Potential complications related to pterygomaxillary disjunction have been widely described in the literature, most of them being due to the inaccurate and blind approach involved. The present study used preoperative virtual planning to establish a surgical cutting guide for pterygomaxillary osteotomy. It was placed in the maxillary tuberosity supported by molars, and a flapless vertical osteotomy was performed with a piezoelectric saw. Then, maxillary down-fracture was performed with slight pressure through an anterior approach. The use of the surgical guide added accuracy and predictability to the procedure, with no prolongation of the surgery time. There were no undesired fractures or bleeding. Regarding manipulation of the surgical guide in the posterior area, it was found to be easily manageable and very stable over the posterior teeth, due to its small size and precision, respectively. In conclusion, this technique seems to improve the accuracy of pterygomaxillary disjunction without prolonging the surgery time. Furthermore, it reduces potential complications related to the conventional procedure. Nevertheless, a larger body of patient data is needed to confirm the benefits of the technique.