We evaluated bioactive glass graft (S53P4) in patients undergoing Le Fort I osteotomy, with nongrafted patients as controls. Computed tomography facial scans of the 25 patients submitted for Le Fort I were divided into two groups: Group 1-S53P4 group and Group 2-without grafting. CT scans were analyzed in the immediate postoperative period (T1) and 6 months later (T2), for linear bone gap measurements, tomographic radiodensity and behavior of the maxillary sinus. A Kruskal-Wallis test on bone gap data adopted α significance levels (p ≤ 0.05). The Friedman test (p ≤ 0.05) was used to evaluate sinus reaction cores. For gap measurements, we observed a decrease in median data between T1 and T2 in both groups, with statistical significances observed between groups in T0; G1 presented statistical difference in its two studied times (p ≤ 0.0001). For bone density, the studied data behaved inversely. G1′s bone density decreased from T1 to T2, whereas in G2 there was an increase from T1 to T2. S53P4 did not elicit increased reactions and/or sinus infections in the G1 group (p ≥ 1.00). S53P4 did not impact on Le Fort I osteotomies as a coadjuvant and a favorable factor in bone formation, and appeared innocuous in the maxillary sinus. Orthognathic surgery mobilizes and repositions the jaw bone base via osteotomy, to ensure functional and aesthetic results for dental-skeletal discrepancies 1-3. Tridimensional surgical movements of the upper jaw are considered unstable with larger bone gaps, thus increasing the need for bone grafts, especially in upper jaw advances of > 4 mm, which normally generate bone discontinuities of > 3 mm 1-7. Autogenous grafts minimize large bone discontinuities in the osteotomy line 4,6-8. Similarly, several bone substitutes have been created to decrease morbidity in patients 9-11. This follows recent technological innovations that cater for increased tissue regeneration and pathogen inhibition 12-14. In 1969, Hench et al. developed materials based on bioactive glass 12,13. Since then, these materials have been used in modern clinical applications such as dentistry, orthopedic surgeries and otorhinolaryngology 12. S53P4 produces osteoconductive biological responses at tissue-biomaterial interfaces, by forming silica gel layers that attract and differentiate osteoblasts into bone. The material interacts with growth factors to stimulate angiogenesis and pathogen inhibition via elevated pH and osmotic pressure 12,13,15-17. No studies have yet explored S53P4 in linear bone defects of few walls as in Le Fort I osteotomies, considering the anatomical proximity to the maxillary sinus and its behavior in front of bioactive glass. Therefore, we evaluated S53P4 in patients undergoing Le Fort I osteotomies, with non-grafted patients as controls. Materials and methods This retrospective observational case-control study evaluated data from medical records and CT scans of individuals who underwent Le Fort I osteotomy using a bioactive glass graft, when compared with non-grafted individuals. Ethical considerations...