CHAPTER 05: CRANIOFACIAL

Question 1

How are congenital craniofacial abnormalities classified?

Answer 1

Classification (American Soc of Cleft lip and Palate)

1. Clefts – Lip / Palate / Facial, Encephalocoeles
2. Synostosis (syndromal or non-syndromal)
3. Hypoplastic conditions (HFM, hemifacial atrophy)
4. Hyperplastic and neoplastic conditions (fibrous dysplasia)

Question 2

What is the aetiology of craniofacial clefts?

Answer 2

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)

Question 3

Who classified craniofacial clefts?

Answer 3

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

Question 4

Is there another classification?

Answer 4

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

Question 5

Who wrote the seminal paper on facial clefts?

Answer 5

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

Question 6

What are the principles of cleft craniofacial surgery?

Answer 6

• MDT
• Tailored to each patient
• Protect Vital Functions – Airway, Feeding, Eye
• Separation of Facial Cavities

Anatomic Subunit Repair – David Fisher Toronto – PRS June 2005

1. Facial Skeleton: Remove abnormal elements, transpose skeletal components, bone graft defects
2. Facial muscles: reattach to the skeleton in correct anatomical position
3. Soft Tissues: reconstruct with local, regional or distant flaps.

Question 7

What are encephalocoeles?

Answer 7

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

Question 8

What is Treacher-Collins Syndrome?

Answer 8

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

1. Orbits - lower lid coloboma cleft 6, Hypertelorism, Anti-mongoloid slant, lacrimal apparatus may be absent
2. Nose - narrow, deviated hooked, broad bridge
3. Cheek - Absent or hypoplastic zygoma cleft 7
4. Palate - cleft / high arch
5. Mandible - Maxillary and mandibular hypoplasia, hypoplastic ramus TMJ
6. Mouth - macrostomia
7. Ear - abnormalies of external, middle and inner ear, microtia, cryptotia, hearing defects, BAHA

Question 9

What is the treatment for Treacher-Collins Syndrome?

Answer 9

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.

Question 10

What is craniosynostosis?

What is Virchow’s law?

What is the incidence of craniosynostosis?

Answer 10

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

Question 11

What is the history of craniosynostosis?

Answer 11

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

Question 12

What is the aetiology of craniosynostosis?

Answer 12

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

1. Endocrine: hyperthyroidism, Vit D deficiency, renal osteodystrophy, low P, high Ca
2. Haematological: bone marrow hyperplasia (sickle cell, thalassaemia)
3. Microcephaly (abnormal brain growth)
4. in utero compression, hydrocephalus decompression e.g. after VP shunt

Question 13

How is craniosynostosis classified?

Answer 13

Classification

1. By location of affected suture(s)
2. By resultant head shape
3. Primary or Secondary
4. 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)

Question 14

What are the clinical features of synostoses?

Answer 14

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

Question 15

How does positional plagiocephaly differ from synostotic?

Answer 15

Positional = distortion of the skull by external forces. Rx conservatively.

Differentiate by:
1. Skull shape
True: Trapezoid
Pos: Rhomboid

2. Ear position
   True: displaced back
   Pos: displaced anterior
3. Brow and Cheek shape (frontal bossing)
   True: contralateral prominence
   Pos: ipsilateral prominence
4. Ipsilateral & contralateral occiput
   Both: ipsilateral occipitoparietal flattening
   True: contralateral parietal bossing
   Pos: contralateral occipital bossing

Question 16

How is positional plagiocephaly managed?

Answer 16

All managed non-surgically
Most infants improve with repositioning manoeuvres and physiotherapy for torticollis
US - moulding helmets for severe cases

Question 17

Name some syndromal synostoses

Answer 17

• > 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

Question 18

What is Apert’s syndrome? (Acrocephalosyndactyly type 1)

Answer 18

• 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

Question 18

How did Upton classify Apert hands?

Answer 18

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

Question 19

What is Saethre-Chotzen Syndrome? (Acrocephalosyndactyly type 3)

Answer 19

• 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

Question 20

What is Pfeiffer Syndrome? (Acrocephalosyndactyly type 5)

Answer 20

• 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

Question 21

What is Crouzon Syndrome? (Acrocephalosyndactyly type 2)

Answer 21

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

Question 22

What is Jackson-Weiss Syndrome?

What is Patau syndrome?

Answer 22

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

Question 23

What is Carpenter syndrome?

Answer 23

• 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

Question 24

What is Beckwith-Wiedemann Syndrome?

