Invasion of the maxillary sinus and establishment of a direct communication with the oral cavity is referred to as an oro-antral fistula.
Factors influencing creation of oro-antral fistula:
Ü Teeth size and configuration of the roots.
Ü Hypercementosis and bulbous roots.
Ü Density of alveolar bone and thickness of sinus floor
Ü Size of the sinus.
Ü Relation of sinus to the root of upper teeth.
Ü Rough extraction and misguided manipulation.
Ü Apical pathosis and attached granulomas.
Ü Periodontal diseases which may erode sinus floor.
Ü Presence of cysts and neoplasm.
Ü Invasive surgery e.g. cleft and dental implants placement.
A Video On Buccal Advancement Flap