“He who rejects change is the architect of decay. The only human institution which rejects progress is the cemetery.”
Harold Wilson, British Prime Minister
Text, New York Times, January 24, 1967, pg. 12
When I was a much younger dentist, which now seems ages ago, I thought I had a lot of answers and not too many questions. Now, of course, it’s the opposite: I have a few answers, but plenty of questions. Many of those questions revolve around the controversies involved with the diagnosis and treatment of temporomandibular joint (TMJ) problems and related orofacial pain. I thought I’d help myself out by ordering and carefully reading a spate of glistening new textbooks on the subject. I thought I’d find answers. All I found was more questions! The question that stands out from the rest is why is there a definite dichotomy between what a certain viewpoint in academia says, and what a certain viewpoint from the clinical world says? I think I have discovered several important reasons, and have devised a simple solution that may resolve at least some of the difficulties responsible for such polarization of opinion.
There are a number of huge mistakes being promulgated and/or that remain pathetically unresolved in the current ranks of organized dentistry. One of the chief areas of concern is the rift between the steadily evolving yet contradicting schools of thought on the relationship of dysfunctionally-induced TMJ pain-dysfunction disorders (or whatever you want to call it) to occlusion in general and orthodontics specifically. The politically correct effete in our profession like to refer to it as a diaphanous conundrum. However, due to the surprising levels of contentious controversy that still envelop this theater of operations, it just might be better described in two more common words of every day language, i.e., an embarrassing mess. In a profession filled with highly intelligent and ostensibly well-educated individuals, why is this so? Many reasons could be paraded out, but in an effort to parse purple passages of propaganda, a more agrestic view of the issue might resolve itself down to a representation of the problem by two other common, everyday words, i.e., class and homework!
With respect to the former, i.e., class, much of the culpability for modern organized dentistry’s inability to resolve the endergonic controversies in these areas can putatively be laid squarely at the feet of one of the founding fathers of the discipline of orthodontics itself, Dr. Edward Hartey Angle (1855-1930).
The tripartite classification system of malocclusion into the three broad categories of Class I, Class II, and Class III that was originally developed by Dr. Angle has stood as a telamon of diagnostic description that has been universally used in the world of orthodontics for over a century. There is only one problem with it, and it is a big one. It is obsolete. This fact appears to be responsible for some enormous consequences.
At the heart of all the controversy over what constitutes correct diagnosis and treatment of that certain pathophysiologically degenerative orthopedic, neurologically manifest global mosaic dynamic flux referred to (sometimes) as temporomandibular joint-pain-dysfunction disorder (TMJD), is surely the central notion of the actual significance of functional condylar position. There is one school of thought which holds that it has everything to do with the dysfunctionally induced TMJD symptomatic picture.
An opposing school of thought basically contends that it does not. (Both are actually right.) One thing however is certain. Both sides feel compelled to cite the literature to act as a source of support for the veracity of their position at the expense of the repudiation of the other’s. Does this mean that somebody’s literature is lousy? Yes, probably so. But if so, why? Could it have anything to do with the type of measuring rod being used?
Let us suppose, for the sake of argument, that a group of investigators wish to study the relationship of TMJD to malocclusion, a seminal and contentious subject indeed. Using the traditional Angle Classification System of malocclusion to categorize occlusions for analysis in such a study would be the equivalent of using an old fashioned 12-inch wooden straight ruler to precisely measure the exact length of a common chicken egg. Might not be the best tool for the job, especially if you want to be really accurate. It appears that the same type of problem has haunted some of the research done in the field of TMD in the past. Here’s why.
What is a Class II malocclusion? Is it dental, skeletal or some combination of both? How does that relate to just where the condyle is seated in the fossa in a given Class II case at full occlusion? Is it possible to have a dental Class II malocclusion of teeth in a skeletal Class I lower jaw to upper jaw cephalometric relationship? If so, what does that have to do with just where a given condyle seats in such a given case? Could such a combination of any type of Class II (whatever that means) arrangement of teeth and jaws exist in conjunction with a related condyle that is anatomically seated in the fossa, solidly on the disk at full occlusion in an internal joint relationship such as a Gelb 4/7 position? Conversely, could a nearly identical cephalometric, Class II skeletal/dental arrangement exist in conjunction with a related condyle that is excessively superiorly and posteriorly displaced in the fossa at full occlusion and off the disk? Are they the same? Is one a true Class II (whatever that means) and the other merely a skeletal Class I sized mandible that has become progressively displaced over time to the point where it now represents a Class I mandible bodily deflected as a whole by the fit of the related habitual occlusion back posteriorly to where it now merely appears cephalometrically to assume a skeletal Class II disguise? Would the severely displaced condyle in the fossa, off the anteriorly displaced disk at full occlusion, be the indictment? What would the overall total length of the mandible in these two compared scenarios have to do with it all? Could a given condyle be slightly, or even severely posteriorly displaced, up off the displaced disk in the absence of any major symptomatology? If so, what do you do about it? What if, in such a scenario, orthodontic treatment is required: what should be done then? What if it is an adult patient who merely needs a single molar crown? Would treatment be different if, instead of a single crown, a number of crowns and/or fixed bridges were needed? If so, how?
