Re: Dr. Simon Weinberg’s Letter to the Editor, September, 2005

While there are still disagreements as to the many causes of TMDs, the management of these painful, “ubiquitous” conditions has progressed dramatically over the past 35 years.

It has been well-established in the scientific literature that the accuracy of even detecting the presence of a TMJ internal derangement is about 50% … the flip of a coin. An accurate clinical determination of the type or stage of derangement falls further to about 15%. In fact, it is actually very difficult to find two clinicians who can independently agree (without consultation) on the same clinical diagnosis of internal derangement. That implies that a clinical diagnosis of a specific stage of internal derangement is probably most often no more than a guess! (Dworkin et al Clin. J of Pain, 1988, Paesani et al. Oral Surg Med and Path, 1992, Hardison & Okeson, Cranio, 1990).

While we agree with the statement, “the presence of pain in patients with internal derangements cannot always be explained on the basis of the internal derangement,” if a patient has an internal derangement and pain only in that specific joint, the two may well be related. One certainly wouldn’t just assume that the pain under those circumstances was of neurogenic origin. Nowhere in the articles by Rondeau and Marangos was the implication stated that all TMD patients have “posterior condylar displacement” (one diagnosis) or that anterior repositioning of the mandible is the universal TMD treatment (one treatment).

It is well understood by the authors that pain specific to the TM joint is usually only present in the acute stage of internal derangement, not the chronic stages. It is also understood that pain is often present in muscles, fascia, teeth, etc. that may be unrelated to either joint. The recommendations in these articles are specific to the patients presented and not suggested as universal approaches to all TMD cases. However, they may be very applicable to similar cases. In two, long-term, multi-centre studies in The Journal of Craniomandibular Practice, Gaudet and Brown (Jan 2000, Vol 18 No.1, and Oct 2002, Vol 20, No.4) report the outcomes of treatment and diagnosis. Mandibular positioning appliances were more effective than flat plane appliances in the treatment of disc displacements.

It is understandable that a surgeon would prefer surgical diagnostic procedures, such as arthroscopic examination or even a procedure as invasive and painful as arthrography, to a simple, inexpensive non-invasive procedure like JVA that any clinician can perform in his office in about five minutes. While JVA doesn’t always obviate the need for expensive imaging or surgical diagnostic procedures, it helps the general practitioner; 1) better understand the patient’s condition, 2) decide whether additional tests are needed and 3) whether a referral should be made. Since JVA is very often used as a screening test, it is less likely to be used in a referral practice. For example, by the time a patient is referred to an oral surgeon, hopefully, at least a tentative diagnosis has already been established. In Ontario, it is virtually impossible for a general dentist to order an MRI, the waiting list for surgical procedures is long and both the MRI and surgical procedures are invasive, expensive and far from conservative.

As we all know, scientifically, it is never possible to prove infallibility, only fallibility. Inasmuch as there are more than 30 well-controlled scientific studies published over the past 15 years that demonstrate the efficacy of JVA (there are none that demonstrate inefficacy), it seems odd that anyone who is involved in TMD would be completely unaware of JVA. Even Jeffery Okeson, who seems adamantly opposed to almost all diagnostic testing that involves measuring physiological variables, acknowledged as editor of the 1996 edition of the AAOP’s Orofacial Pain: Guidelines for Assessment, Diagnosis and Management that “A negative analysis finding [with JVA] is highly accurate for identifying a normal joint, and a positive finding is more accurate for identifying a reducing disc displacement than a clinician’s examination for joint sounds or a patient’s perception of joint sounds.” While no device can be expected to perform perfectly, it would appear that the overwhelming weight of evidence supports JVA as a useful tool to assist the general practitioner in his efforts to diagnose internal derangements.

In contrast, here is what Okeson, on behalf of the AAOP, has said in the same publication about arthrography: “Because of the invasiveness of the procedure, radiation, discomfort and the wide availability of MRI, TMJ Arthrography is limited to selected patients when dynamic imaging results will alter the course of treatment or when the arthrogram is immediately followed by a therapeutic treatment such as joint lavage.” It appears that TMJ Arthrography is also not considered a “standard of care” by the majority of TMD treatment providers.

Considering the dearth of scientific “evidence” on the subject, spontaneous remission may be no more than an indication that the patient has simply reached his or her “end stage” of the disease. As a rule, Stage five [Wilkes] joint conditions are non-painful, regardless of the degree of degeneration of the joint and concurrent loss of function. When the condylar compression of the richly innervated posterior attachment tissues has continued for a period of time, the tissues denervate, devascularize and either resemble connective tissue (sometimes referred to as a pseudo-disk) or, in some cases perforate. In any case, the acute pain usually subsides. It is also true that internal derangements do not always progress. Some reach stability at each stage along the established progression. However, it is also not possible to predict at what stage a given patient will spontaneously stabilize. Therefore, it is incumbent on the TMD practitioner to; 1) be aware of his/her patients’ TM Joint status, 2) monitor any progression of disease and 3) keep patients informed of all treatment options available.

While it is true that joint vibration analysis is not recommended as a “standard of care” in the diagnosis of temporomandibular disorders by the American Association of Oral and Maxillofacial Surgeons, it is has been officially “accepted” as such by the American Dental Association for more than a decade!

“BioJVATM is accepted as a measurement device for the evaluation of the temporomandibular musculo-skeletal complex. Responsibility for the proper selection of patients for testing and the interpretation of test results rests with the dentist.” [Council on Scientific Affairs, American Dental Association]

With respect to the issue of condylar position as seen on tomograms, it is true that errors in the procedure can occur that distort the image. However, when successive x-rays are taken of the same joint by the same technician with the same machine they are substantially reduced. In the case you are specifically referring to, there were 3 slices (views) taken (as is the case with each patient), a lateral cut, center cut and medial cut. The variation in normal anatomy is certainly an option, but this would usually be seen only on one cut. For this patient it was seen on all 3 slices suggesting more than an anatomical variation. Again, according to Okeson and apparently the AAOP, “Tomograms can show narrowing of the joint space and thereby suggest disc displacement without reduction. Corrected tomography depicts bony changes at various lateral to medial sections, and is preferred over transcranial projections, ARTHROGRAMS and MRI for identification of osteoarthritic changes.” Without having to invade the joint, tomograms seem to be a very useful diagnostic tool.

Finally, it is encouraging that this issue has stimulated a dialogue and discussion about TMD; this is long overdue. The guidelines you have referred to date back to 1995. The way we practice dentistry today is very different from 10 years ago in all areas of dentistry, restorative, periodontics, endodontics, implant
ology, orthodontics and even surgery. What makes us think that the area of TMD and craniofacial pain are immune from change? With your comments and thoughts, we should encourage a change or review of the RCDSO Guidelines of 1995. Just because someone has not heard of something (JVA) does not mean it does not exist nor does it mean it is not a useful instrument in the diagnosis of TMD. Aristotle stated, “Without diagnosis there can be no treatment.” The ultimate goal here is to have patients who are pain free, can function and are stable orthopedically.

Dr. Dennis Marangos, BSc, DDS