The Right Bite - Dentistry going through Change

X-Ray of Jaw Area

X-Ray of Jaw Area

CMD, pain in the jaw, occlusion, pain in the jaw joint – these are the subject of frequent internet searches and it’s always about the jaw joint.

What’s new about the right bite and functional analysis? We’d not only like to give you a little specialist knowledge here but also to demonstrate a new development in dentistry concerning the face-bow and axiography.

Generally speaking, medicine is going through an exciting upheaval at the moment, one which is also causing excitement in dentistry. Only those with a good overview of the changes will be able to use the best ones for themselves. By means of this article we’d like to show both patients and dentists some of the most important current and past developments and illustrate their effects by means of a concrete example.

Generally change finds that on the way from a completely subjective empirical to an evidence based medicine this development doesn’t reach its conclusion for a long time. At present the scientific community is busy with intense discussion whilst getting more and more detached from the patient’s practical point of view. People and animals are being compared time and again with robots, appliances and machines even though living biological entities can only be compared with the greatest of care to non-living systems. The conclusions of such observations must be interpreted very carefully – more about this in the following text.

Conventional Medicine Going Astray

The mechanistic point of view was and is usually very helpful to medicalisation. However today we know that in many cases it is not people but rather mainly corporations busy in the health sector that are doing well.

The industry quickly realised, early in the 19th century that it could make a lot more money out of chronic illness than out of good health. Many doctors played and play a part in this (Hans Weiss "Korrupte Medizin – Ärzte als Komplizen der Konzerne" Kiepenheür & Witsch). For this reason, pharmaceutical companies have, for time immemorial, invested a hundred times more in advertising and marketing than in scientific research. (Hans Weiß "bittere Pillen" Kiepenheür & Witsch). Very few patients know that much of the medicine on the market has not been adequately investigated and, objectively considered, is not of much use. (John Virapen "Side Effects Death – Confessions of a Pharma-Insider" Mazaruni).

Alternative medicine: Different Philosophy, Similar Methods

Most of you have heard the buzzword with which the great change in medicine began in 1990: ‘Alternative Medicine’. Unfortunately this new movement soon got commercialized and today alternative medicine is marketed very profitably under numerous names: gentle medicine, traditional medicine, orthomolecular medicine, homeopathic medicine and so on.

Once again people are trying to make money out of others‘misfortune and on the shakiest of scientific bases. Millions of patients are being led on lucratively towards the ‘light’ by big-interest groups. This time, however, it won’t take a century for people to realise what a swindle it is, as once happened with conventional medicine.

Important: Not all companies and doctors behave this way. Just recently there has been a big rethink, especially amongst doctors.

The Trend to Evidence-based Medicine

No matter what we call medicine, the use of a treatment should be proven by reliable data originating from scientific, sustainable research work. The values and wishes of patients should be able to be integrated and the consulting doctor should be up to date with research. Empathy, tolerance, and ethics should take on an increasing role in medicine.

These basic values arise from the so-called evidence based medicne (EBM), the internationally acclaimed top standard in medical research and care. This is the current trend in medicine. In EBM research and treatment methods are comparatively complex but more and more doctors, researchers, corporations and patients are seeing the advantages of this thorough and patient-friendly approach. More about this in the article "Evidence Based Medicine".

Checkdent.com backs this re-think together with many dedicated colleagues and companies.

Changing Medical Ethics: The Face Bow, an example demonstrated

Face Bow

Face Bow

The story of the face bow illustrates all these developments in dentistry very clearly; by means of the jaw joint and the face bow we’d like to show you the ethical evolution that is taking place in medicine at the moment.

Prior Knowledge about our Bite

The facebow was used in dentistry as a diagnostic aid – was used, since the facebow has no longer been used for some time.

The jaw joint is a hinged joint with a lot of room for jaw movements. A knee joint, in comparison, is a joint with little room for movement as movement is limited by bone and ligaments. Not so with the jaw. We can move our lower jaw forward, backward and to the side in addition to the turning movement. The heads of the lower jaw have no real place of their own in the large socket. In people with teeth the location of the lower jaw and thus the lower jaw heads depends on the presence of teeth in the lower and upper jaws.

The problem with the lower jaw heads‘ position

So where would the lower jaw and therefore the lower-jaw heads come to rest when there are only a few – or indeed no – teeth ? The answer is simple: wherever they feel comfortable.

Doctors aren’t interested in „feeling comfortable“ as there are too many new developments which needed to be tested and so people started, with the introduction of the x-ray, to measure and categorise all areas of the human body, including the skull.

In the x-ray the rear-upper was the highest point shown of the socket and so we came up with the theory that the lower-jaw heads should come to lie on top at the back, i.e. at the highest point.

