Is Sleep Bruxism a Disorder, a Risk Factor for Disorder, or a Behavior?

Objectives: To critically examine possible inferences about the health-related consequences of sleep bruxism, driven by the 2013 international consensus criteria on defining and grading of bruxism
Methods: This presentation outlines three alternate views of sleep bruxism (SB) as: (1) a common behavior, varying in frequency in the population, (2) a risk factor for oral health problems, increasing likelihood of an individual developing an oral health disorder when it occurs, and (3) a disorder itself, associated consistently with both harm and internal-dysfunction (known or inferred physiological dysfunction). Criteria for each alternative will be presented and evaluated with respect to existing data.

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Results: Studies supporting the role of SB as a risk factor for oral health outcomes are mainly based on less reliable assessment methods and are not replicated the by state-of-the-art polysomnography studies.

SB, as defined in 2013, is a behavior that is presumably common. Given poor correspondence between self-report, clinical evaluation, and polysomographic evidence of SB, strong evidence to date evaluating SB as a risk factor for oral health problems is limited. Polysomnographic studies rarely find risk of oral disease associated with documented SB. Whether it is a clinically useful risk factor worthy of routine evaluation in clinical settings depends on ease of accurate evaluation and degree and consistency of risk associated with oral health outcomes. Because of failure to establish associated harm, SB does not meet disorder criteria using 'disorder' standards requiring both harm to the individual and internal-dysfunction.
Conclusions: Based on gold standard polysomnographic studies measuring SB using standardized criteria, SB does not meet criteria as a clinically useful risk factor and therefore does not rise to consideration as a disorder itself.

Further research may elucidate conditions under which well-measured sleep bruxism, possibly interacting with other factors, may lead to a clear increased risk of oral health problems