Prosthodontics Flashcards

When constructing a complete denture, what determines the correct occlusal vertical dimension (OVD)?

Answer: Assessment of freeway space, facial proportions, phonetics, and patient comfort

The correct OVD is established by assessing multiple factors: the freeway space (2–4mm between the rest vertical dimension and OVD), facial proportions (lower facial height), phonetic tests (closest speaking space during 's' sounds), patient comfort, and the pre-extraction records if available. No single method is reliable alone.

What is the primary purpose of a facebow record in prosthodontic treatment?

Answer: To transfer the relationship of the maxilla to the hinge axis of the mandible to a semi-adjustable articulator

A facebow records the spatial relationship of the maxillary arch to the transverse hinge axis (or an arbitrary point near the condyles) and transfers this to a semi-adjustable articulator. This ensures that the arc of closure on the articulator mimics the patient's jaw movements, improving the accuracy of the occlusal scheme.

A patient wearing a complete upper denture complains of gagging. Which denture feature is most commonly responsible?

Answer: The posterior border of the denture extends too far beyond the vibrating line onto the soft palate

Over-extension of the posterior palatal seal area beyond the vibrating line (junction of hard and soft palate) is the most common denture-related cause of gagging. The soft palate is highly sensitive, and contact with the denture triggers the gag reflex. Correct identification of the vibrating line during impression taking is essential.

Which type of connector is most appropriate for a Kennedy Class I removable partial denture (bilateral free-end saddle)?

Answer: Anterior-posterior palatal bar design with indirect retention

Kennedy Class I (bilateral free-end saddle) RPDs benefit from an anterior-posterior palatal bar or palatal strap design that provides rigidity, cross-arch stabilisation, and indirect retention. The indirect retainers (rests anterior to the fulcrum line) resist the distal extension saddle lifting away from the ridge during function.

What is the function of a post dam (posterior palatal seal) in a complete upper denture?

Answer: To create a seal at the posterior border to aid retention by preventing air entry under the denture

The post dam creates a compressive seal between the denture and the soft tissues at the junction of the hard and soft palate. This prevents air from entering beneath the denture, which would break the vacuum-like retention. It is formed by slightly overcontouring the posterior border area of the denture into the compressible tissue of the vibrating line.

When selecting teeth for a complete denture, what guide should be used to determine the width of the upper anterior teeth?

Answer: The inter-alar width (distance between the sides of the nose) as a guide for the combined width of the six upper anterior teeth

The inter-alar width (distance between the outer edges of the alae of the nose) provides a useful guide for the combined width of the six upper anterior teeth. While not exact, this anthropometric relationship helps in selecting appropriately sized teeth when pre-extraction records are unavailable.