WHAT ARE TMJ and TMD’s?
Temporomandibular disorders are often called “TMJ” by doctors, sufferers and even insurance agencies; even though the term TMJ is actually an acronym referring only to the jaw joints themselves.
For the purpose of this article, we will go over the basics of TMJ, and then in future discussions, I will bring you more in depth information into each of the areas we touch on today.
As mentioned, the TMJ is characteristic of the type of joint called a “ball and socket”. The ball is the rounded part technically known as the “condyle” of the joint. The condyle rotates in a cuplike depression (the socket) technically known as the “fossa.” Although the joint looks like it is attached immediately to the sinuses, it is actually separated from them by soft tissue ligaments, which completely enclose the joint, but are not visible even on an x-ray. Also not visible on an x-ray is the meniscus which is a disk of cartilage, which surrounds the space between the condyle and the fossa and is able to move forward and backward as the jaw opens and closes. The condyle and the fossa are each covered with a thin layer of inflexible cartilage of their own. All three layers of cartilage help to provide smooth, frictionless surfaces for easy joint function.
The Joints Work With the Neuromuscular System The movement of the jaw is orchestrated by a multifaceted set of muscles, which are, in turn, controlled by the body’s local and central nervous system. Together, they are called the neuromuscular system. The whole jaw-joint system is held together by ligaments, which place perimeters on their range of motion in all directions just as they do in all the joints of the body.
A Distinctive System of Many Parts The TMJ joint system is unique in many ways. The left and right joints must coordinate, working at the same time for the jaw to move. While the opening, lateral and forward movements of the jaw are controlled by the shape of the bones and are a function of muscles and ligaments, the closing end-point of the jaw movement is controlled by the coming together of the teeth the bite or occlusion. No other joint in the body has such a rigid end-point limit.
When a dentist thinks of TMJ, he or she usually considers the issue at large more than just the anatomy of the joint itself. The joint is really a part of the total complex system that makes the jaws operate correctly. To a dentist, the appropriate, vigorous function of the TMJ system requires normal structure and utility of all the component parts, including muscles, nervous system, ligaments, joints, bones, discs, connecting tissues and the dental occlusion. In fact, it is usually pain in these structures that compels most people toward TMJ treatment.
Through modern dentistry, there are several different terms used to describe the problems associated with TMD (defined as a group of symptoms which have a common source). Each term commonly corresponds to a particular “era” in the history of the study of the disorder, but all are still in general use and mean basically the same thing with weight on slightly different characteristics of the syndrome. They include MPD (MyoFascial Pain dysfunction), MFPDS (MyoFascial Pain dysfunction Syndrome), the more general TMD (TemperoMandibular Dysfunction) and the latest in a long line, Craniomandibular Disorders (CMD).
For the purposes of this article, I will use the term TMD to differentiate the painful symptoms of the disease from “TMJ”, the name for the actual joint itself.
Some Symptoms of TMD (an overview)
All of these TMD symptoms can vary in seriousness from mild to debilitating. On the mild end, the sufferer may attempt to ignore the discomfort, perhaps not even seeking any relief at all. Escalating on the pain scale a bit, the person may still not fully realize they even need to see a qualified professional, and attempt to get by with over the counter pain relief. At some point, however, sleep disruption, or a variety of other painful, or quality of life issues will begin to crop into the sufferer’s life to the degree where they must pursue professional advice and assistance.
In future articles I will delve into how each of these different symptoms, many of them so seemingly unrelated, can all be so blessedly relieved by a qualified dentist, if indeed it is determined that your troubles are caused by your TMJs.
Differences Between the Sexes
Age as a Factor