How we've ended up regulating medicine to the nth degree, but when it's teeth we're like "oh well, lol", continues to mystify me.
> For the longest time, surgeons, dentists and optometrists weren't part of the medical profession. You'd have a barber who could give you a shave or pull your teeth, or a butcher who could cut up a hog, or cut off your gangrenous leg. Optometrists were craftsmen who made the spectacles in their shop. Doctors were University educated in Latin and Greek to read ancient medical texts and despised the uncouth yokels.
> Surgeons muscled their way into the medical profession, originally with the help of the Royal Navy, who only had space for one or two people in charge of both cutting off legs and looking after crew health on their ships.
> Dentists and optometrists never did, so they started their own universities, certification boards, etc. By the time they became respectable enough for people to try to merge them with the medical establishment, in the 1920s, they had no desire to give up their independence.
> The first insurance policies were private contracts with groups of doctors and the system developed from there.
Details vary from country to country of course, but the gist of it generally holds true.
And the final form of dentists, oral-maxillofacial surgeons are an all in one and have to study general medicine, surgery and dentistry.