[MUSIC] Welcome, to appropriately examine the patient for suspected TMD. The clinician must examine the relevant structures in a thorough and systematic manner. Clinicians who are unaccustomed to this type of examination may feel uncomfortable performing initially, but will gain confidence in these techniques with experience. For patients presenting orofacial pain complaints, it is generally recommended to perform a cranial nerve examination. Complaints of altered sensation or loss of sensation of facial structures may indicate a non-TMD facial pain condition, and a cranial nerve examination should be performed to detect cranial nerve abnormalities that may indicate central nervous system pathology. If abnormalities are detected on cranial nerve examination, patient should be promptly referred to an appropriate health care provider for further evaluation and management. Measurement of interincisal opening is completed to evaluate the patient's ability to open their jaw. A measurement device with a millimeter scale, placed between the maxillary central incisors and mandibular central incisors with the patient in the open position is typically how this measurement is obtained. Normal range of opening is approximately 35 to 55 millimeters in adults, but this may vary due to many factors. Clinicians should know presence, location, and severity of pain with jaw opening and closing. Lateral jaw movements are evaluated by asking the patient to move their mandible left and right, and measuring the range of motion with the measuring devices previously mentioned. Normal lateral movements typically range between 8 to 12 millimeters in adults. To appreciate mandibular deviation, ask the patient to open and close their jaw in a regular manner, and look for mandibular movements that do not follow a typical straight opening and closing pattern. Patients with TMJ articular discs that are stuck, often demonstrate mandibular deviation in a straight line to the affected side. Other individuals who have TMJ discs that are malpositioned, but in a physiological position may demonstrate a c shaped or s shaped deviation on opening and closing movements. Auscultation of the TMJ may be accomplished by using a stethoscope to listen for joint noises. Placing the diaphragm of the stethoscope in front of the ear, known as the preauricular area, and asking the patient to repeatedly open and close their mandible, allows the clinician to hear joint noises, such as clicking, popping, or crunching if they are present. These sounds should be noted if heard on either opening or closing movement or both. In addition, the clinician should ask the patient, if they feel pain when experiencing the joint noises. Alternatively, the clinician may also place their pinky fingers inside the patient's external auditory meatus, and ask the patient to open and close to appreciate joint noises and pain. Palpating the TMJ will inform the clinician if a patient is experiencing pain in and around the joint. Typically, pressure ranging from two to four pounds is exerted when palpating the TMJ, and associated structures. And if pain is reported when performing this technique, it is commonly associated with an inflammatory condition of the TMJ, such as capsulitis and/or synovitis. Palpation of the masculatory muscles is a critical component of the TMD examination, as many patients with TMD experience pain associated with these muscles. Using pressure as noted previously, the clinician should palpate all portions of the temporalis and masseter muscles bilaterally from an external approaching, and noting severity of pain if present. The medial and lateral pterygoid muscles are typically palpated from an intra-oral approach with the patient in an open position to gain access to these muscles. Again, the clinician should note presence of, and severity of pain when palpating these muscles as this is often an indication of a masticatory muscle disorder. In addition, the patient's dental relationship should be grossly evaluated in the closed or biting position to determine if there are any major bite discrepancies. Finally, it is important to assess the patient's teeth for signs of wear that may be indicative of a parafunctional habit. TMJ articular disorders refer to malpositioning of the articular disc relative to the condyle and articular eminence. Typically, the articular cartilages in the 12 o'clock position superior to the condyle. The majority of articular disc disorders represent disc displacement anterior to the condyle. The term TMJ articular disc disorder with reduction refers to an anteriorly displaced disc that resumes its position on top of the condyle on opening movement, which does not typically cause restricted movement. Clinically, this phenomenon is most commonly observed as a joint click with opening. It is common to hear joint clicking when a patient closes their mandible. This is known as a reciprocal click. The clinician should note if there is pain associated with the clicking noise and severity if present. The term TMJ articular disc disorder without the reduction, refers to a disc that remains mal-positioned on opening attempts, resulting in restricted mouth opening in acute cases. Another term for the condition is closed lock. Patients with this condition typically open to approximately 20 millimeters as the condyle is capable of rotational movement only. This condition often causes significant pain and dysfunction, and patients typically seek acute care to treat this condition as it often compromises nutritional intake, daily function, and overall quality of life. Subluxation of the jaw is considered a hypermobility disorder. Patients with hypermobility typically have laxity of their ligaments and tendons, thereby increasing their flexibility and range of motion. Subluxation of the jaw occurs when patients open very wide, resulting in overextension of the disc-condyle complex beyond the articular eminence. Individuals who can easily open their jaw to 55 millimeters or greater are considered to be hypermobile. Another key feature of subluxation is that patients can passively return their jaw to a comfortable resting position, meaning a return to the normal disc-condyle position in relation to the articular eminence without typically getting their jaw stuck or locked in an open position. Joint dislocation occurs when the entire disc-condyle complex extends beyond the articular eminence, combined with the inability to return passively into the fossa. This is also commonly referred to as open lock. This can be very distressing for patients as it is often accompanied by significant pain, emotional upset, and negative social implications. Patients with open lock are typically seen on an urgent basis, and correction of this problem usually requires use of potent analgesics, and muscle relaxants, coupled with physical manipulation of the mandible to its normal position. The most common etiology for TMJ articular disc disorders is trauma, and may be considered in three categories, Macrotrauma, microtrauma, and