When a yawn causes your jaw to lock, it can be a surprising and unsettling experience. This phenomenon, where the jaw temporarily gets stuck, often brings discomfort.
Understanding Jaw Locking
The temporomandibular joint (TMJ) connects your lower jawbone, the mandible, to the temporal bone of your skull, located just in front of each ear. Between the bones of the TMJ is an articular disc, a small, flexible pad of fibrocartilage that acts as a cushion and ensures smooth movement.
During a typical yawn, the jaw opens widely, involving both a hinge-like rotation and a sliding motion where the condyle (the rounded end of the mandible) glides forward along the temporal bone. Jaw locking, or “open lock,” occurs when the jawbone or, more commonly, the articular disc moves out of its normal position and gets stuck, preventing the jaw from closing properly. This dislocation can be acute, happening suddenly, or chronic, recurring over time.
Underlying Reasons for Jaw Locking
Several factors can predispose an individual to jaw locking during a yawn. Temporomandibular joint (TMJ) disorders are a common cause, where inflammation, displacement of the articular disc, or wear and tear within the joint can lead to locking. This can result from the disc being displaced forward, potentially getting caught as the jaw attempts to close.
Jaw hypermobility is another contributing factor, as some individuals have naturally looser ligaments and joints. This excessive mobility increases the risk of the condyle sliding too far forward and becoming dislocated. Conditions such as Ehlers-Danlos Syndrome, which involve generalized joint hypermobility, are associated with an increased likelihood of TMJ issues, including locking.
Muscle spasms or imbalances in the jaw muscles, such as the masseter, temporalis, and pterygoids, can also contribute to locking. Tight or imbalanced muscles can pull the jaw out of alignment or hinder its smooth return to position after a wide opening. Stress and bruxism, which is the clenching or grinding of teeth, significantly strain these jaw muscles and joints, making them more susceptible to locking. Persistent tension from bruxism can lead to muscle pain and tension, potentially contributing to jaw locking.
When to Seek Professional Help
If the locking occurs frequently or is recurrent, it warrants professional attention. Pain accompanying the locking, especially if it is severe or persistent, is another indicator for seeking help.
Difficulty opening or closing the mouth fully, even when not yawning, suggests a need for evaluation. Other signs include clicking, popping, or grinding sounds in the jaw joint that are painful or disruptive. Jaw deviation, where the jaw moves to one side when opening or closing, or associated headaches, earaches, or facial pain, also indicate that a healthcare provider should be consulted. Early intervention can help prevent further complications.
Managing and Preventing Jaw Locking
For immediate relief if the jaw locks, remaining calm and relaxed is beneficial, as anxiety can cause jaw muscles to contract further. Applying a warm compress to the jaw joints for 10-15 minutes can help relax the muscles. Gentle pressure can then be applied to the jaw joints with the palms, slowly moving the jaw from side to side. If the jaw does not unlock easily, it is important not to force it, as this can cause further damage.
Preventative measures during yawning can significantly reduce the risk of locking. Consciously controlling jaw opening during yawns, for example, by placing a fist under the chin to limit how wide the mouth opens, can be effective. Lifestyle adjustments also play a role in long-term prevention. Stress reduction techniques, avoiding hard or chewy foods, and maintaining good posture can alleviate strain on the jaw. Being mindful of jaw clenching, especially during sleep, can also help.
Simple jaw exercises, such as gentle stretches and relaxation techniques, can improve jaw mobility and muscle balance. For example, placing the tongue on the roof of the mouth and slowly opening the jaw can promote controlled movement. Over-the-counter pain relievers, like ibuprofen, may help manage any associated discomfort or swelling.