Dental occlusion and bite registration
The dental occlusion or the bite is the relationship between the upper and the lower teeth when they approach each other. It is very important to determine the exact bite when a restoration is designed.
The dental occlusion has to be analysed in 2 different circumstances : when the jaw is moving and when the jaws are closed and stationary.
Static occlusion refers to contact between teeth when the jaw is closed and stationary. The correct static occlusion is the position where the upper teeth make the most possible contacts with the lower teeth. That is why, in dentistry, this position is also known as maximum intercuspation.
correct static occlusion
Patients must reach this position without unusual efforts. Unnatural efforts to reach this position may sometimes lead to difficulties in registering the correct occlusion.
When large restorations are planned, it is extremely important to establish the correct static occlusion. It is ideal not to disturb a correct bite by leaving the restoration high (or low).
Dynamic occlusion refers to occlusal contacts made when the jaw is moving. These contacts are made when the mandible is moving sideways, forwards, backwards, or at an angle.
The dynamic occlusion contacts depend on both the teeth positions and shapes and the shape of the TMJThe temporomandibular joint (TMJ) is the joint of the jaw between the mandible and temporal bone. It is important to determine whether some of these contacts can interfere with the planned reconstruction during various functional movements.
Bite registration procedure
The bite registration captures the static occlusion. It is imperative to register the correct static occlusion. The dentist should give some advice to reach this position.
The correct bite is reached when :
- the teeth close "where they meet best"
- the bite is "heaviest" on the back teeth
- the bite is evenly spread over all the back teeth
- there is little weight on the front teeth
- this position can be reached after the tip of the tongue touches the back part of the oral palate (the "roof of the mouth")
- this position can be reached after the patient swallows
- other factors can also be considered
The bite is usually recorded with a rigid impression material.
The material is prepared by mixing a putty base with the catalyst. A self mixing impression material syringe can also be used.
The prepared material is positioned over the entire length of a dental arch (upper or lower) or just in the posterior (back) parts. Special trays can be used.
The patient is invited to "bite" in the correct occlusion.
After material sets (it usually takes 1-2 minutes), the record is sent to the dental laboratory together with the other impressions.
The technician will utilize this record to position the two dental casts (upper and lower) in the correct occlusion.
What side effects may occur during impressions ?
Usually there are no side effects. Impression materials have good smell and taste and setting time is relatively short. In limited cases there may be some minor reactions.
- accumulation of large quantities of saliva
- small breathing problems especially if patients cannot breathe normally
- nausea when the impression is extended
Last review and update: November 2020