indirect trauma. Perhaps, the most evident type of macrotrauma that can cause articular disc disorders is direct injury to the face, mandible, or TMJ area. Direct injury to these areas typically occurs during physical altercations, motor vehicle accidents, bicycle accidents, and sports related injuries. Dental procedures may also be attributed to development articular disc disorders. Dental procedures that create excessive force on the mandible, and/or TMJ area, may cause development of an articular disc disorder. It is common for patients to complain of new onset joint clicking and pain after their jaw has been opened for a long period of time owing to prolonged dental procedures. Microtrauma has historically been attributed to application of prolonged forces on the TMJ complex over a period of time. Jaw parafunction has long been considered the type of microtrauma that might cause TMJ articular disc disorders, as well as jaw muscle pain. Indirect trauma has been implicated in TMJ articular disc disorders. The most common type of indirect trauma that may precipitate TMDs including articular disc disorder is whiplash injury. This refers to a violent jerking motion of a body part during a sudden traumatic event. In the case of TMD, whiplash injuries of the head and neck have been associated with TMJ articular disc disorders, which often occur during motor vehicle accidents. Patients may complain of immediate facial or TMJ pain after the incident, but it is not uncommon for patients to develop TMD pain and/or dysfunction months after the incident. We will now discuss another type of disorder that commonly causes TMJ pain and/or dysfunction. Arthritis typically affects various joints of the body, and the TMJ is no exception. The most common type of arthritic condition to affect the TMJ is osteoarthritis. This is also commonly referred to as degenerative joint disease. Osteoarthritis is considered a non- to low-inflammatory condition that can cause bony changes, which may be evident in the TMJ area. Ultimately, these bony changes can cause pain and/or dysfunction in the TMJ area. The etiology of TMJ osteoarthritis is usually attributed to mechanical overloading of the articular services, which leads to the degeneration of bony and/or cartilaginous structure of the TMJ complex. This condition is more frequently seen in elderly individuals compared to younger patients due to more years of joint use. Patients with TMJ osteoarthritis are often very specific regarding their pain complaints. These individuals typically complain of unilateral joint pain often pointing directly to the TMJ area, which is exacerbated with jaw movement. In addition, many patients with TMJ osteoarthritis complain of crunching or crackling sounds, referred to as crepitus in the TMJ area with jaw movement. Careful examination of a patient with suspected TMJ osteoarthritis often yields important diagnostic clues. Patients with this condition often have limited jaw opening, as stated previously, it is common to detect crepitus on auscultation of the TMJ which is highly suspicious for osteoarthritis. Palpation of TMJs affected by osteoarthritis is often painful, the most basic type of plain film imaging of the TMJs is the panoramic radiograph. This type of imaging is completed in the dental office, and allows for visualization of the maxillary and mandibular bones, and the bony structures of the TMJ. In patients with TMJ osteoarthritis, it is typical to see varying degrees of flattening of the condylar head, possible erosion of the condylar surface and/or bone spur formation in these areas. Other less common types of arthritic conditions that effect the TMJs are rheumatoid arthritis, and traumatic arthritis. In contrast to the non and low inflammatory nature of osteoarthritis, rheumatoid arthritis is considered a persistent inflammatory disorder, that leads to destruction of articular surfaces, and bony structures of the TMJ. This disease has an autoimmune etiology, and is typically diagnosed through laboratory evaluation and clinical history. It is not uncommon for patients to present with signs and symptoms consistent with TMJ arthritic pain, who are not aware they have rheumatoid arthritis. In my practice I've seen several adolescents and teenagers complaining of TMJ arthritic pain, and after appropriate evaluation were discovered to have juvenile idiopathic arthritis, historically known as juvenile rheumatoid arthritis. Finally, traumatic arthritis can cause signs and symptoms of TMJ arthritic pain, as evidence on clinical examination and radiographic imaging. This type of arthritis manifests as bony changes that develop secondary to sudden macrotrauma, the most common being direct injury to the TMJ area from incidents such as motor vehicle accidents, sports-related injuries, and/or physical altercations. We now turn our attention to TMD muscular disorders, these account for many cases of TMD, either as the sole ideology, or a combination with articular disorders, and/or arthritic conditions. It is important to understand basic terminology of muscular disorders, as they are often used interchangeably and not always in the appropriate context. Myalgia refers to localized muscle soreness that does not typically include or affect other muscles. For example, if a patient has pain only of the masseter muscle without referred pain, it would be appropriate to diagnose the condition as myalgia of the masseter muscle. Myalgia also typically causes muscle weakness, in contrast, myofascial pain refers to regional muscle soreness associated with trigger points. Which are hypersensitive areas or bands within the affected muscle that typically cause referred pain throughout the affected region. Pain arising from trigger points within the masseter that radiates throughout the facial region would be consistent with myofascial pain. Typically, this is the most common type of TMD muscular disorder encountered in clinical practice. Since most TMD muscular disorders are consistent with a myofascial pain diagnosis, we will discuss some key considerations for patients with TMD myofascial pain. Many patients with this condition often complain of dull, achy pain, and/or the sensation of fatigue involving the masticatory muscles. These patients also complain of pain at rest that typically increases with jaw function. Trigger points, which represent firm, hypersensitive bands of muscle are felt on palpation. Thy symptoms of TMD myofascial pain can be wide ranging, from mild ache, or pain of the jaw muscles to severe disabling pain that may compromise function and significantly effect a patient's quality of life. TMD myofascial pain disorders maybe, and are often associated with TMJ articular disc disorders and arthritic conditions, and often cause referred pain to other structures of the head and neck. Therefore, active therapy for TMD muscular disorders is often indicated for patients with these conditions. In the next segment, we will discuss, Imaging considerations and management strategies for TMDs.