Answer 24

- 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

Question 25

How should a patient with craniosynostosis be managed?

Answer 25

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

Question 26

Pre-operative assessment for craniosynostosis

Answer 26

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

Question 27

What preoperative imaging is used?

Answer 27

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

Question 28

What are the indications for surgery? | What considerations are taken into account?

Answer 28

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

Question 29

What are the treatments for synostosis?

Answer 29

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)

Question 30

What are the complications following surgery?

Answer 30

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)

Question 31

What follow-up care is required?

Answer 31

- continue head circumference measurements - check suture does not refuse - watch for signs of raised ICP

Question 32

What is the difference between 1. hypertelorism 2. hypotelorism 3. telecanthus 4. pseudo-telecanthus

Answer 32

1. Hypertelorism = ↑ distance between the bony orbits 2. Hypotelorism = ↓ distance between orbits (can be caused by metopic synostosis ) 3. Telecanthus = ↑ intercanthal distance (ICD) (dist between bony orbits may be normal) 4. Pseudo-telecanthus = illusion of telecanthus caused by a flat nasal bridge or prominent epicanthal folds.

Question 33

What are the causes of hypertelorism?

Answer 33

1. Median and paramedian facial clefts - Type 1&2 2. Syndromes → Aperts, Crouzon’s, Craniofacial nasal dysplasia 3. Sincipital (frontal / nasofrontal) encephalocoeles 4. Midline tumours e.g. Midline dermoid tumours

Question 34

What is the treatment for hypertelorism?

Answer 34

Box osteotomy - Rectangular osteotomies made around each orbit, bone bn removed and orbits are moved medially towards each other. Used in patients with isolated hypertelorism & a normal midface width. Facial Bipartition - whole facial skeleton is divided vertically in the midline - central bony segment is removed and two lateral segments containing orbits are moved medially towards each other.

Question 35

What is hemifacial microsomia?

Answer 35

Hemifacial microsomia - Congenital underdevelopment of one side of the face. Aka first and second branchial arch syndrome and otomandibular dysostosis. - 1 in 5000 live births - usually asymmetrical (TCS - symmetrical)

Question 36

What are the hypoplastic craniofacial conditions?

Answer 36

1. Hemifacial microsomia (cleft 7) 2. Treacher Collins (TCS) (cleft 678) 3. Goldenhars (cleft 8) 4. Hemifacial atrophy

Question 37

Tell me about HFM.

Answer 37

- spectrum of morphogenetic anomalies involving the cranial skeleton, soft tissue, and neuromuscular structures derived from the first and second branchial arches - incidence of 1:5600 live births - unilateral in 80% of cases - M:F = 3:2 - R:L = 3:2 - most cases sporadic, 3% 1st degree relatives - familial - AD & AR, chr 8, 22q, 14q Pathogenesis theories 1. stapedial artery hematoma during the fourth to eight weeks of gestation 2. failure of neural crest cell development and migration ('mesodermal insufficiency' Stark)

Question 38

What is HFM also know as?

Answer 38

Otomandibular dysostosis (Francois & Haustrate 1954) 1st and 2nd branchial arch syndrome (Stark and Saunders 1962, Grabb 1965) Oculoauriculovertebral sequence (Gorlin 1956) Lateral facial dysplasia (Ross 1975) Craniofacial microsomia (Converse 1979)

Question 39

What is the OMENS plus classification?

Answer 39

``` O 0 Normal orbit 1 Abnormal size 2 Abnormal position 3 Abnormal size and position ``` ``` M 0 Normal mandible 1 Hypoplastic mandibular ramus 2 Hypoplastic and malformed mandibular ramus 3 Absence of ramus, glenoid fossa ``` ``` E 0 Normal ear 1 Auricular hypoplasia 2 Absence of external auditory canal 3 Absent auricle and malpositioned lobe ``` ``` N 0 Normal facial nerve 1 Upper facial nerve involvement (TZ) 2 Lower facial nerve involvement (BMC) 3 All branches affected (TZBMC) ``` S 0 No soft tissue abnormality 1–3 Minimal, moderate, severe soft tissue/muscle deficiency (Does not include e.g. other CN V, XI, macrostomia or auricular anomalies) Plus Extracraniofacial abnormalities

Question 40

What classification is used for mandibular malformations in hemifacial microsomia?

Answer 40

The Pruzansky classification of mandibular hypoplasia Type I - all components of the mandible are present but hypoplastic - TMJ present, but cartilage and joint space reduced Type IIA - condylar process is cone shaped - articulation allows hinge but not translatory mvmt Type IIB - no condylar process articulates with temporal bone, - coronoid process of varying size is present Type III - entire mandibular ramus is absent

Question 41

What is the SAT Classification of HFM?

Answer 41

SAT classification | - skeletal, auricular, and soft tissue involvement

Question 42

What are the goals of reconstruction for HFM?

Answer 42

Anatomical - construction and reshaping of craniofacial skeleton - augmentation of soft tissue - treatment of e.g. auricular malformation. Functional - TMJ articulation and occlusion - facial paralysis

Question 43

What is Goldenhar's syndrome?

Answer 43

- Oculoauriculovertebral sequence - Variant of hemifacial microsomia with additional epibulbar dermoids, preauricular skin tags and vertebral anomalies

Question 44

What are the features of Goldenhars syndrome?

Answer 44

