Mouth-Sinus Holes
Oro-Antral Communications)
What is an Oro-Antral Communication (OAC)?

This is a communication between the maxillary sinus /
antrum and the oral cavity / mouth.

What is an Oro-Antral Fistula?

If an OAC is not treated, this can become lined with
epithelium (skin).  Hence, an oro-antral fistula is an
epithelised tract linking the maxillary sinus to the mouth;
the tract becomes 'permanent'.

(Alternative names for an OAC / OAF include
oro-antral &
oral fistulæ, sinus perforations and antra-oral fistulæ).
Photos of Oro-Antral Communications
CT Scan Showing Oro-Antral Fistula
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
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 (
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 / tuberosity
  • Thickened tooth cement / tooth fused to jaw bone
  • Infected teeth / long-standing decay
  • Marked periodontitis / gum disease
  • Lone-standing
  • Previous history of OAC’s.

Treatment of the Acute OAF:

If an
OAC has been created, then:

  • Do not probe the defect
  • Promote good blood clot
  • The gingival / gum margins around the socket should
    be approximated as close as possible
  • Physical agents placed in the socket to stop excess
    bleeding (Surgicel, Spongostan or Haemocollagene)
  • Antibiotics should be prescribed (Amoxycillin,
  • Nasal decongestants can be used (Ephedrine nasal
    drops, Oxymetazoline)
  • Steam inhalations can be used (Menthol &
  • Antiseptic mouth-wash should be used (Corsodyl)
  • No nose-blowing or smoking

How to Recognise the Chronic OAC / OAF:

The OAC is likely to become chronic if:

  • OAC is greater than 5mm in diameter
  • Gingival tissues / gums around the socket can’t be
  • Post-op régime is not followed
  • Wound dehiscence / breakdown
  • Enucleation of a dental / dentigerous cyst
  • May develop 4 – 6 weeks post-extraction
  • Problems with smoking, eating or drinking
  • Cacogeusia / foul taste
  • Chronic maxillary sinusitis
  • Antral polyp herniating into the mouth
  • Purulent (pus) discharge from nose
Last Updated 4th November 2010
Treatment of the Chronic / Larger OAC / OAF:

  • The OAC is assessed with X-rays & CT's.