The BiteFX Blog for All Things Relating to Occlusion

Premature Wear: The Hidden Causes - Follow-up Questions and Answers

Posted by Doug Brown on Mon, Jun 06, 2016 @ 11:06 AM

In May 2016, Dr. Alain Aubé, president of the Canadian Occlusion Institute, presented:

"Premature Wear: The Hidden Causes"

with the main goal:

"To better understand the masticatory system and its tendency to change"

In his presentation Dr. Aubé described the prevalence of TMJ disk displacement and walked through a number of case studies which illustrated the signs and symptoms of such displacements.

The presentation was very well received and stimulated many questions
- too many to answer in the allotted time for the webinar.

This blog provides Dr. Aubé's written answers to all the questions asked during the webinar, which I'm sure you will find most interesting.

Platinum members who missed this webinar can view it in the
BiteFX Members' Area under Webinar Recordings.

Non-Platinum members can call us to purchase viewing access.



Questions cover:

Diagnosis of Disc Displacements and Tools Used

Q1. (Dr. Donald Reid) Are these mostly lateral pole displacements and can't we observe these changes by joint sounds? 

A1. (Dr. Aubé)
Joint sounds are present in many different conditions. Most cases are both pole displacements. Sounds are not always easy to interpret, but they most often do indicate joint damage.

Q2: (Dr. Donald Reid) If we have an ' intact medial pole' meaning not a fully anterior displaced disk, can we use that as a reliable posterior border?

A2: (Dr. Aubé) If, but rare, the medial pole is truly intact, joint can be relatively stable.  

Q3: (Dr. Donald Reid) Do you use a T-scan to evaluate distribution of forces ... which would allow us to ensure non excessive pressures on the molars?  

A3: (Dr. Aubé) I used to use the T-Scan. Was one of the first users a long time ago. Do not use it right now, waiting for a future model I’ve been told should be coming out at the end of this year. The new model, I was told, should also measure objective force level which is what I require now to demonstrate and make objective measurements of the amount of force reduction. It is a good instrument.

Q4: (Dr. Donald Reid) The Doppler is an excellent tool but it’s almost prohibitive to take MRI's on all teenage girls?? What do we do to cover our butts?

A4: (Dr. Aubé)

Always consider the joints as being possibly injured. Most of them are.

Whatever you do, include it in your consent form.

Hopefully MRI will someday be standard of care. Look at “Imaging of the Temporomandibular Joint: An Update”  World Journal of Radiology, Aug 2014, by Asim K. Bag.

We image everything except the joint….why? 

Seriously …why?  

Isn’t the joint the cause of the most pain, headaches, severe and premature tooth structure breakdown?

Wouldn’t it be nice to know in what state it is?

The joint is the most influential part of the system relative to tooth structure loss.


Q5: (Dr. Donald Reid) I use a CBCT and can view the TMJ in slices and the joint space and even though there are lateral pole displacements the medial pole is totally silent during rotation motion and I have to rely on an intact medial pole and equilibrate the occlusion as best possible to prevent further anterior displacement.     

A5: (Dr. Aubé)

Joint space is a very good indication but not fully reliable as some displacements are not anterior but strictly lateral or medial … the medial pole can be off but the space can still be there if the disc only moved half way towards the lateral pole. If the disc slipped medial only, the lateral part is in the space over the condyle and again it looks like the space is there, but the medial pole is off and the joint can be unstable.

Do you also look at joint position? If the condyle is distal, the disc is forward.         

Q6: (Dr. Donald Reid) Deformed joints yes but if not showing bony changes on CBCT still stable – observation.

A6: (Dr. Aubé)

Stability of the joint is relative to three factors:

  • Effusion,
  • Potential disc movement and
  • Condyle breakdown.

Some joints have good bone but are unstable.

Q7: (Dr. Donald Reid) CBCT?

