Josiah Flagg. Portrait of Josiah Flagg (1788- 1853), the American dentist who invented the dent- al chair & porcelain false teeth. Flagg was one of the earliest oral surgeons in the USA, working in Boston. He fought in the 1812 War against the British but was captured and taken to the UK. After gaining parole, he set up a practice in London before returning to the USA. He devised the dental chair by adding a moveable head rest to an ordinary, wooden chair. He devised porcelain false teeth in 1833, these were an improvement over ones made from bone or teeth which tended to rot. Flagg was an early believer in homeopathy and opposed attempts to patent anaesthetic methods.