Perfect teeth, perfect everything for that matter is not something you should dwell on. Lauren Hutton, a famous model of the 60s has a gap between her teeth, Kate Moss does not have perfect teeth and many models are not perfect. I have a gap between my teeth and although a smile is nice to show for commercial print modeling (the area of modeling a shorter model should focus on), having perfect teeth should not be your goal. Perfect teeth or not it doesn't mean an agency will book you, want to work with you, and promise anything. Modeling is unstable and you can not bank on anything, it is all about what you make of it.
It is better to be you, be yourself and not to try tooo hard. Modeling is about modeling a product -that is why models are needed. So knowing how to model something casually and naturally is best. Such as a handbag, shoes, etc.
Marketing yourself with the right photos to the right agencies is how you will get ahead. By being realistic and also not giving up. It is easy to quit, give up, settle or fall for amatuer modeling land.
If you know that modeling is more than being perfect you will see more opportunities out there for you. You have to chase them and be prepared for the grit, the work, the time to invest to market yourself the right way.