Abstract : This study focused on the effect of first and second molars roots tips proximity to maxillary sinus using advanced imaging modality. Information from Skyview images of 50 subjects was contributed in this study (30 females; 20 males). Measurements were recorded for each tooth (first and second molars) such as the vertical distances between three roots tips and sinus and the cortical bone thickness between these roots and against a plate. Data variables were tested for significance using SPSS version 23 according to gender. The nearest root to maxillary sinus was the mesiobuccal root of the second molar and the farthest one was the mesiobuccal root of the first molar. The cortical bone thickness against the mesiobuccal root of first molar was thinner, while it was thicker for the mesiobuccal root of the second molar. The three dimensional analyzed of information about the proximity of molars roots tips to sinus very valuable for best approaching and treatment plan