Skin Remodeling Using Hyaluronic Acid Filler Injections in Photo-Aged Faces.

[BACKGROUND] Hyaluronic acid (HA) filler is an important dermatological procedure. Although many studies have reported clinical improvement with this procedure, histology with morphometric evidence is not well documented.

[OBJECTIVE] To evaluate the clinical and histological results of a HA filler injection and to quantify dermis remodeling at 3 and 9 months after HA injections into aged faces.

[MATERIALS AND METHODS] Twenty patients were enrolled in this study. Hyaluronic acid filler was injected into the nasolabial folds and preauricular regions of the patients. Skin biopsies of the preauricular regions were performed before the procedure and at 3 and 9 months after the procedure.

[RESULTS] Sixteen women (aged 40-50 years) completed the clinical study and demonstrated improvement for 12 months. Twenty patients completed the histologic studies. Morphologic evaluation showed increases in the epidermal layers. The morphometric study showed a statistically significant increase in collagen fibers at 3 and 9 months after the procedure (34.2% ± 31.5% and 39.5% ± 39.7%, respectively, p < .05).

[CONCLUSION] Sustained clinical results for HA filler can be explained not only by the presence of HA gel on the dermis but also by the dermal remodeling induced by HA filler injected into the face.