``` Upper eyelid coloboma Epibulbar dermoids Antimongoloid slant Preauricular appendices External auditory meatal stenosis Middle and inner ear malformations Vertebral anomalies Maxillary hypoplasia Unilateral facial hypoplasia Aplasia of mandibular ramus and condyle Macrostomia Laryngeal abnormalities Cardiac defect Cranial anomalies Small-for-dates Feeding difficulties ```

Question 45

What are the features of Goldenhars syndrome?

Answer 45

- Hemifacial microsomia - Epibulbar dermoids - Vertebral abnormalities - Craniofacial microsomia : hypoplasia of pinna, TMJ, middle ear, muscles of mastication, parotid - Vertebral & rib anomalies - Cardiovascular defects - CL(P), CP – not a typical feature - renal anomalies

Question 46

What is the treatment for Goldenhar's syndrome in stages?

Answer 46

< 2 yrs → Remove auricular appendages Correct macrostomia with commissuroplasty +/- Fronto-orbital advancement 2 - 6 yrs → Distraction of mandibular ramus (Prozansky 3 may require recon w costochondral rib graft) ``` 6 - 14 yrs → Orthodontic treatment Ear recon Soft tissue augmentation (implant / free tissue transfer) Zygomaticoorbital complex reconstruction ``` > 14 yrs → Bone grafting to deficient areas Orthognathic surgery

Question 47

What is Nager Syndrome (Acrofacial Dysostosis)?

Answer 47

- AR - Craniofacial and upper limb abnormalities - Hypoplasia of orbits, zygoma, maxilla, mandible and soft palate

Question 48

What is hemifacial atrophy (Parry Romberg’s disease)

Answer 48

- Acquired condition ~ 5 yr → late teens - 95% unilateral, F:M 3:2 - slowly progressive atrophy of soft tissues of 1/2 of face (starts above maxilla, NL fold area) - process 'burns-out' in 2-10 yrs - left with unilateral permanent soft tissue deficiency of face - cause: ? localised scleroderma, abnormal sympathetics Sites affected - 'En coupe de sabre' deformity - sc atrophy in a line from chin to malar, eyebrow & forehead - Skin → localised atrophy, hyperpigmentation, vitiligo - Hair → pigment change or loss - Eye → enophthalmos, refractive error - Iris → pigment change (heterochromia iridis) - Forehead → a sharp depression, occasionally into the hairline (coup de sabre) - Cheek → soft tissue atrophy - Tongue, salivary gland → atrophy - Skeleton → underlying hypoplasia Neurological - seizures, trigeminal neuralgia

Question 49

What is the treatment of hemifacial atrophy?

Answer 49

Treatment - No treatment while condition active and progressive - Reconstruction when stable for at least 6 months o Skeletal - Onlay grafts / implants or osteotomies o Fat and Dermofat grafts o Temporoparietal fascia and temporalis muscle transfers o Free tissue transfer → scapular, parascapular, omentum, groin (over correct)

Question 50

What is the treatment of hemifacial atrophy?

Answer 50

Treatment - No treatment while condition active and progressive - Reconstruction when stable for at least 6 months o Skeletal - Onlay grafts / implants or osteotomies o Fat and Dermofat grafts o Temporoparietal fascia and temporalis muscle transfers o Free tissue transfer → scapular, parascapular, omentum, groin (over correct)

Question 51

What is fibrous dysplasia?

