maxillary sinus(antrum)
Last reviewed 01/2018
The maxillary sinuses flank the nasal cavity. They are the largest sinuses, each with a volume of 15-30 ml. Mucus and debris are cleared by the cilia of the lining respiratory epithelium and not by gravity. The cilia direct the debris to the sinus ostia, openings into the medial meati, located high in the medial wall of each sinus, one on each side.
The infraorbital nerve lies within the roof of the sinus. Blow out fractures of the eye may damage the nerve or trap orbital contents. Posteriorly, the sinus may allow access to the pterygo palatine fossa and the maxillary artery. Inferiorly the roots of premolar and first molar teeth may project into the sinus cavity.
Secondary sinusitis may complicate dental infection as the roots of the premolar and first molar teeth frequently project into the maxillary sinus.