Fluorosis
Fluorosis is an excessive level of fluoride in the body. It may result from chronic inhalation of industrial dusts or gases contaminated with fluorides, prolonged ingestion of water containing large amounts of fluorides, or accidental ingestion of fluoride-containing insecticides. The condition may lead to calcified spinal ligaments, softened bones, or degenerative conditions, like
spinal stenosis.
Ossification
Ossification of the posterior longitudinal ligament occurs when calcium deposits form on the ligament that runs up and down behind the spine and inside the spinal canal. These deposits turn the fibrous tissue of the ligament into bone. (Ossification means "forming bone.") These deposits may press on the nerves in the spinal canal.