Test on Treacher-Collins Syndrome: Surgical Management

Question 1: The hypoplastic mandible in Treacher The hypoplastic mandible in Treacher–Collins syndrome typically features a severe shortening of the ascending ramus and a long, retruded chin.

A. Yes

B. No

Explanation: The study materials state that the mandible in Treacher–Collins syndrome is hypoplastic, with a severe shortening of the ascending ramus. It also notes that the chin is long and retruded.

Question 2: Bilateral mandibular distraction osteogenesis in Treacher–Collins syndrome can simultaneously improve respiratory and digestive function.

A. Yes

B. No

Explanation: The study materials state: 'Bilateral distraction osteogenesis corrects hypoplasia of the mandibular ramus and body with simultaneous improvement of respiratory and digestive function.'

Question 3: Which of the following are characteristic orbital abnormalities associated with Treacher-Collins syndrome, according to the provided study materials?

A. Absence of the lateral orbital rim

B. Inferior migration of the superolateral portion of the frontal bone

C. Poor definition of the inferior orbital rim

D. Total absence of the medial wall of the orbits

Explanation: The study materials state that the absence of the zygomatic bone is responsible for the absence of the lateral orbital rim and the poor definition of the inferior orbital rim. It also mentions that the inferior portion of the lateral wall of the orbits is often absent and there is inferior migration of the superolateral portion of the frontal bone. There is no mention of the total absence of the medial wall of the orbits.

Question 4: According to the study materials, which statements accurately describe surgical reconstruction for Treacher–Collins syndrome?

A. Parietal bone grafts are used for augmenting the malar eminence.

B. Colobomas and macrostomia are repaired after bony reconstruction.

C. Bilateral distraction osteogenesis is used to correct mandibular ramus and body hypoplasia.

D. Microtia is typically treated in early infancy, between 1 and 2 years of age.

Explanation: The study materials state that 'Parietal bone grafts are used to augment the malar eminence' and that 'Bilateral distraction osteogenesis corrects hypoplasia of the mandibular ramus and body'. It also specifies that 'Colobomas and macrostomia are repaired prior to bony reconstruction' and 'microtia is treated between 9 and 10 years of age', making options 1 and 3 incorrect.

Question 5: Intraoral myofunctional devices, such as the Fränkel III style, are primarily used short-term to manipulate callus during the consolidation period.

A. Yes

B. No

Explanation: Intraoral myofunctional devices, such as the Fränkel III style, are used in the long term to maintain bone structures and teeth, not primarily short-term for callus manipulation during the consolidation period, which is the role of orthodontic elastics.