Sinus augmentation is a routine surgical procedure in dentistry. At present, various animal models are available for the research purpose on this topic. In particular, for the first time, we have performed a morphological study on sheep sinus, using cone beam computed tomography (CBCT), to precisely define the anatomy of the ovine sinus. Then, we compared the sheep and human sinus morphological parameters, in order to uniform the research approach to the sinus augmentation procedures and to standardize this experimental model. Six fresh heads of adult female sheep were studied with CBCT and histologic examination to determine the dimensions and the organization of the ovine maxillary sinus. The comparison of the dimensional values between man and sheep shows evident differences between the two species; CBCT offers detailed information for studying normal maxillary sinus. Human and sheep maxillary sinus show anatomical differences that must be taken into account in experimental procedures.