The blood supply to both the lateral wall of the maxillary sinus and the overlying membrane originates from the posterosuperior alveolar artery (PSAA) and the infraorbital artery. The purpose of the present study was to evaluate the anatomic characteristics of the PSAA in a large number of subjects of the Lebanese population. Images of 696 sinuses were analyzed using cone beam computed tomography (CT). Coronal, axial, and sagittal CT images were evaluated for the presence of an osseous canal in the lateral wall of the sinus, and the prevalence, position, and location of the canal were studied and presented.