Answer 51

- Abnormal proliferation of bone forming mesenchyme (70-80% monostotic) - Membranous bones of children - Presents as enlarging mass in maxilla or mandible - Lesions are osseous rather than fibrous - elevated ALP, urine hydroxyproline - Xray: ground glass appearance, expansion . deformity - MRI (if ?malignant) Cherubism o familial polyostotic fibrous dysplasia → mandible and maxilla. May occur as early as 1 yr old. ``` Albright's syndrome (AD) o Fibrous dysplasia o Precocious puberty o Café-au-lait skin lesions o Tumours of the pituitary gland ```

Question 52

How does facial growth occur?

Answer 52

Facial skeleton is suspended from skull base Enlow's principle - midface and mandible grow by - displacement: whole bone mass moves - remodelling: occurs behind wave of displacement Moss' functional matrix principle - osteogenic membranes (e.g. periosteum) react to functional and morphogenic processes acting on them - e.g. brain growth, pull of muscles of mastication, dentition growth

Question 53

What is the treatment for fibrous dysplasia?

Answer 53

Treatment Medical - iv bisphosphonates, calcium & phosphate supplements, vit D Surgical - curettage (20-30% recurrence) - Resection of abnormal areas - Defects reconstructed with carved calvarial bone grafts - Radiotherapy may induce malignant transformation (0.5% osteosarcoma)

Question 54

Tell me about craniofacial embryology

Answer 54

- face is recognisable by end of wk 8 - majority of craniofacial anomalies arise in 1st 12wks - face is derived from 5 facial prominences (frontal nasal process, paired maxillary and mandibular processes) - they fuse day 46-47 Facial clefting theories - failure of fusion - failure of migration of mesoderm into a bilaminar ectodermal membrane → loss of support to overlying epithelial seam

Question 55

What factors contribute to craniofacial anomalies?

Answer 55

Genetic - e.g. FGFR mutations Radiation - assoc w microcephaly Maternal infection - toxoplasmosis, rubella, CMV Maternal health - PKU, DM, vit deficiency, smoking Encephaloceles - herniation of cranial contents thru skull defect - 1:5000 births - Meningocoele - meninges - Meningoencephalocoele - meninges and brain - Meningoencephalocystocoele - meninges, brain and ventricle Encephalomeningocoele - congenital midline swelling - herniation from ant cranial fossa via foramen caecum - assoc w metopic synostosis and hypertelorism - sites: occipital (80%), parietal, frontal, nasal, nasopharyngeal - Ix: skull XR, CT/MRI

Question 56

Please define 1. Malformation 2. Dysplasia 3. Disruption 4. Deformation 5. Syndrome

Answer 56

1. Malformation: intrinsic inborn area of fetal developmental process 2. Dysplasia: abnormal organisation of cells into tissue (e.g. Stickler's) 3. Disruption: normal fetus subjected to tissue injury/breakdown (vascular, infection, metabolic) 4. Deformation: abnormal external forces causing secondary distortion/deformity e.g. amniotic band 5. Syndrome: dysplasia affecting 2 or more sites not linked embryologically

Question 57

What are the aims and principles of reconstruction of facial clefts?

Answer 57

Aim: Functional and aesthetic correction of deformities - Eyelids (to prevent corneal exposure) - Macrostomia - Confluent oral, nasal and orbital cavities Principles 1. Excision of cleft scar tissue and abnormal elements 2. Layered soft tissue closure (local skin flaps) & reattach soft tissue to correct position 3. Delay skeletal recon until child is older, remove abnormal bone elements and reconstruct with transposition of neighbouring bone or bone grafts

Question 58

Name the oronasal clefts

Answer 58

Tessier 0-3 Cleft 0 (median craniofacial dysraphia) - Due to failure or delay in closure of anterior neuropore -> midline cleft - may be assoc with encephalocoeles and hypertelorism - median cleft lip (absent prolabium), bifid nose, tongue, maxillary midline cleft Cleft 1 (paramedian craniofacial dysraphia) Cleft 2 (paranasal) - cupid's bow → lateral to alar dome - maxillary alveolar cleft lateral to lat incisor Cleft 3 (oculonasal) - MOST COMMON Tessier oronasoocular cleft - Due to failure of fusion of lateral nasal process with maxillary process - cupids bow → lacrimal punctum, medial canthal ligament agenesis, colobomata - cleft from maxilla (lat incisor and canine), secondary palate → nasomaxillary groove → lacrimal bone

Question 59

Name the oroocular clefts

Answer 59

Tessier 4-6 ``` Cleft 4 (oculofacial 1 cleft) - medial to infraorbital foramen ``` ``` Cleft 5 (oculofacial 2 cleft) - lateral to infraorbital foramen ``` Cleft 6 - b/t maxilla & zygoma - absent lower lashes, lateral coloboma - 6, 7, 8 = Treacher Collins

