The terms 'orthodontist' and 'dentist' are used a lot interchangeably, and while there are similarities between the two, they also have distinct differences. For starters, dentistry is the branch of medicine that deals with teeth, jaw, nerves and gums, while orthodontics is a speciality within dentistry that focuses on correcting teeth straightness, occlusion and bites. To become an orthodontist, you need to have studied dentistry first.