Teeth grinding or bruxism is an oral condition where patients clench, gnash or grind their teeth. Bruxism can be experienced day and night but interestingly, each has their own set of causes or etiology that requires different treatment protocols and management.
Daytime or ‘awake’ bruxism is usually caused by psychosocial factors leading to stress and anxiety in daily life. On the other hand, night or ‘sleep’ bruxism may be triggered by obstructive sleep apnea. That’s because at night, the activity of the oral masticatory muscles is limited to maintaining proper breathing when your body is in sleep mode.
What is obstructive sleep apnea?
Obstructive sleep apnea is a breathing problem that occurs when throat muscles relax too much during sleep. This causes your airway to narrow to the degree where blood oxygen levels can drop along with a build-up of CO². Your subconscious brain recognises and corrects these levels by rousing you from your sleep temporarily, so you can take in some deeper breaths. This action can be accompanied by sudden choking, snorting, snoring or gasping. If your airway gets obstructed continuously, this sleeping / breathing pattern can repeat itself many times an hour all night long.
How does sleep apnea cause tooth grinding?
Researchers have determined a few factors that contribute to teeth grinding while you sleep. One factor is that airway instability and low blood oxygen levels cause the subconscious brain to signal your jaw muscles to tighten. This in turn stiffens the sides of your throat – enabling you to breathe better without interruption. However, along with this ongoing jaw action is continuous clenching and grinding of your teeth, which can lead to severe tooth wear.
Other theories link gastroesophageal reflux disease (GERD), another sleep-related condition, to bruxism.