A7: (Dr. Aubé) Yes - when  both advantages and limitations are fully understood

Q8: (Dr. Richard Rogers) In your career, are you seeing this evaluation of the joints getting more frequently done in these cases or is it relatively infrequent?

A8: (Dr. Aubé) Sadly I see the cases that have had problems…my point of view may be biased…but I see and hear of only a small percentage of joint evaluation period…it’s just not in the thought pattern.   

Prevalence of Problems

Q9: (Prof. Dr. Liviu Steier) The claims published in the email invitations to this webinar ("Most patients have displaced discs" and "More than half the population has osteoarthritic damage in their TMJ's”) are not scientific. I have 100 MRIs of patients in Germany that would contradict these claims.

A9: (Dr. Aubé) Fact 1..most patients have displaced discs as demonstrated in the paper “Prevalence of TMJ disc displacement in a pre-orthodontic adolescent sample” by Brian Nebbe phd, professor University of Alberta, published Dec 2000, The Angle Orthodontist. The first serious study on TMJ disc displacement done with the only means of assessing disc position: MRI. Can’t argue with the results. Girls, age 15 or less, have 72.5% displaced discs on the left and 76.9% on the right. Combine the numbers and you get a whopping 94% of girls hat have at least one displaced disc. Boys…60% left, 63.6% right…over 80% have at least one….

I have personally looked at over 2000 MRIs of TMJs…rare, very rare are the normally placed discs

Fact 2. Personally have held stats on over 350 consecutive patients…based on radiologists’ reports…58% have osteoarthritic damage. I agree that this has not been published yet…but that doesn’t take the truth away from it. I have found osteoarthritic damage in children as young as 12yo.

We would each need to review each other’s MRIs to be sure we are analyzing them to the same standard.

Causes of TMJ Disc Displacement

Q10: (Dr. Donald Reid) So what causes this extremely high prevalence of the disk displacement in a nutshell? - Chewing gum, injury, or birth genetic deformity as we see in general with long faces and narrow jaws?

A10: (Dr. Aubé) Ligament breakdown is, through orthopedic principle, usually caused by trauma…but why are we so easily traumatized….many possible answers…genetics, pollution, hormones in food, soft diet…all possibilities…no real sure answer.

Q11: (Dr. Richard Rogers) I have heard some who have studied with Mark Piper to say that Class II occlusions do not occur in nature but are rather always a result of displaced discs. Do you agree with this position or do you believe there are Class II occlusions with healthy joints?       

A11: (Dr. Aubé)

Whatever my beliefs are…won’t change what the truth is….

I still have to see a class 2 with an intact set of discs…after over 2000 MRIs…have not met one yet…doesn’t mean they don’t exist.

Q12: (Dr. Hal Stewart) Wouldn’t the occlusion cause the displaced disc in the first place?

A12: (Dr. Aubé)

This is a possibility…but in most cases the discs are displaced at an early age.. see the Nebbe study…the permanent occlusion is not yet completed but the discs are already displaced.

As much as I do think that the occlusion can cause disc displacement…I must confess that observation leads to the conclusion that most disc displacements are caused early and by other causes…

I would more readily say that a poor occlusion, and the following excessive pressure on the joint, cause continued disc displacement and further joint injury.

Q13: (Dr. Hal Stewart) Dr. Aubé’s comment was that the disc displaces, then this causes the occlusion issue....I contend that the occlusal issue (outside of a traumatic accident) caused the displaced disc.

A13: (Dr. Aubé)

Again…observation and the Nebbe study presently direct to the point of view that early trauma caused the disc displacement and ensued a poor occlusion that in turn caused excessive pressure on the joint and a vicious circle is created.              

Treatment of Displaced Discs

Q14: (Dr. Donald Reid) Sounds like we need to treat all joints very early ...girls and boys. Have early signs ... what do you do to treat before they need the metal condyle (shown in one of Dr. Aubé’s slides)?

