are also known as infraorbital ethmoidal air cells
or maxilloethmoidal cells
. They are extramural ethmoidal air cells that extend into the inferomedial orbital floor
and are present in 2 - 45% of patients, depending on their exact definition. In most instances they are asymptomatic, and (although some controversy exists 4-5) they are generally not thought to be associated with increased rates of sinusitis. They may become clinically significant in a number of situations; become infected, with the potential for extension into the orbit, may narrow the ipsilateral osteomeatal complex (OMC) if large and may thereby predisposing the ipsilateral maxillary antrum to obstruction may lead to inadvertent entry into the orbit if unrecognised at endoscopic surgery.
Hope this was useful...