Mandibulofacial Dysostosis (Treacher Collins Syndrome) Workup

Updated: Feb 09, 2016
  • Author: Marie M Tolarova, MD, PhD, DSc; Chief Editor: Luis O Rohena, MD, FAAP, FACMG  more...
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Workup

Laboratory Studies

See the list below:

  • Midtrimester ultrasonography can detect facial dysmorphology and, because of its noninvasive quality, is preferred to fetoscopy, which greatly aided prenatal diagnoses in the 1980s. [22, 23] The images below are examples of fetal findings.
    Anteroposterior view of 19-week-old fetus with Tre Anteroposterior view of 19-week-old fetus with Treacher Collins syndrome. Diagnosis was confirmed based on fetoscopy images. Tolarova M, Zwinger A. The use of fetoscopy by inborn morphological anomalies. Acta Chir Plast. 1981;23(3):139-51.
    Lateral view of 19-week-old fetus with Treacher Co Lateral view of 19-week-old fetus with Treacher Collins syndrome. Diagnosis was confirmed based on fetoscopy images. Tolarova M, Zwinger A. The use of fetoscopy by inborn morphological anomalies. Acta Chir Plast. 1981;23(3):139-51.
  • Mutations of the TCOF1 gene can be detected as single-nucleotide polymorphisms. Thus, prenatal diagnosis is possible but not yet clinically available. A prenatal diagnosis requires the following:
    • Blood samples from family members
    • Fetal cells obtained via chorionic villi sampling (performed at 10-11 weeks' gestation) or via amniocentesis (performed at 16-17 weeks' gestation)
  • Assessment and monitoring of postnatal functions
    • Pulse oximeter monitoring of hemoglobin saturation with oxygen
    • Assessment of feeding efficiency
    • Audiologic testing
    • Neuroophthalmologic assessment
    • Full craniofacial CT scan (axial and coronal slices, from the top of the skull through the cervical spine)
    • Evaluation and genetic diagnosis by a medical geneticist
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Imaging Studies

See the list below:

  • The following imaging studies should be obtained to visualize craniofacial dysmorphology in detail and repeated, as needed, for surgical planning:
    • Anteroposterior and lateral cephalography
    • Full craniofacial CT scan (axial and coronal slices from the top of the skull through the cervical spine)
    • As follow-up, CT scans from orbits through mandible (usually enough for surgical planning)
    • Panoramic radiography
    • Brain MRI for inner auditory canal (IAC) study preferred (If MRI is not available, CT scan may be obtained for IAC.)
  • If the clinical diagnosis of Treacher Collins syndrome is in doubt, radiological assessment can be useful. These tests are more helpful when mild expression is suspected upon clinical evaluation. The occipitomental projection of the skull (Waters view, anteroposterior with the canthomeatal line extended 45° with no inclination of the incident ray) can confirm zygomatic arch hypoplasia or aplasia. Orthopantomography should be used to demonstrate mandibular hypoplasia and changes in mandibular configuration. Temporomandibular joint abnormalities and asymmetry can be evaluated on these orthopantomograms. Roentgenography can also reveal any bony asymmetry in mild cases of Treacher Collins syndrome. If a patient needs any surgical correction or treatment, CT scan or MRI is mandatory.
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