A research review suggests that patients with sleep apnea who are tired during the day because they can’t wear a CPAP mask all night to keep their airways open may be able to reduce daytime sleepiness by using a dental device instead, Reuters reports.

“Most doctors still consider CPAP as first-line treatment for patients with obstructive sleep apnea,” Kohler said by email. “If a patient cannot really use CPAP adequately e.g. only two to three hours per night, but does fine with a MAD which he can tolerate for seven hours a night, then he should be treated with a MAD.”