0751 The use of a Digitally Milled Oral Appliance in the Treatment of Severe Obstructive Sleep Apnea
Authors: Murphy Mark , Remmers John , Mosca Erin 
Published: May 2022

Abstract

Introduction
Oral appliances (OAs) that advance the mandible are commonly used for the treatment of mild to moderate obstructive sleep apnea (OSA) but are less accepted as a therapy for severe OSA, likely due to their supposed lower rate of therapeutic success in that population. However, the preference for OAT over CPAP and relative lack of other non-surgical treatment options highlights the need for acceptance of OAT for all severities of OSA. Data from two prospective studies that collected data on OAT efficacy were analyzed retrospectively to evaluate the success rate of OAT in severe OSA using a digitally milled OA.

Methods
Data from the severe OSA cohorts of two studies conducted for the validation of an in-home auto-titration test were evaluated. Study participants (n = 41 with severe OSA) received a precision iterative advancement OA (ProSomnus Sleep Technologies, Pleasanton, CA). The OAs used in the studies were CAD/CAM generated from digital intraoral scans and precision milled from control cured grade PMMA. The OAs consisted of sets of upper and lower trays that, when interfaced together, allowed for advancement of the mandible to a treated position. Oral appliances were set to the target protrusion provided by an in-home auto-titration test that predicts response to OAT (MATRx plus; Zephyr Sleep Technologies, Calgary, Alberta, Canada). Participants not predicted to respond to OAT were assigned a sham mandibular protrusion. Oral appliance therapy was initiated at the target protrusive position, sham position, or highest tolerated position for individuals who were unable to have their OA inserted at target. Once participants were habituated to OAT, a 2-night home sleep apnea test (HSAT) was conducted to assess treatment efficaciousness, and the mandible was advanced as necessary to lower the respiratory event index (REI).

Results
The study population included 36 male and 5 female participants with a mean age of 50.6 ± 8.4 years (range: 32-74 years), mean BMI of 32.1 ± 5.5 kg/m2 (range: 19.8-45.4 kg/m2), mean baseline REI of 49.5 ± 17.1 h-1 (range: 30.3-101.8 h-1), and median Epworth Sleepiness Scale (ESS) score of 10 (range: 0-23). Oral appliance therapy was well-tolerated in the study population. The majority of study participants achieved some level of therapeutic success, with 73.2% of participants achieving a decrease in REI from baseline of at least 50% and 68.3% achieving an REI &lt; 15 h-1. Of the study participants who achieved an REI &lt; 15 h-1, the average protrusive position of the OA was 86.7±15.3% (range: 54.8-100%).

Conclusion
The OAs used in the studies provided efficacious treatment for the majority of individuals with severe OSA, indicating that oral appliance therapy could be a suitable alternative to CPAP. The rate of therapeutic success was higher than that reported previously in the literature and might be a result of the precision of appliances generated from digital intraoral scans using a CAD/CAM approach.

Support (If Any)
Study data were collected by and used with the permission of Zephyr Sleep Technologies. ProSomnus Sleep Technologies provided the OAs used in the studies.