This theory was not really examined or closely questioned, it was simply installed in the medical profession by the dominant opinion makers. Most of these opinion makers are university professors. I’m sure you know the story about the Emperor’s new clothes. In a short time, with the aid of industrial business interests we not only had a new “optimum position” of the heads of the lower jaw but in addition the necessary devices such as the face bow had been developed so that dental technicians could replicate this "optimum position" which the matching replacement teeth had to conform to. The teeth were fixed to the prosthetic plate depending on the position of the lower jaw in relation to the upper jaw in order to achieve the ideal dentition.

And so many patients‘ lower jaws were dragged into a new position thanks to the new replacement teeth in which the lower-jaw heads came to lie high up at the back. The result was disappointing as many pain-free people suddenly started to feel strong facial pains thanks to their new prostheses. Doctors at first didn’t find this particularly interesting since other sources of pain were discovered. In this context one was very well-liked – the so-called trigeminal neuralgia. Many patients were driven from pillar to post by their pain and often ended up needing psychiatric treatment as a result of their peregrinations from doctor to doctor. The source of the pain was often a badly-fitting prosthesis which brought the lower jaw into an uncomfortable position.

Why uncomfortable? Now then, at the back and top of the jaw joint socket there’s a cushion made up of connective tissue which doesn’t show up in x-rays. (In x-rays only hard tissue, i.e. bone, is visible but not connective tissue. This cushion has blood and lymph vessels and nerves running through it. Due to replacement teeth the new position of the lower jaw leads to a compression in this cushion by the heads of the lower-jaw bone – ouch!

Jaw Joint

Jaw Joint

A few years ago people reacted to this situation. A new thesis was advanced: the lower jaw heads shouldn’t come to lie at the top-back part of the jaw joint socket but rather at the top-front part. However, we’ve kept something back from you: throughout all this time when there was much amateurish puzzling and research about the position of the heads of the lower jaw, where these new positions were tested on patients, unfortunately not by means of studies, a truly amateur science developed. Suddenly lots of doctors began to focus on research on the joint of the jaw. Wild theories were put forward and defended without ever meeting evidence based medical criteria. The patient was never a priority and problems weren’t treated, only symptoms such as, for example, a drifting of the lower jaw to one side. More about this in the video ‘Myoarthropathy’. Nowadays we know that this is a normal drift which doesn’t require treatment. This medicalisation however had a purpose since more treatments brought in more money for doctors and for the industry, or so they thought. Something similar can be seen in all branches of medicine with regard to addiction illnesses (Sylvia Kloppe – die Konstruktion der Sucht).

Seen over a long time such a situation would only increase people’s suffering but we find ourselves in just such a way of life. We can therefore still read in the internet and in specialist medical publications thousands of non-serious articles about the joint of the jaw, about jaw joint fluids (athrocentesis), about occlusal splints and about functional analysis.

All these activities about the joint of the jaw and the position of the heads of the lower jaw bone are encompassed by the term functional analysis in dentistry. The techniques of functional analysis are now being examined by a team of scientists who believe in evidence-based guidelines and the results are a cause for concern. The methods of functional analysis are not reproducible and all the data available is incorrect. (Tinnemann P et al "Zahnmedizinische Verfahren der instrumentellen Funktionsanalyse unter Berücksichtigung gesundheitsökonomischer Aspekte" Health Technology Assessment 2010)!

Just as before we find countless articles which give incorrect information about this theme to young doctors. The relief of the chewing surface is thus connected to the inclination of the articulation of the jaw socket – specialists speak of inclination of condylar guidance. We try to determine the inclination of condylar guidance with the help of various appliances, thus with the help of the so-called axiograph to match the condylar guidance with the top surfaces of the teeth.

By means of the axiograph movements of the lower jaw are described with the assistance of various instruments. Through the paths of the movements of the lower jaw we then try to calculate the inclination of the condylar guidance mathematically. Since this procedure is very complicated and mainly only catered for in universities, the facebow has been developed for the ‘settled’ areas. By this means it should also be possible, according to the scientists for the "small" dentist to determine the position of the upper jaw in relation to the rest of the skull and then to transpose these values to an Articulator.

Dental Articulator

Dental Articulator

An Articulator is a machine which attempts to simulate chewing movements. New developments appear frequently (Wire Occludator, Evans Occludator, Wustrow Articulator, Grittmann Articulator, Gysi Simplex Articulator, Eltner Articulator, Gysi’s, Schröder’s and Balter’s Rotations Articulator, De Trey Articulator, Földvari System, Dentatus Articulator, Biokop and many others). The idea is that with the data which one gains from axiography, the facebow and the impression of the dentition one programmes the articulator so that it simulates the individual’s chewing movements. In practice this method has never succeeded since the investigations are not reproducible, are susceptible to error and are as such illogical (Morneburg TR et al "Anwendung des Gesichtsbogens beim funktionsgesunden Patienten im Rahmen restaurativer Massnahmen“ DGZPW 2010).

