CHAPTER 05: CRANIOFACIAL Flashcards
How are congenital craniofacial abnormalities classified?
Classification (American Soc of Cleft lip and Palate)
- Clefts – Lip / Palate / Facial, Encephalocoeles
- Synostosis (syndromal or non-syndromal)
- Hypoplastic conditions (HFM, hemifacial atrophy)
- Hyperplastic and neoplastic conditions (fibrous dysplasia)
What is the aetiology of craniofacial clefts?
1 in 25000 live births
Possible aetiology
- Failure of fusion of prominences
- Lack of mesodermal penetration
- Intra-uterine compression by amniotic bands
- Clefts can involve any or all layers of the face
- Soft tissue defect may not correspond to the bony abnormality
- May have hairline markers (hair growing along the line of the cleft)
Who classified craniofacial clefts?
TESSIER CLASSIFICATION
- Facial clefts down from orbit
- Cranial clefts up from orbit
- Midline = 0
- Clefts can connect -> add up to 14
- Described as orbital and nasal clock-faces that overlap
- Orbitocentric/ Nasocentric/ Mixed/ Extended
Is there another classification?
Van Der Meulen Classification
Cerebral Craniofacial Dysplasia
- Interophthalmic dysplasia
- Ophthalmic dysplasia
Craniofacial Dysplasia - Clefts and Synostosis
- Dysostoses (described according to anatomical location e.g. frontal, nasal, maxillary, zygomatic, temporal, maxillary, mandibular, and combinations of)
Craniofacial Dysplasia of other origin
- e.g. neurofibromatosis, vascular anomalies, fibrous dysplasia
Who wrote the seminal paper on facial clefts?
Tessier Classification (J Max Surg 1976)
- excluding CL/P + CP, incidence of facial clefts = 5:100 000
- lateral clefts - tend to have more severe bony abnormalities
- medial clefts - tend to have more severe soft tissue abnormalities
What are the principles of cleft craniofacial surgery?
- MDT
- Tailored to each patient
- Protect Vital Functions – Airway, Feeding, Eye
- Separation of Facial Cavities
Anatomic Subunit Repair – David Fisher Toronto – PRS June 2005
- Facial Skeleton: Remove abnormal elements, transpose skeletal components, bone graft defects
- Facial muscles: reattach to the skeleton in correct anatomical position
- Soft Tissues: reconstruct with local, regional or distant flaps.
What are encephalocoeles?
Caused by herniation of the brain or its lining through a defect in the skull
Skeletal defect can be due to a craniofacial cleft
Classified by their composition
o Meningoceles = contain meninges
o Meningoencephaloceles = contain meninges and brain
o Cystoceles = meninges, brain and a portion of ventricle
o Myeloceles = portion of spinal cord
What is Treacher-Collins Syndrome?
Mandibulofacial dysostosis, Franceschetti syndrome
- Chromosome 5q31-33 - AD
- 1 in 40000 - 70000 live births
- Characterised by Tessier 6, 7 and 8 cleft centred around zygoma
- Bilateral abnormalities of 1st & 2nd branchial arches – Failure of first arch neural crest and failure of fusion of mandibular and maxillary prominences.
Abnormalities
- Orbits - lower lid coloboma cleft 6, Hypertelorism, Anti-mongoloid slant, lacrimal apparatus may be absent
- Nose - narrow, deviated hooked, broad bridge
- Cheek - Absent or hypoplastic zygoma cleft 7
- Palate - cleft / high arch
- Mandible - Maxillary and mandibular hypoplasia, hypoplastic ramus TMJ
- Mouth - macrostomia
- Ear - abnormalies of external, middle and inner ear, microtia, cryptotia, hearing defects, BAHA
What is the treatment for Treacher-Collins Syndrome?
Airway → difficulty due to mandibular and maxillary hypoplasia → nursing prone, trache.
Zygoma and Orbits → Calvarial bone graft to augment orbital floor and zygoma, > 7yrs old
Mandible → rib grafts, mandibular advancement, bimaxillary procedures, distraction.
Ear→ reconstruction, bone conduction hearing aids.
What is craniosynostosis?
What is Virchow’s law?