The same holds true for Class I malocclusions. What is a skeletal Class I malocclusion? Is it a maxillo-mandibular Class I relationship of anterior skeletal cephalometric reference points only, a normal appearing jaw-to-jaw relationship that is merely harboring passenger teeth that are somehow dentally maloccluded? Could such a Class I malocclusion exist in conjunction with a condyle that is superiorly and posteriorly displaced, up off the disk, at full occlusion? If so, why? Is it because, due to the individual relative proportions of total mandibular length, it is merely a skeletal Class III malocclusion of a displaced, posteriorized, oversized mandible, presenting itself in cephalometric skeletal Class I disguise, again with the severely posteriorly displaced condyles, up off the displaced disks at full occlusion being the proof? Is it then still a Class I, or would it be considered a pseudo-Class I, or a “housed” Class III relationship? Aren’t mandibles and condyles connected together all in one piece? What are you measuring?
And what about that condylar position at full occlusion? What does it mean? Some say everything, some say nothing! Regardless of what type of skeletal and/or dental malocclusion is driving the condyle into place in the fossa at full occlusion, what causes symptoms? Could there be major classic TMJD symptomatology (whatever that means) in a case where the condyle is seating normally in the fossa, squarely on the disk at full occlusion? If so, what then would it be from? The occlusion? If so, why? If not, why not? And if there are major TMJD symptoms with accompanying headaches/neckaches/facial pains and reciprocal clicking in conjunction with a condyle that is both superiorly/posteriorly displaced up off a torn loose, anteriorly displaced disk, are such symptoms related to the degree and severity of posterior condylar displacement? What role does host resistance play? What is to be implied when the condyle in such a scenario is repositioned permanently via anterior repositioning techniques and the cadre of headache, orofacial pains, and other symptoms associated with the case dramatically subside with due dispatch? Is that a quid pro quo relationship? If so, how does it relate to the type of occlusion (or malocclusion) extant, either skeletally, dentally, or in combination? Does the occlusion have anything to do with condylar position? Is that a quid pro quo relationship also? Do the nebulous terms Class I, Class II, and Class III have any significance whatsoever in categorizing such circumstances? Are there Class I, Class II, and Class III condylar relationships in the fossa at full occlusion? Such has never been defined. Why not? What would it mean if it were? How would that be described relative to Angle’s malocclusion classification system? How would that relate to manifestation of symptoms, and what constellation of symptoms would they be? Would these symptoms include chronic recurrent headaches? Would those symptoms include migraine phenomena? If so, why? What are we talking about here? Someone help me out!
So, if certain studies are conducted to explore the relationship of malocclusion to signs and symptoms of TMJD, what good is it if the malocclusion definitions do not include, or fail to consider in any way, that particular malocclusion’s individualized relationship to condylar position effected by the habitual fit of its own teeth at full occlusion? And further, what if the effect of condylar position at full occlusion and its relationship to signs and symptoms is undefined? How could investigators engage in any sort of intelligent discussion whatsoever on the relationship between TMJD and malocclusion, when the term malocclusion as related to condylar position at full occlusion has no true accurate definition regardless of how Angle defines it? And what do they mean by symptoms? What symptoms constitute real TMJD? Would that be symptoms of masticatory muscle myalgia, hyperalgesia, and allodynia? Would it be TM joint arthralgia, either static or functional? Would it include headaches? If so, what kind? Would a more global view of the problem, which is the way the body actually deals with it, be more revealing? Are we standing too close to the specimen we are examining?
How can any reasonable person draw any sort of conclusions at all from studies conducted that examine the relationship of TMJD and malocclusion, when the two key components of such investigations, e.g., malocclusion and TMD, have incomplete, inaccurate, meaningless definitions? In the real world what could such studies really say? Would it be something valid enough that one could justify staking an entire career on it? What meaningful conclusions could actually be drawn? What true significance could they have in the grand scheme of things? How much credibility should one place in them? The answer is obvious. None!
