One of the most persistent dental headlines throughout the pandemic has been how dentists have seen an increase of tooth grinding due to stress – one of the most common causes of daytime bruxing. (“Bruxism” is the clinical term for habitual clenching and grinding.) It can cause nighttime bruxing, too, although it’s not the only cause. Some evidence, for instance, suggests that it may be a symptom of sleep apnea.
Regardless of when it happens, it’s hardly a harmless habit. It wears down irreplaceable tooth enamel. It can even chip or crack your teeth. It can encourage gum recession and raise your risk of gum disease. The extra pressure can lead to TMJ problems and the associated head, face, jaw, and neck pain.
More, as the American Sleep Association notes,
Sleep bruxism can disrupt the natural sleep cycle. This can result in not only reduced total sleep, but also in sleep that occurs for the same amount of time but does not provide as much actual rest. Less time spent in the deeper stages of sleep leaves a sleeper feeling unrested, even if a healthy amount of time is spent sleeping.
A night guard is the usual go-to solution – an oral appliance that resembles the mouth guards worn by athletes to protect their teeth. Similarly, this device serves mainly to protect the teeth and jaws from bruxing’s wear and tear.
And that brings us to a recent study which looked at the possibility of a relationship between vitamin D levels and bruxing. As its authors note, some evidence suggests that D may play a key role in brainstem control during sleep and thus may play a role in sleep disorders, including nighttime bruxism.
One hundred adults aged 40 and under took part in the study. First, they completed surveys to gauge whether they bruxed and, if so, the severity of their condition. Most reported bruxing to some degree while about one-quarter did not. Blood samples were then drawn from each participant so their 25-hydroxyvitamin D levels could be checked. (This is the metabolized form of vitamin D.)
Forty-three percent of all patients had vitamin D deficiency (lower than 20 ng/ml). Low D levels were found to be particularly common for those reporting moderate to severe bruxism. In fact, all but roughly 9% of those deficient in D were bruxers. And of those whose D levels were considered “insufficient,” about two-thirds reported bruxing.
While noting the limitations of their study – for instance, its reliance on self-reporting – the authors thus concluded that “25(OH) D concentrations have a possible association with bruxism level variation.”
Notably, these results are in line with those of a study published last year in BMC Oral Health. Not only was vitamin D deficiency linked with bruxing but also low calcium consumption and frequent headaches. Anxiety and depression were also considered as possible factors.
These findings suggest that anxiety, depression, vitamin D deficiency, low level of dietary calcium intake, and frequent headache could be involved in the development of sleep bruxism. So, Chi-squared testing was conducted to check association between sleep bruxism and categories of anxiety, depression, calcium intake, vitamin D, and headache. Results revealed significant association between sleep bruxism and vitamin D deficiency, low dietary calcium intake, abnormal HADS-anxiety and depression categories, and frequent headache. However, further regression analysis revealed that sleep bruxism was significantly associated with vitamin D deficiency and insufficiency, low dietary calcium, and frequent headache but it was not associated with anxiety or depression.
As ever, it’s important to note that such studies only show that an association between D deficiency and bruxing exists. They don’t prove that one condition causes another. Different types of studies must be done to prove or disprove that.
Still, they point researchers in a fascinating direction.