A comprehensive examination of topographic thickness of skin in the human face.

Background Knowledge of topographic skin thickness is important to plastic surgery of the face as it may guide resection and restoration in oncologic, aesthetic, and reconstructive procedures. Objective The purpose of this study is to report the relative thickness of the face throughout 39 distinct subunits. Methods Full-thickness punch biopsy samples were obtained at 39 predetermined anatomic locations of the face from 10 human cadaveric heads. Tissue was fixed in paraffin-embedded slides and analyzed using triplicate measurement of dermis and epidermis using computerized measurements. Data were analyzed using univariate statistical analysis and expressed as mean thickness values and relative thickness (RT) values based on the thinnest portion of the face. Results The area of the face with the thickest dermis was the lower nasal sidewall (1969.2 µm, dRT: 2.59), and the thinnest was the upper medial eyelid (758.9 µm, dRT: 1.00). The area with the thickest epidermis was the upper lip (62.6 µm, eRT: 2.12), and the thinnest was the posterior auricular skin (29.6 µm, eRT: 1.00). Our results confirm that eyelid skin is the thinnest in the face. The thickest portions of the skin appeared to be in the lower nasal sidewall, but the measurements are comparable to those in the ala and posterior auricular skin, which are novel findings. Conclusions The greatest epidermal, dermal and total skin thickness are found in the upper lip, right lower nasal sidewall, and left lower nasal sidewall respectively. The least epidermal skin thickness is in the posterior auricular skin. The least dermal skin thickness, and the least total skin thickness, are both in the upper medial eyelid.