Craniosynostosis Flashcards
When does skull development start?
23-26 days gestation
How do the cranial vault and skull base form?
Cranial vault - forms from intramembranous ossification of the memebranous neocranium
Skull base - forms from endochondral ossification of the cartilaginous neocranium
Embryology of facial bones
From viscerocranium
First pharyngeal arch - maxillary process forms maxilla, zygoma, squamous temporal bone
Mandibular process forms mandible, malleus, and incus
Second pharyngeal arch - stapes, styloid process of temporal bone, lesser horn and superior body of hyoid
When is brain adult size? Trajectory?
25% at birth, 50% at 6 months, 75% at one year, full adult volume by 2.5 years
When do the fontanelles close
Anterior closes at 2 years of age
Posterior closes at 2 months of age
Sinus development
Maxillary 3 months gestation - childhood
Sphenoid 5 months gestation - childhood
Ethmoid 5 months gestation - puberty
Frontal 5 years (only one to appear postnatally) - adolescence
When do the sutures fuse?
Metopic - 3 to 9 months
Sagittal - 20 to 22 years
Coronal - 23 to 24 years
Lambdoid - 26 years
Virchows law
Growth restriction occurs perpendicular to the affected suture, compensatory skull growth occurs parallel to the affected suture
Most common craniosynostosis
Sagittal (>50%) followed by unilateral coronal (20%)
Findings associated with metopic synostosis
Trigonocephaly Pointed forehead Frontal bossing Bitemporal narrowing Hypotelorism Recessed superior orbital rims
Harlequin deformity
Lack of ipsilateral descent of sphenoid during development with unicoronal synostosis
Most common syndromic synostosis
Bicoronal
Kleebattschadel deformity
Syndromic pancraniosynostosis with cloverleaf deformity
Aperts syndrome
Craniosynostosis Hypertelorism, parrot beak nose, mid face hypoplasia Severe syndactyly of hands and feet Mental status variable FGFR2 mutation
Crouzons syndrome
Autosomal dominant FGFR2 mutation Coronal and lambdoidal synostosis Exorbitism/proposis Midface hypoplasia Conductive hearing loss Normal extremities Mental status variable
Saethre Chotzen syndrome
Autosomal dominant TWIST 1 mutation Asymmetric coronal synostosis Shallow orbits, eyelid ptosis Low hairline Midface hypoplasia Partial syndactyly Normal extremities
Pfieffers syndrome
Autosomal dominant FGFR1, 2, 3 mutations Coronal and/or sagittal synostosis Hypertelorism, midface hypoplasia ***Broad thumbs and great toes*** Mental status variable
Which craniofacial syndrome is autosomal recessive
Carpenter
Carpenter syndrome
Autosomal recessive Variable synostosis Flat nasal bridge Low set eyes, abnormal globes and canthi Brachydactyly, syndactyly of hands and feet Short stature Impaired mental status
Boston type craniosynostosis
Autosomal dominant MSX2 mutation
Craniosynostosis, soft palate cleft
Short first metatarsal head, triphalangeal thumb
Craniosynostosis syndrome with joint problems
Muenke syndrome
Craniosynostosis with white forelock of hair
Waardenburg syndrome
