This area can be effectively treated with Muscle Relaxing/Botulinum Toxin injections, particularly when the lines are fine or shallow. When the lines are deeper, the main problem then is usually loss of volume/fat tissue from the side of the face, in which case replacing that volume is the best option.
In the case of Botulinum Toxin, the effects take 2-7 days to take effect and will last about 3 months in this area.
Replacing the lost volume can be achieved using Sculptra, or Fat Transfer, particularly the newer techniques of Micro-Fat.