Aim of the study: To evaluate the Dento-skeletal effects of maxillary skeletal expander (MSE) assisted with two techniques of microosteo-perforations. using cone beam computed tomography (CBCT). Material and Methods: A total sample of 18 patients presented with constricted maxilla were randomized into two equal groups. (Group 1) MSE with micro-osteoperforations (MOPs) in mid palatal suture only (MP) (4 males and 5 females), group 2 MSE with MOPs in both midpalatal suture and buccal sides (MPB) MSE (4 males and 5 females). The age ranges from 18 to 22 years (Y) with mean age 19.57±1.81 and 19.13±1.25 Y respectively. CBCT records were taken before expansion (T1) and after six months (T2) of RME; using Mimics software (version 17. Belgium). Results: 16 variables were analyzed; the paired t test was used to compare the pre and post values. independent-sample t-tests were used to compare the two osteoperforations methods. Conclusions: Regardless of the type of MOP technique, RME using MSE in conjunction with two techniques has a positive impact on transverse dimensions in young adults.