The anatomy of maxillary sinus, the structure and the distribution of arteries and nerves

Abstract

  Maxillary sinus（MS）locates in the center of maxilla and is surrounded by 5 bony walls that form four-side pyramid structure toward the apex to the zygomatic process. It is the largest of all paranasal sinuses and drains into the middle nasal meatus through the hiatus semilunaris. Lining membrane of MS（Schneider membrane）is composed of the pseudostratified cilliary epithelium containing goblet cells that secret mucus on the surface of epithelial layer. At 5 weeks of gestation, the development of MS initiates as invagination of epithelium into the mesenchymal stem cells, which become uncinate process and inferior nasal concha. Subsequently, invaginated epithelium makes small lacuna that will be pneumatic cavity of MS. Although the development of MS is never fast during the gestational stage, its volume rapidly increases after birth and reaches a peak in the adult. The distribution of arteries and nerves in MS are complicated. Two major branches of maxillary artery, infra-orbital artery（IA）and posterior superior alveolar artery（PSAA）, are main nutrient arteries for MS. Anterior superior alveolar artery, another branch of IA, also provides blood in front of MS and makes a circle with the branches of IA and PSAA. Notably, intra-osseous branch and extra-osseous branch of PSAA are observed around MS. Especially, the access to extra-osseous branch demands great caution in surgical treatment, because their branches pass by an origin of buccinators on maxilla. On the other hand, the branches of maxillary nerve, infra-orbital nerve（IN）and posterior superior alveolar nerve（PSAN）, innervate MS. PSAN is a component of superior dental plexus anastomosing with the branches of IN, anterior superior alveolar nerve and middle superior alveolar nerve. This review will be good information for dental implant treatment.