The above problems have led to an expressed concern noted by certain individuals in recent times over the “. . . failure to achieve science transfer . . .” from the academic research community in orofacial pain to the clinical community. This is not as big a problem as the complaining academics think it is. The real problem lies in something far more sinister. The difficulties described above associated with the process of generating a body of dependable literature on the relationship of TMJD to occlusion, difficulties that occur due to failure in key definitions used in such research, are not in that it generates a “. . . cognitive dissonance . . .” in members of the clinical community, but rather that it allows the protected emergence of something far more pernicious—an agenda!
Citing of the literature in science is common and accepted. Selective citing of carefully culled literature to support a favored position amidst controversy is understandable. Selective citing of literature that itself is based on construct flaws that fail to coincide with the universally observed results of others merely to support an idee fixe is perverse. This is especially so in the noble profession of health care, which is grounded upon sincere efforts of forthright individuals to better the hapless plight of their suffering fellow man.
In order to conduct intelligent research and more meaningful communications in the future in the realm of the appropriate diagnosis and treatment of TMJD, a number of things could be done. One simple but highly effective thing that would prove of great service is the expansion of the Angle system of classification of malocclusions. It could be expanded in the following way.
As an important serif to the existing Angle classification system, a denotation of defined condylar position at full occlusion could easily be added as an addendum to the existing classification construct. Only two further simple designations need be used. These would be the designations, Condylar Class I and Condylar Class II, and their clearly understandable and simple definitions would be as follows:
• Condylar Class I: Condyle on disk at full occlusion with a posterior joint space equal to or larger than the anterior joint space of condyle outline against fossa outline.
• Condylar Class II: Condyle off disk at full occlusion with a posterior joint space equal to or smaller than the anterior joint space of condyle outline against fossa outline.
This system, of course, implies the acquisition of an appropriate joint image of some sort that can be evaluated in conjunction with its related extant occlusion (malocclusion). It is also applicable to any qualified type of individualized joint image (except panographs), since it is based on condyle/fossa joint spacing ratios at full occlusion, and not on linear measurements. Simple!
For example, instead of merely describing a certain occlusion as a Class II, Division I malocclusion, the more descriptive term, Class II, Division I, CC-II (Condylar Class II) could be much more meaningfully substituted. Or instead of describing an occlusion as a Class II, Div. 2, it could be described as Class II, Div II, CC-II. A Class I malocclusion could also be more clearly defined as either a Class I, CC-I or Class I, CC-II malocclusion, something that could represent a huge difference with respect to categorizing samples of various types of malocclusion as related to TMJD symptomalology. One can readily discern how this would likely significantly alter the outcome results of many studies already performed on the TMJD/occlusion relationship that did not use such a malocclusion categorizing system. That being said, this begs the question as to what changes would then possibly emerge, and how would the conclusions differ? Would they even differ at all? It would seem likely. The system is simple, direct, easy to employ, and right to the point, something the world of TMJ is not exactly famous for in recent times. Its universal adoption would also render an orthodontic diagnosis of malocclusion incomplete (and therefore
not within the standard of care) without an adequate pretreatment joint image. (It would also have a pro-found effect on the area of prosthodontic full mouth rehabilitation.)
With respect to the second of the two words alluded to at the beginning of this treatise, homework, much more of it needs to be done by certain factions in the field of TMJ, as well as its sister discipline, orthodontics. This is true, not of most of the rank and file of common practitioners in these two intimately related disciplines, but rather by the few who take agenda-driven, extremely polarized positions in the two respective fields. (They really are one and the same in a global sense.)
In brief, orthodontics has to accept the fact that, like it or not, it is intimately one with TMJD therapeutics on an orthopedic and myofunctional level. Similarly, the “GMDF” (Global Mosaic Dynamic Flux) of the field of TMJD diagnosis and therapy is intimately entwined with not only occlusion, but also necessarily with that subsection of the discipline of orthodontics that is known as Functional Jaw Orthopedics. The two subdivisions of ortho and TMJ are symbiotic fraternal twins of the mothering super-science of Global Maxillofacial Orthopedics, plain and simple, and the literature agrees. You just have to know where to look and how to interpret what you see. That changes everything!
Terrance J. Spahl, D.D.S.
Saint Paul, Minnesota
© 2009-2012: The Journal of Craniomandibular Practice. Site by Medium