This question is very open ended and there are many ways to answer this question. However, I don't think they want to hear about your life story, about your family, or about your pets. I would just introduce yourself and talk about your educational background.
Don't ramble on too much because the interviewer might get bored. Just give them a few sentences and then you can ask them if they want to know more. If they say yes, then you can go into how you became involved in dentistry or maybe some specifics about your educational career.
This will give YOU more control and allows you to steer the interview in a direction that will benefit you and enhance your strong suits. 🙂