Intrusion of the maxillary posterior segment has always been a challenge to the orthodontic community. Definitive intrusion of the maxillary posterior segment is feasible only by means of orthognathic surgery. Miniscrew implants offer a paradigm change in treatment mechanics of intrusion of the posterior segment alleviating extensive surgical management. The following poster highlights the different types of intrusion of the maxillary posterior segment and the their indication. The biomechanics involved in first order, second order and third order control have been enumerated. The disadvantages of each mechanics are put forth. Comparing the different biomechanics in three dimensions of space (first order, second order, thrid order) the ideal appliance system for three dimensional control has been put forth. Keywords: miniscrew, intrusion, posterior segment