This review article covering maxillary and mandibular tumours is from an edition of the Clinics covering paediatric head and neck masses from frequently encountered congenital malformations to the rarities. There is a wide differential diagnosis for childhood mandibular or maxillary masses and many have non-specific radiological findings making open biopsy essential. The conditions covered in this chapter are divided into odontogenic causes and non-odontogenic. Fibrous dysplasia (FD) is caused by a sporadic mutation in the GNAS1 gene on chromosome 20, causing replacement of normal bone with fibrous connective tissue with a slow clinical progression. FD is not a neoplastic disease, is characterised by ground glass appearances on CT and is divided into monosteotic, the majority of cases, and polyosteotic. Polyosetotic disease involves two or more bones and in combination with café au lait spots and endocrinopathies suggests McCune-Albright syndrome. Treatment is symptom driven, and also depends on sites involved and maturity of the skeleton. Bone pain may be aided with bisphosphonates and for those who require treatment, it is usually surgical. A comprehensive review article of lesions arising in the facial skeleton from simple cysts to histiocytosis.