There are several common reasons for the protrusion of forehead bones: 1. Physiological, there are coarse bulges, bulges and protrusions of the skull, these are the normal anatomical structure of the skull, and the skull is not flat. Due to individual developmental differences, some people are higher and some people are lower. If not accompanied by any discomfort and adverse symptoms, it is a physiological phenomenon, do not need to worry. 2, common in the early childhood had suffered from rickets, resulting in square skull patients, after adulthood will remain frontal bone protrusion. 3, seen in the frontal bone after recovery from trauma, frontal bone is more prominent, larger area parts, easy to suffer impact and impact. When suffering a more serious impact, the outer plate of the skull may suffer damage, and after repair there will be local osteophytes, producing a frontal bone bulge. 4, frontal bone tumors, relatively rare, common tumors include chondrosarcoma of the frontal bone and epithelioid cyst of the frontal bone.