Often during sleep disorders when breathing stops, the brain signals to the muscles of the face and throat to contract. This causes the jaw to move forward creating a more open airway space. Unfortunately this also triggers the muscles to initiate clenching  and bruxing. Since reflux is also a side effect of sleep apnea, stomach acid is forced  up into the oral and nasal cavities. Irritating the throat and over time can cause esophageal cancer. The acid also erodes the teeth accelerating enamel destruction thru abfriction during bruxism. Since most sleep disordered breathing is thru the mouth, the nasal membranes become dry and irritated by the acid as well.