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DENTAL OCCLUSION EXPLAINED.

What does dental occlusion mean?

I looked a long time ago at the issues of jaw alignment and function. The branch dealing with this type of pathology is occlusal therapy.Since the writing of my first thesis, I underlined the damages caused by the heterogeneous aspect of dental reconstructions (crowns, fillings, bridges) which were filling my patients mouths and which perfectly reflected the passing of the patient into various dental chairs.

Dr Jean-Pierre Toubol, dental occlusion specialist.

It is important to know that jaws filled with their teeth form a system called manducatory system and that this system is extremely precise. Indeed each of us is able to feel an allowance of 16 thousandth of a millimeter which would be interposed between its upper teeth and lower teeth, the equivalent of a human hair! This is what we call “the perceptibility threshold”.

bad bite

The posterior height loss aggravating the closing until lower incisors complete coverage, created a significant mobility of the 4 upper incisors which had to be extracted.

bad dental occlusion

After extraction of the four upper incisors and restoration with dental bridge

 

 

 

 

 

 

 

 

 

Do dentists work with such a precision? Certainly not; but nature is quite kind and is willing to adapt, to a certain extent, to our approximations so long as they are not excessive and they fit each one’s “adaptability threshold”.

This adaptability threshold varies between people mostly depending on the various adjustments which have already been requested to the system. When an additional restoration is placed, the system might also fall into pathology because the threshold had been exceeded.

Here we go to a badly functioning system, the symptoms of which may be multiple. Indeed the manducatory system is not isolated and it is a part of a larger system called orthopostural system. We are not sliced like salami following medical specialties and our body functions as a whole system with interactions between all organs.

This orthopostural system is associated with the eye, spine, and the way feet are in contact with the floor.

Dental occlusion symptoms, or manducatory dysfunction most common signs, are dental occlusion headaches, joint pain around the ears which sometimes resemble otitis, or even dizziness.

These problems must be diagnosed by a practitioner skillful with those pathologies and a treatment plan will then be proposed, which will require a complete exam of the system and a return of the lower jaw to a correct position in relation with the upper jaw.

Factors affecting dental occlusion.

These problems are sometimes caused by several associated factors between jaws, spine, and the individual overall posture.

If that is the case, an intermediate phase will be required to estimate the manducatory system part in the symptomatology and the patient must wear a dental occlusal guard for a while, to prove that by correctly repositioning the jaws, symptoms disappear.

This is called a differential diagnosis and thus allows to confirm that there is a need for intervention on the patient’s teeth to correct this dysfunction. Occlusal therapy must be handled with caution and care to achieve a complete harmony in the connections of the upper teeth and lower teeth both in a static relation (mouth closed , teeth clenched) and in a dynamic relation (easy chewing without important mouth opening problems and without jawbones joint snapping).

It is pleasing to observe that in such a case it is always associated with the harmonious appearance of front teeth, bringing a bright smile with perfectly aligned teeth. .

To understand better the functioning of the system, we need to consider that the front teeth involved in the smile form the two halves of a pair of scissors and are therefore intended to slice food.

The posterior teeth serve as pestle and motar and they crush food. Moreover when they are simply clenched together, they ensure the limitation of closing force, thus preserving front teeth from excessive strain.

When posterior teeth wear out or are missing and the opening limitation leads to an excessive strain on front teeth, these are going to mobilize and tilt forward while moving apart from each other and becoming loose, up to definitive tooth loss.

Treatment for dental occlusion.

As explained above, each case is a particular case and people showing great occlusal disorders may not present any symptomatology of whatsoever nature. However, healthy teeth may lead to important disorders at the slightest disruption, because the adaptability threshold is exceeded.

An occlusal diagnosis must be accurately performed, first by a clinical examination of the entire masticatory muscle and the way in which the mouth opens; namely a sufficiently broad and straight opening, without the lower jaw moving to the right or to the left.

When this examination points up the presence of pathologies whether muscular or articular, we will perform a dental occlusion analysis or “occlusal analysis” on a motion simulator also called articulator.

This analysis is essential to diagnose precisely the existing problems with teeth. It will help find incorrect positioning of the lower jaw (mobile) in relation to the upper jaw (fixed, since connected to the cranium).

It is impossible to diagnose accurately without this analysis which will allow to ascertain the existing defects and apply a correction too, on plaster models, on the simulator, in order to simulate in advance corrections that will further be realized into the mouth of the patient: this is occlusal adjustment.

The photograph on the left shows the simulator with models of a patient fitted in the same relation as the one of the jaws in the mouth. The photograph on the right shows the upper teeth complete lack of contact with the lower teeth on this patient. This defect will need to be corrected by heightening the lower teeth which do not contact. This analysis is not achievable directly in the mouth, that is the reason why we need to perform this diagnosis on simulator.

occlusal simulator

The simulator with models of a patient fitted in the same relation as the one of the jaws in the mouth.

occlusal diagnosis

Upper teeth complete lack of contact with the lower teeth on this patient.

 

 

 

 

 

 

 

 

 

 

The lower jaw position and its consequences.

In a normal position, the teeth of the lower mobile jaw (mandible) bite the teeth of the fixed upper jaw (maxilla) and thus remain in a fixed position when teeth are clenched.

a normal occlusion

This photograph shows the normal position of the lower jaw whose teeth are covered and placed by the upper teeth. This is a normal occlusion.

When teeth had been worn out, the position of the lower jaw might then be very disrupted and cause serious disorder with various symptoms such as headaches, backache, cervical pain, dizziness, tinnitus, joint snapping, limited mouth opening, jaw deviation upon opening, and even leading to a disability if many of these symptoms are associated.

worn teeth

This photograph shows very worn teeth.

Occluso therapy

Plaster models of the patient’s jaws and teeth show a significant gap with the lower jaw.

 

 

 

 

 

 

 

 

 

Occlusal consultation

This is a consultation that will have to be done in three stages:

1- Clinical examination:

– Mandibular mobility observation.

– Chewing muscles and neck palpation.

– Closing of the jaws checkup.

– Postural balance checkup. .

2- Occlusal analysis:

This is as explained above a simulation with models representing the patient’s jaws to analyse their position and diagnose the corrections to be made (see figures).

3- Symptomatic treatment

When the analysis indicates it, a splint is prescribed, which will have to show that symptoms disappear when the lower jaw is correctly repositioned. This is called the differential diagnosis.

Occlusal treatment

This whole part of investigations must precede a treatment with permanent modification of teeth whether by grinding or by coverage to permanently reposition the lower jaw.

bruxism

These photograph show the impact of bruxism and its consequences.

bruxim treatment

The two jaws had to be completely reconditioned and all teeth had to be given a sufficient volume and a normal height.

 

 

 

 

 

 

 

 

 

 

 

 

Occlusal treatment may take different forms since the position of the lower jaw can be rebalanced whether by grinding certain teeth which interfere in the closing, or by covering certain teeth to recover a lost contact. Occlusal diagnosis will determine the treatment to be applied.