Treacher Collins (“Mandibulafacial Dysostosis, or MFD”) syndrome. Children with Treacher Collins syndrome have underdeveloped structures on each side of the face, usually to the same degree. And, unlike some children with asymmetrical First and Second Pharyngeal Arch conditions, children with Treacher Collins syndrome do not have weakness of the facial muscles. The features of Treacher Collins syndrome include some or all of the following: downward-slanting eyelids; notching (colobomas) of the lower eyelids; underdevelopment of the bones of the face, including the cheekbones (zygomas), lower jaw (mandible), and upper jaw (maxilla); an abnormal bite (malocclusion); a smaller than average face; underdeveloped and/or malformed ears; hearing loss, which is often severe, due to a narrowing or absence of the ear canal.
Learn more about Mandibulafacial Dysostosis, MFD in Related Articles: First and Second Pharyngeal Arch Syndromes