As we age the collagen and elastin components of the skin can reduce in volume and effectiveness making the skin limp and this causes the cheek to move downwards resulting in downturned mouth corners. This can make people look sad even when at rest or when the person in question is not sad. This can be worsened by the over-activity of the DAO (Depressor Anguli Oris) muscles. These muscles act from the jawline and to the corner of the mouth and its contraction brings the corner of the mouth to the jaw.
At NU-U we can treat the overactivity of this muscle with injections leading to a more neutral or happy look at rest. As the muscles relax the corners of the mouth come up and the downturned smile improves markedly.