Australian Study Brings Dentists “One Step Closer” to Individualizing OSA Therapy

A study led by Monash University’s Bradley Edwards produced encouraging results for dentists and other sleep medicine practitioners who wish to better predict the efficacy of oral appliances for obstructive sleep apnea.

By Tariq Kamal

Patients who suffer from obstructive sleep apnea but cannot tolerate continuous positive airway pressure (CPAP) therapy are often fitted for oral appliances (OAs). But predicting success is difficult, and this represents an “important clinical barrier” to predicting which patients will respond to OA therapy, according to Bradley Edwards, PhD, who led a team of researchers that produced what could prove to be a groundbreaking study.

“What our research shows is that we think we can a priori pick who is likely to have their OSA resolved based upon their underlying physiology,” says Edwards, who serves as laboratory head for the sleep and sleep disorders department at Monash University in Melbourne, Australia, to Dental Sleep Corner. “Thus, if we were able to provide this physiological prediction to the clinician, they can better counsel their patients as to what to expect from an oral appliance and what the best therapeutic option may be for them.”

Edwards and his team recruited 14 patients who had a documented apnea hypopnea index (AHI) of greater than 10 events per hour and whose dentists had fitted them with an oral appliance. Each subject checked themselves in for two clinical sleep studies, one with their appliance in place and one without.

Bradley Edwards, PhD

The results, which were published in the May 15 issue of the American Journal of Respiratory and Critical Care Medicine, were definitive: Having the appliances in place reduced the average AHI from 30 (±5) to 11 (±2) events per hour, and no changes in muscle function, loop gain, or arousal threshold were detected. Edwards says his research team anticipated the OAs might improve upper airway function by, for example, reducing the mechanical load and allowing those muscles to more efficiently reopen the airway in response to elevations in respiratory drive, but the data proved otherwise.

While noting that he would like to see future studies conducted with larger groups of “treatment-naïve” OSA sufferers, Edwards is confident the Monash study represents an important first step toward more accurately identifying patients who likely will (or will not) benefit from oral appliance therapy.

“The major clinical application of our work is that it provides support for the concept that measuring the pathophysiology causing OSA is critical in understanding who will respond to certain non-CPAP treatments, thus our findings now take clinicians one step closer to individualizing therapy for patients with OSA,” Edwards says.