Objectives: The purpose of this study is to create a 3D printed cutting guide that facilitates precise osteotomy cuts for the lateral window in sinus augmentation, in order to avoid damaging the anastomosis between postero-superior alveolar artery (PSAA) and infraorbital artery (IAO). Material and methods: We examined 3 cadaver heads (6 maxillary sinuses) obtained from the collection of the Department of Anatomy, Université catholique de Louvain, Brussels. CBCT of the skull was performed. Using Planmeca ProModel service, we created the surgical guide for the lateral window. To assess the accuracy of the guide, measurements between reproducible points from the guide and the skull were performed, twice, by 2 independent observers, on planned model and on printed model. Results: The mean value of the differences between the two measurements was 0.69 ± 0.51 mm and ranged from 0.07 to 1.64 mm. Conclusions: The 3D printed surgical guide for the lateral window, in sinus augmentation, reduces intraoperative risks, but does not eliminate the risk of damaging the intraosseus artery. [ABSTRACT FROM AUTHOR]