FAC Materials & Techniques 3 — Questions and Answers
Question 1: Which cannula tip design is preferred to minimize the risk of intravascular injection compared to sharp needles?
- Beveled needle
- Blunt-tip microcannula (Correct answer)
- Spinal needle
- Hypodermic needle
Correct answer: Blunt-tip microcannula
Blunt-tip microcannulas deflect off vessel walls rather than piercing them, substantially reducing the likelihood of intravascular filler placement.
Question 2: The recommended injection depth for treating nasolabial folds with a high-G' HA filler is typically:
- Intradermal
- Subdermal/deep dermis
- Subcutaneous (Correct answer)
- Supraperiosteal
Correct answer: Subcutaneous
Nasolabial folds are best addressed subcutaneously, where the filler can volumize the underlying tissue without creating a visible ridge in the skin.
Question 3: When performing a thread lift with PCL (polycaprolactone) threads, the primary long-term advantage over PDO threads is:
- Faster absorption within 3 months
- Longer duration due to slower degradation (up to 2 years) (Correct answer)
- Greater barb density for immediate lift
- Suitability only for the neck region
Correct answer: Longer duration due to slower degradation (up to 2 years)
PCL degrades more slowly than PDO, maintaining its structural support and collagen-stimulating effect for up to 18–24 months.
Question 4: Lidocaine is commonly added to HA filler preparations to:
- Increase the filler's G prime
- Reduce patient discomfort during injection (Correct answer)
- Extend the longevity of the product
- Prevent biofilm formation
Correct answer: Reduce patient discomfort during injection
Pre-mixed lidocaine in HA formulations provides in-situ analgesia, improving patient comfort without affecting the filler's volumizing properties.
Question 5: The retrograde linear threading technique involves:
- Injecting product while advancing the needle forward
- Depositing filler as the needle is withdrawn along the treatment path (Correct answer)
- Fanning the needle at multiple angles from one entry point
- Using a cannula to create a depot bolus
Correct answer: Depositing filler as the needle is withdrawn along the treatment path
In retrograde threading, product is released during needle withdrawal, creating an even column of filler along the desired plane.
Question 6: Which filler material is most appropriate for periosteal placement to restore malar (cheekbone) projection?
- Soft, low-G' HA filler
- High-G' HA or CaHA filler (Correct answer)
- PLLA biostimulator only
- Collagen-based filler
Correct answer: High-G' HA or CaHA filler
Deep supraperiosteal placement requires a firm, high-G' product or CaHA to provide structural lift and project the malar complex effectively.
Question 7: Hyaluronidase dissolves HA filler by cleaving:
- Disulfide bonds in the cross-linking agent
- Glucosaminidic bonds within the HA polysaccharide chain (Correct answer)
- Peptide bonds in the gel carrier
- Ester linkages between HA and BDDE
Correct answer: Glucosaminidic bonds within the HA polysaccharide chain
Hyaluronidase is a hydrolase enzyme that cleaves the beta-1,4 glucosaminidic bonds of the HA backbone, breaking down both native and cross-linked HA.
FAC Materials & Techniques 3
Which cannula tip design is preferred to minimize the risk of intravascular injection compared to sharp needles?