Background and purpose:Evaluation of maxillary bone is very essential for the diagnosis, treatment planning, and management of maxillofacial procedures. This study aimed to evaluate the maxillary jaw bone quality and quantity in a sample of Egyptian patients with diabetes mellitus (DM) compared to another nondiabetic sample using Cone Beam Computed Tomography (CBCT) and also to correlate between the maxillary jaw bone quality and quantity and other factors as glycated haemoglobin (HbA1c) values, disease duration, type of medication, extraction period, and gender.Methods:After approving the study protocol by the local Ethics Committee, sixteen patients with diabetes mellitus and sixteen control subjects were included in this study. Three maxillary bone measurements (alveolar ridge height, bucco-palatal dimension, and trabecular bone density) were performed on selected CBCT cross-sectional images. These measurements were performed by two radiologists once and one of them carried out the measurements twice. Results:Thisstudy demonstrated that there was no significant difference between the normal and diabetic groups regarding all maxillary measurements except for the maxillary trabecular bone density of the normal group which was statistically lower than that of the diabetic group. Maxillary trabecular bone density was correlated significantly with most of the studied variablessuch as disease duration, type of DM medication, teeth extraction period, and gender.Conclusion:Diabetes is not an absolute contraindication for any maxillofacial surgeries and each diabetic patient indicated for any maxillofacial surgery should be evaluated independentlyregarding the maxillary bone quality and quantity as well as the contributing local factors.