We know there is a correlation between bruxism and sleep apnea, but how does the one contribute to the other?
It has been observed that a third of bruxism patients also suffer from sleep disorders like sleep apnea, restless legs syndrome, etc. Bruxism may be the effect or the cause of many types of sleep disorders including obstructive sleep apnea, snoring, daytime lethargy.
The effects of stress, anxiety and caffeine ingestion come into play here. Studies link high anxiety levels to bruxism, and the symptoms of sleep apnea itself may cause anxiety. Additionally, the daytime sleepiness caused by apnea may lead to high levels of caffeine consumption which, in turn, is linked to a high risk of bruxism. This is the vicious cycle.
The relationship between sleep bruxism and sleep apnea can be attributed to an arousal response. When an apnea event ends, various oral phenomena may occur: snoring, gasping, choking, grunting and teeth grinding. Immediately after the apnea episode, a physiological compensation occurs. The jaw will open and close, thus dilating the upper airway in order to facilitate normal breathing. The patient then pushes the tongue forward to move away from the air tract and forces it against the teeth.
Research has shown that increase of teeth grinding is directly proportional to the increase of frequency of apnea episodes.The results of these studies suggest that when sleep bruxism is related to apnea/hypopneas, the successful treatment of these breathing abnormalities may eliminate bruxism during sleep.