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Oral Surgery

How Do I Manage Oroantral Communication? Key Points

This Urgent Care Scenario (USC) is presented by the JCDA Oasis Team in collaboration with Dr. Archie Morrison and is also available through the JCDA Oasis Mobile


Oroantral Communication (Oroantral Fistula)

Oroantral Communication (OAC) is an abnormal communication between the maxillary sinus and the oral cavity. It may be the result of different pathological processes and often occurs following an extraction. Other causes for OAC include: infection, inflammatory conditions, neoplasm, Paget’s disease, iatrogenic injury, and trauma. 



  • Individuals who recently underwent maxillary posterior tooth extractions.
  • Individuals presenting for extraction of a long-standing lone posterior maxillary molar.
  • Individuals presenting with a radiographic signs of large maxillary molar roots or close root proximity to the sinus floor.
  • Elderly people presenting with large bulbous roots with more bone expansion and possible fracture of the thin sinus floor.
  • Individuals with the loss of lamina dura on the maxillary posterior teeth to be extracted.


  • Bulbous expansion of the alveolar bone from large roots with increased risk of root and alveolar bone fracture
  • Fracture of the antrum floor
  • Attachment of sinus lining and associated fractured bone and roots upon extraction
  • Dark opening into the sinus visualized with appropriate lighting
  • Loss of the socket blood clot in the days immediately following extraction


  • Patient complains of fluid going from mouth to nose when drinking.
  • Patient feeling a sensation of air rushing through the socket as they breathe.
  • Pain severity: Usually not painful unless secondary sinusitis develops. 
  • Ask the patient about fluid rush to the nose while drinking.
  • Perform a complete extra- and intra-oral examination as well as radiographic examination to rule out local pathologies.
  • With appropriate lighting, rule out the loss of the blood clot or granulation tissue in the socket.
  • Confirm the suspected small openings into the antrum.
  • Perform a gentle Valsalva test, if there is still question of an opening after taking a history and examining the patient and not finding a definitive opening. 

Based on clinical examination and radiographic findings, a diagnosis of oroantral communication (oroantral fistula) is determined.


Common Initial Treatment: Estimate the fistula diameter

  • 1-2 mm: No treatment required as it will usually naturally heal.
  • 2-4 mm: Carefully follow the patient after 1-2 weeks and advise to avoid straining the area (no holding back sneezes, no smoking, no use of straws, no pressure on the sinus). 
  • 6 mm or larger: Follow up at 2-4 week intervals for 3-4 months prior to referring for surgery. Consider referral to an Oral & Maxillofacial Surgeon for further evaluation.
Drug Therapy
  • Amoxicillin (500 mg/adults) 3 times daily for at least 1 week and maybe 2 from the outset. 
  • Use Clindamycin in penicillin-allergic patients. 
  • For resistant infections consider using levofloxacin 500 mg once daily.
  • Use over-the-counter sympathomimetics, such as Otrivin or Sudafed to control sinus congestion for a maximum of 3 days.
  • Consider a nasal steroid spray, such as Flonase to limit inflammation of the sinus lining. 

Surgical Procedure

  • Debride the socket and pack with Gelfoam to help form a blood clot.
  • Close with a buccal advancement flap: advance some buccal soft tissue over onto the palate and secure it with sutures. 
  • In case of a large opening: swing a palatal pedicle finger flap into the area and cover it with a buccal advancement flap.
  • For very large chronic defects, consider using a buccal fat pad graft into the socket before covering with your flaps.

Possible Complications

  • Chronic sinusitis
  • Osteomyelitis with maxillary bone loss although less common.

Follow-up: What further information would you like on this topic? Email us at jcdaoasis@cda-adc.ca

Readers are invited to comment on this initial response and provide further insights by posting in the comment box which you will find by clicking on “Leave a reply“ below. You are welcome to remain anonymous and your email address will not be posted .


  1. aaron fenton March 20, 2013

    Hello Editor O’keefe: Consider adding prosthetic to treatment options after mediciations and surgery. While uncommon, I have provided small obturator when surgical closure was unsuccessful.
    PS: I have case report which I could submit if desirable. a.

