Jaw clicking or popping is a common sensation, known medically as an audible joint sound or crepitus, that many people experience. This sound often occurs while talking, chewing, or yawning, and it can range from a soft click to a louder, more noticeable pop. The source of this noise is the complex joint that allows for all the movements of the lower jaw.
Understanding the Temporomandibular Joint
The movement of the lower jaw is controlled by two temporomandibular joints (TMJs), located just in front of the ears, one on each side of the head. The TMJ is a unique structure that functions as both a hinge for opening and closing and a gliding joint for forward and side-to-side movements. It is formed by the articulation of the mandibular condyle, which is the rounded end of the lower jaw bone, and the mandibular fossa, a socket in the temporal bone of the skull.
Sitting between these two bony surfaces is the articular disc, a small, fibrous, cushion-like piece of cartilage. This disc acts as a shock absorber and prevents the bones from rubbing directly against one another, allowing for smooth, pain-free motion. The disc is held in place by small ligaments and divides the joint into two separate synovial cavities. The coordinated movement of the condyle and the disc is what allows the jaw to function correctly.
The Physical Reason for the Popping Sound
The most frequent reason for the audible clicking is a phenomenon called disc displacement with reduction. This occurs when the articular disc shifts out of its normal position, typically forward, relative to the mandibular condyle. As the mouth begins to open, the condyle pushes against the displaced disc until it suddenly snaps back into its proper place on top of the condyle. This sudden realignment of the disc creates the distinct “click” or “pop” sound.
This sound is often referred to as the “opening click” or “reduction” of the disc. As the jaw closes, the disc often slips forward again, sometimes producing a second, quieter click as it moves out of position. This pattern of clicking on both opening and closing is known as reciprocal clicking. Less common causes for joint sounds include the presence of joint surface irregularities or the sound of ligaments snapping over bony structures.
Common Causes of Jaw Clicking and Popping
The underlying causes that lead to disc displacement or muscular problems are varied and often involve chronic strain on the joint. One of the primary triggers is high levels of stress, which can lead to unconscious clenching or grinding of the teeth, a condition known as bruxism. This continuous, excessive pressure strains the muscles surrounding the joint and stretches the ligaments that stabilize the articular disc.
Trauma or injury to the face, head, or neck can also cause the joint to move out of alignment or damage the internal structures. Even a minor blow to the jaw can have long-term effects on the proper function of the joint. Specific habits place undue strain on the joint over time, such as habitually chewing gum, biting nails, or resting the chin on the hand.
An imbalance in the way the upper and lower teeth meet, known as malocclusion, forces the jaw to work harder and move improperly during chewing and speaking. This uneven pressure can wear down the joint structures and contribute to the displacement of the disc. Furthermore, inflammatory conditions like arthritis can affect the TMJ, causing degenerative changes that lead to joint noise and dysfunction.
When Jaw Popping Becomes a Concern
An occasional, painless click or pop, particularly during a wide yawn, may not be a sign of a serious problem. However, when the clicking becomes frequent, is accompanied by pain, or is combined with other symptoms, it suggests the development of a temporomandibular disorder (TMD). Specific red flags indicate a need for professional evaluation.
These concerning symptoms indicate a need for professional evaluation:
- Constant, severe pain or tenderness around the jaw, ear, or temple area.
- Limited range of motion or a feeling that the jaw is locking in an open or closed position.
- Persistent headaches, especially those that feel like tension headaches.
- Chronic earaches that are not due to an ear infection can also be linked to joint dysfunction.
While waiting for a consultation, initial self-care steps can help manage symptoms and alleviate strain on the jaw joint:
- Temporarily adopt a soft diet to reduce strain on the joint.
- Apply a warm or cold pack to the sore area.
- Practice gentle jaw stretching exercises.
- Reduce stress and avoid habits like excessive gum chewing.