Closure of Oro-antral Communication

This is a common complication, which may occur

during an attempt to extract the upper back teeth or roots
(premolars & molars).

The mouth-sinus communication (oro-antral
communication) may  be confirmed by observing the
passage of air or bubbling of blood from the post-
extraction socket  when the patient tries to exhale gently
through their nose while their nostrils are pinched
(Valsalva test). If the patient exhales through their nose
with great pressure, there is a risk of causing oro-antral
communication, even though communication may not
have occurred initially, such as when only the lining
(mucosa) of the maxillary sinus is present between the
tooth socket and the sinus.

Mouth-Sinus communications (oroantral communications)
may be the result of:

• Displacement of an impacted tooth / root tip into the
  sinus (maxillary antrum) during extraction.
  

• Closeness of the root tips to the floor of the sinus
  (maxillary antrum). The bony portion above the root
  tips is often very thin or may even be absent,
  whereupon oro-antral communication is inevitable
  during extraction of the tooth, especially if the socket
  is ‘cleaned’ unnecessarily.
  

• The presence of a root-tip infection (peri–apical
  lesion) that has eroded the bone wall of the sinus
  floor.
  

• Extensive fracture of the maxillary tuberosity,
  whereupon part of the maxillary sinus may be
  removed together with the maxillary tuberosity.
  

• Extensive bone removal for extraction of an impacted
  tooth / root.

The OAC / OAF is closed using the following flaps:

• Buccal Advancement Flap most common.
  
• Described by Rehrmann & made popular by Berger.