The forehead is not full may be the forehead flat, not full due to the acquired thinning, or congenital frontal bone development abnormality, can take hyaluronic acid filler or autologous fat filler way. 1. Acquired factors: first of all, we need to actively treat the primary disease, and then carry out symptomatic treatment. Hyaluronic acid filler is a kind of commonly used filler, mainly injecting hyaluronic acid into the part of forehead that is not full, the amount of injection is different in different situations of individuals, and it can effectively fill the forehead, but hyaluronic acid doesn’t last for a long time, and it can only be maintained for about 6 months to 1 year, so if you want to maintain the shape for a long period of time, you need to repeat the filler. 2. Congenital factors: due to congenital developmental abnormalities, only symptomatic treatment, usually can take the way of autologous fat injection, from other parts of the body, such as thighs or abdomen to extract excessive fat, after special treatment, injected into the forehead part of the recessed area, can play the effect of full forehead, and once the autologous fat molding, the effect lasts for a long time. The forehead is not full in the filler treatment, be sure to choose a regular hospital, to avoid the adverse consequences of improper operation.