Laser light is nowadays routinely used in the aesthetic treatments of facial skin, such as in laser rejuvenation, scar
removal etc. The induced thermal damage may be varied by setting different laser parameters, in order to obtain a
particular aesthetic result. In this work, it is proposed a theoretical study on the induced thermal damage in the deep
tissue, by considering different laser pulse duration. The study is based on the Finite Element Method (FEM): a
bidimensional model of the facial skin is depicted in axial symmetry, considering the different skin structures and their
different optical and thermal parameters; the conversion of laser light into thermal energy is modeled by the bio-heat
equation. The light source is a CO2 laser, with different pulse durations. The model enabled to study the thermal damage
induced into the skin, by calculating the Arrhenius integral. The post-processing results enabled to study in space and
time the temperature dynamics induced in the facial skin, to study the eventual cumulative effects of subsequent laser
pulses and to optimize the procedure for applications in dermatological surgery. The calculated data where then validated
in an experimental measurement session, performed in a sheep animal model. Histological analyses were performed on
the treated tissues, evidencing the spatial distribution and the entity of the thermal damage in the collageneous tissue.
Modeling and experimental results were in good agreement, and they were used to design a new optimized laser based
skin resurfacing procedure.