Treacher Collins Syndrome (TCS) is a rare genetic disorder characterized by deformities of the face, eyes, ears and jaw. It is caused by mutations in the TCOF1 gene. Clinical features include downward slanting eyes, ear abnormalities, cleft palate and a recessed chin. Treatment involves surgery to reconstruct facial structures and manage airway issues in infancy. Further reconstructive surgeries are often needed as the child grows. Prognosis is good with treatment, though facial differences typically remain.

1. Treacher Collins Syndrome
 Treacher collins syndrome (TCS), also called mandibulofacial dysostosis
 It occurs with a frequency of 1 in 25,000 to 1 in 50,000 live births
 Males and females are equally affected (Gorlin et al., 1990)
 According to Tessier's classification of clefts, this syndrome consists of a cleft between the 6
through 8 positions
 It is an autosomal dominant disorder with a variable degree of penetrance.
 Gene mutation of TCOF1
Genetic hypothesis (Dixon 2007)
 Abnormal NNC migration
 Improper cellular differentiation
 Haplo-insufficiency of TCOF1 results in a depletion of neural crest cell precursors through
high levels of cell death in the neuro-epithelium, which results in a reduced number of neural
crest cells migrating into the developing craniofacial complex (dixon 2007)
Clinical features of TCS
The degree of malformation present at birth is believed to be relatively stable and non-
progressive with age (Roberts et al., 1975).
I. Eyes:

2.  The eyes have an anti-mongoloid slant with colobomas (eyelid notch) along the lateral one-
third of the lower lid.
 Lashes are absent from the medial two-thirds of the lower eyelid.
 Dystopia
II. Ears
 External ears are absent, malformed, or malposed,
 Profound conductive hearing loss is common in severe cases, and children must be fitted early
with bone-conducting hearing aids (BAHA) to facilitate development of normal speech
III. Nose
 Prominent nasal dorsum
 Choanal atresia or stenosis
IV. Zygoma
 Affected patients have malar hypoplasia and a cleft in the zygoma 79% [29,42].
 The lateral aspects of the orbits are hypoplastic with a resulting inferiorlateral orbital dysplasia
V. Maxillo-mandibular region
 The maxilla and mandible are hypoplastic,
 The face has a convex profile with a retrusive chin and jaw, which is associated with a class 2
malocclusion
 Steep clockwise rotation of the maxillomandibular complex
 Absent, hypoplastic, or deformed TMJ
 Muscular hypoplasia (muscles of mastication)
VI. Intra-orally
 Cleft lip and palate may occur 24%.
 Angel class II molar relationships
 Anterior open bite
 Dental abnormalities (enamel opacities, dental agenesis, eruption disturbances)

3. Differential diagnosis
 Craniofacial microsomia: features are asymmetric and usually unilateral
 Pierre Robin sequence: children with TCS may also have PRS features
 Stickler syndrome comprises a group of hereditary conditions involving eye, ear, and joint
deformities
 Nager syndrome includes malformed short upper limbs as well as cleft palate and severe palatal
hypoplasia
Classification of TMJ-mandibular deficiency
 Kaban and colleagues (1980) designed a classification system to define the degree of TMJ-
mandibular deficiency similar to that used in hemifacial microsomia.
 This classification is also useful for defining the mandibular morphology in the TCS patient.
Considerations during infancy into early childhood
1. Prenatal diagnosis of pregnancies at increased risk for TCS is possible through analysis of
DNA extracted from fetal cells obtained by amniocentesis performed at about 15 to 18 weeks’
gestation or by chorionic villus sampling (CVS) at about 10 to 12 weeks’ gestation. The
malformation-causing allele of an affected family member must be identified before prenatal
testing can be performed.
2. Family-to-family support is of great psychological value
3. Airway
I. The airway may be compromised as a result of (Posnick, 1997):
 The maxillary hypoplasia, which tends to constrict the nasal passages and result in a degree of
choanal stenosis or atresia.
 The presence of mandibular micrognathia
 retropositioned tongue

4.  Deformation of oropharyngeal and hypopharyngeal spaces
II. Patients with airway and feeding difficulties may require surgery during the first couple of
years of life [43-45]. These procedures may include
 prone positioning
 Tongue-lip adhesion (glossopexy),
 Distraction osteogenesis of the mandible, a mandibular ‘‘lengthening’’ procedure carried out
early in life will not avoid the need for either maxillary and chin surgery or further mandibular
reconstruction planned closer to the time of skeletal maturity.
 Tracheostomy
 Correction of cleft lip and/or palate and choanal atresia,
4. Feeding
 Gavage-assisted feedings
 Gastrostomy tube placement
5. Hearing: pediatric otolaryngologist, in combination with formal audiologic testing, will give
an indication of the extent of conductive hearing loss and allow for the early fitting of hearing
aids to assist the infant with the acquisition of communication skills and encourage the normal
bonding process with the family
6. Vision: pediatric neuro-ophthalmologic assessment is useful to assess extraocular muscle
function, corneal exposure, and visual acuity
7. CT scan: At some point early in life, a complete craniofacial CT scan (axial and coronal slices)
from the top of the skull through the cervical spine, with three-dimensional re-formation, is
useful for documenting the extent of craniofacial skeletal dysmorphology
8. Genetic evaluation by a medical geneticist is indicated for documenting other possible
malformations and for family-planning issues (Roberts et al., 1975)
9. Staged of craniofacial reconstruction timing and techniques
A. Zygomatic and orbital reconstruction

