Teeth contacting habit as a contributing factor to chronic pain in patients with temporomandibular disorders.

Many different factors are known to cause and perpetuate the symptoms of temporomandibular disorders (TMD). However, the roles of parafunctional factors have not been clearly elucidated. We found one of these habits in the clinical setting. This parafunctional habit involves daily light touching of the upper and lower teeth, when the mouth is closed. We named this habit Teeth Contacting Habit (TCH). [OBJECTIVES] To investigate the following hypotheses: 1) TCH is associated with perpetuation of chronic pain of TMD patients; 2) TCH is associated with other behavioral factors. [METHODS] Two hundred and twenty-nine TMD outpatients with chronic pain were analyzed with multivariate logistic regression models. [RESULTS] TCH was found in 52.4% of patients. Patients with TCH and pain lasting for more than four months were less likely to experience improvements in pain at the first visit (OR = 1.944, p = 0.043). Other factors associated with TCH were as follows: unilateral chewing (OR = 2.802) and involvement in a precision job (OR = 2.195). [CONCLUSION] TCH can prolong TMD pain and is associated with other behavioral factors.

Difficulty of food intake in patients with temporomandibular disorders.

PURPOSE: Although patients with temporomandibular disorders (TMD) often report impaired eating, the features of food intake difficulty have rarely been estimated. This study compared subjective difficulty in 4 categories of food intake situations among 3 subgroups of TMD patients. MATERIALS AND METHODS: A total of 511 TMD patients (402 women, 109 men, mean age 36.4 +/- 15.4, range 12 to 82) participated in this study. Subjects were divided into 3 TMD subgroups: myofascial pain (MFP), disc displacement with/without reduction (DD), and arthralgia or osteoarthritis (Arth). Patients' level of food intake difficulty was assessed using a visual analogue scale (VAS) for 4 categories of food intake situations: difficulty in putting food into mouth (PUT), difficulty in biting off foods (BIT), difficulty in grinding down foods (GRD), and overall difficulty in consuming a meal (OAL). RESULTS: Nearly all patients (98.6%) exhibited food intake difficulty in at least 1 category. In the category of PUT, the DD group exhibited significantly more difficulty than the MFP and Arth groups (P < .048), and the Arth group had a higher VAS score than the MFP group (P = .030). With regard to BIT and GRD, there was no significant difference among the TMD subgroups. In OAL, the DD group showed more difficulty than the MFP group (P = .046). CONCLUSION: TMD patients experienced impaired food intake ability. In particular, the DD group experienced more difficulty than the MFP group. Concerns about types of food and food intake behavior for each TMD subtype should be taken into account in the management of TMD patients.