Also known as Treacher Collins syndrome, mandibulofacial dysostosis (MFD) is a rare syndrome characterized by underdeveloped facial bones and a very small lower jaw and chin, called micrognathia. The most obvious facial differences are the underdeveloped cheekbones and the drooping lower eyelids. Some children with MFD also have a cleft palate. The child's ears may be normal, or they may be small, malformed or missing altogether, and hearing impairment is often part of the syndrome.
Most children with MFD have complications related to speech, hearing, vision, swallowing and breathing. In severe cases, underdeveloped facial bones may restrict an infant's airway, causing potentially life-threatening respiratory problems that may require a tracheotomy, a surgical procedure to open the windpipe.
MFD is a genetic condition that follows an autosomal dominant inheritance pattern, meaning if one parent has the syndrome, they have a 50 percent chance of passing it on to their child. It can also result from a spontaneous genetic mutation in the person with the syndrome. This person will then have a 50 percent chance of passing the condition on to his or her children.
MFD is primarily diagnosed based on its physical characteristics, although there is now a genetic test for the syndrome.
Treatment for MFD depends on the child's age and the severity of the condition. In infancy, breathing and eating problems will be monitored. Sometimes, a tracheotomy — a breathing tube placed in the windpipe — is required to help the child breathe. If the child has a cleft palate, surgery to repair the cleft may be performed at around 1 year of age.
Hearing management is extremely important and children should be seen by an audiologist (hearing specialist) and otolaryngologist (ear, nose and throat doctor). CT scans can help determine whether surgery to restore hearing is likely to be successful. Most children and adults with MFD will need hearing aids.
Some children with MFD have speech difficulties and will need to see a speech therapist. The speech problems may be related to a repaired cleft palate or to hearing loss.
In addition, most children with MFD will need extensive orthodontic treatment.
Other treatments may include surgery on the ears, lower eyelids, cheekbones and jaws, to improve both function and appearance.