A Classification System for Facial Fat Atrophy
Authors: Napolez Adolfo , Park Jung Il 
Published: January 2017

Introduction: With aging, senescent fat atrophy occurs, with progressive degenerative changes in elastin and collagen in conjunction with marked bony resorption. The resultant effect is a noticeable deflation of the volume and contour of the face over time. We present here a study of facial fat atrophy in an attempt to develop a useful and transferable classification system for each type of identifiable area of noted volume loss. Materials and Methods: Three groups of patients (group I, 9 patients aged 10–30 years; group II, 8 patients aged 31–45 years; and group III, 9 patients aged 46–70 years) were evaluated by computed tomography head scans using standard radiologic cuts measuring 4 distinct areas of localized facial fat deposition: (1) periorbital, (2) buccal, (3) preauricular, and (4) temporal. The areas were measured on the right (R) and left (L) sides of the face, and an average value determined for each age group. Results: Buccal fat measurements for group I were (R) 23.84 mm, (L) 20.76 mm; for group II, (R) 27.56 mm, (L) 29.63 mm; and for group III, (R) 15.51 mm, (L) 14.34 mm. Group I exhibited a midrange of buccal fat in comparison to groups II and III, whereas group II showed the largest amount and group III the least. Preauricular fat measurements for group I were (R) 10.84 mm, (L) 10.00 mm; for group II, (R) 14.00 mm, (L) 13.82 mm; and for group III, (R) 6.86 mm, (L) 6.83 mm. Again, group I exhibited a midrange of preauricular fat in comparison to groups II and III, whereas group II showed the largest amount and group III the least. Temporal fat measurements for group I were (R) 12.04 mm, (L) 11.76 mm; for group II, (R) 18.86 mm, (L) 19.68 mm; and for group III, (R) 15.67 mm, (L) 16.63 mm. In this area, group I had the smallest amount of temporal fat, whereas group II had the largest amount, and group III showed a decline from the amount noted in group II. Periorbital fat measurements for group I were (R) 6.22 mm, (L) 5.72 mm; for group II, (R) 6.31 mm, (L) 7.21 mm; and for group III, (R) 7.33 mm, (L) 7.61 mm. In this instance, group I had the least amount of fat noted infraorbitally, with group II midrange, and group III had the most because of pseudoherniation of orbital fat. Discussion: The data collected in this paper display for each area of localized facial fat—except the periorbital area, which reflects the pseudoherniation of orbital fat contents—a progressive increase in localized facial fat deposits from group I to group II, with a subsequent decrease in group III in each area, consistent with senescent facial fat atrophy. Four types of facial fat atrophy classifications are thus described: type I, with fat atrophy limited to 1 area, minimal skin laxity, and minimal bony resorption; type II, with fat atrophy limited to 2 areas, mild skin laxity, and mild bony resorption; type III, with fat atrophy limited to 3 areas, moderate skin laxity, and moderate bony resorption; and type IV, with fat atrophy in all 4 areas, severe skin laxity, and severe bony resorption. Conclusion: Facial fat atrophy occurs progressively with aging in conjunction with loss of skin elasticity, collagen degradation of the skin, and bony resorption of the facial skeleton. This results in a progressive deflation of the face with obvious volume loss and subsequent skin redundancy. This classification system attempts to organize and categorize this occurrence.