Too much fluoride results in dental fluorosis and/or skeletal fluorosis. In some areas, skeletal fluorosis is endemic. In moderate to severe fluorosis, teeth are weakened and suffer permanent physical damage. A significant side effect is mild to moderate dental fluorosis. McKay's work had established that fluorosis occurred before tooth eruption. As of now, there are no established treatments for skeletal fluorosis patients. Individual susceptibility to fluorosis is also influenced by genetic factors. Dental fluorosis may or may not be of cosmetic concern. Dental fluorosis can be prevented at a population level through defluoridation. This condition is neither caused by nor the equivalent of dental fluorosis. Some work has focused on combating fluorosis through increased calcium intake by consuming local plants. The adequate diagnosis of fluorosis can be diagnosed by visual clinical examination. The condition then started to become termed "dental fluorosis". In ancient times, Galen describes what is thought to be dental fluorosis. This increases to 40% when considering fluorosis of any level not of aesthetic concern.