    1. aishwarya December 16, 2013

      Hi,Aaron,maxillofacial surgeon closed maxillary sinus at my clinic but it has relapsed .
      can you provide me further details about obturator as how u designed it.If possile provide pictures of the same case.

      thanks & regards,

  2. Douglas Paterson March 20, 2013

    Large oro-antral communications should never be left for a period of weeks! This is inviting a flagrant and often severe sinusitis with foul smelling discharge and dramatic hyper plastic polyploid tissue filling the Antrum. No oral and Maxillofacial surgeon would appreciate this approach. The magnitude of the defect will be obvious at the time of the extraction and this is the time for the practitioner to seek help. Immediate closure at this time will take nearly all patients to a successful outcome.

  3. Mosaab Hawsawi March 20, 2013

    Thanks for the brief discussion..
    Though, I still have a question:
    What would be the immediate management if this OAC was encountered by a general dentist?

    1. JCDA Oasis March 20, 2013

      Hi Mosaab, thank you for the question. The Urgent Care Scenario is developed for the general dentist. The treatment approach is also geared towards the general dentist with the option of referring to an Oral & Maxillofacial Surgeon.

  4. Cheryl Cable March 21, 2013

    Patients with a history of radiation to the area may experience OAC. Ideally this is treated surgically, but if the patient is a poor surgical candidate or the situation is unstable, a maxillofacial prosthodontic approach with an obturator may be the best initial course of treatment.
    Do not forget to inquire about recreational drug use (cocaine) that will cause significant vasoconstriction. This will affect all forms of intervention.

  5. P Kwong March 23, 2013

    I would choose to use Augmentin(amoxicillin & Clauvanate acid) instead of just amoxicillin to treat OAF. I ‘ll instruct the patient to sneeze with his mouth open and not to blow his nose for 2 weeks. Have him to return in 2 weeks to check if OAF still present. Pinch his nose first and ask him gently blow his nose. If your mirror putting right under the OAF does not get a hissing sound that air goes through from the nose to the mouth, then OAF is closed.

  6. fawzia March 23, 2013

    i like this kind of discussion.thank u very much indeed editor.it’s useful.

    1. JCDA Oasis March 25, 2013

      Fawzia, We’re glad we are of assistance to our dentists our there!! Keep the questions coming.

  7. Maxillo3D Montréal March 26, 2013

    Communications of more than 4-5mm are most predictably treated immediately. I generally prefer to see these patients same day or next day, and certainly within the first 2 weeks.

  8. dr abdul qadus May 1, 2013

    nice artical but two points missing fist nose blowing test second management of chronic condition

    1. JCDA Oasis May 2, 2013

      Thank you Dr. Abul Qadus, I will review the article with the author and make the necessary changes. JCDA Oasis Team

  9. MERCY May 11, 2014

    is there some extra precaution to be taken when the patient is diabetic??

  10. Angela May 23, 2014

    What happens if a patient goes under for a sinus closure and a week later notice pressure and the tiniest bit of air still escaping from the gum hole? Is there a non evasive way of getting this to heal??????! Please help. 🙁 -Very nervous patient

  11. Deb Dennis March 24, 2018

    I would welcome your views on treating patients at risk for biophosphate related osteonecrosis of the jaw. When an OAC is anticipated based on the positioning of the extracted tooth and the depth of root intrusion into the sinus. What measures would encourage the most positive outcome ? At the time of the extraction the size and severity of the OAC is not always readily apparent. Aggressive approach to ensure full closure, or conservative “wait and see” approach. If “wait” for how long?

  12. Fiona Manonn October 10, 2020

    I would have embolized the fistula and not exposed the patient to restenosis in the prox lad using the joined graft unless the size of the fistula prohibited safe coil embolization. assuming the guide shots are with a 6f system the fistula does not appear to be larger than 3mm. this is a more elegant solution that avoids trauma to the lad. Another thought: does the fistula need embolization. the ant wall ischemia may be due to the stented lad atherosclerosis and nothing to do with the fistula. A shunt study should be performed prior to deciding to close the fistula by whatever method. great case for discussion!.


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