- Maxillary sinus is a hollow space in the maxilla. Sometimes the roots of upper molars project into this hollow space. This can be easily diagnosed over a radiograph.
- When such teeth are extracted for any reason, there is a passage created between the sinus and the oral cavity, called an Oro-antral fistula. This fistula fails to heal by itself and becomes a passage for the liquids to pass from mouth into the maxillary sinus which comes out through nose.
- This leads to chronic sinusitis and nasal regurgitation .
- This condition has to be surgically corrected by closing the fistula via various surgical procedures.
