By Dr Oh Xue Ling (B.D.S Adelaide)
Not many people know of the intimate relationship between our maxillary sinus and the mouth. The maxillary sinus is a space above the upper teeth and beside the nose. Often, dentists will warn you of possible communication between the sinus and the mouth following extractions of your top teeth. This is known as oroantral communication (OAC).
What is an Oroantral Communication (OAC)?
An Oroantral communication (OAC), is an unnatural communication between the mouth and the maxillary sinus. As a result of this hole, liquids can move from the mouth into the maxillary sinus and out through the nose. If it is left untreated, chronic infection of the nose can occur, as bacteria from the mouth can enter the nose via this communication.
How can it happen?
There are many causes of OAC, the most common being extractions of upper posterior teeth that have roots that are very close to the sinus (fig 1). The sinus is lined with a thin membrane and a thin piece of bone, which may fracture during the process of extraction. Sometimes, the roots of the teeth extend into, or very close to the sinus, resulting in an OAC after extraction.
Fig. 1 Illustration of the proximity of the maxillary sinus with roots of upper teeth
Other causes also include facial trauma, surgery, malignant tumors, implant surgery.
Depending on the size of OAC, there are different treatment methods. For very small holes, it will generally close up by itself with no additional surgery needed. Bigger OACs will require minor surgical treatment to close up the gap.
Signs and Symptoms of OAC
Some of the symptoms that patients with OAC commonly experience include:
● Nasal regurgitation of liquid
● Foul smell/taste in the mouth
● Whistling sound while speaking, change in vocal resonance
The dentist will also check for clinical signs to verify the presence of OAC, such as asking you to blow through the nose while pinching your nose to check for the presence of any air bubbles.
If an OAC is detected, as part of the treatment the dentist will prescribe you some medications, which may include:
● Nasal decongestants to keep the sinus clear
● Painkillers if necessary
● Steam inhalation with menthol/eucalyptus may also be helpful to moisten the airways.
● Add one teaspoon of menthol/eucalyptus to a bowl of 500ml hot water, with your head 6-12 inches away and a towel over your head. This should be done for around 5-6 minutes and can be repeated every 6 hours.
What to take note of if you have an OAC
For the next 2 weeks, special instructions will be given to you to avoid increasing pressure in the sinus. These include:
● No nose blowing
● No smoking
● No sucking with a straw
● Sneeze with mouth open
● Do not play any wind instruments
● No diving or snorkelling