Li Shizhen (1518–1593) – one of the most renowned pharmacologists and physicians in Chinese history – belonged to the late Ming period. His "Bencao Gangmu" is a medical text with 1,892 entries, each entry with its own name called a "gang". The "mu" in the title refers to the synonyms of each name. Inoculation, although it can be traced to earlier Chinese folk medicine, was detailed in Chinese texts by the sixteenth century. Throughout the Ming dynasty, around fifty texts were published on the treatment of smallpox. In regards to oral hygiene, the ancient Egyptians had a primitive toothbrush of a twig frayed at the end, but the Chinese were the first to invent the modern bristle toothbrush in 1498, although it used stiff pig hair.