Impaired jaw function and eating difficulties in whiplash-associated disorders

Eating requires mouth opening, biting, chewing and swallowing and should be performed without dysfunction or pain. Previous studies have shown that jaw opening-closing movements are the result of coordinated activation of both jaw and neck muscles, with simultaneous movements in the temporomandibular, atlanto-occipital and cervical spine joints. Consequently, it can be assumed that pain or dysfunction in any of the three joint systems involved could impair jaw activities. In fact, recent findings support this hypothesis by showing an association between neck injury and reduced amplitudes, speed and coordination of integrated jaw-neck movements. This study investigated the possible association between neck injury and disturbed eating behaviour. Fifty Whiplash-associated disorders (WAD) patients with pain and dysfunction in thejaw-face region and 50 healthy age- and sex-matched controls without any history of neck injury participated in the study. All participants were assessed by a questionnaire, which contained 26 items about eating behaviour, jaw pain and dysfunction. For the WAD group there were significant differences in jaw pain and dysfunction and eating behaviour before and after the accident, but no significant differences between WAD before and healthy. The healthy and the WAD group before the accident reported no or few symptoms. The WAD patients after the accident reported pain and dysfunction during mouth opening, biting, chewing, swallowing and yawning and felt fatigue, stiffness and numbness in the jaw-face region. In addition, a majority also reported avoiding tough food and big pieces of food, and taking breaks during meals. Altogether, these observations suggest an association between neck injury and disturbed jaw function and therefore impaired eating behaviour. A clinical implication is that examination of jaw function should be recommended as part of the assessment and rehabilitation of WAD patients.