What is Temporomandibular Joint Disease?

N.B. Work in progress, subject to revisions and additions.

MPD vs. Intra-articular Disease

One of the most important concepts to understand is the basic difference between true interarticular disease and the myofascial pain complex of symptoms which the lay press tends to erroneously label as TMJ. These two entities can, and often do, coexist but they are not synonymous. In patients where both are present it is almost always helpful and desireable to treat the MPD first and then address the interarticular pathology. The most notable exception to that treatment sequence is the onset of acute interarticular disease in a previously healthy joint.

Surgical vs. Non-Surgical Treatment

For MPD the majority of treatment options are non-surgical however, some consider brisement used for trismus secondary to immobilization syndrome a surgical procedure. Warmth, massage, physical therapy including range of motion exercises, non-steroidal anti-inflammatories reduction in parafunctional activity and patient education form the bulk of the treatment protocols. Many practicioners believe in the construction of intraoral "splints" of a variety of types to treat parafunction. Some purport to treat interarticular disease with these devices. The ability of such devices to treat interarticular disease is not supported by the scientific and orthopedic literature. Their efficacy in the treatment of muscle spasm/myofascial pain is perhaps a little higher but often no better than what can be obtained through the utilization of over the counter rubber mouthpieces such as are provided for high school athletes in contact sports.

True intra-articular disease which requires treatment almost always is best treated with "surgical" intervention though that intervention may be very minimal in nature (for example the diagnostic/therapeutic block described later). It is important to note that radiographic changes and/or joint noises without limitation in function or pain are not necessarily indications for treatment.

Etiology of Intra-articular Pathology

Macrotrauma
Microtrauma
Degenerative Joint Disease
Systemic Illness
Anomalies of Growth and Development

Characteristics of Intra-articular Disease

Condylar Deformity
Fossa Deformity
Meniscal Deformity
Soft Tissue Deformity
Ankylosis and Adhesions

Diagnosis

Treatment Rationale

Isolate Variables

Within the population that presents for "TMJ" are many subpopulations. These include:
Patients with True Intra-articular Disease
Patients with Myofascial Pain
Patients with both Myofascial Pain and True Intra-articular Disease
Chronic Pain Patients with or without Intra-articular Disease

It is important to isolate the variables and treat each accordingly. Treating the signs and symptoms of non articular disease first often helps patient and doctor to set reasonable surgical goals. This may require a multidisciplinary approach particularly in the case of the chronic pain patient.

Conservative Modalities First

The single most important caveat here is that what may appear to be conservative treatment may not, in actuality, be either the most conservative course or in the patient's best interest.

Consider this example: A 38 year old white female with a long history of both MPD and TMJ now presents with acute onset of closed lock (inability to attain an internincisal opening of greater than 10 mm) s/p trauma one week prior to presentation. MRI reveals anterior displaced right meniscus without reduction. Patient has been self medicating with nonsteroidal antiinflammatories resulting in relief of pain at rest but continued pain on function and continued close lock. The most conservative treatment for this patient at this time is to immediately reposition the disk and restore the range of motion.

Surgical Options

Arthrocentesis
A relatively simple in office procedure which allows expansion of the joint space, lysis of adhesions and lavage via blind input and outflow catheters. The advantages include low cost to the patient secondary to the surgeon's ability to perform this procedure in the office and low morbidity. Disadvantages include: lack of visualization, only limited ability to lyse adhesions, almost no ability to reposition the disk except via insufflation of the joint space and indirect manipulation.

Many practicioners consider a diagnostic / therapeutic intracapsular injection to be a variant of arthrocentesis. In this case, there is no outflow catheter but medications may be instilled into the joint space and the capsule is certainly insufflated by the amount of fluid in the injection.

Arthroscopic Surgery

A highly touted form of treatment in some surgeons hands and spurned by others, this modality allows visual access to the joint space. As a diagnostic tool it's greatest strength is the ability to "see" and record the state of the hard and soft tissues of the joint. Disadvantages nclude: increased cost as compared to arthrocentesis and other in office procedures, need for outpatient hospitalization, need for general anesthesia.

Operative arthroscopy while technically possible, and a viable tool in selected cases, often takes longer and usually allows less surgical flexibility than an open joint procedure. The perceived benefit in most patient's eyes is "a smaller procedure, a smaller scar".

Open Arthroplasty
Joint Reconstruction / Prosthetic Joint Replacement

Conclusions

1. Not all patients with preauricular pain have intra-articular disease.
2. Many patients with true internal derangement also have MPD.
3. Elimination of MPD symptoms prior to surgery increases the chances for success.
4. Physical therapy/rehabilitation is likely the single most important factor in successful surgical cases.
5. The first operation is the best chance to "cure" the disease.

Copyright Kim E. Goldman, D.M.D. 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 2004

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