Understanding Trismus

Trismus is a condition where the muscles that control the opening and closing of the jaw become tight and rigid.  The rigid muscles can make it difficult to open the mouth, causing problems with chewing, nutrition, speech and oral hygiene.  Those being treated for head and neck cancers with surgery or radiation therapy are at greater risk for developing Trismus. It can occur during, right after or even years after radiation therapy is complete.

The Oral Cancer Foundation states, "It should be noted that Trismus is frequently overlooked. Patients may assume that the reduction in jaw mobility is 'normal', or that it will resolve on its own. It is also easy for radiation oncologists, surgeons and their nurses to overlook the condition."

Trismus usually develops slowly. Treatment that begins in the earliest stages is more likely to be effective. It is important to be proactive in looking for early signs of Trismus. A simple test for restriction is called the "three finger test". Insert three fingers stacked vertically into the mouth. If all three fingers fit between the front teeth, opening is considered normal. If less than three fingers can fit, restriction is likely.

Prevention and treatment includes stretching to keep the muscles and joints mobile.  Click HERE for printable self-care instructions from Memorial Sloan Kettering Cancer Center.  A mechanical stretching device may be prescribed by your doctor to increase range of motion.  Treatments may also include physical therapy or massage therapy.

Inform your Physician and Dentist if you have signs of Trismus.  Report any past trauma to the head, neck or jaw, as well as clicking, popping or locking of the jaw joint.  Also report frequent headaches, pain in the jaw or ear and habits such as clenching or grinding your teeth. These are all important factors to make an accurate diagnosis.