Many people think they have "TMJ," which stands for temporomandibular joint. Somehow, TMJ has become a diagnosis when the truth of the matter is that it describes an anatomical part of the human body. It connects the jaw to the skull. The "T" in TMJ stands for the temporal bone, which is part of the skull. The "M" in TMJ stands for mandibular. The jaw is referred to as the mandible. The "J" in TMJ stands for joint. The jaw joint is a very unique joint since it is the only joint in the body that requires two joints to cause a movement and it is the only joint in the body that involves two separate movements, which are a hinge movement and a translational movement. You can learn more about TMJ movements on the TMJ animation page. Having said that, most of the people consider TMJ pain is due to muscle pain.
The site of the pain is in red and the source of the pain is indicated by the black "X." The more dense areas of red are not necessarily more painful that the less dense areas but they are the more common areas of referred pain.
The deep masseter is a closing muscle of the jaw. It is on the outside of the jaw but underneath the superficial masseter muscle.
The medial pterygoid is a closing muscle of the jaw. The "p" in pterygoid is silent. This muscle is found on the inside of the jaw so the animation shows you the red areas, which is where patients report pain, and it shows a window cut into the jaw so you can see that the muscle is located on the inside of the mandible (jaw).
The lateral pterygoid is a muscle that moves your jaw side-to-side and front and back. This is the muscle that gets very sore when people grind their teeth.
The clavicular head of the sternocleidomastoid muscle, which is abbreviated as SCM, is the muscle on the side of your neck that turns your head side to side. It can refer pain into the ear. This muscle can also refer pain behind the ear, to the forehead, and it can refer pain to the opposite forehead.
The sternal head of the sternocleidomastoid muscle, which is abbreviated as SCM, is the more superficial muscle on the side of your neck that turns your head side to side. It can refer pain in front of the ear. This muscle can also refer pain behind the ear, to the forehead, to the cheek, to the chin, into the eye, under the jaw, and into the breastbone.
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