A14: (Dr. Aubé)

Discs can be recaptured only in childhood through dentofacial-orthopedics. But the disc must recapture in light protrusive.

If the disc doesn’t recapture in a child….surgical disc repositioning may be considered.

If you are past early adolescence, joint stabilization through a splint is the best way to start before equilibration…again I do not equilibrate until proof of joint relative stability.

Joints need to be diagnosed, and treated accordingly…exactly as decay…!!!

Q15: (Dr. Donald Reid) Headaches? Go away by equilibration so do we do that equilibration as early as possible and yet understand we'll need to further equilibrate as changes ensue.

A15: (Dr. Aubé) Yes!!!                    

Q16: (Dr. Donald Reid) But if the disk is still on the medial pole we are always equilibrating with non-fully displaced disk and trying to maintain an intact disk.

A16: (Dr. Aubé) As much as possible…!

Q17: (Dr. Richard Rogers) Interesting that Rheumatologists for years have prescribed 'light forces and repetitive motion' for the treatment and maintenance of Osteoarthritis. You have done a great job in explaining this principle as dentistry addresses arthritic changes in the TMJ. Light Forces = A Balanced Occlusion. Repetitive Motion = Restoring Proper Range of Motion.

A17: (Dr. Aubé) Orthopedic principles are one of my main sources…you are absolutely right Dr Rogers!!

Q18: (Dr. Philip Millstein) This is very tricky and then what do you do about it and what if the treatment backfires. 
I have seen too many setbacks and money problems that follow for the patient like lingering emotional problems and second and third mortgages. This subject requires much EBD before entering into treatment.

A18: (Dr. Aubé) 

This is a good point to discuss.

Yes the title was catchy. On purpose to stimulate interest and debate.

The statements however are true. B. Nebbe, Phd, demonstrated the prevalence of disc displacement in an article in The Angle Orthodontist in dec 2000. The study was MRI based, and the conclusions from radiologists. As for the osteoarthritic changes, they are my  2 radiologists' and my own observations of over 2000 cases.

When it comes to treatment, Dr Millstein is right that there have been many cases of unnecessary over treatment that have in addition caused more damage than good both to the patient’s health and wallet.

That era is over. Or at least should be.

Treatment today is simple and based on orthopaedic principles. For most patients treatment starts with a simple splint I will discuss in the next webinar. It is a slightly modified version of a popular splint, but the slight modification makes the whole difference. No other treatment is done before the patient’s joints are stable from a medical standpoint. Modus operandi is a combination of splint, physiotherapy and stress level management. In approximately 5% of cases the intervention of a maxillofacial surgeon is required. That first line of action is a simple I-PRF injection into the joint. If that doesn’t succeed sufficiently then arthroscopy with lavage comes next. By then 99% of cases are resolved. Only 1% require open surgery.

Joint stability from a medical standpoint means three things in addition to strongly reduced symptoms ( muscles and joints ) : A stable disc position, a non-degenerative condyle, absence of instability from varying levels of joint effusion.

Orthopaedic principles point to load reduction on an osteoarthritic joint. In the next webinar I will explain in detail how this is done using the proposed splint, both physiologically and mechanically. The load reduction is the key to most successes. It is a simple but sound, tested and accepted orthopaedic line of action. We have demonstrated, MRI confirmed, condylar cortical bone reformation where damage had been.  Our present success rate is high, very high, but still with limited numbers of patients ( 15 consecutive cases, 15 consecutive condylar cortical bone reformation). Many more will be needed to draw conclusions, and studies with control groups still need to be done. However the first results do seem promising. I will show a few in the next webinar.

Nothing is ever promised to the patient. This is a medical condition that is uncurable. We can manage it, help the patient, and do some level of repair, but by no means can we make « promises »  of this or that to the patient. Our successes are at the management level.

