Removable Prosthodontics - Occlusion & Occlusal Schemes

Flashcards covering concepts of occlusion, occlusal schemes, tooth forms, and selection factors in removable prosthodontics.

What is point centric according to the gnathological concept?

It is the condition where maximum intercuspation [MI] coincides with centric relation [CR].

In what percentage of people do centric relation [CR] and maximum intercuspation [MI] NOT coincide naturally?

In $90\%$ of people.

What is slide in centric?

A $2$-$3$ dimensional sliding movement that the mandible makes as it moves from retruded contact position [RCP] to maximum intercuspation [MI].

What factors cause centric relation and centric occlusion [CO] to be different in slide in centric?

Wear, caries, and loss of teeth.

What is freedom of centric (long centric)?

A flat area created between centric relation [CR] and centric occlusion [CO] position on the occlusal surfaces of teeth.

How can freedom of centric be created?

It can be created by occlusal adjustment of natural teeth or by altering the fossa in complete dentures to give freedom of movement.

What characterizes balanced occlusion in an eccentric position?

Even contacts between the maxilla and the mandible on the working side and multiple contacts on the non-working [balancing] side.

What is the cusp angle of posterior teeth used in balanced occlusion, and under what conditions is it indicated?

The cusp angle is $33^\circ$, and it is indicated only in cases of well-developed ridges and class $1$ occlusion.

How are teeth arranged in unbalanced (monoplane) occlusion?

No attempt is made to create balanced occlusion; teeth are set at the horizontal.

What are the advantages of monoplane occlusion?

It can be used in class $2$ and class $3$ malocclusion and crossbites, non-anatomical teeth allow freedom eliminating horizontal forces, it accommodates better to negative changes in ridge height, is comfortable with longer efficiency, and is easy and less time-consuming for the dentist.

What are the cusp angles of maxillary and mandibular teeth in a lingualized occlusal scheme?

Maxillary teeth are anatomical $33^\circ$ and mandibular teeth are anatomical $10^\circ$.

How are mandibular teeth modified in a lingualized occlusal scheme to maximize contact?

The buccal aspects of lower teeth are reduced in height and the central fossa is widened.

When is a lingualized occlusal scheme indicated?

When the patient wants high aesthetics but has severe ridge resorption, class II jaw relation, or displaceable supporting tissues.

What is the definition of an occlusal scheme?

The type of tooth form (cusp or cuspless) that the dentist chooses to establish the occlusal concept.

What four factors must be considered before choosing an occlusal scheme?

1. Height and width of residual ridge, 2. Aesthetic demands of the patient, 3. Skeletal jaw relation [class $1$, $2$, $3$], and 4. Neuromuscular control and parafunctional habits.

What occurs if anatomical teeth are used and articulation is not balanced?

Denture instability and trauma to denture-bearing tissues.

What type of articulator is used with non-anatomical / cuspless / zero degrees teeth?

A simple hinge articulator.

Why are sluiceways made in teeth with lingualized features?

To increase chewing efficiency.

Under what condition are acrylic resin teeth used according to the source notes?

In implant-retained prostheses against natural teeth.

When are metal teeth indicated in removable prosthodontics?

When acrylic teeth wear was very rapid.