Blood supply to the maxillary sinus relevant to sinus floor elevation procedures.

The maxillary blood supply is essential for preserving the vitality of the affected maxillary region, integration of the grafting material, and wound healing such as following sinus floor elevation. Although it is well established that edentulous maxillae demonstrate a decreasing vascularity as bone resorption progresses, the vascular conditions relevant to sinus floor elevation procedures have not been investigated yet. This study deals with maxillary arteries relevant to sinus floor elevation surgery and examines the vascularization of the lateral maxilla after tooth loss. The vessels of the lateral maxilla of 18 maxillary specimens (10 male, 8 female, mean age 67 years) were prepared anatomically and the local main arteries, the number of macroscopically discernible branches and anastomoses, their calibers, and the distance between the caudal main branches and the alveolar ridge recorded. The lateral maxilla is supplied by branches of the posterior superior alveolar artery (PSAA) and the infraorbital artery (IOA) that form an anastomosis in the bony lateral antral wall, which also supplies the Schneiderian membrane. This intraosseous anastomosis was found in all of the specimens. Eight of 18 also showed an extraosseous anastomosis between PSAA and IOA, vestibular to the antral wall, giving off an average of 3 branches cranially and 5 branches caudally. The two anastomoses form a double arterial arcade to supply the lateral antral wall and, partly, the alveolar process. The PSAA had a mean caliber of 1.6 mm and exhibited an average of 2 endosseous and 1 extraosseous branches. The IOA had a mean diameter of 1.6 mm and showed an average of 1 endosseous and 3 extraosseous branches. The mean distance between the intraosseous anastomosis and the alveolar ridge was 19 mm in 2 defined measuring sites. Its mean length was 44.6 mm. The epiperiosteal vestibular anastomosis was situated further cranially at a mean distance of 23 to 26 mm from the alveolar ridge and had a mean length of 46 mm. The rather large caliber of the vessels supplying the lateral antral wall seems to be crucial to the fact that the periosteal blood supply is maintained even in severe maxillary atrophy and after complete disappearance of the centro-medullary vessels.