Orofacial Dysostosis

Question 1

What is Treacher collins syndrome

Answer 1

Autosomal dominant inheritant affecting 3 genes (TCOF1, PLOR1D, PLOR1C) and caused by bilateral abnormalities of the structures from FIRST and SECOND branchial arch

Question 2

Presentation of Treacher collins syndrome

Answer 2

1. Orbito-Zygomatic complex hypoplasia —-> Downward slanting of the palpebral fissures & inferiorly positioned lateral canthi
2. Class II skeletal deformity d/t clockwise rotation of maxillomandibular complex
   - Mandibular hypoplasia (esp condyle & ramus)
   - obtuse mandibular plane angle
   - retrogenia
   - airway obstruction
   - TMJ and its components hypoplastic
3. Microtia +/- hearing impairment
4. Associated facial musculature hypoplasia
5. Orofacial clefting
6. Macrostomia

Question 3

Whats acrofacial dysostosis?

Answer 3

Oromandibulat dysostosis associated with limb abnormalities - Nager syndrome

Question 4

General recon stages of Treacher collins

Answer 4

1. Orbitozygomatic recon
2. Mandibular recon
3. Microtia recon
4. Soft tissue recon
5. Orofacial clefting repair like clp repair
6. Macrostomia correction

Question 6

Classification of CFM

Answer 6

OMENS

Pruzansky & Kaban

Question 8

Describe Kaban classification

Answer 8

It tells the anatomy & function of TMJ unit (mandibular ramus condyle in glenoud fossa), facial musculature AND the Timing of surgical recons

I- mandible mildly hypoplastic; condyle in glenoid fossa; muscles of mastication present; TMJ function normal

IIA- mandible moderately hypoplastic; condyle displaced anterior & medially: muscles of mastication hypoplastic; TMJ function normal

IIB- mandible severely hypoplastic; condyle displaced anterior & medially but posterior point of contact still remains; muscles of mastication severely hypoplastic or partially absent; TMJ function abnormal

III- mandible & TMJ unit absence; most of muscles of mastication absent; No TMJ function - mandible free floating without posterior contact

Question 9

Difference between Sequence and Syndrome

Answer 9

Sequence is one developmental defect leading to chain of secondary defects

Question 10

Describe Pierre Robin sequence

Answer 10

Primary defect is arrested mandibular development

Causing cascade of abnormalities including 1) glossoptosis 2)cleft palate —-> airway obstruction

Question 11

Syndrome that most commonly associated with PRS

Answer 11

Stickler syndrome - collagen disorder that affects mandibular growth causing 
- micrognathia
- cleft palate
- nasal hypoplasia
- midface hypoplasia
Also assoc with 
- blindness
- sensorineural hearing loss
- other musculoskeletal abnormalities

Question 12

Whats the cause of craniofacial microsomia?

Answer 12

Injury to stapedial artery affecting the neural crest development and migration leading to hypoplasia of the first and second branchial arch

Question 14

What is Goldenhaar syndrome?

Answer 14

OAV or oculo-auriculo-vertberal spectrum of malformation