What is the Connection between Bruxism and Sleep Apnea?
We know there is a correlation between bruxism and sleep apnea. But how does the one contribute to the other?
Systemic interdependence is demonstrated by the comorbidities of sleep apnea, which include acid reflux, high blood pressure and sleep bruxism.
Nocturnal bruxism is characterized by nighttime teeth grinding, gnashing or clenching. People with this condition unconsciously grind their teeth during sleep. Many are unaware of their problem. Bruxism can happen to any adult or child at any point in their lifetime. Some identified causes are a high level of stress or anxiety, excessive consumption of alcohol; caffeine; use of some types of antidepressants; smoking; abnormality in teeth alignment; effect of a condition like Parkinson’s, or it could be sourced back to earache or pain in another part of the body. Sleep disorders like sleep apnea and restless legs syndrome are found to be concurrent during teeth grinding. The clinical manifestations of bruxism are attrition or fractures of the incisal edges of anterior teeth, wear on the occlusal surfaces of posterior teeth and abfractions occuring on the facial sufaces at the cemento-enamel junction (CEJ).
Sleep Apnea Sleep apnea is a sleep disorder with potentially dangerous complications. It involves repeated stops and starts in breathing. People with this condition usually snore loudly during sleep and feel tired when they awake. There are two main types of sleep apnea: obstructive sleep apnea and central sleep apnea. OSA, the more common form, occurs when throat muscles relax during sleep. Central Sleep Apnea involves problems with brain signals that control breathing. Complex sleep apnea, a less common form, combines the two. Sleep apnea results from a narrow or blocked airway. The lapses in breath arouse the sleeper and reopen the airway. The process may repeat several times throughout the night even though most people do not remember awakening. Apnea events may occur many times during a night. The risk of OSA.may be increased by obesity, high blood pressure, medications, alcohol consumption and smoking.
Causal relationships 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 are in play. 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.
Treatment Options When bruxism is associated with OSA, certain therapies may treat both problems. CPAP (Continuous positive airway pressure) and OAT (Oral Appliance Therapy) will keep a sleeper’s airway open to allow for normal breathing. It has also been shown to decrease sleep bruxism. Mandibular Advancement Appliances (MMAs) have been seen to reduce events of bruxism by as much as 50 to 83%. Studies have reported that sleep bruxism rarely occurs in isolation. In a study in Israel of sleep bruxism and risk factors in the general population, it was found that among the associated sleep symptoms and disorders, obstructive sleep apnea (OSA) was the highest risk factor for tooth grinding during sleep. Two polysomnographic (PSG) recordings were carried out. The first showed 67 events of sounded tooth grinding, most of them appearing as an arousal response at the end of apnea/hypopnea events in both the supine and lateral postures. The results of this study suggest that when sleep bruxism is related to apnea/hypopneas, the successful treatment of these breathing abnormalities may eliminate bruxism during sleep.
Sleep apnea and sleep bruxism: how it all happens Most of the sleep bruxism events happen when a subject is lying on his or her back. This makes us believe that sleep bruxism could happen because of narrowing of airway or due to rise in the resistance from airways. Immediately after the apnea episode, when the ventilation process resumes, activation of the process of jaw-opening and closing begins which in turn dilates the upper airway and reduces the resistance in order to ease normal breathing. The patient tries to force the tongue to move away from the air tract and forces it against the teeth. In a study on nighttime bruxism in patients who are affected by sleep apnea as well, it was found that there was a marked decrease of apnea/hypopnea episodes as well as events of night bruxism were completely eliminated. Therefore, it can be concluded that if sleep bruxism is caused by sleep apnea then correcting the breathing irregularities can significantly improve or even eliminate sleep bruxism.
Research has revealed that increase of teeth grinding is directly proportional to the increase of frequency of apnea episodes. Since the link between arousals and bruxism during sleep is already established, it is fair to say that increase of nighttime bruxism is directly linked to arousals caused by sleep apnea. When an apnea event ends, various oral phenomena may occur: snoring, gasping, choking, grunting and teeth grinding.