Occlusion and interceptive techniques

Occlusion and interceptive techniques

28 Jan 2011

Dr Tif Qureshi, BACD President-elect, discusses occlusion and interceptive techniques...

Occlusal disease, in its various forms, is the number one reason most restorations fail.1 Yet, thinking back to my university training, it is the part of dental university education I remember least – except for one lucid moment highlighted at the end of my article. 

The most vivid memory I have is extracting a four-year old’s upper incisors under general anaesthetic in a mess of blood and my own sweat – something I have never done since, and never want to do again, but, every single day, we all see patients presenting with occlusally-related issues.

For most of us, it is something we learn by watching lectures, going on courses, and trial and error. I am not sure how this has changed, but certainly from speaking to several undergraduates recently, the situation seems the same. Maybe the argument is that there is enough to learn with just the basics and occlusion is quite a hard concept to grasp and would take too long to cover? A fair point perhaps.

Or maybe it’s because there seem to be so many camps of thinking that it becomes difficult for a dentist to know who and what to believe. What is clear is that many of these approaches do work, but the dentists in each camp feel strongly that they are right. 

I (try) to stick to Jose-Luis Ruiz and Gorden Christensen’s three Golden rules to occlusion approach.2,3,4

To summarise very briefly, these are:

1. We should have bilateral and even occlusal contacts, because of the massive forces produced by masticatory muscles, we want proper load distribution and a stable occlusion.

2. We should have posterior tooth disclusion through anterior and canine guidance. Lateral and protrusive movements will cause the anterior teeth to contact and the posteriors to separate. Masticatory muscles significantly decrease in activity when posterior disclusion occurs because of anterior guidance.5,6

3. We want an unobstructed envelope of function7 because, while chewing, the jaw moves laterally and protrusively, and when closed, it then returns to its centric stop. The correct amount of overjet allows for this movement to occur without interference.

The treatment of large tooth wear cases can often provide some of the most amazing transformations for patients with often life-changing results.

Most great speakers will have a few large wear cases that they throw into a presentation and this will rightly wow and stun the audience. It takes training and skill to be able to restore these cases once a large amount of tooth structure has been lost and muscle activity is high.

However, if more of us were using interceptive techniques early on, would we see fewer patients ever needing to have these hugely expensive showcase treatments?

Splint therapies, while there is plenty of proof that these work, have one flaw – many patients just don’t wear them. So here is a suggestion, try the Dahl principle.8,9

I find that just using composite in mild- moderate wear cases with less than 4mm of tooth wear is enough to de-programme and treat these patients predictably. This acts like a splint that they cannot remove and is economically viable as no prep or expensive materials are required. I will often prop open the anterior teeth, (usually eight, the worn lower teeth), and focus load on the canines and premolar with a long centric on the incisors. I build the canines to establish guidance. 

The open posterior spaces will close through over eruption and arguably a little anterior intrusion will develop over two to three months. I have used the technique literally hundreds of times and have countless photographed cases. It is not the answer to massive wear cases and very few patients still need splints, but I would love it to be used far more because I believe that many more patients could benefit from receiving good interceptive treatment of mild wear if more dentists were using it. So much so that I doubt many of these wear cases would develop in the way they do. I have met quite a few dentists that do use this technique, but people seem a little quiet and embarrassed about it, almost as if we belong to some kind of “secret society” – there is no need to feel this way.

Maybe wider use in the dental hospitals could help? Besides, the first time I came across this technique was courtesy of a certain Mr Bevans and Dr Dunne King’s College 1990. Thank you to them.            

 

References

1. Ruiz JL. Achieving longevity in esthetic dentistry by proper diagnosis and management of occlusal disease. Contemporary Esthetics and Restorative Practice. 2007;11:24-27. 

2. Ruiz JL, Paul R. Practical occlusion for everyday dentistry. Dentaltown. 2009;10:48-56.
3. Christensen GJ, Ruiz JL. Restorative dentistry: current developments and a look to the future. Dent Today. 2008;27:98-102.
4. Christensen GJ. Abnormal occlusal conditions: a forgotten part of dentistry. J Am Dent Assoc. 1995;126:1667-1668.
5. Manns A, Miralles R, Valdivia J, et al. Influence of variation in anteroposterior occlusal contacts on electromyographic activity. J Prosthet Dent. 1989;61:617-623.
6. Manns A, Chan C, Miralles R. Influence of group function and canine guidance on electromyographic activity of elevator muscles. J Prosthet Dent. 1987;57:494-501.
7. Dawson PE. Evaluation, Diagnosis, and Treatment of Occlusal Problems. Second edition. St Louis, MO: Mosby; 1989:28-55, 434-441.
8. Dahl BL Krogstad O (1975) An alternative treatment in cases with advance localized attrition. J Oral Rehab 2: 209-214
 9. Dahl BL, Krogstad O (1982) The effect of a partial bite raising splint on the occlusal face height. An X-ray cephalometric study in human adults. Acta Odontol Scand 40: 17-24.                  

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