Evaluation - ICCMO.IT

When a patient sees a dentist for a (TMJ) TMD problem, the initial step involves taking a detailed history and conducting a specialized clinical examination. This includes a thorough assessment of the head, neck, and muscles, as well as an evaluation of jaw movements and TMJ joint sounds.

When light finger pressure, known as palpation, is applied to a muscle, it shouldn't cause tenderness or pain. If it does, this indicates inflammation, hyperactivity, or spasm within that muscle.

The dentist gently palpates the muscles responsible for jaw movements on the sides of the temples (the temporalis muscles) and the sides of the cheeks (the masseter muscles). The masseters are also pressed between fingers both outside and inside the mouth. Both of these muscle groups close the mouth. You can feel your masseter tense when you clench your teeth.

Below the jaw, a group of muscles works to open the mouth. The most important of these, the digastric muscles, are palpated below the jaw and at its rear corners. The angle of the mandible (the back corner of the jaw below the ears) is also palpated. In patients with TMD, this area is often tender because it includes muscles and ligaments closely associated with mandibular movement.

Inside the mouth, the dentist palpates two very significant muscles on each side. In the upper rear of the mouth, behind and above the last molars, are the external or lateral pterygoid muscles. These are crucial for the jaw's lateral (side-to-side) movement, as well as for opening the mouth.

Adjacent to the lateral pterygoid muscles is another muscle, the tensor veli palatini, which helps open the eustachian tube. This tube connects the middle ear to the back of the throat and equalizes pressure in the ear with the outside air. TMD patients may experience spasms of the lateral pterygoid muscle and the adjacent tensor veli palatini, preventing the eustachian tube from opening properly. This can lead to muffled sounds or ear pain due to inadequate ventilation of the middle ear.

In the lower rear of the mouth, on the inner aspect of the jaw's lowest corner, are the internal or medial pterygoid muscles. These are part of the system that closes the mouth.

The dentist also examines how much the upper front teeth overlap the lower front teeth. Excessive overlap (a deep overbite) is frequently found in TMD patients (Figure #1). This is commonly associated with an "overclosure" of the jaw and backward pressure in the TMJ joint near the ear.

The edges of healthy front teeth are typically smooth and rounded. If they appear worn flat, sometimes with brown stains, it signals an abnormal functional habit that wears away tooth structure. This is often observed in TMD patients (Figures #2 and #3).

The dentist will also palpate the muscles that support and move the head and neck. This examination includes muscles on the front, sides, and back of the neck, as well as the shoulders. Since TMD can co-exist with cervical (neck) musculoskeletal dysfunction, these muscles are often tender. Because the jaw and neck function together, neck musculoskeletal dysfunction commonly coexists with TMD. Disorders within the neck muscles and nerves can cause pain that's referred elsewhere in the body, which can complicate the diagnostic and treatment process.

Your dentist could also evaluate your posture. Abnormal head and neck posture can affect your jaw's position, contributing to a TMD condition. Conversely, TMD can also cause abnormal head and neck posture. A forward head posture or a tilted head can lead to pressure on the neck vertebrae, resulting in nerve pressure and muscle fatigue. All of these structures are interconnected, impacting the relationship between the jaw and skull, their nerve supply and muscle system, and how the teeth fit together. Other body postural asymmetries in the shoulders, hips, and back can also negatively affect head, neck, and jaw posture.

The dentist measures the space between your upper and lower front teeth when your mouth is opened to its widest position (normally 35-50 mm). Abnormalities are indicated by a reduced ability to open, opening with pain in the muscles or TMJ joints, or opening towards one side instead of straight down. The dentist also observes the quality of the opening motion, noting whether it's fluid or staggered and strained. The intentional movement of the jaw to the left and then to the right is also assessed, recording the maximum range of motion.

The TMJ itself is palpated on both sides of the face with the mouth wide open and closed. Pain or tenderness over the joint indicates inflammation within the joint capsule or inside the joint itself. The uppermost portion of the jaw (the condyle) normally rotates and moves forward as the mouth opens wide. You can feel this by placing your fingers on the condyles in front of your ears as you open and close your mouth. If the condyle cannot move forward and downward along the joint's slope when you open wide, it suggests that either muscles or something within the joint is obstructing this forward movement (translation). A click may be felt beneath the dentist's fingers, which also indicates an abnormal state.

