A weak jawline can be genetic or a result of aging. With age the loss of definition along the jawline forms jowls, this is a result of loss of volume in the mid-face and changes to the skin and connective tissue. Dermal fillers along the jawline to stiffen the skin will reduce the weakness of the jawline. Treating the jawline especially in older patients usually requires correction of multiple areas in the face to achieve the best results. For males who want a more masculine square jaw, jawline fillers can sharpen the jawline and the mandibular angle.