The extraction of a maxillary tooth (typically a maxillary first molar which lies close to the lowest point of antral floor although any premolar or molar can be affected) is the most common cause of an OAC (which can then progress to an OAF as described above). Extraction of primary teeth are not considered a risk of OAC due to the presence of developing permanent teeth and the small size of the developing maxillary sinus. Other causes
Other causes of an OAC are: maxillary fractures across the antral floor typically Le Fort I, displacement of posterior maxillary molar roots into antrum and direct trauma. An OAC can happen for many other more unusual reasons, such as acute or chronic inflammatory lesions around the tip of a tooth root which is in close proximity with the maxillary antrum, destructive lesions/tumours of the maxilla, failure of surgical incisions to heal (e.g. Caldwell-luc antrostomy), osteomyelitis of the maxilla, careless use of instruments during surgical procedures, Syphilis, implants and as a results of complex surgery (for example removal of a large cysts or resections of large tumours involving the maxilla. Diagnosis
Clinical examination and x rays can help diagnose the condition. For examples :
Valsalva test (nose blowing test): Ask the patient to pinch the nostrils together and open the mouth, then blow gently through the nose. Observe if there is passage of air or bubbling of blood in the post extraction alveolus as the trapped air from closed nostrils is forced into the mouth through any oroantral communication.
The flap used is dependent on the size and position of the defect. Buccal advancement flap
The buccal advancement flap is the most commonly used due to its simplicity, reliability and versatility. It involves cutting a broad based trapezoid shaped mucoperiosteal flap with two vertical incisions. The flap is cut buccally, is three sided and extends to the full depth of the sulcus. Buccal fat pad flap
The buccal fat pad flap is also a popular option due to its high success rate. It is a simple procedure where the buccal extension of the anatomical fat pad is used for closure. These two flaps can be used in combination where the buccal fat pad covers the communication followed by a further covering via the buccal mucosal flap described above. This double layer flap has advantages over a single layer as it provides stable soft tissue covering, reduces the incidences of wound breakdown and defect recurrence as well as reducing the risk of postoperative infection.Sutures, either non-resorbing or slowly resorbing, are generally used in the surgical repairs of OAC. Non-surgical interventions
Ultimately, surgery is usually required to close an OAC/OAF. However, if surgery is not immediately available then non-surgical methods can be used to encourage the growth of oral mucosa between the oral cavity and the antrum. The aim of these methods is to protect the blood clot within the socket and help to prevent infection.