Frown lines between the eyebrows are due to contraction of the corrugator and procerus muscles. This contraction can occur when we are angry or concentrating or sometimes for no good reason at all, purely out of habit. Over time deep frown creases can develop, making you look permanently grumpy even when you are not.
The frown line is the most commonly treated area of the face at Vice Aesthetics. In many patients results tend to last longer with each subsequent treatment as they break the habit of frowning unnecessarily.