A dysostosis (from Ancient Greek δῠσ- (dys-) 'bad, difficult' and ὀστέον (ostéon) 'bone') is a disorder of the development of bone, in particular affecting ossification.

[1] Examples include craniofacial dysostosis, Klippel–Feil syndrome, and Rubinstein–Taybi syndrome.

It is one of the two categories of constitutional disorders of bone (the other being osteochondrodysplasia).

[2] When the disorder involves the joint between two bones, the term synostosis is often used.

This article about a disease of musculoskeletal and connective tissue is a stub.