Accurate assessment of the location of the maxillary sinuses, incisive canal, and nasal cavity, as well as the height, width, and angulation of bone is essential for implant treatment planning. The purpose of this study was to introduce the clinical application of a cone-beam computerized tomography system (Ortho-CT) to assess multiple two-dimensional (2D) images for the preoperative treatment planning of maxillary implants. To evaluate the multiple 2D images scanned using the Ortho-CT system the maxillary region placed with radiopaque template in the maxilla. Ortho-CT images provided useful information for evaluating the morphology of the maxilla, for locating the incisive canal, maxillary sinuses, nasal cavity, and for showing the relationship of the template to the bone. It is concluded that the Ortho-CT system is a useful aid for diagnosis and treatment planning for maxillary implant treatment.