Don't worry about the dentist too much. Mine never opened his mouth for them till he was 3, and only then, just enough for them to see that he had teeth! They said they only really counted them before that anyway. As long as you can get him to clean his teeth well twice a day, and don't let him have sugary snacks and drinks all day, his teeth will be fine.
As for the doctors, that's another thing. I think you just have to pin them down (gently!) to have their ears checked etc., then placate with stickers/chocolate buttons/fav toy. It will get better - remember it's all a stage.