#3  THE ORAL MANIFESTATIONS OF OSA 

NOCTURNAL BRUXISM

The coincidence is very high between Obstructive Sleep Apnea  and grinding and bruxing while asleep.
Most of the sleep bruxism events happen when a subject is lying on his or her back.
Immediately after the apnea episode, when the ventilation process resumes, activation of the process of jaw-opening and closing begins. This is an involuntary effort to dilate the upper airway and reduce the resistance in order to ease normal breathing.  
This continuous, repeated process of empty-mouth mastication throughout a night of apnea events causes wear on the occlusal surfaces and incisal edges which is readily detected in a dental exam.  
There is a marked decrease of nocturnal bruxism when apnea/hypopnea episodes are completely eliminated.