Hi, it is evident that there is volume and fat loss over your temples and extending to the forehead as well. This are normal signs of aging.
It is aesthetically significant because it breaks the smooth silhouette of the head. To some, it is desirable to have a smooth curvy silhouette of the head from the forehead to temples to cheekbones to jawbone and to the chin (forming a heart-shaped outline) for the best aesthetic outcome.
Treatment will be using fillers and my preference is using a cannula (blunt needle) to spread the filler like a thin carpet under the skin and superficial temporal fascia. Experience and technical skills are very important here due to the challenging anatomy and superficial plane (easily leading to lumpiness in poor techniques or poor experience).
My filler of choice is the collagen-stimulating filler Ellanse for ladies who want that extra collagen boost, or Teosyal RHA3/4 for younger ladies.
