we treat mild to low moderate apnea in our office with mandibular sleep devices. I mostly do mild apnea, but I'll make appliances for someone in the moderate range if they feel they can't wear the cpap at all, or want on for travel.
I think the story @Neo describes is important. those multiple episodes per hour are dangerous. look up an apnea video, and it's shocking to watch someone gasp for breath. the thought it everyone of those episodes pumps cortisol into your system, and those constant spikes are assumed to lead to heart attacks. this is why we hear stories about people dying in their sleep due to apnea. also as @Neo mentioned, looking for signs of grinding can help with the diagnosis. when you grind, you teeth have to meet. this means the mandible isn't resting passively on your airway, reducing the number of episodes.
i took some courses from a guy in florida about it. this dude has two practices where the only dentistry he does is sleep apnea.