Radium jaw is an occupational disease brought on by the ingestion and subsequent absorption of radium into the bones of Radium dial painters. The symptoms are necrosis of the mandible (lower jawbone) and the maxilla (upper jaw) as well as constant bleeding of the gums and (usually) after some time, severe distorion due to bone tumours and porosity of the lower jaw.

The disease was first recognised by Dr. H.S. Martland in 1924, as symptomatic of radium paint ingestion after many female workers from various radium paint companies reported similar dental and mandibular pain. The condition is similar to Phossy jaw, an osteoporitic and osteonecrotic illness of matchgirls, brought on by phosphorus ingestion and absorption. The disease was the main reason for litigation against the United States Radium Corporation by the so-called Radium girls.