Function and physiology of the maxillary sinus

Abstract

Background The question of the "true" function of the maxillary sinus and the paranasal sinuses (PS) has been a controversial issue in the literature for decades, leading to many discussions and speculations. Objective This review briefly summarizes various theories on the possible physiology and functions of the maxillary sinus/PS that have been discussed over the centuries. Materials and methods A literature search was conducted in PubMed using a combination of the search terms "physiology," "function," "maxillary sinus," and "paranasal sinuses." Results Current and scientifically evidenced theories are described. "Sinusology" is the science of the PS. The maxillary sinuses might simply serve to improve the respiratory function of the nose. A flow of inspiratory air does not occur. The maxillary sinuses are decisively involved in the production of nitrogen monoxide (NO) and thus in supporting the immune defense of the nasal cavity. The mucosa of the maxillary sinus continuously synthesizes NO and serves as a reservoir of NO. Other important functions are protection of the orbit and the brain in case of skull fractures, as well as weight reduction of the skull. Conclusion The various theories about the function of the PS still raise many questions and their true function is yet not fully understood. Possible functions of the maxillary sinuses are local immune defense through the production of NO. The PS serve as a crumple zone for vital cerebral structures in the context of craniocerebral traumas.