5.  Posnick et al. (1993, 2000) believe that reconstructing the malar and orbital deficiencies before
5 years of age is not indicated unless uncontrolled corneal exposure problems occur and are
thought to be the result of the skeletal deformity.
 By 5 to 7 years of age, the cranio-orbitozygomatic bony development is nearly complete
(Waitzman et al., 1992b). Therefore, adult-sized cheekbones may be constructed and placed
with limited concern about how further growth will alter the initial result achieved
 Other surgeons have recommended varied methods and timing for correction of the zygomatic
and orbital deformities associated with TCS
 Malar construction can be made by:
1. full-thickness calvarial bone grafts
2. nonautogenous reconstruction using titanium mesh base
3. hydroxyapetite bone cement (bone- source).
B. Maxillo-mandibular reconstruction
 Maxillo-mandibular reconstruction in TCS is identical to that with CFM. The first
consideration in the timing and technique of jaw reconstruction is to define whether the TMJ-
mandibular deformity is a Kaban type I, IIa, IIb, or III.
 The type I, IIa, and IIb mandibular deformities do not need TMJ construction. In these patients,
adequate TMJ function and condyle/ascending ramus form is present to allow for mandibular
reconstruction through ramus osteotomies, with preservation of the ‘‘working TMJ.’’

6.  Types i and iia mandibular deformities are best reconstructed at the time of early skeletal
maturity (13 to 16 years of age) using sagittal ramus osteotomies of the mandible in
combination with a le fort i osteotomy and an osteoplastic genioplasty.
 Mandibular and possibly maxillary first premolar extractions may be advantageous to
Orthodontically unravel dental crowding and normalize the inclination of the incisor teeth in
preparation for the aesthetic repositioning of the jaws to restore the occlusion, facial heights,
and projection.
 Type iib deformities may be severe enough that the family, once fully informed and educated,
decide to go forward with first-stage mandibular reconstruction either through BSSO with
immediate repositioning or with ramus osteotomies and gradual distraction techniques over
several months (diner et al., 1997; roth et al., 1997; cohen et al., 1998; hollier et al., 1999).
When a first stage mandibular procedure is performed in the mixed dentition for the type IIB
patient, the need for additional mandibular osteotomies, in conjunction with a Le Fort I
osteotomy and an osteoplastic genioplasty, should be anticipated at the time of skeletal
maturity.
 The type iii glenoid fossa and condyle-ascending ramus deformity will require surgical
construction of the congenitally missing parts. Osteotomies alone, with either immediate or
delayed repositioning of the mandibular segments, will not be adequate. The approach usually
include:
A. Mixed dentition: first-stage mandibular reconstruction for the type iii deformity is generally
performed when the child is 6 to 10 years of age
 using a costochondral graft
 Construction of the glenoid fossa is best performed in conjunction with the zygomatic and
orbital reconstruction.
 At operation, the distal mandible is repositioned anteriorly and held in place through a
prefabricated, interocclusal acrylic splint securing the mandible to the maxilla in the preferred
occlusion. The proximal mandible on each side is then constructed with an autogenous
costochondral graft. Fixation of the rib graft to the native (distal) mandible is done with an
extended miniplate from the graft forward along the inferior border of the body of the mandible
on each side. Graft placement and fixation are performed through an extraoral (risdon) neck
incision. The avoidance of intraoral incisions and dissections during this procedure is important
to minimize the incidence of infection, with subsequent graft loss or tmj ankylosis.
 Reasons why mandibular surgery in the mixed detention is generally not performed are:

7. I. To avoid injury to the developing permanent detention and the inferior alveolar nerves;
II. To avoid soft tissue and skeletal scarring that may limit the final overall functional and aesthetic
result achievable at the time of skeletal maturity;
III. To avoid the perioperative complications associated with an additional general anesthetic and
surgical procedure;
IV. To limit postoperative cooperation difficulties and negative psychological memories that may
occur when this procedure is performed in childhood;
V. To avoid iatrogenic deformation of the mandible that could add to the overall mandibular
dysmorphology.
VI. Unfortunately, this will not resolve the mandibular deformity long term. Problems with
costochondral graft overgrowth, undergrowth, and asymmetrical growth continue to plague the
reconstructive surgeon (ellis and carlson, 1986; daniels et al., 1987; henning et al., 1992).
B. Permanent dentition: Final orthognathic surgery of the upper jaw, lower jaw, and chin will later
be required at the time of early skeletal maturity.
C. Nasal reconstruction
Rhinoplasties are also best reserved until skeletal maturity, after completion of any
orthognathic corrections. Dorsal nasal reduction and infracture, along with tip repositioning
and reconstruction, are typically required.
D. Soft tissue reconstruction
Finally, the contour of the facial soft tissues generally requires correction at a later stage when
the patient has achieved facial skeletal maturity. The use of microsurgical free flap transfer has
improved correction of facial soft tissue contours [49].
E. External ear reconstruction
The successful grafting of a well-sculpted cartilage framework is the foundation for a sound
auricle repair. According to Brent, there is adequate rib cartilage for the repair in most children
by age 6. The syncondrotic region of ribs 6 and 7 will then provide an ample cartilage block to
form the framework of the ear.