When and only when symptoms are strongly reduced and the joints are confirmed stabilized, then occlusal correction may be planned. Most patients require no more than an equilibration. Again equilibration, in the stated conditions, serves to reduce muscle hyperactivity and reduce pressure on the structures. Equilibration should only be done with stable joints. Equilibration should be done to maintain health, not so much to gain health, joint wise.

Some patients require orthodontics/surgery to be able to get a sound occlusal function. Equilibration usually follows. Some people can’t afford these treatments or just do not want them…we can go for a  compromise…light equilibration combined with night time wear of a splint. This is sufficient for many people.

Very few and rare patients require major restorative. The ones that do, need tooth work. We should not see restorative as a TMJ treatment…it is not. It comes when all else is good, and  tooth condition warrants it.

Hopefully these words will reassure Dr Millstein’s legitimate concerns.

Splint Therapy

Q19: (Dr. Donald Reid) Curious about types of splints Dr. Aubé uses and why per situation?

A19: (Dr. Aubé) Most of the time I use a full coverage permissive anterior flat plane with lightened posterior contacts…see on YouTube:  “Plaque occlusale parfaitement equilibree”

Q20: (Dr. Joseph Gaudio) Is there not a difference between a lateral pole displacement vs a medial pole displacement in terms of restorative treatment vs splint therapy?

A20: (Dr. Aubé)
A strictly lateral pole displacement is more stable. Can be restored with little worry.

A medial pole displacement can be less stable and often requires splint therapy to stabilize the joint before restoration.

Strictly lateral pole displacements are rare in my practice. Most often the medial pole will show some form of displacement as well. However the less displacement there is at the medial pole, the more stable the joint is.

Q21: (Dr. Joseph Gaudio) A full coverage splint and not a deprogrammer would be correct in splint therapy in order to minimize pressure on the joints and hopefully recapture the disc?

A21:(Dr. Aubé)
I do prefer full coverage over anterior. Better control over what is going on. Will detail in next webinar.

True disc recapture is rare. The disc displaces following trauma to the collateral ligaments. Ligaments don’t repair on their own. Even when a patient stops cliking, the disc is not necessarily recaptured. Instability may persist.

Q22: (Dr. Donald Reid) How can we take the pressure off the joint with a splint? McCarthy Farrar study used forward positioning appliances, did ortho and sometimes jaw surgery and the cases always released to a CR position?

A22: (Dr. Aubé) Will explain details in the splint webinar (during this webinar Aubé agreed to present a webinar solely on splint treatments – later scheduled for Tuesday, November 15, 2016), …forward repositioning is not necessary to reduce pressure…we get sufficient pressure reduction to get MRI confirmed cortical bone reformation just with our simple splint.

Q23: (Dr. Donald Reid) I don’t understand how we can ever take pressure off the joint with any flat or permissive split cause they can go to CR and then the joint is loaded.

A23: (Dr. Aubé) Through physiological and mechanical principles. Again…will explain details in splint webinar. But definitely possible.

Treatment of Class II Occlusions

Q24: (Dr. Richard Rogers) In your experience what percentage of cases of Class II occlusions, being treated with an orthognathic surgical approach, are being screened for TMJ/Condylar damage or changes?

A24: (Dr. Aubé)

OMG….not enough…..

Surgeons are starting to be aware of condylar breakdown as one of the main causes of relapse…some do bone imaging to assess condylar bone quality prior to surgery.

Dr. Aubé’s Classes

Q25: (Dr. Joseph Gaudio) Does Doc Aube provide CE courses on this topic?

A25: (Dr. Aubé) Yes in French!

Q26: (Dr. Joseph Gaudio) Can we do it in Paris?  :)               

A26: (Dr. Aubé) Of course!


See Dr. Aubé’s Presentation

Again, if you missed the presentation:

Platinum members who missed this webinar can view it in the BiteFX Members' Area under Webinar Recordings

Non-Platinum members can call us to purchase viewing access.

Tags: Dental Technique

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