A young child presents with bilateral, painless, symmetric expansion of the jaws (especially the posterior mandible) giving a chubby-cheeked appearance, with multilocular radiolucencies. This inherited condition is:

Cherubism is a benign autosomal-dominant (SH3BP2) fibro-osseous condition of childhood causing bilateral, symmetric, painless jaw enlargement with multilocular radiolucencies; it typically stabilizes and regresses after puberty.Other options: Paget disease affects older adults; osteosarcoma is a painful malignant tumor; osteomyelitis is an acute painful infection; none give symmetric childhood 'cherub' facies.Key exam takeaway: Bilateral symmetric painless jaw expansion in a child = cherubism (autosomal dominant, self-limiting after puberty).