Dysostosis is a hereditary or inborn malformation of the skeletal system. The following types of dysostosis are distinguished: clavicular-cranial, craniofacial (Crouzon's dysostosis, hypertelorism), multiple (Pfaundler-Garler dysostosis, gargoylism), enchondral epiphyseal (Ribbing's disease), enchondral metaphisal (Morkio disease). Unlike chondrodystrophy, when children are maimed at birth, with dysostosis, growth disorders become noticeable only during the first year of life, in the process of ossification.
In the clavicular-cranial dysostosis, the underdevelopment of the clavicles and the bones of the skull are combined; shoulders can be brought together to full contact. There may be short stature, shortening of the shoulder and hip, clubfoot and other changes in the skeleton.
In craniofacial dysostosis, premature fusion of cranial sutures is noted; the patient's eyes are wide apart, the nose is coracoid, the lower jaw is much bulged up, the sky is high, the chest and spine are deformed. There are headaches and mental retardation, eye gleam, nystagmus, optic nerve atrophy.
In case of multiple dysostosis, the enchondral and periosteal ossification is disturbed, a large ugly skull, saddle nose, rough facial features, and lumbar kyphosis are noted. The glycoprotein metabolism is impaired, patients are weak-minded, the liver and spleen are enlarged,
When enchondral epiphyseal dysostosis, there are small sizes and deformations of a large number of bone nuclei and a tendency to soften, especially the nuclei of the proximal epiphysis of the femur and scaphoid bone. Growth is not always delayed. The disease is often combined with symptoms of hypothyroidism.
With enchondral metaphyseal dysostosis, the metaphysis is curved, resulting in a distorted shape of the chest and spine and growth is delayed. The skull, face and diaphysis remain intact. The joints of the arms are relaxed. Mental abilities are normal.
Treatment of dysostosis is not known.