Why does your jaw make a popping sound when you open your mouth?

Answer 1

it is called TMJ (Temporo Mandibular Joint) and theres like a disc in your jaw ,so when you close it ,it falls out of place and when you open your mouth thats it popping back into where it belongs.

Answer 2

The upper or hinge part of the lower jaw (mandible) is shaped like a U. The head of the rear-most leg of the U, called the condylar process, articulates with the skull; the front-most leg of the U, called the coronoid process, serves as an attachment for the temporal muscle which attaches to the side of the skull and extends from the parietal bone to the sphenoid bone and then funnels down to the coronoid process to aid in the closing of the jaw.

The head of the condylar process of the mandible articulates with a fossa (concavity) in the base of the temporal bone of the skull, the two being separated by an articular disc and held in place by supporting ligaments. As the mouth opens, for the first 3/4-inch or so, the mandible simply rotates in an arc. As the mouth continues to open, the mandible not only rotates, it begins to slide forward - translate - along the front wall of the fossa until it reaches its end-point, variously called the articular eminence, a knob, of sorts, at the edge of the fossa. During the course of these actions, the articular disc travels with the head of the condylar process, maintaining itself between it and the base of the skull to avoid bone grating on bone.

Popping or crepitus is an event that is both felt and heard. As crepitus occurs, the mandible will feel like its grinding or bumping and emit a sound as if one is banging one's knuckles on a book or mat - muffled knocking, if you will. Without going into a terribly detailed description of the role of the various parts and ligaments, the cause is due to the fact that the articular disc "squirts" beyond the articular eminence at the edge of the fossa. Think of a watermelon seed being squeezed between the fingertips. In the TM joint, the disc is squeezed between the head of the condylar process and the wall of the fossa and squirts past the articular eminence. When that happens as the mouth opens, one feels and hears a "pop." Then, as the mouth is closed, the disc is pulled back into its normal position within the fossa and a closing "pop" is heard and felt.

Crepitus is variously attributed to anatomic anomalies, bruxing (teeth grinding while sleeping), awake jaw clenching, malocclusions, and other head-neck or psychological issues, e.g., stress. In the overwhelming majority of instances, however, crepitus, in and of itself, does not command treatment. It might, along with a host of other signs and symptoms, be a part of a TM joint syndrome that due to pain, e.g., might warrant further investigation and treatment - with limited degrees of success.

I might also mention that, as in the case of the articular disc, on rare occasions, the head of the condylar process may travel beyond the articular eminence and render one's jaw "stuck" open. In this case, the temporal muscle, which is pulling the jaw upward, does not allow the jaw to travel downward and rearward past the eminence. Often this is readily corrected by having one relax their jaw, as best as possible, while another quickly presses or thrusts the jaw downward forcibly by pressing with the thumbs on the back teeth (molars).

Answer 3

you could have a bone out of place which moves when you open your mouth to make it pop.