Why Does My Jaw Lock or Get Stuck When I Open My Mouth?

A jaw that locks or gets stuck when you try to open your mouth is one of the more alarming symptoms that can come from TMJ disorder. It can happen suddenly, or it can develop gradually, starting as a minor catching sensation and progressing to actual limitation in movement. Here is what causes it and what it means for your jaw health.

Why does the jaw lock in the first place?

Inside each temporomandibular joint there is a small disc of fibrocartilage that acts as a cushion between the lower jaw and the skull. Under normal circumstances, this disc moves smoothly along with the jaw as it opens and closes. When the disc becomes displaced, meaning it has shifted out of its proper position, it can interfere with the smooth movement of the joint.

A clicking or popping sound when opening the jaw is often the first sign that the disc is not tracking properly. Over time, if the displacement worsens, the disc can become lodged in a position where it actually blocks full opening of the jaw. This is what is called a closed lock, and it is one of the more advanced stages of disc displacement.

Are there different types of jaw locking?

Yes. A closed lock means the jaw cannot open fully, the disc is blocking forward movement of the condyle. An open lock, which is less common, means the jaw gets stuck in an open position and cannot close easily. Both involve the disc and condyle not moving as a coordinated unit.

Some patients also experience intermittent locking, where the jaw catches momentarily and then releases, often with a loud pop, rather than getting stuck in one position.

What other symptoms tend to accompany a locking jaw?

• Pain or aching in and around the jaw joint

• Clicking, popping, or grating sounds that may have preceded the locking

• Difficulty chewing or limited ability to open the mouth wide enough to eat comfortably

• Muscle soreness in the jaw, temple, and neck

What should you do if your jaw is locking?

A locking jaw is a sign that the joint needs attention rather than just time. Conservative treatments can be effective, particularly when the condition is addressed before significant joint damage has occurred. These may include bite splints, physical therapy, anti-inflammatory management, and in some cases specialist referral. At Wonder Family Dental & Dentures, we evaluate jaw joint health as part of comprehensive care and can help you understand what is going on and what options are available.