Mouth-Sinus Holes (Oro-Antral Communications)

When an OAC is created, it allows the flow of food, smoke or fluid from the mouth into the nose. Not just these but also bacteria, fungi and viruses. This can set up a maxillary sinusitis, which depending on how long the communication lasts for, may either yield an acute / chronic maxillary sinusitis.

Causes of OAC’s:

The vast majority of OAC’s are created when upper molars and premolars are removed (almost 50%), tumours (18.5%), bone infections (osteomyelitis) (11%), operations to access the maxillary sinus (Caldwell-Luc procedures) (7.5%), trauma (7.5%), dentigerous cysts (3.7%), correction of septal perforations (3.7%), perforation of the sinus floor from the tooth socket when trying to remove an upper tooth and localised florid gum disease (HIV-related periodontitis) or tooth-tip infections (chronic apical infection).

Predictive Factors:

As a very broad generalisation, the following may be thought to predispose to an OAC being formed:

• Proximity of sinus floor / tuberosity
• Thickened tooth cement (hypercementosis) / tooth fused to jaw bone (ankylosis)
• Infected teeth / long-standing decay
• Marked periodontitis / gum disease
• Lone-standing
• Previous history of OAC’s.