Question 60

Name the lateral clefts

Answer 60

Tessier 7-9 Cleft 7 - hemifacial microsomia - 10% bilateral - commonest cleft 1 in 3000, M>F - sporadic, secondary to disruption of stapedial artery - structures affected centred on line b/t oral commissure and ear: macrostomia, ear defects, facial and trigeminal nerve, parotid - Runs between zygoma and temporal bone - bony structures: ascending ramus (mandible), maxilla Cleft 8 - component of Goldenhar syndrome - Outwards from the lateral canthus - b/t zygoma and temporal bone into greater wing of sphenoid (frontozygomatic suture) Cleft 9 - rarest - supraorbital rim into forehead (continuation of cleft 5) - associated with encephaloceles, facial nerve palsy, cranial base abnormalities

Question 61

Name the cranial clefts

Answer 61

Tessier 10-14 Cleft 9-11: Start in supraorbital region, each more medial, assoc with 5, 4, 3 clefts (they add up to 14) Cleft 10 - middle 1/3 of supraorbital rim - fronto-orbital encepahlocele displaces eye inferolaterally → hypertelorism Cleft 11 - medial 1/3 of upper lid and eyebrow, bony cleft lateral to ethmoid → hypertelorism Clefts 12,13,14 - Cranial extensions of 2, 1, 0 (add up to 14) - Do not involve orbit, may be assoc with hypertelorism and widening of cribriform plate Cleft 12 - medial 1/3 of eyebrow - hypertelorism, telecanthus, enlarged frontal and sphenoid sinuses Cleft 13 - medial to eyebrow → hypertelorism - wide cribriform plate, hypertrophied ethmoid cells Cleft 14 - holoprosencephaly, frontonasal encephalocele, bifid crista galli Cleft 30 - Median cleft of lower lip and mandible, inferior extension of cleft 0, may go into neck (hyoid bone, sternum).

Question 62

What are the principles of craniofacial surgery?

Answer 62

Good access Rigid fixation (absorbable plates preferable) Autologous bone graft - split calvarial (parietal), split rib Mepore (porous polyethylene, methylmethacrylate, hydroxyapetite Pericranial / galeal flaps

Question 63

What are the suggested timings for CF surgery?

Answer 63

Marchac (BJPS 1994) - brachycephaly: 3mths - others: 9-12mths Wall (BJPS 1994) - unless raised ICP or severe exorbitism, operate after 12mths - both suggest later surgery reduces re-op rates (~5%)

Question 64

When is frontofacial monobloc advancement indicated in infancy?

Answer 64

- only if severe exorbitism in infancy Risks - infection - blood loss intraop - deformity may return (op <5yrs old)

Question 65

What is the usual treatment algorithm for craniosynostosis with midface hypoplasia (e.g. Apert, Crouzon)?

Answer 65

1. Frontal advancement 2. Le Fort III facial advancement (age 6-12) (+/- facial bipartition to correct hypertelorism) +/- 3. Le Fort I advancement for correction of bite (age 12-18)

Question 66

What are the key steps in e.g. fronto-orbital remodelling?

Answer 66

- transcoronal zig zag incision, subperiosteal dissection - burr holes, craniectomy, elevate bone off dura (risk of entering sinuses) - elevate temporalis, cut and advance frontal bar - cut barrel staves and out-fracture - split calvarial bone grafts - replace bone flaps, fix with absorbable plates, mix bone dust with Tiseel and add to gaps - close with drains

Question 67

How do you correct sagittal synostosis?

Answer 67

- aim: reduce AP length and increase width - Sagittal strip craniectomy - Frontal, parietal and orbital remodelling (barrel stave)

Question 68

How do you correct unicoronal and bicoronal synostosis?

Answer 68

Unicoronal - Aim: advance and restore supra-orbital rim - Bilateral fronto-orbital advancement, frontal remodelling Bicoronal (e.g. Aperts, Crouzons) - frontal advancement within 1st yr - mid-face advancement Le Fort III osteotomy age 9-12 - may require secondary Le Fort I osteotomy (risk of causing VPI) - alternatively: monobloc advancement (Monasterio) but higher risk of infection & need for bone graft

Question 69

How is multiple sutures synostosis e.g. Kleeblattschadel treated?

Answer 69

- Aim: correct exorbitism, exophthalmos, hydrocephalus, mid-face hypoplasia - urgent cranial vault expansion - repeat / revisional procedures usually needed

Question 70

How is metopic synostosis treated?

