How long does a locked jaw last?

Lockjaw, which is clinically called trismus, is a painful condition that is characterized by the jaws not opening all the way. This can interfere with speaking, eating, and oral hygiene and lead to repercussions that diminish the quality of life, if not worse. To classify as lockjaw, the mouth won’t open more than 35 millimeters. Trismus can arise because of injury or trauma to the jaw, infection, oral surgery, cancer, or treatments for some cancers in the throat or head. The causes of lockjaw vary, and there’s no definitive answer to how long a locked jaw will last. In most cases, trismus is temporary and subsides within a couple of weeks, but some cases of lockjaw might last longer, and some might even be considered permanent. In general, earlier treatment leads to a more favorable outcome. In most cases, treating the underlying condition that led to lockjaw will resolve the issue.

Inflammation and injury are two possible causes of TMJ disorder or lockjaw. The jaw can become injured or experience trauma if the jawbone fractures from injury, if the jaw joint or supporting muscles are bruised or otherwise traumatized, or when the tissues that support the jaw are irritated or inflamed following dental surgery, including but not limited to wisdom tooth extraction. Following dental surgery, the jaw may feel limited in its range of motion as it recovers from being held open for the duration of a surgery, though this range of motion is usually not serious enough to qualify as trismus. In cases of injury or trauma, lockjaw will often resolve as the injury heals. Most people with lockjaw subsist on a diet of soft yet nutritious foods and liquids while they wait for symptoms to subside.

Trismus may also arise because of medical conditions that involve inflammation in the mouth, like impacted molars, or because of arthritis flare-ups in the jaw, and some systemic conditions, like scleroderma or soft tissue fibrosis, can also contribute to the likelihood of lockjaw developing. Some infections can also contribute to lockjaw; these include tonsillitis, tetanus, mumps, infection or abscess around the tonsils, and certain cancers and cancer treatments like radiation. Following treatment for these conditions, symptoms usually subside. In addition to the locked jaw that defines trismus, symptoms of trismus include pain and tension in the jaw, the inability to swallow certain foods, difficulty eating and brushing the teeth, earaches, and headaches. When lockjaw occurs because of infection in the jaw, it’s also possible for this infection to cause inflammation in the skin outside the jaw.

The first line of treatment for a locked jaw is to treat the underlying cause. To relieve symptoms while more comprehensive treatments address the underlying issues, common recommended treatments for lockjaw include medications like muscle relaxers and anti-inflammatory drugs to relax the jaw and help restore range of motion. In some severe cases these medications may include prescription pain relievers or other drugs that are injected directly into the jaw. Many doctors and physical therapists also recommend using mechanisms that stretch the jaw, which have been shown to help increase the amount the mouth opens by about 5 to 8 millimeters. In most cases, medications, physical therapy, and other conservative treatments can relieve the effects of lockjaw and prevent complications from arising, and early treatment provides optimal outcomes, so if you’re concerned about lockjaw, make an appointment with your dentist to discuss the condition and your treatment options.

What Causes a Jaw to Lock?