What is the incidence of craniosynostosis?
Premature fusion of one or more sutures in the cranial vault or skull base → growth retarded in plane perpendicular to suture
Virchow’s law = compensatory skull growth parallel to a fused suture in craniosynostosis
Incidence
1 in 2500 live births
Non-syndromic = isolated (90%)
- 0.6 in 1000
- may be due to gestational / toxic influences
- sporadic congenital findings
- usu single suture
Syndromic (10-20%, 50% hereditary)
Genetic mutations in
- 70% of Crouzon, Pfeiffer or Saethre-Chotzen
- 100% of Apert
FGFR genes encode tyrosine kinase receptors
- FGFR 1: assoc w Pfeiffer
- FGFR 2: assoc w Pfeiffer, Apert, Crouzon
What is the history of craniosynostosis?
400 BC Hippocrates described skull & cranial suture morphology
1830 Wilhelm Otto recognised premature fusion as primary cause of cranisynostosis
1851 Virchow described growth restriction in skull perpendicular to the prematurely fused suture, and is enhancement in plane parallel
1910, 1920 Crouzon and Apert noted craniosynostoses as part of syndromes
1950s Moss noted removal of affected suture did not alter abnormal skull growth, therefore abnormal growth was at level of skull base and follows brain development. Changed entire concept of surgery - to complex cranial expansion procedures
1960 Tessier - father of modern craniofacial surgery, including fronto-orbital and midface advancements
1978 Jane & Park - pi procedure for sagittal synostosis
What is the aetiology of craniosynostosis?
3 possible sites:
Virchow = primary sutural abnormality
McCarthy = dural abnormality - intrinsic suture biology, secondary to osteoinductive properties of dura mater
Moss = abnormality in skull base (exerts abnormal tension)
? Abnormalities of fibroblast growth factor receptors 1,2 & 3 (FGFR)
Primary - defect in mesenchymal layer ossification in cranial bones
Secondary
- Endocrine: hyperthyroidism, Vit D deficiency, renal osteodystrophy, low P, high Ca
- Haematological: bone marrow hyperplasia (sickle cell, thalassaemia)
- Microcephaly (abnormal brain growth)
- in utero compression, hydrocephalus decompression e.g. after VP shunt
How is craniosynostosis classified?
Classification
- By location of affected suture(s)
- By resultant head shape
- Primary or Secondary
- Syndromic vs non-syndromic
Sagittal = Scaphocephaly (35%)
- keel shaped skull
Coronal (Uni = 15%)
- Unilateral: twisted skull - ant plagiocephaly
- Bilateral: short skull (brachycephaly), compensatory growth upwards (turricephaly/acrocephaly).
- Also associated with upper and mid face hypoplasia, elliptical orbits (Harlequin feature), poorly formed supraorbital ridge
Metopic (5%) = Trigonocephaly
Lambdoid
- Unilateral: Posterior Plagiocephaly
- Bilateral: Brachycephaly
Synostosis of multiple sutures
- Clover leaf skull - Kleeblattschädel
Primary = suture fused prematurely Secondary = early fusion of sutures due to primary failure of brain growth (microcephaly - all sutures fuse)
What are the clinical features of synostoses?
Primary changes - Abnormal skull shape - Symptoms/signs Raised ICP = Irritable, headache, difficulty sleeping, tense fontanelles, papilloedema, psychomotor retardation, fits 13% of single suture synostoses 40% with multiple sutures
Secondary changes
- Abnormal skull shape
- Harlequin appearance of lateral orbit on AP (superior displacement of the lesser wing of sphenoid)
- Copper beaten, thumb printing and wormian appearance, absent suture line if raised ICP
How does positional plagiocephaly differ from synostotic?
Positional = distortion of the skull by external forces. Rx conservatively.
Differentiate by:
1. Skull shape
True: Trapezoid
Pos: Rhomboid
- Ear position
True: displaced back
Pos: displaced anterior - Brow and Cheek shape (frontal bossing)
True: contralateral prominence
Pos: ipsilateral prominence - Ipsilateral & contralateral occiput
Both: ipsilateral occipitoparietal flattening
True: contralateral parietal bossing
Pos: contralateral occipital bossing
How is positional plagiocephaly managed?