Answer 70

Aim: correct trigonocephaly, hypotelorism - frontoparietal advancement & remodelling with barrel stave osteotomies - supra-orbital bar advancement - hypotelorism self-corrects

Question 71

How is lambdoid synostosis treated?

Answer 71

Aim: correct occipital flattening on affected side - remodel occiput - occipital bandeau with barrel staving or spiral osteotomy

Question 72

What are the causes of craniofacial asymmetry?

Answer 72

Congenital - HFM - unicoronal synostosis - Beckwith-Wiedemann syndrome Acquired - hemifacial atrophy - lipodystrophy - DXT in childhood / surgery - hypoplasia

Question 73

What is the typical Tessier treatment timing?

Answer 73

Neonate - airway (tracheostomy), secondary vision, feeding, hearing issues 6 mths - CP repair 5-6yrs - split calvarial onlay grafts (inferolateral orbit & zygoma) 6rys - soft tissue correction, coloboma, ear recon, macrostomia commissuroplasty, reset hairline / sideburn 6-12 yrs - orthodontics, jaw surgery: Le Fort III maxillary advancement, mandibular sagittal split osteotomy, advancement or distraction 12-18 yrs - Le Fort I advancement, sliding genioplasty 18yrs - rhinoplasty (broad nasal bridge)

Question 74

What is the difference b/t hypertelorism and telecanthus? What is Tan and Muliken's classification of hypertelorism (1997 PRS) Treatment

Answer 74

Hypertelorism - inc dist b/t bony orbits Telecanthus - inc intercanthal dist Classification - Frontonasal malformation (median cleft syndrome) - Craniofrontonasal dysplasia (Cohen syndrome) - Craniofacial clefts (paramedian) - Encephaloceles (interorbital) - Misc: Apert Pfeiffer Noonan Facial bipartition - removal of central bony segment Box osteotomy - rectangular osteotomy around each orbit, remove / add bone if needed. Good for asymmetry

Question 75

Miscellaneous HN conditions 1. Craniofrontonasal dysplasia 2. Binder's syndrome 3. Klippel Feil sequence

Answer 75

1. Craniofrontonasal dysplasia (Cohen syndrome) - - unicoronal synostosis, hypertelorism, bifid nasal tip, broad nasal bridge, dry frizzy hair, long grooved nails 2. Binders - maxillonasal dysostosis, hypoplastic mid-face - decreased vertical height of maxilla, absent ant nasal spine, class III malocclusion, short flat nose, short columella, acute NL angle, perialar flatness, convex upper lip, shallow philtrum, vertebral anomalies 50% 3. KF - 1 in 40000, AD variable penetrance - failure of segmentation of cervical spine esp C2-3, Sprengel's deformity, congenital scoliosis, low hairline, hearing loss 30%, cleft palate 20%, may be feature of other syndromes e.g. Goldenhars

Question 76

4. Cutis aplasia congenita | 5. Hurler's syndrome

Answer 76

4. Cutis aplasia congenita - usu sporadic, isolated, 25% multifocal - absence of midline vertex, sharply demarcated patch - may be associated with skull defects, exposed dura, sagittal sinus or brain Rx: usu conservative, dressings and secondary healing 5. Hurlers - mucopolysaccharidosis (deficient alpha-L-iduronidase - AR - gargoylism: coarse features, prominent forehead, corneal clouding, short stature, progressive metal disability, life expectancy 10yrs Rx - enzyme replacement, haematopoietic stem cell transplant

Question 77

What is the assessment for genioplasty What are the different types?

Answer 77

Assessment - medical and orthodontic hx, dentition, occlusion - Ricketts E line (pogonion - nose tip should lie just anterior to lips) - chin-nose relationship - Cephalometrics - Frankfurt plane, pogonion, menton, subspinale, supramentale, nasion Imaging - OPG - Cephalogram

Question 78

What are the different types of genioplasty?

Answer 78

Osseus - Sliding - Jumping - Wedge - Interpositional - Reduction - Centralising (or asymmetric) Implant - Snythetic (silicone, medpor, bylon mesh, expanded PTFE, hydroxyapetite) - Biological - autologous bone

Question 79

What is the technique for implant augmentation?

Answer 79

submental exposure intraoral exposure fixed / not fixed

Question 80

What are the complications of genioplasty

Answer 80

``` haematoma infection nerve injury (mental, inf alveolar) malposition under / overcorrection, asymmetry ```