Occlusion, do I really need to bother?
I am often asked this question, and some dentists manage to avoid any serious involvement with occlusion and are quite happy to continue in this blissful state of ignorance.
It is, however, a risky strategy if we are planning on providing anything other than simple fillings and single units, and even then we can get caught out if we have not even had a critical look at the existing occlusion prior to treating the patient.
My approach to occlusion is quite simple, stability is the key word! We do not do anything that will promote instability, our work should maintain, and where possible, improve stability in the patient’s occlusion.
How do we know whether we are achieving these ideals? The first thing we should do, for all of our patients, is carry out a simple occlusal examination. This will involve nothing more than a quick assessment of the stability of centric occlusion, a look at lateral excursions for tooth contacts on the working, and non working sides, tooth contacts in protrusion, and finally the slide from centric relation to centric occlusion.
Having carried out this quick, chairside assessment we are in a position to decide whether or not any of the restorations we are proposing could have a destabilising influence on the existing occlusion. In the majority of cases we will be fine to carry on without any further occlusal concerns, confident because we have had a look at the present scheme.
However, in some cases it might be that a tooth we are planning to restore plays an important role in guidance, or is an interference. In such cases we may well need to modify our preparation to allow for this, or select a more appropriate material for our restorations, or even adjust the contact. A more detailed look at the occlusion now becomes necessary.
For these cases, we will need to take some impressions for accurate study models, and get them mounted on a semi-adjustable articulator. This will enable us to carry out a more thorough examination of the occlusion and tooth contacts in function. For a majority of the patients, we will still be able to adopt a comformative approach, but we will be confident in our decisions because we have had a detailed look at the occlusion and its influence on our proposed treatment.
For some patients, as a result of our occlusal examination, we may want to explore the option of changing the bite, whether it be an alteration to the guidance or even increasing the vertical dimension. These proposed changes can be tried out on the mounted models, and a risk/benefit assessment performed. Does the benefit of any such alterations to the patient’s existing occlusion outweigh any risks involved? If so, we can discuss these with the patient. Such proposed changes can be carried out on the model, either by the addition of wax, or by modification to the teeth.
Easy as one, two, three
A discussion of occlusion with dentists often brings about drooping of the eyelids and a nodding of heads, particularly if it takes place after a large lunch. It is, however, not a complex subject, and aside from easily acquired knowledge, dentists only need to have mastered three clinical skills.
Firstly, the ability to take an accurate impression, and this is one we should already have acquired. Secondly, to be able to use a facebow, and finally, the ability to be able to find and record centric relation.
Armed with these skills, and some awareness of the features that promote stability in an occlusion, we are well placed to take on more complex cases, and provide patients with restorations in the sure and certain knowledge that we are promoting stability in their occlusion, and that this will add to the longevity of our work.
Despite popular belief, the study of occlusion is not one of the dark arts, it is interesting, challenging, and can even be fun!