All managed non-surgically
Most infants improve with repositioning manoeuvres and physiotherapy for torticollis
US - moulding helmets for severe cases
Name some syndromal synostoses
- > 70 syndromes associated with craniosynostosis
- Characterised by bilateral coronal synostosis, often with some degree of sagittal synostosis
- Brachycephaly = shortened AP diameter of skull and corresponding enlargement of the bitemporal and biparietal diameter
- Also oxycephaly, scaphocephaly, and turricephaly
Acrocephalosyndactyly type
1) Apert’s syndrome
2) Crouzon syndrome
3) Saethre-Chotzen
5) Pfeiffer
Jackson-Weiss
Carpenter
Beckwith-Wiedemann
What is Apert’s syndrome? (Acrocephalosyndactyly type 1)
- Eugene Apert 1906 (French Paed)
- 1 in 160 000 live births
- FGFR2 gene mutations
- sporadic, advanced paternal age
- Bicoronal synostosis
- Midface hypoplasia
- Acne
- Small beaked nose
- Class 3 malocclusion
- Cleft palate in 20%
- vertebral fusions C5-6
- low set ears, conductive hearing loss
- Complicated hand deformities – incl. acrosyndactyly (Upton)
o Type 1 – Spade or Paddle Hand +/- bony fusions at P3
o Type 2 – Mitten – thumb fused to central mass (simple) +/- bony fusions at P3
o Type 3 – Rosebud – bony union of thumb to central mass
How did Upton classify Apert hands?
Spade hand
thumb is foreshortened, radial clinodactyly (delta phalanx of the proximal phalanx)
separate from the index finger
shallow first web space.
complex syndactyly of index, middle and ring fingers because of osseous or cartilaginous union of the distal phalanges.
simple syndactyly of little and ring fingers, complete or incomplete
DIPJ of little finger is well formed and functional
Mitten / spoon hand
simple incomplete or complete syndactyly of the thumb and index ray, without any osseous union, no synechia
large, concave palm
bony union of distal phalanges of the index, middle and ring fingers
simple but complete 4th web syndactyly
Rosebud / hoof hand
tight osseous or cartilaginous union between all 5 fingers
All 5 nailplates are conjoined +/- longitudinal ridges, which indicate separate underlying distal phalanges
thumb is indistinguishable from the index ray
little finger, although joined by a common fingernail, does not have an osseous union at the distal phalanx and remains a simple but complete syndactyly
metacarpal synostosis of little and ring finger rays
What is Saethre-Chotzen Syndrome? (Acrocephalosyndactyly type 3)
- 1 in 25 - 50000
- TWIST gene, AD
- Bicoronal synostosis
- Low set hair line
- Ptosis
- Small posterior displaced ears
- No hand problems or incomplete syndactyly esp 2nd WS
- developmental delay
What is Pfeiffer Syndrome? (Acrocephalosyndactyly type 5)
- Rudolf Pfeiffer - German geneticist 1964
- 1 in 100 000
- AD
- FGFR 1&2 gene mutations
- Bicoronal synostosis, turribrachycephaly
- Facial appearance like Aperts
- BROAD THUMBS AND BIG TOES +/- ankylosis of elbows
- normal intelligence
Muenke Syndrome = variant of Pfeiffers
- FGFR3 gene mutation
What is Crouzon Syndrome? (Acrocephalosyndactyly type 2)
Crouzon Syndrome (Acrocephalosyndactyly type 2)
- Octave Crouzon 1912 (French neurologist)
- AD
- FGFR2 & 3 gene mutations
- 1 in 25 000 live births
- Bicoronal synostosis
- Midfacial hypoplasia
- shallow orbits - ocular proptosis, exorbitism, keratitis
- parrot-beaked nose
- conductive hearing loss
- normal intelligence usu
- HANDS NORMAL
What is Jackson-Weiss Syndrome?
What is Patau syndrome?
