Objectives: Progressive resorption of the alveolar ridge in the posterior maxilla and pneumatization of the maxillary sinus creates a challenging situation for rehabilitation with endosseous dental implants. Lateral wall sinus augmentation technique has proved to be predictable in gaining vertical bone height by the addition of bone graft under the schneiderian membrane. Cone beam computed tomography (CBCT) is essential for planning this bone augmentation technique to identify any concerns such as the presence of bony septae, sinus pathology, an intraosseous vascular canal, etc. that may contribute to potential complications. The purpose of this study is to investigate the prevalence of intraosseous anastomosis of the posterior superior alveolar artery (PSAA) and infraorbital artery (IOA) in the lateral wall of the maxillary sinus in patients of Temple University Kornberg School of Dentistry utilizing cone beam computed tomography (CBCT). Materials and Methods: 821 CBCT scans taken at Temple University Kornberg School of Dentistry Department of Oral Maxillofacial Radiology between January 2009 to December 31, 2015 were analyzed with iCATVisionQ software for the presence of an intraosseous artery in the lateral wall of the maxillary sinus, the most anterior tooth associated with the canal and the vertical distance from the artery to the floor of the sinus. Age, gender, ethnicity, and dentition status were also evaluated. Of the 821 scans reviewed, 447 patients met the inclusion criteria of the study. The 447 patients were subdivided by gender into 249 females and 199 males, and subdivided by ethnicity into 292 Caucasians, 42 Asians, 24 Hispanics, and 90 African Americans. The data was documented in an excel spreadsheet and analyzed. Results: Based on the 447 scans included in this study, there was an anastomosis of the posterior superior alveolar artery and infraorbital artery in the lateral wall of the sinus in 752 (84%) of the sinuses evaluated. The majority of the detected vascular canals were seen bilaterally. There was also a presence of multiple canals in 155 (17%) sinuses, the majority being two canals. The highest number of canals visualized was four canals in four sinuses. The tooth most associated with the vascular canal was the second premolar. The average distance from the vascular canal to the floor of the sinus was 12mm. Conclusions: Based on the results of this retrospective study, the prevalence of an intraosseous anastomosis in the lateral wall of the maxillary sinus is greater than previously reported (30-70%). In some cases, multiple intraosseous vascular canals were identified. With this knowledge, the importance of locating the vascular canals prior to surgery is important to minimize bleeding complications. Cone beam computed tomography (CBCT) should be a diagnostic tool for surgeries involving the lateral wall of the maxillary sinus. / Oral Biology