mandibulofacial dysostosis


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Related to mandibulofacial dysostosis: Juliana Wetmore

dysostosis

 [dis″os-to´sis]
defective ossification; a defect in the normal ossification of fetal cartilages.
cleidocranial dysostosis an autosomal dominant condition in which there is defective ossification of the cranial bones, complete or partial absence of the clavicles, so that the shoulders may be brought together, or nearly together, in front, and dental and vertebral anomalies. See illustration.
Cleidocranial dysostosis. From Dorland's, 2000.
craniofacial dysostosis an autosomal dominant condition marked by a pointed or conical skull, protruding wide-set eyes, strabismus, parrot-beaked nose, and hypoplastic maxilla with relative mandibular prognathism. Called also Crouzon's disease.
mandibulofacial dysostosis a hereditary disorder occurring in two different forms: the complete form is Franceschetti syndrome and the incomplete form is Treacher Collins syndrome. Persons with the condition have downslanting eyes (antimongoloid palpebral fissures); absence of all or part of the lower lid; underdeveloped cheekbones that appear depressed; a prominent nose, wide mouth, and small receding chin; underdeveloped, malformed, or prominent ears; and small tufts of hair in front of the ears. There is often, but not always, some degree of hearing loss, usually conductive.
metaphyseal dysostosis a skeletal abnormality in which the epiphyses are normal or nearly so, and the metaphyseal tissues are replaced by masses of cartilage, producing interference with endochondral bone formation and expansion and thinning of the metaphyseal cortices.
orodigitofacial dysostosis orofaciodigital syndrome.

man·dib·u·lo·fa·cial dys·os·to·sis

a variable syndrome of malformations primarily of derivatives of the first pharyngeal arch; characterized by palpebral fissures sloping outward and downward with notches or colobomas in the outer third of the lower lids, bony defects or hypoplasia of malar and zygomatic bones, hypoplasia of the mandible, macrostomia with high or cleft palate and malposition and malocclusion of teeth, low-set malformed external ears, atypical hair growth, and occasional pits or clefts between mouth and ear.
See also: Treacher Collins syndrome.

mandibulofacial dysostosis

[mandib′yəlofā′shəl]
Etymology: L, mandere + facies, face; Gk, dys, bad, osteon, bone
an abnormal hereditary condition characterized by an antimongoloid slant of the palpebral fissures, coloboma of the lower lid, micrognathia and hypoplasia of the zygomatic arches, and microtia. Evidence indicates that this disorder is transmitted as an autosomal-dominant trait. The condition occurs in the complete form as Franceschetti's syndrome and in the incomplete form as Treacher Collins' syndrome. See also dysostosis.

Treacher-Collins syndrome

A disorder of craniofacial development (OMIM:154500) characterised by bilateral downwardly slanting palpebral fissures, colobomas of lower eyelids with few eyelashes medial to the defect, hypoplasia of facial bones, cleft palate, malformation of external ears, external auditory canal atresia, and bilateral conductive hearing loss.

Molecular pathology
Defects of TCOF1, which encodes a nucleolar protein involved in ribosomal DNA gene transcription, cause Treacher Collins syndrome.

Treach·er Col·lins syn·drome

(trēch'ĕr kol'inz sin'drōm)
Mandibulofacial dysostosis characterized by bone abnormalities of structures formed from the first pharyngeal arch, including downward sloping palpebral fissures, depressed cheek bones, deformed pinnae, a receding chin, and a large, fishlike mouth with dental abnormalities. Atresia of the external acoustic meatus (auditory canal), defects of the external acoustic meatus and ossicles, and cleft palate are most common.
Synonym(s): mandibulofacial dysostosis.

man·dib·u·lo·fa·cial dys·os·to·sis

(man-dib'yū-lō-fā'shăl dis'os-tō'sis)
Variable syndrome of malformations primarily of derivatives of pharyngeal arch; characterized by bony defects or hypoplasia of malar and zygomatic bones, hypoplasia of mandible, macrostomia with high or cleft palate, malposition and malocclusion of teeth.
Synonym(s): mandibulofacial dysplasia.