Concavity in the temporal area reflects a deficiency in the bulk of the temporalis muscle or overlying temporal fat pad. It may be a reflection of senescence, low body fat, exaggerated adjacent skeletal or soft-tissue contours, idiopathic progressive atrophy, or postsurgical deformities. The authors describe the application of methyl methacrylate (MMA) to fill depressions in the temporal area. In instances in which no previous surgery has been performed or when the temporal area has served as a dissection plane for surgery in adjacent areas (eg, a subperiosteal facelift), the implant material is placed beneath the temporal muscle through a limited incision in the hair-bearing scalp. When previous reconstructive surgery has been performed in the temporal area, the area of depression is accessed through existing surgical incision scars to place MMA over the temporal muscle. These operative techniques have been reliable, durable, and relatively free of complications.