The fullness and firmness of male pectoral muscles is one of the signs of youthful bodybuilding. Developed chest muscles make men look strong and burly. Pectoralis major is a fan-shaped flat muscle, which can be divided into three parts according to the direction of muscle fibers: upper, middle and lower. Generally, pectoralis major can be developed through targeted exercise to form a bodybuilding appearance. But for some people who are unwilling or inconvenient to strengthen their muscles through exercise, and some people with congenital diseases (such as Polish syndrome), plastic surgery provides a shortcut, which can make men have strong breasts quickly through surgery. Methods Similar to female breast augmentation, a prosthesis in the shape of pectoralis major was implanted subcutaneously to instantly increase the chest volume.