While brushing the outside surfaces of your teeth, position the brush at a 45-degree angle where your gums and teeth meet. Gently move the brush in a circular motion several times using small, gentle strokes. Use some pressure while putting the bristles between the teeth, but not so much pressure that you feel any discomfort. When you are done cleaning the outside surfaces of all your teeth, follow the same directions while cleaning the inside of the back teeth. To clean the inside surfaces of the upper and lower front teeth, hold the brush vertically.