An association between temporomandibular disorder and gum chewing.

This single center, randomized, small study sought to investigate the prevalence and frequency of chewing gum consumption, and whether there is a relationship between these factors and the presence of symptoms associated with temporomandibular disorder (TMD). Subjects were divided into 7 groups based on their parafunctional oral habits. Of these, subjects who chewed gum were divided into 5 subgroups (A-E) based on their gum chewing habits. Group A chewed gum <1 hour/day (n = 12), Group B chewed gum 1-2 hours/day (n = 11), Group C chewed gum 3 hours/day (n = 6), and Group D chewed gum >3 hours at a time (n = 8); the frequency of gum chewing in Groups A-D was once a week. Group E subjects chewed gum 1-3 times/week for at least 1 hour each occurrence (n = 2). Sixty-three percent of the subjects in Group D reported TMD symptoms of arthralgia and myofascial pain. Thirty-three percent of the subjects in Group C showed symptoms of arthralgia. Eighty-three percent of the subjects in Group A and 27% in Group B reported myofascial pain. All subjects in Group E reported masseter hypertrophy. The remaining 2 groups were Group F, subjects that didn't chew gum but had other parafunctional oral habits (n = 2), and Group G, subjects who didn't have parafunctional oral habits (n = 12).