The phenomenon of frontal concavity may be due to congenital factors or acquired factors, such as bone fracture, tissue edema and so on. 1. Congenital factors: some people may show the phenomenon of frontal concavity due to the large curvature of the frontal bone caused by the underdevelopment of the frontal bone, which can be alleviated by the overall leveling of the frontal bone. 2. Acquired factors: Fracture: if the body due to external violent impact and lead to frontal bone depressed fracture, which will lead to localized depression of the forehead, the phenomenon of frontal concavity of a piece of the phenomenon. Tissue edema: if the body due to allergies or plastic surgery excessively lead to localized edema of the face, which will show traces of depression when pressed, accompanied by redness, swelling, pain and other symptoms. The concave forehead may also be other reasons, it is recommended to go to the regular hospital in time to identify the cause of the disease and actively cooperate with the doctor to deal with.