: obstructive sleep apnea, oral appliance therapy, mandibular advancement device, adherence, thermal microsensor, objective monitoring, self-report bias, craniofacial morphology, Epworth Sleepiness Scale, CPAP, sleep medicine, longitudinal study

The letter, written by Nashmia Faraz, Haider Imran and Abdul Basit of the Department of Medicine at Foundation University Medical College in Islamabad, Pakistan, takes aim at the gap between objective and subjective measures of adherence in oral appliance therapy. Published in September 2026, the correspondence responds to emerging longitudinal evidence on how adults with obstructive sleep apnea actually use their appliances over a full year, and it argues that the field must refine how adherence is defined, measured and interpreted before the therapy’s real-world effectiveness can be judged fairly.

The concern is not academic hair-splitting. An oral appliance that sits in a drawer delivers no therapeutic benefit, no matter how well it was designed or how effectively it advanced the jaw in a laboratory titration study. Adherence is the hinge on which the entire treatment turns. For CPAP, this lesson was learned early and painfully: studies famously showed that early patterns of use in the first days and weeks strongly predicted long-term adherence, prompting sleep medicine to invest heavily in objective compliance monitoring, telehealth coaching and early intervention programs. Modern CPAP machines log every hour of use, and those data streams are now woven into routine care. Oral appliance therapy, by contrast, has largely depended on what patients report at follow-up visits.

Self-report is a notoriously fragile foundation for clinical decisions. Patients may genuinely believe they wear their devices more than they do, because nights of fragmented sleep blur memory and because social desirability nudges people toward the answers they think their clinicians want to hear. The literature cited in the letter makes the scale of the discrepancy unmistakable. A landmark 2013 study published in Chest by Dieltjens and colleagues compared objectively measured compliance, captured by embedded microsensors, with self-reported compliance among patients using mandibular advancement devices for sleep-disordered breathing. The objective data revealed substantially lower usage than patients reported, exposing a gap large enough to distort outcome studies, cost-effectiveness analyses and clinical audit alike.

Embedded microsensors have since become the technical benchmark for objective adherence measurement in oral appliance therapy. These tiny temperature-sensitive chips sit inside the appliance and register when the device is actually in the mouth, distinguishing genuine use from mere possession. When the appliance is inserted, oral temperature triggers the sensor; when it rests on a bedside table, no temperature change is recorded. The approach mirrors the objective compliance chips that transformed CPAP monitoring, and it offers sleep medicine something it has long lacked for dental devices: a truthful, time-stamped record of real-world use patterns, including how many nights per week the appliance is worn and for how many hours per night.

The new longitudinal pilot data that prompted the letter tracked both objective and subjective adherence in adults with obstructive sleep apnea over one year, providing a rare window into how usage evolves well beyond the initial adaptation period. The corresponding letter argues that such data should push the field toward a more nuanced adherence framework, one that distinguishes between objective device use, patient-perceived use and clinical response, rather than collapsing them into a single self-reported figure. The authors, who conceptualized and drafted the correspondence with no external funding and no competing interests, position their contribution as a call to tighten the methodological standards of oral appliance research.

Why does this refinement matter now? Oral appliance therapy is expanding rapidly. Clinical guidelines recommend it for patients with mild to moderate obstructive sleep apnea and for those with severe disease who cannot tolerate or decline CPAP. Dental sleep medicine has grown into a distinct subspecialty, and the global market for mandibular advancement devices continues to climb as obesity rates and disease prevalence rise. Every prescription implicitly assumes that the device will be worn consistently. If adherence measurement lags behind prescription volume, the field risks both overtreatment, with devices dispensed to patients who will never use them, and undertreatment, with genuine adherence problems overlooked until symptoms return or cardiovascular risk quietly accumulates.

The letter also draws an instructive parallel with the CPAP literature, including the 2007 study by Budhiraja and colleagues in the journal Sleep demonstrating that early CPAP use identified subsequent long-term adherence. That finding reshaped clinical practice, motivating early follow-up and, eventually, remote monitoring programs that flag struggling patients within days. For oral appliances, the analogous evidence base is younger and thinner, but studies such as the 2022 investigation by Kwon and colleagues in the Journal of Sleep Research show that remote monitoring and structured feedback can measurably improve objective compliance with mandibular advancement devices. Together, these strands of evidence suggest that objective adherence measurement is not merely a research nicety; it is the enabling technology for the same kind of proactive, data-driven care that rescued CPAP adherence a generation ago.

The technical challenges, however, are real. Microsensor data must be validated against true wear events, sensors can fail or be damaged during cleaning, and different sensor generations may not produce comparable metrics. The field lacks universally accepted adherence thresholds for oral appliances, whereas CPAP benefited from widely used conventions such as the Medicare definition of four hours per night on seventy percent of nights, itself a contested standard. Without consensus definitions, meta-analyses of appliance effectiveness will continue to mix studies whose adherence figures mean different things, blurring genuine differences in therapeutic efficacy with differences in measurement practice. The authors of the letter imply that resolving this definitional tangle is a prerequisite for the next generation of oral appliance research.

What would refined adherence assessment look like in practice? The ingredients are already on the table: objective sensor-derived metrics reporting nights and hours of use, patient-reported measures captured with validated questionnaires, and clinical outcomes such as the apnea-hypopnea index on follow-up polysomnography or home testing. Longitudinal designs, like the one-year pilot study that sparked the correspondence, add the crucial temporal dimension, revealing whether adherence decays over months and which patients are at greatest risk of abandoning therapy. Integrating these data streams into electronic health records and telemedicine platforms could finally give dental sleep medicine the feedback loops that clinicians need, allowing early, targeted interventions before non-adherence becomes entrenched. As oral appliance therapy takes its place alongside CPAP in mainstream sleep medicine, the message from Islamabad is clear: the therapy can only be as good as the evidence that patients are actually using it, and measuring that use honestly is the field’s next essential task.

Subject of Research: Objective versus subjective adherence assessment in oral appliance therapy for obstructive sleep apnea

Article Title: Refining adherence assessment in oral appliance therapy for obstructive sleep apnea

Article References: Faraz, N., Imran, H., & Basit, A. (2026). Refining adherence assessment in oral appliance therapy for obstructive sleep apnea. Journal of Clinical Sleep Medicine, 22(1), Article 158. https://doi.org/10.1007/s44470-026-00176-7

Image Credits: AI Generated

DOI: 10.1007/s44470-026-00176-7

Keywords: obstructive sleep apnea, oral appliance therapy, mandibular advancement device, adherence measurement, microsensors, CPAP, sleep medicine, self-reported compliance, remote monitoring, dental sleep medicine, Journal of Clinical Sleep Medicine, Refining