Low-Impact Crashes Can Lead to Long-Term Jaw Pain
Adults involved in motor vehicle collisions often experience a range of head and neck symptoms caused by whiplash trauma that persist long after the accident. The connection between whiplash and jaw symptoms, including temporomandibular joint disorder (TMD), is a subject of ongoing research and some controversy. Although studies have shown that whiplash can increase the risk of jaw disorders by 3.4%, other researchers have discounted this conclusion.
One difficulty in understanding the relationship between jaw pain and whiplash arises because people involved in a collision may not report jaw pain or masticatory (chewing) problems until some time after the original incident. This may be because patients do not recognize jaw pain as a serious issue in the acute aftermath of a crash or because the symptoms do not show up until some weeks after the incident. Either way, the delay makes it difficult to directly attribute jaw symptoms to a collision.
Researchers based at the University of Gothenburg in Sweden set out to help define the prevalence of jaw problems in whiplash patients by tracking symptoms in 128 patients over the course of a year. The participants completed an initial assessment that analyzed a long list of crash conditions, including impact direction and the subject’s posture at the time of the crash. They also underwent an initial physical examination that assessed their range of neck motion and the presence of jaw signs (asymmetrical or reduced mouth opening and associated pain. The participants then completed a follow-up questionnaire and physical examination after one year.
After a year, examiners found jaw signs in 23% of men and 24% of women. For around 10% of the women, these signs had developed during the course of the year. Women with jaw signs during the first exam were more likely to also report experiencing headaches than those without, but this divergence was not significant among the men. Jaw problems were more common for patients involved in rear-end collisions.
One of the most interesting findings, however, was that there was no correlation between the severity of the initial crash or impact speed and the prevalence of jaw symptoms. This conclusion contradicts the assumption that the change in speed at the time of the crash can predict the severity of injuries. Participants involved in slower crashes were just as likely to experience longer-term jaw problems, although the direction of the impact and the sex of the vehicle occupant did seem to be significant factors.
These results suggest that the long-term risk of jaw problems following a collision many be sex-specific, with women at greater risk of developing symptoms. The researchers conclude that jaw problems may be easily overlooked in the acute phase of a crash and discounted over the long term. Health professionals should evaluate patients over the long term to catch the full range of symptoms that may crop up after a motor vehicle collision.
Severinsson Y, Bunketorp O, Wenneberg B. Jaw symptoms and signs and the connection to the cranial cervical symptoms and post-traumatic stress during the first year after a whiplash trauma. Disability and Rehabilitation, 2010; 32(24).