Facial filler may be used in selected patients to restore volume or modify particular contours. Injectable materials, most commonly hyaluronic acid products, are placed at a depth chosen according to anatomy and the treatment goal. A filler cannot correct every skin concern, wrinkle or scar, and different products are not interchangeable. Areas such as the cheeks, tear troughs, lips, nose and chin have different indications and risks, so suitability requires individual medical assessment.