Heather Stephen talks to some top London dentists about how to take years off your face with a younger looking smile. You might freshen up with a touch of Botox or fillers but what about your teeth?  The old saying ‘never look a gift horse in the mouth’- exists for a reason – your teeth and gums reveal a lot about your age and overall health. But taking care of your smile can be an effective path to a more youthful look. “Many think that addressing skin issues is the best way to a younger appearance but your teeth can…