There is a circular band of muscle that surrounds the lips called the orbicularis oris. Clench your lips tightly together or say “Ooooo” and this is the muscle you are using.

As the muscle wastes away, the lips become thin and the mouth starts to turn downwards, giving a permanent expression of sadness. 

Keeping this muscle toned will keep the shape of the mouth and prevent wrinkles forming at the side of the mouth.

Put the fingers of your left or right palm together and tilt your hand horizontally. Place your forefinger side of the palm between your lips. Press your lips down onto your finger.

Keep your lips tucked back against your teeth during the exercise, and try not to wrinkle your nose or pout. Work just the mouth muscles in isolation. Hold the tension up to the count of 30 then slowly relax. 

As the muscle develops, you should feel a ring of tension around your lips as you perform the exercise.