Facial Prosthetics Design & Fabrication Flashcards

Which cross-linking mechanism is used in addition-cure (platinum-catalyzed) silicone compared to condensation-cure silicone?

Answer: Hydrosilation reaction with no byproduct

Platinum-catalyzed addition cure proceeds via hydrosilation, producing no volatile byproducts and resulting in more dimensional accuracy.

For a patient wearing spectacles, how should the nasal prosthesis be designed to accommodate eyeglass frame retention?

Answer: The nasal bridge area should be relieved or extended to interface with the frame

Designing the prosthesis to interface with the spectacle frame leverages the eyeglasses as an additional retention aid and conceals the prosthesis margin.

Which anatomical structure serves as the primary landmark for determining the superior border of an auricular prosthesis?

Answer: The helical root emerging from the temporal scalp

The helical root position establishes the superior attachment of the auricle and anchors the ear's position relative to the scalp.

Magnet retention systems for implant-retained prostheses may be contraindicated for patients who require:

Answer: MRI imaging procedures

Ferromagnetic magnets can deflect, heat, or cause image artifacts in MRI machines, making them problematic for patients needing frequent MRI scans.

The 'lost wax' casting technique as applied in facial prosthetics involves:

Answer: Burning out a wax pattern from a mold to create a void that is then filled with prosthetic material

In lost wax technique, the wax trial prosthesis is eliminated from a rigid mold, leaving a cavity that is packed with the final silicone or acrylic material.

A patient reports skin irritation confined to the adhesive contact zone beneath an auricular prosthesis. The first clinical step is to:

Answer: Patch-test the patient with the current and alternative adhesives

Patch testing identifies the specific allergen or irritant in the adhesive formulation before selecting a compatible alternative.

When performing a wax try-in for a facial prosthesis with the patient, the evaluation should include assessment of:

Answer: Contour, symmetry, margin adaptation, and patient psychological acceptance

The wax try-in is a comprehensive checkpoint evaluating shape, symmetry, edge seating, and whether the patient accepts the aesthetic result before final fabrication.