One of the things that really keyed us into the fact that airway and breathing disorders are very significant is that we began to see some things from studies that were done overnight that showed that it's very common for patients that have, let's say, sleep apnea, to have an apneic event, and at the end of that event, to have a bruxism episode.
The lack of oxygen causes a 'fight or flight' response, which causes tension
And so the thought now is that whether it's at the end of an apneic event or before an apneic event or just through struggling breathing in those that have upper airway resistance syndrome without sleep apnea, that there is a change dynamically in the system during sleep that affects the tension in the whole system.
And we now believe that that is a turn-on of the sympathetic response, that fight or flight response that says, "We're not getting enough oxygen. We're choking to death here. We've got an emergency." We begin to release cortisol and stress hormones from the adrenal glands. That rushes through the blood stream, speeds up the heart rate trying to pump blood and oxygen throughout the body. But with that, it also creates that fight or flight response throughout the whole body, which can create tension or stress in the body.
This tension is in the masticatory and causes the patient to brux, to move the mandible out of the airway
There are a few possibilities:
- Clenching and bruxism are related to that sympathetic turn-on and the extra stress that it creates that could create, also, a tension in the masticatory muscles
- If it's also part of a corrective mechanism, that is the airway is blocked, so we're going to clench to raise the hyoid bone and open the airway or we're going to brux to move the mandible out of the airway along with the tongue and open up the airway
But we know that there's a significant relationship between bruxism, and clenching, and airway problems, and oxygen desaturation, and even lowering of pH in the esophagus which can go along with gastric reflux, which often goes along with sleep apnea. So these are things that we're learning about the systemic effects of what's going on in the body that can also produce dental effects that we're all familiar with, but we haven't always been very familiar with why they occur.
Learn more about the correlation between bruxism and airway disorders at our International Airway Symposium