There are a few reasons the face loses volume over time, such as significant weight loss, genetics, a naturally low body fat percentage, or aging. When this happens, hollows may be created in the temples (cougars sign), cheeks, around the mouth, and beneath the eyes. As a board-certified plastic surgeon, Dr. Frank L. Stile has treated many patients who wish to restore volume to their facial features using the fat-transfer/ fat-grafting procedure.