Many authors have studied variation in the maxillary artery but there have been inconsistencies between reported observations. The present research aimed to examine the courses and branching patterns of the trunk and branches of the maxillary artery in a large sample of Japanese adult cadavers. The course of the maxillary artery should be reclassified into seven groups as a clear relationship was found between the origin of the middle meningeal artery and the course of the maxillary artery. This indicates that conventional theory about the formation of the maxillary artery, which was considered to be a direct derivative of the stapedial artery, might be inaccurate. Many variations in the origin of the inferior alveolar artery were found. Notably, the inferior alveolar artery origin from the external carotid artery and a double origin of the inferior alveolar artery was also observed. Thus, the maxillary artery might be derived from a combination of both the external carotid and stapedial arteries.