- distraction o. a technique of inducing new bone formation by dividing a bone and applying tension through an external fixation device to lengthen the bone.
- o. imperfecta (OI) a group of connective tissue disorders of type I collagen, characterized by bone fragility, fractures on trivial trauma, skeletal deformity, blue sclerae, ligament laxity, and hearing loss. The Sillence system, which is a clinical, radiographic, and genetic classification, shows four types; inherited as autosomal dominant, caused by mutation in either the collagen type I alpha-1 gene (COL1A1) on chromosome 17q or the alpha-2 gene (COL1A2) on 7q. SYN: brittle bones.
- Type I o. imperfecta [MIM*166200] a mild form characterized by blue sclerae, hearing loss, easy bruising, prepubertal bone fragility, and short stature.
- Type II o. imperfecta [MIM*166210] a perinatal lethal form associated with stillbirth or lifespan less than 1 year; very fragile connective tissue, and radiographic findings of in utero fractures, large soft cranium, micromelia, tubular long bones, and beaded ribs.
- Type III o. imperfecta [MIM*259420] a progressive deforming form with severe bone fragility, easy fractures, triangular facies with relative macrocephaly, skeletal deformities with scoliosis, pectus and bowing of limbs, dwarfism, and radiographic findings of metaphyseal flaring of long bones with sutural bone formation. Most cases are autosomal dominant disorders, but autosomal recessive inheritance has also been described.
- Type IV o. imperfecta [MIM*166220] a moderately severe form, characterized by short stature, bone fragility, preambulatory fractures, and bowing of long bones.
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os·teo·gen·e·sis (os″te-o-jenґə-sis) [osteo- + -genesis] formation of bone; the development of the bones. osteogenetic adjMedical dictionary. 2011.