Why not reproducible?

The facebow and the cradle of the axiograph are placed over the skin on reference points of the skull. The skin however has a certain amount of play, that is to say a certain flexibility, expansibility, what we call resilience, so a reproducible result is never possible. Now you’d think that a couple of millimetres shouldn’t make much of a difference but consider how you feel when you bite into an apple and a sliver of apple skin gets stuck between your teeth. The few µm of apple skin feel like a metre when stuck between your teeth. How can you manage to get a good representation of the dentition with the help of an appliance that doesn’t take into effect several millimetres of play?

Why illogical?

Since axiography is expensive and in addition it has been seen that the values it achieves are not reproducible it is seldom made use of. The data of the axiography is however needed for the programming of the Articulator in order to be able to fix the inclination of the condylar guidance. So, if it hasn’t been calculated an average which has again been obtained by means of the inaccurate axiography method is simply programmed instead. If you think about the example of the apple skin then it will be clear to you that this cannot work since your condylar guidance doesn’t conform to an average value.

Why do some dentists continue to insist on the right bite?

To many dental technicians and dentists the Articulator and the facebow mean nothing but frustration but some dentists swear by the facebow. Why?

As explained above, according to the concept of functional analysis the dental technician needs the bow, the data from the axiography and the impression of the bite in order to programme the Articulator and to be able to fix the plaster model of the jaw in the Articulator "correctly in the skull".

Ideally the teeth of the plaster model should then fit together just like they do in the mouth but this never happens so the plaster model is unceremoniously and simply articulated in the Articulator according to the remaining teeth and not according to the data. The dental technician finishes the prosthesis as usual according to how he is used to doing so, however he doesn’t need to discuss this ill-fitting prosthesis with his client, the dentist and doesn’t run the risk of perhaps losing his client. The dentist is happy, the technician is happy and so developments take their course. What do you think will happen when a dentist, after 30 years of experience with the facebow, reads this article?

Although the meaningfulness of this method of investigation has long been doubtful, indeed has been refuted, many dentists still believe firmly in the facebow, for the above-mentioned reasons – have a look at ‘The Emperor’s New Clothes’!

It’s not only the face bow that’s a must in jaw-joint diagnostics and therapy, there are many such examples which are propagated by the same school of thought, such as, for example, that patients who grind their teeth also often suffer from muscle and joint complaints. This, however is not correct (Manfredini D. et al "Relationship between bruxism and TMJ disorders" Oral surg Oral med Oral Pathol Oral Endo 2010). Neither is there any relationship between the position of the lower jaw and any possible jaw-joint problems. The entire diagnostic imaging of the jaw joint is being called into question. Many jaw joints look terrible in x-rays and MRT scans yet their owners have no problems! In comparison there are radiological images where ‘textbook’ joints are depicted and yet these patients complain of pain. More about this in the videos ‘CMD’ and ‘TMJ’.

These developments aren’t limited to dentistry. Over 75% of knee investigations are, according to evidence-based examination, useless, unnecessary or incorrectly interpreted (Hofmann B "Too much of good thing is wonderful" Med Health Care Philos 2010)! Critical questions are being asked more and more frequently and published in studies – "Just what are we doing to people?"

Many physicians unfortunately only observe their immediate area yet, thanks to the internet and the resultant networking, the flow of information is getting better all the time. Portals like checkdent.com are working hard to improve this networking but we’re still at an early stage.

What do we mean by „Observe their area”?

We’d like to give you one last example. Two physicians, A and B, both experts in their field, treat patients with bone inflammations, in different cities. Physician A receives numerous patients from all over the country, since he is well-known for his experience and a good approach with the medicinal treatment of cases of bone inflammation. Physician A can heal more than 80% of the patients that come to him. The remaining 20% he passes on to physician B.

Physician B is a surgeon who receives patients not only from physician A but also from the entire country in those cases which cannot be treated successfully with medication. Physician B doesn’t know about the 80% cure rate, he only sees what works for him, namely the scalpel and the saw. Would you ask physician B what he thinks about medicinal therapy for bone inflammation?

When we write about change, it’s a slow process. Many developments must be taken into account and the industry always measures the success or failure of a treatment in terms of growth of revenue. Medicine cannot only be measured in terms of growth since something which takes a long time to grow will be considered as malignant in medicine and would eventually kill the business.

Checkdent is committed to being a platform for dedicated dentists, companies and interested patients and stands for serious, fair-to-patients access to research, science and medicine.

This post is also available in: German

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