Bruxism unaccompanied by mandibular movements."A movement disorder of the masticatory system characterized by teeth-grinding and clenching during sleep as well as wakefulness." "Non-functional contact of the mandibular and maxillary teeth resulting in clenching or tooth grinding due to repetitive, unconscious contraction of the masseter and temporalis muscles." "Parafunctional grinding of teeth or an oral habit consisting of involuntary rhythmic or spasmodic non-functional gnashing, grinding or clenching of teeth in other than chewing movements of the mandible which may lead to occlusal trauma." "Periodic repetitive clenching or rhythmic forceful grinding of the teeth." Bruxism can be subdivided into two types based upon
Bruxism over 50% of normal infants. Often sleep bruxism develops during adolescence, and the prevalence in 18- to 29-year-olds is about 13%. The overall prevalence in adults is reported to be 8%, and people over the age of 60 are less likely to be affected, with the prevalence dropping to about 3% in this group. A 2013 systematic review of the epidemiologic reports of bruxism concluded a prevalence of about 22.1–31% for awake bruxism, 9.7–15.9% for sleep bruxism, and an overall prevalence of about 8–31.4% of bruxism generally. The review also concluded that overall, bruxism affects males and females equally, and