For quite some time, I have been treating patients with TMJ disorders. The causes can vary widely. The origin of pain may be neurologic, muscular, bony, or related to the disc. Neuromuscular dentistry seeks to identify where all of these systems overlap and interact.
The TMJ is a joint. It has a capsule of surrounding tissue, muscles, synovial fluid, ligaments, and an articular (cartilaginous) disc. There are two TMJs—just like the hips or shoulders—yet the chin connects both sides. When the right side moves, the left side follows. To complicate matters further, when the jaw moves to the right, the left pterygoid muscle activates. This can be very confusing for patients. They may feel pain on the opposite side from where they are moving the jaw. In addition, the jaw can both rotate and translate (shift side to side without opening very wide).
It follows, then, that accurate diagnostics are essential.
We can view the joint with imaging. Many patients come to me with MRI scans, which can reveal muscle tears or disc damage but only indirectly show the bones. In my opinion, a medical CT scan is larger and less ideal for proper TMD diagnosis.
A dental CBCT machine offers the ideal resolution and detail for evaluating the sinuses, TMJs, bones, and spaces of the head and neck. I have identified issues in patients’ spines, brains, and even clogged arteries, leading to referrals to cardiologists and orthopedic surgeons.
Older CBCT machines had a very small field of view and often captured only the TMJ itself. Below is an example of a limited TMJ-only view.
With today’s improved, highly sensitive digital capture systems, we can now use a much wider field of view. I am able to capture the entire head, neck, TMJs, and jaws in one scan. The ability to manipulate a 3D skull and examine it from multiple angles is extremely helpful.
For example, the image below is from an older machine and may have been taken by a provider who does not evaluate the entire system of bones, muscles, ligaments, and teeth. In many cases, I find that muscle pain originates from a malpositioned occlusion. Think of it like walking in a shoe with a broken, angled sole. You can still walk, but the tilted position puts abnormal pressure on your ankle, knee, and hip. Eventually, the weakest structure will hurt.
The same principle applies to the teeth. If the teeth are crowded or positioned incorrectly, they deflect the jaw—possibly forward, backward, or to one side. This puts pressure on the condyles and ligaments while forcing the muscles to compensate. The constant abnormal movement causes wear and tear on structures that should not experience such repeated stress.
Imagine walking comfortably on a soft, flat sandy beach where your feet fit perfectly. Now picture walking on a rocky, uneven surface. The constant imbalance strains the ankles, knees, and eventually the hips. If your hip hurts at the end of the day, it is likely not due to a nerve disease but rather to improper motion stressing the ligaments and fatiguing the muscles.
This is why imaging the joint alone gives us a limited view. We may detect arthritis or bony pressure necrosis, but if the TMJ problem originates from an occlusal issue (how the teeth come together), a small TMJ image will miss it entirely.
I believe we need a comprehensive image of all the involved structures: the upper and lower jaws, the teeth, the TMJs, and the spine. These elements have interconnected roles, and viewing them together is critical.
A few years ago, I invested in a state-of-the-art Planmeca ProMax 3D Mid CBCT machine. At the time, it was one of only two or three machines offering a 0.07 mm voxel size while also prioritizing low radiation exposure.
The image below reveals much more than the small TMJ-only view could show.
We can see that the condyle is in a seemingly good position. However, when we view the full jaw relationship in the larger image, a different story emerges. This patient was asked to bite down normally. You can see that only the front incisors are touching, while the back teeth do not meet. The condyles appear correct, but the teeth are not.
When the patient bites fully on the back teeth, the lower jaw shifts backward, moving the condyles with it into the back of the fossa—a position that causes pain. The patient subconsciously holds the jaw forward in a muscle-supported, unnatural position, which has flattened the front teeth. Clenching on those front teeth can cause the jaw to twist, tooth pain, frontal headaches, and TMJ discomfort.
Is this a disc problem? It can become one if the pressure continues, but the root cause is that the back teeth do not touch until the jaw moves into a painful condylar position. Correcting the occlusion often resolves the source of the pain. This critical relationship cannot be seen with a TMJ-only image.
Imaging is key.