[Muscular aging and its involvement in facial aging: the Face Recurve concept]

Cutaneous ageing is responsible for the increasingly creased appearance of the skin, pores opening, skin dyschromia, while the ageing of the structures of the face is attributed primarily to the effect of gravity on the tissues. The theory expounded below sets out to prove that the main and initial cause of this ageing is the repeated contractions of the mimic muscles. This concept attributes only a secondary role to gravity in the ageing process, which is initially brought about by muscular contractions. An MRI study recently made it possible to demonstrate the anterior convexity curve of the mimic muscles in the young subject. This curve is due to the existence of a deep fat pad at the back of these muscles. While this mass of fat is effectively a mechanical sliding plane, its convexity constitutes the founding principle behind this new ageing theory. In the young subject, the extent of its convexity and its location give a specific, youthful character to the movements, in terms of direction and amplitude, of the facial muscles. With age, the muscle gradually straightens and shortens, due to the repeated contractions that expel the underlying fat and increase the tonus at rest. The structural ageing becomes visible and with time, the expression of the subject is consequently more rigid.