Cherubism

Cherubism is a rare genetic disorder of childhood in which the lower jaw and sometimes the upper jaw enlarge as normal bone is replaced by excessive fibrous tissue, producing a rounded fullness in the lower face that gave the condition its name, after the chubby-cheeked cherubs of Renaissance art. It typically becomes noticeable around age seven and can progress through puberty, sometimes disturbing the eruption of permanent teeth and causing early loss of baby teeth, though in many cases the bone remodels back toward normal after puberty ends. The disorder is inherited in an autosomal dominant pattern and is linked to mutations in the SH3BP2 gene on chromosome 4. Only a few hundred cases have been formally documented worldwide, more often in males than females, and severe cases that do not regress may require surgery to remove the overgrown tissue and reshape the jaw.