Reducing or eliminating pain is one of the cornerstones of having a successful treatment outcome for TMD . The DC/TMD myogenous diagnostic subsets consisting of myalgia, local myalgia, myofascial pain, myofascial pain with referral, and headache attributed to TMD, although distinct, will be collectively be referred to as myalgia for the purpose of this discussion. Myalgia is the most prevalent diagnostic subset among all diagnostic subsets of TMD with arthralgia being the second most common diagnostic subset [21, 22]. The DC/TMD diagnostic criteria for myalgia and arthralgia requires pain to be present in the past 30 days. In addition pain must be present during the examination, and it must increase or decrease in response to provocation tests. This includes palpation to the muscles of mastication or TMJ capsule and/or pain that is modified by active or passive movements of the jaw.
The DC/TMD criterion for the remaining six intra-articular disorders (IADs) does not require pain to be present. These six IADs are diagnosed by patient complaints of noise or difficulty opening or closing their mouth. Though these symptoms can be annoying and disconcerting to the patient, they are often not painful . An accurate diagnosis of the six IADs is necessary in order to educate the patient on their condition and provide a prognosis of their intra-articular disorder either with or without treatment. The diagnostic criteria for the remaining six IADs are as follows:
- • Disc displacement with reduction
- • In the past 30 days, patient has had joint noises (click) with jaw movement or function with noises present during the exam.
- • Disc displacement with reduction with intermittent locking
- • In the past 30 days, patient has had joint noises (click) with movement or function, and jaw has locked for a moment with limited mouth opening.
- • Disc displacement without reduction with limited mouth opening
- • Patient has a prior history of a disc displacement with reduction with or without intermittent locking. At the time of the exam, patient’s jaw is locked, so the mouth cannot open all the way with limitations in jaw opening severe enough to limit jaw opening and interfere with the ability to eat.
- • Disc displacement without reduction without limited mouth opening
- • Patient has a prior history of a disc displacement without reduction with limited opening but currently no limitation in jaw opening.
- • Degenerative joint disease
- • At the time of the exam, joint noises (crepitus) with jaw movement.
- • Subluxation
- • In the past 30 days, patient complains of jaw locking or catching in a wide-open mouth position, even for a moment, so the patient could not close from the wide- open position and there is inability to close the mouth from a wide-open position without a self-maneuver.
- • If pain is accompanying any of the six IADs, clinicians should first consider myalgia and/or arthralgia as the patient’s primary source of pain. Myalgia and arthralgia should generally be viewed as mutually independent conditions unrelated to the six IADs [23, 24]. Achieving a satisfactory treatment outcome is initially dependent on making an accurate diagnosis of one or multiple TMD diagnostic subsets and differentiating between diagnostic subsets that are known to be painful (myalgia and arthralgia) from subsets that may or may not be painful (six IADs). Finally and equally important is developing a treatment plan that addresses the patients primary pain source.