JWS
- AD
- Craniosynostosis
- Broad Halluces
- Fused tarsal and metatarsals
PS
- trisomy 13
- microcephaly
- wide sagittal suture & fontanelles, cutis aplasia congenita (holoprosencephaly)
- micro / anophthalmia, coloboma, retinal dysplasia
- CL/P (60-80%)
- low set ear, conductive hearing loss
- camptodactyly, polydactyly, rocker bottom feet
What is Carpenter syndrome?
- AUTOSOMAL RECESSIVE
- British physician 1909
- Rare 1 in million
- Various sutures involved, usu scaphocephaly
- Partial syndactyly of the fingers
- DUPLICATE THUMB / SYMBRACHYDACTYLY- - cong heart defects
What is Beckwith-Wiedemann Syndrome?
- Overgrowth syndrome
- 85% sporadic, 1 in 15000
- Metopic synostosis, microcephaly
- Macroglossia (90%), gaping mouth, prognathism
- Large prominent eyes
- Large prominent ears, pits / grooves in earlobe
- Large body size
- Visceromegaly
- Midline abdo wall defects (Exomphalos / umbilical hernia, diastasis recti)
- Wilms Tumour, Hepatoblastoma (~10% develop cancer: regular USS screening)
- Neonatal hypoglycaemia
How should a patient with craniosynostosis be managed?
Joint clinics, MDT setting
Paediatric neurologist
- evaluate cause and differentiate primary from secondary craniosynostosis
- plot head circumference and growth
Geneticist
- evaluate for associated syndromes
Plastic Surgeon
- evaluate any associated facial deformities
Neurosurgeon
- evaluate primary craniosynostosis and elevated ICP
Paediatrician
- e.g. hyperthryroid etc
Pre-operative assessment for craniosynostosis
Observe position of
Forehead
Eyebrows
- downward displacement in coronal
Eyes
- hypertelorism - CF cleft
- hypotelorism - metopic
- exophthalmos - bilat coronal
Nose
- curvature = facial scoliosis - uni coronal, mandibular hypoplasia
Cheeks
Mandibles
- uni/bilat mandibular hypoplasia - hemifacial microsomia
Ears
- ant & inf displacement - skull base synostosis
What preoperative imaging is used?
Plain Xray - shows fused sutures
CT 3D - shallow anterior fossa, deformed dystopic orbits, abnormal calvarial contour, and asymmetric cranial base
Cephalometry (using measurements from CT)
MRI -soft tissue
What are the indications for surgery?
What considerations are taken into account?
Indications for surgery
- progressive facial and cranial deformity
- raised ICP / intracranial hypertension
- progressive exophthalmos with risk to vision
- within 1st year (may be recurrent age 5-10, may require midface advancement at 10-15)
- use cell salvage and tranexamic acid to reduce bleeding
- neuro ICU postop, ICP monitoring
Techniques
- Calvarial vault remodelling
- Endoscopic surgery
- patients with facial deformities may require staged surgical approach
What are the treatments for synostosis?
Sagittal strip craniectomy
- Rx early isolated sagittal synostosis
- longitudinal strip of bone over suture excised & constriction released
- +/- spring assisted surgery
Fronto-orbital advancement
- Advances frontal part of skull
- Allows anterior skull growth
- Rx usu < 1yr old
Le Fort III Osteotomy
- Corrects midface retrusion
- Advancements limited to ~ 1 cm
Skeletal distraction
- Recent technique
- Osteotomies similar to Le Fort III advancement, a RED frame (rigid external distraction device) fitted, can advance >1cm
Monobloc advancement
- Advances fronto-orbital and Le Fort III segments as one block
- Communication between cranial and nasal cavities → high infection rate
Internal distraction devices
Endoscopic techniques (Jimenez, Barone)
What are the complications following surgery?
Death (1-2%) - due to uncontrolled intraop haemorrhage, air embolus, cerebral oedema, resp infection/obstruction, CSF leak and meningitis
Other complications
- optic nerve injury
- persistent CSF leak
- seizures, raised ICP, hypdrocephalus
- plate migration
- infection 2.5% (lower rate in infants c.f. older children)
- facial swelling including orbital
- airway obstruction
- cosmetic disappointment / recurrence of defect (27% of syndromic cases, 6% isolated)
What follow-up care is required?
- continue head circumference measurements
- check suture does not refuse
- watch for signs of raised ICP
