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Maxillofacial Dysostosis


Synonyms of Maxillofacial Dysostosis

  • autosomal dominant maxillofacial dysostosis

Disorder Subdivisions

  • No subdivisions found.

General Discussion



The symptoms and physical findings associated with maxillofacial dysostosis may vary from one person to another. Because so few cases have been identified and reported, it will be difficult to obtain an accurate clinical picture of the disorder. Affected individuals or parents of affected children should talk to their physicians and medical team about their specific case and associated symptoms.

Characteristic findings associated with maxillofacial dysostosis include an underdeveloped (hypoplastic) upper jaw (maxilla), an abnormal downward slant of the opening between the eyelids (palpebral fissures), minor external ear malformations and speech abnormalities.

Although most individuals with maxillofacial dysostosis have normal intelligence, they are often mistakenly thought to be mentally challenged due to their language problems. Their progress should be carefully monitored and educators should be informed of the potential for delayed onset of speech and difficulties with speech development including poor speech articulation (dysarthria).

External ear abnormalities may include malformation of the upper, outer portion of the ear (pinna or auricle). Hearing loss was not seen in any of the individuals with maxillofacial dysostosis reported in the medical literature. Additional symptoms that have been reported in some cases of maxillofacial dysostosis include a sunken chest (pectus excavatum), incomplete or underdeveloped nipples, an abnormally flat skull, and a flattened bridge of the nose. Certain eye abnormalities including drooping of the upper eyelid (ptosis), crossed eyes (strabismus), and rapid, involuntary movements of the eyes (nystagmus) have also been reported.



Affected Populations

Maxillofacial dysostosis is extremely rare and the exact incidence of the disorder is unknown. Approximately 12 cases have been reported in the medical literature. Researchers believe that cases of maxillofacial dysostosis may go misdiagnosed or unrecognized making it difficult to determine the true frequency of the disorder in the general population. Maxillofacial dysostosis most likely affects males and females in equal numbers.

Related Disorders

Symptoms of the following disorders can be similar to those of maxillofacial dysostosis. Comparisons may be useful for a differential diagnosis.

X-linked maxillofacial dysostosis, sometimes referred to as Toriello syndrome, is a rare genetic disorder characterized by an abnormally small jaw (micrognathia), underdevelopment of the middle portion of the face (midface hypoplasia), ear abnormalities, and an abnormal downward slant of the opening between the eyelids (palpebral fissures). Additional symptoms include short stature, cognitive impairment, a slightly webbed neck and hearing loss. The disorder is believed to be inherited as an X-linked recessive trait.

Nager syndrome (also known as mandibulofacial dysostosis) is a rare inherited disorder characterized by craniofacial malformations similar to those in Treacher Collins syndrome occurring in association with abnormalities of the arms, hands, and/or feet. Craniofacial malformations include underdevelopment of the cheekbones (malar hypoplasia); incomplete development of the lower jaw (mandibular hypoplasia), causing the jaw to appear abnormally small (micrognathia); hypoplastic and/or malformed (dysplastic) external ears (pinnae) and blind ending or absent external ear canals (microtia), resulting in hearing impairment (conductive hearing loss); and/or downwardly slanted palpebral fissures, lack or absence of the lower eyelashes, and/or drooping upper eyelids (ptosis). Limb abnormalities include underdevelopment or absence of the thumbs, absence of one of the bones in the forearms (radius), abnormal fusion of bones in the forearms (radioulnar synostotis), permanent flexion of certain fingers (camptodactyly), and/or webbing of the toes (syndactyly). In most cases, Nager syndrome appears to occur randomly, for no apparent reason (sporadic). In other cases, researchers suggest that the disorder may be inherited as an autosomal dominant or recessive trait. (For more information on this disorder, choose "Nager" as your search term in the Rare Disease Database.)



Standard Therapies

A diagnosis of maxillofacial dysostosis is made based upon identification of characteristic symptoms, a detailed patient history, a thorough clinical evaluation and a variety of specialized tests to rule out other disorders.

The treatment of maxillofacial dysostosis is directed toward the specific symptoms that are apparent in each individual. Facial features may improve with age, often resulting in a near normal appearance by adulthood. When facial abnormalities are severe a variety of medical techniques including plastic surgery or orthodontic repair may be necessary.


Investigational Therapies



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Contact for additional information about maxillofacial dysostosis:

James Reynolds, MD, FAAP, FACMG
Medical Geneticist
Shodair Children’s Hospital
2755 Colonial Drive
Helena, MT 59601
Phone: 800-447-6614

Organizations related to Maxillofacial Dysostosis


Gorlin RJ, Cohen MM Jr, Hennekam RCM. Eds. Syndromes of the Head and Neck. 4th ed. New York, NY: Oxford University Press; 2001:809.


Ensink RJH, Brunner HG, Cremers CWRJ. A new type of maxillofacial dysostosis, inherited as an x-linked recessive trait. Gen Couns. 1997;8:285-290.

Escobar V, Eastman J, Weaver D, Melnick M. Maxillofacial dysostosis. J Med Genet. 1977;14:355-358.

Melnick M, Eastman JR. Autosomal dominant maxillofacial dysostosis. Birth Defects Orig Art Ser. 1977;XIII(3B):39-44.

Online Mendelian Inheritance in Man (OMIM). The Johns Hopkins University. Maxillofacial Dysostosis. Entry No: 155000. Last Edited March 18, 2004. Available at: Accessed October 4, 2012.


Report last updated: 2012/10/04 00:00:00 GMT+0