The TMJ can also be palpated through the outer ear by applying gentle finger pressure forward on the front wall of the outer ear canal. The finger is never placed deep into the ear canal. The front wall of the ear canal is actually the rear wall of the TMJ. In the absence of any ear disease, pain on palpation here indicates inflammation in the tissues at the back of the TMJ.

Using a medical stethoscope or a Doppler, the dentist listens to the TMJ as the patient opens, closes, and moves the jaw from side to side. Sounds in the joints are abnormal. The type of sound—whether a distinct click or a crackling sound—is significant, as each represents a different state of joint dysfunction. The position in the open/close cycle where the sound is heard is also important. Many people have sounds in their TMJ without other symptoms and may not require treatment.

While all these clinical examination procedures provide initial diagnostic impressions to the examining dentist, computerized instrumentation plays a crucial role. After the clinical exam, this technology provides precise, objective measurements of jaw movement, muscle function, TMJ function, and joint sounds. These measurements are also taken at various stages of treatment to track progress.

Often, a virtually imperceptible (invisible) misalignment of the jaws, where the upper and lower teeth meet in the wrong place, can be at the root of TMDs. This misalignment can prevent the jaws from resting in a relaxed, naturally intended position, forcing the muscles to function uncomfortably. This misalignment might resemble a typical dental malocclusion or even appear as a "beautiful" occlusion of the teeth. By relying solely on visual observation, feeling, and listening, doctors cannot fully detect and evaluate subtle dysfunction. To pinpoint this malocclusion, or "unhealthy bite," and to measure the associated muscle function, a revolutionary set of computerized instruments, developed over the past forty years, is often necessary.

The CMS is a tracking device that records the delicate, functional movements of the jaw in three dimensions with accuracy down to tenths of a millimeter. Recordings are made by tracking the movement of a small magnet temporarily attached to the gum below the lower front teeth. Opening, closing, swallowing, and chewing movements can be meticulously scrutinized and analyzed. This computerized instrument can identify both the natural occlusion and the healthy neuromuscular occlusion treatment positions. This testing is used at the beginning of treatment and subsequently to evaluate the accuracy of the jaw position during treatment.

This instrument measures and analyzes the electrical activity in the muscles that move the jaw, both at rest and during function. In a healthy state, muscles exhibit low levels of electrical activity at rest and high, balanced activity during function. In TMD, the opposite is often observed. Illustrative data can show resting EMG activity before and after TENS (electrical stimulation therapy to relax muscles), as well as functioning (clench) EMG activity in the natural bite versus the corrected neuromuscular occlusion used for treatment. EMG is a painless test, performed using surface electrodes that resemble band-aids placed on the face, forehead, side of the head, and beneath the chin.

The ESG records sounds produced within the jaw joint (TMJ) during opening and closing of the mouth. This method is more sensitive, precise, and reproducible than traditional stethoscope listening. ESG records the frequency and amplitude (power) of the noise produced, as well as the exact position in the opening/closing cycle where the sound occurs. This allows the dentist to assess whether there is damage within the TMJ and suggests its nature, potentially necessitating further study. The test involves placing a headset-like device with vibration sensors (transducers) over the two temporomandibular joints (TMJ).

The dentist determines the necessary type of imaging for each patient and at what point in the diagnostic or treatment process imaging information is required. TMJ imaging includes various views, such as lateral transcranial, frontal, CT scans, and MRI when medically necessary to aid in a patient's diagnosis and treatment.

The actual diagnosis is made by a TMD-trained dentist, who gathers, analyzes, and assimilates all information from the patient's history, clinical examination, and the various diagnostic tests described above. The computerized testing, while providing valuable information, does not make a diagnosis on its own. It is the trained doctor, assessing all outcomes, who makes the definitive diagnosis and determines the appropriate treatment plan. Actual treatment often involves temporarily establishing a new therapeutic biting position. This neuromuscular occlusion position incorporates healthy muscle function and proper interdigitation of the teeth to create a healthy, comfortable bite.