Jaw Pain and Limited Opening After a Car Accident

“I do not remember hitting my jaw in the accident, but a few days later it began to hurt when I chewed and I could not open my mouth well. Could this be related to my neck injury?”

It can be, but not all jaw pain should be attributed to the neck. New pain when chewing, jaw stiffness, or limited mouth opening after an accident calls for assessment of the jaw joint and chewing muscles, together with the condition of the neck.

The jaw and neck do not move separately

The lower jaw does not act alone when the mouth opens and closes widely. A study of healthy adults found coordinated movement: the head and neck extended as the jaw opened and flexed as it closed. Neck muscles were active during the movement as well.

After an accident, reduced neck movement or tension in the surrounding muscles may therefore change how chewing and mouth opening feel. Conversely, guarding the jaw can alter head and neck posture. Looking at only one region can miss how the symptoms are connected.

Research supports assessing both regions

A 2025 systematic review brought together 14 studies reporting temporomandibular disorder pain after whiplash trauma. In the studies included in the meta-analysis, the mean prevalence of pain was 18.9% in the acute group, 26.8% more than three months after trauma, and 5.7% in controls.

This means that jaw pain after whiplash is not rare and is worth asking about early. However, the figures come from pooled observational studies. They do not prove that every case of jaw pain has a single cause in the accident. Pre-existing teeth grinding or clenching, dental problems, and the prior condition of the jaw joint also need to be separated.

Pain and loss of function matter more than sound alone

Jaw noises without pain are common. The U.S. National Institute of Dental and Craniofacial Research also explains that painless clicking usually does not require treatment. What matters more is whether any of the following changes began after the accident:

• Pain in the jaw or in front of the ear while chewing or yawning
• A clear reduction in how far the mouth opens compared with before the accident
• Catching or locking that stops jaw movement
• A sudden change in how the upper and lower teeth meet
• Jaw pain that worsens at the same time as neck pain or headache

It helps to record when the problem began, whether firm food or speaking is more difficult, and whether it is worse in the morning or evening.

When dental or oral and maxillofacial assessment comes first

Dental or oral and maxillofacial assessment should come first if the face or jaw was struck and the bite has changed, the jaw is locked and barely moves, or there is tooth injury, severe swelling, or bleeding. Numbness or a change in facial shape also calls for evaluation for a fracture.

If these problems have been excluded but jaw and neck symptoms remain together, the next assessment can consider how movement and pain in the two regions affect each other. Jaw pain after an accident should neither be dismissed as something to wait out nor assumed in advance to be only a jaw-joint problem.

See care information for symptoms after a traffic accident

See when headache or dizziness after an accident needs reassessment

References

• Prevalence of temporomandibular disorder symptoms after whiplash trauma: a systematic review and meta-analysis — European Journal of Pain, 2025
• Coordination of mandibular and head-neck movements during jaw opening and closing — Journal of Oral Rehabilitation, 1998
• Symptoms, diagnosis, and treatment principles for temporomandibular disorders — U.S. National Institute of Dental and Craniofacial Research

Written by Dr. Ji-young Heo, KMD, PhD in Pathology of Korean Medicine; former Academic Research Professor of Herbal Pharmacology, Kyung Hee University