A Feedback-Controlled Mandibular Positioner Identifies Individuals With Sleep Apnea Who Will Respond to Oral Appliance Therapy

Abstract

Study objectives: Mandibular protruding oral appliances represent a potentially important therapy for obstructive sleep apnea (OSA). However, their clinical utility is limited by a less-than-ideal efficacy rate and uncertainty regarding an efficacious mandibular position, pointing to the need for a tool to assist in delivery of the therapy. The current study assesses the ability to prospectively identify therapeutic responders and determine an efficacious mandibular position.

Methods: Individuals (n = 202) with OSA participated in a blinded, 2-part investigation. A system for identifying therapeutic responders was developed in part 1 (n = 149); the predictive accuracy of this system was prospectively evaluated on a new population in part 2 (n = 53). Each participant underwent a 2-night, in-home feedback-controlled mandibular positioner (FCMP) test, followed by treatment with a custom oral appliance and an outcome study with the oral appliance in place. A machine learning classification system was trained to predict therapeutic outcome on data obtained from FCMP studies on part 1 participants. The accuracy of this trained system was then evaluated on part 2 participants by examining the agreement between prospectively predicted outcome and observed outcome. A predicted efficacious mandibular position was derived from each FCMP study.

Results: Predictive accuracy was as follows: sensitivity 85%; specificity 93%; positive predictive value 97%; and negative predictive value 72%. Of participants correctly predicted to respond to therapy, the predicted mandibular protrusive position proved efficacious in 86% of cases.

Conclusions: An unattended, in-home FCMP test prospectively identifies individuals with OSA who will respond to oral appliance therapy and provides an efficacious mandibular position.

Clinical trial registration: The trial that this study reports on is registered on www.clinicaltrials.gov, ID NCT03011762, study name: Feasibility and Predictive Accuracy of an In-Home Computer Controlled Mandibular Positioner in Identifying Favourable Candidates for Oral Appliance Therapy.

Keywords: home sleep test; obstructive sleep apnea; oral appliance therapy; predictive accuracy; sleep-disordered breathing.

© 2017 American Academy of Sleep Medicine

Figures

Figure 1. Feedback-controlled mandibular positioner device.

The feedback-controlled mandibular positioner device was composed of a laptop computer for signal processing, a pulse oximeter and nasal cannula to collect physiological parameters of oxygen saturation and airflow, and a mandibular positioner attached to temporary dental trays to move the mandible in response to respiratory events.

Figure 2. Classification error versus number of trees in the random forest.

Classification error is a prediction of the accuracy of the random forest when it is applied to a population other than the one it was trained on. Note that the error stabilizes at approximately 250 trees; 400 trees were used to optimize accuracy.

Figure 3. Study flowchart for parts 1 and 2.

Overview of participant recruitment, flow of study events, and study endpoints. FCMP = feedback-controlled mandibular positioner; OA = oral appliance; ODI = oxygen desaturation index.

Figure 4. Distribution of ODI and BMI for all study participants (n = 179).

Participants who experienced therapeutic success (outcome ODI 10 events/h) are represented by an open circle for part 1 or an open square for part 2. BMI = body mass index, ODI = oxygen desaturation index.

Figure 5. Baseline and outcome ODI for part 2 participants.

Participants predicted by feedback-controlled mandibular positioner automatic prediction to experience therapeutic success (outcome ODI 10 events/h) are shown in panel B. Of the 30 participants predicted to achieve therapeutic success, only 1 was a therapeutic failure. Of the 18 participants predicted to be therapeutic failures, 5 achieved therapeutic success. The horizontal dashed line depicts the border between therapeutic failure and therapeutic success. ODI = oxygen desaturation index.

Figure 6. Efficacious versus predicted target protrusive positions.

Positions are represented as a percent of full protrusion. Data points that fall on the diagonal line represent participants whose target protrusive position was efficacious. The dashed horizontal line depicts the median predicted efficacious protrusion (63%). The shaded area denotes participants with a correctly predicted target protrusion less than 70% who would have been overprotruded with a common titration protocol.