An osteoma (plural osteomas or less commonly osteomata) is a new piece of bone usually growing as a benign tumour on another piece of bone, typically the skull.

[1] Osteoma represents the most common benign neoplasm of the nose and paranasal sinuses.

The cause of osteomas is uncertain, but commonly accepted theories propose embryologic, traumatic, or infectious causes.

Larger craniofacial osteomas may cause facial pain, headache, and infection due to obstructed nasofrontal ducts.

Often, craniofacial osteoma presents itself through ocular signs and symptoms (such as proptosis).