Fat Injection: A Systematic Review of Injection Volumes by Facial Subunit.

[BACKGROUND] Fat grafting to the aging face has become an integral component of esthetic surgery. However, the amount of fat to inject to each area of the face is not standardized and has been based mainly on the surgeon's experience. The purpose of this study was to perform a systematic review of injected fat volume to different facial zones.

[METHODS] A systematic review of the literature was performed through a MEDLINE search using keywords "facial," "fat grafting," "lipofilling," "Coleman technique," "autologous fat transfer," and "structural fat grafting." Articles were then sorted by facial subunit and analyzed for: author(s), year of publication, study design, sample size, donor site, fat preparation technique, average and range of volume injected, time to follow-up, percentage of volume retention, and complications. Descriptive statistics were performed.

[RESULTS] Nineteen articles involving a total of 510 patients were included. Rhytidectomy was the most common procedure performed concurrently with fat injection. The mean volume of fat injected to the forehead is 6.5 mL (range 4.0-10.0 mL); to the glabellar region 1.4 mL (range 1.0-4.0 mL); to the temple 5.9 mL per side (range 2.0-10.0 mL); to the eyebrow 5.5 mL per side; to the upper eyelid 1.7 mL per side (range 1.5-2.5 mL); to the tear trough 0.65 mL per side (range 0.3-1.0 mL); to the infraorbital area (infraorbital rim to lower lid/cheek junction) 1.4 mL per side (range 0.9-3.0 mL); to the midface 1.4 mL per side (range 1.0-4.0 mL); to the nasolabial fold 2.8 mL per side (range 1.0-7.5 mL); to the mandibular area 11.5 mL per side (range 4.0-27.0 mL); and to the chin 6.7 mL (range 1.0-20.0 mL).

[CONCLUSIONS] Data on exactly how much fat to inject to each area of the face in facial fat grafting are currently limited and vary widely based on different methods and anatomical terms used. This review offers the ranges and the averages for the injected volume in each zone.

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