<unk>  causes the bones to be abnormally dense ; the last bones of the fingers (the distal phalanges) to be unusually short; and delays the normal closure of the connections (sutures) of the skull bones in infancy, so that the "soft spot" (fontanelle) on top of the head remains widely open. Because of the bone denseness, those with the syndrome suffer from fractures. Those with the syndrome have brittle bones which easily break, especially in the legs and feet. Other abnormalities involve the head and face, teeth, collar bones, skin, and nails. The front and back of the head are prominent. Within the open sutures of the skull, there may be many small bones (called wormian bones). The midface is less full than usual. The nose is prominent. The jaw can be small. The palate is narrow and grooved. There will be delay in fall of milk teeth. The permanent teeth can also be slow to appear. The permanent teeth are commonly irregular and teeth may be missing (hypodontia). The collar bones are often underdeveloped and malformed. The nails are flat, grooved, and dysplastic. High bone density, Acro-osteolysis and obtuse mandibular angle are the characteristic radiological findings of this disorder.<unk>  also causes problems that may become evident with time. Aside from the broken bones, the distal phalanges and the collar bone can undergo slow progressive deterioration. Vertebral defects may permit the spine to curve laterally resulting in scoliosis. The dental problems often require orthodontic care and cavities are common. Patients with PYCD are at a high risk of severe obstructive sleep apnea (OSA) due to upper airway obstructions. OSA must be managed to prevent long term pulmonary complications. Amongst infrequent complications, attention should be paid to maxillofacial anomalies. Snoring can be one of the presenting complaints and this needs early evaluation and management of obstructive sleep apnea if present to prevent long term pulmonary complications.
Pycnodysostosis
Cleidocranial dysostosis
Acrodysostosis
Dysostosis
Melorheostosis
Cemento-osseous dysplasia
Gerodermia osteodysplastica
Metaphyseal dysplasia