Injection Depth in Intradermal Therapy: Update and Correction of Published Data.

This paper sought to compare calculated injection depth data with published report claims concerning intradermal therapy and skin rejuvenation of the face, hands, neck, and décolleté.A mathematical formula was employed to assess the injection depth, and data from literature were retrieved and compared with the calculated figures to determine whether the claims about the injection depth proved correct.Based on a study by Della Volpe et al., involving 140 skin residues adapted for plastic surgery, we have calculated injection depths from published reports on intradermal therapy and skin rejuvenation while comparing these figures with the published injection depth claims.Most injections were not performed at the claimed depth, with over 70% of them carried out in the fat layer, thus, the hypodermis. This is not the recommended depth for a refined injection technique in the intradermal therapy field.Whilst examining our study results, two different possibilities come to mind. We must either: 1) review and correct the existing histological classification; and/or 2) better learn to correctly inject in the superficial-dermis, mid-dermis, and deep-dermis. In other words, a perfect control over the needle penetration angle and implanted part appears urgently required. J Drugs Dermatol. 2018;17(1):89-96. .