35 years old male patient referred with a complain of inadequent smile aesthetic. Intraoral examination, radiologic and cephalometric analysis revealed presence of Class III malocclusion and unilateral cross bite in right maxillary quadrant. Treatment plan consisted in application of surgically assisted rapid maxillary expansion (SARME) by bilateral corticotomy using erbium laser (Er:YAG); application and activation of rapid palatal expander appliance; subsequent to retention of maxillary expansion, fixed orthodontic treatment for alignment and levelling, mini-screw anchorage for mandibular distalization. Treatments were executed according to abovementioned plan. Er:YAG laser was choised due to its atraumatic behaviour on bone cutting process. By use of laser-assisted SARME method an atraumatic surgery was performed and the goal of expansion, retention and adequate Class I occlusal relations and aesthetic smile was achieved.