Accessory Maxillary Ostia: Prevalence of an Anatomical Variant and Association with Chronic Sinusitis.

The presence of an accessory maxillary ostium may contribute to the development of maxillary and ethmoidal sinusitis. Further studies are needed to elucidate this association and determine indications for incorporating the natural and accessory ostia when performing middle meatus antrostomy during endoscopic sinus surgery.