Week 5 Abdalla- Craniofacial malformations & cleft management Flashcards
What are the stages that can impact embryonic craniofacial development?
-
Neural crest problems
- Germ layer foration
- Neural tube formation
- Migration of neural crest cells
-
Lack of fusion
- Organ system formation
- Primary palate
- Secondary Palate
-
Suture problems
- Final differentiation of tissues
What are features of fetal alcohol syndrome?
Caused by maternal alcohol use during pregnancy
- Microcephaly
- Smooth philtrum
- Thin upper lip
- Micrognathia
- Mid face deficiency
- Enamel hypoplasia
- Cleft lip/palate
What is alcohol use in early vs late pregnancy associated with?
- Early: craniofacial malformation
- Late: cognitive and behavioural development
What are features of treacher collins syndrome?
- Microtia or anotia
- Conductive deafness
- Zygoma deficiency
- Md hypoplasia
- Cleft palate plus facial clefting
What is the cause of treacher collins syndrome?
- 3 gene mutations identified (autosomal dominant)
- Mutation effects neural crest cells resulting in overall lack of mesenchymal cells and thus lack of tissues on lateral parts of face
What is hemifacial (craniofacial) microsomia?
- Part of one side of the face is underdeveloped and does not grow normally
- Most common craniofacial anomaly after cleft lip
- Can occur bilaterally (10-15% cases)
- Defect of 1st and 2nd brachial arch
- Congenital but not inherited
What are features of hemifacial (craniofacial) microsomia?
- Mandibular and ear defects
- Facial nerve weakness
- Maxillary hypoplasia
- Significant facial asymmetry
What structures can be affected by hemifacial microsomia?
OMENS
- Orbits
- Mandible
- Ears
- Nerves
- Soft tissues
What is craniosynostosis?
- Early close of skull sutures
- Can be divided into syndromic and non syndromic
What are features of non-syndromic craniosynostosis?
- Head shape altered
- Very rare
- Can cause increased intracranial pressure but rare
What are clinical features of syndromic craniosynostoses?
- Cranial vault deformities
- Mid face deficiencies
- Cleft palate
- Hand and foot syndactyly
- Compromised airways
- Feeding problems
- Raised intracranial pressure → neural development and vision problems
How can syndromic craniosynostoses be managed?
- May need cranial vault expansion
- Craniofacial surgery
- Distraction osteogenesis
What is distraction osteogenesis?
- Extend fracture site to encourage new bone growth by turning screws
- 1mm per day bone growth
- No need for bone graft
What is Pierre Robin Sequence?
- Micrognathia caused by posture in utero
- Elevation of tongue obstructs upper airway and causes cleft lip and palate
What is the diff between syndrome and sequence?
- Syndrome: pattern of anomalies that occur together in predictable fashion due to specific etiology
- Sequence: group of anomalies that stem from single major anomaly that alters development of surrounding structures
When/how does primary palate form?
Week 6: medial nasal process and mx process fuse forming lip and primary palate
How does the secondary palate form?
- During 6th week, bilateral outgrowths from the maxillary processes grow vertically down the side of the tongue
- Subsequently, the palatal shelves elevate to a horizontal position above the tongue, contact one another and commence fusion
- Fusion of the palatal shelves separates oral and nasal cavities
