Talk:Oroantral fistula/Draft

An oroantral fistula is a pathological communication between the antrum and oral cavity which may be followed by development of epithelial lining of the tract. The fistulous opening may be situated on the alveolus or gingivolabial sulcus.

Signs and symptoms
History of recent surgery in the vicinity of maxillary sinus associated with excruciating pain in and around the region of affected sinus,along with escape of air and fluids from the nose through the mouth is an indication of oroantral fistula.The pain becomes negligible when the fistula is fully formed.The enhanced column of air, causes a change in the voice.It may also be associated with persistent, purulent or muco-purulent, foul smelling, unilateral nasal discharge Other symptoms include unilateral epistaxis and tricking of nasal discharge to the pharynx from the posterior nares which may result into hoarseness of voice, earache, nocturnal cough or catarrhal deafness.

Physical examination of the site of extraction of surgery confirms the presence of fistula. Examination with instruments like silver probe should not be done.The diagnosis of oroantral fistula is confirmed by performing Nose blowing test. A cotton wisp is placed over the fistulous opening, the patient is asked to blow through the mouth. The nostrils are kept close.In presence of fistula, air passes through the defect displacing the cotton fibres placed over it.To test the patency of communication the patient is asked to rinse the mouth or water is flushed in the tooth socket.Unilateral epistaxis is seen in case of collection of blood in the sinus cavity.

Cause
Oroantral fistula can occur after extraction of posterior maxillary teeth.The development of maxillary sinus gets complete by 15 years of age, therefore development and perforation of oroantral fistula is more common in adults than in children. Acute or chronic inflammatory lesions around the apex of tooth root present in close proximity with the maxillary antrum may lead to formation of fistula.Necrotic lesions of the maxilla can also contribute to the formation of Oroantral communication.Failure of sublabial incision to heal after Caldwell-luc antrostomy,multiple and extensive fractures of the facial region, osteomyelitis of the maxilla,removal of a large cyst or resection of large tumour involving maxilla can cause oroantral fistula as the walls of maxillary sinus are thin, development of tumour may erode these walls and cause destruction of bone, which may lead to loosening of teeth and development of fistula.Other causes like injudicious use of instruments during oral procedures,malignancy involving the maxillary sinus, syphilis or malignant granuloma,radiation therapy and implant denture may result in the formation of oroantral fistula.

Diagnosis
Oroantral fistula can be easily confirmed by examination using a mirror and a good light. The interior of the antrum may or may not be visible. Gentle suction applied to the socket often produces a characteristic hollow sound. To test for any oroantral openings the patient is asked to blow the nose gently while pinching the nostrils. Air unable to escape from closed nostrils is forced into the mouth through any oroantral communication thereby producing bubbles in the socket. Care should be taken not to confirm the presence of a suspected oroantral fistula by irrigation or probing as it can lead to sinusitis due to pushing of contaminated fragments or oral flora into the antrum. It can also lead to formation of a new fistula or widen an existing one. Other methods like radiographs (occipitomental, OPG and periapical views) can also be used to confirm the presence of any oroantral fistulas.

Prevention
In case or operations where there may be a risk of oroantral fistula formation, the patient should be warned preoperatively and steps must be taken to prevent this complication. Usually surgical exodontion is preferred as compared to forceps removal as it allows more control over bone structure. In surgeries, where the mucoperiosteal flap is raised, it should be done in such a way so as to allow its design to be modified for future oroantral fistula repair if necessary.

Treatment
The primary aim of treatment of a newly formed oroantral communication is to prevent the development of an oroantral fistula as well as chronic sinusitis. If the opening of oroantral fistula is small, care should be taken not to irrigate the cavity neither should it be probed to avoid contamination. In small openings a small clot may be formed which can later heal spontaneously without any complications. However, if the opening is large and not expected to heal normally, in such cases immediate closure should be done to prevent contaminating and further formation of oroantral fistula.

Early treatment
The aim of this treatment is to encourage the growth of new bone between oral and antral cavites. Here the blood clot within the socket is protected to prevent infection of antrum while bone formation and organization takes place. If further surgery is contraindicated then an acrylic base plate can be used to support the clot or dressings like Whiteheads varnish can be sutured across the defect.

Further options
If immediate measures fail to heal oroantral communication then further treatment is preferred. Oroantral fistula is most commonly accompanied by chronic maxillary sinusitis.Hence the treatment of oroantral fistula involved closure of the fistula along with management of sinus through Caldwell-luc operation. Generally tissues from local flaps are used to close oroantral communication. However distal flaps (e.g.-from tongues) and grafting can also be done. Closure of oroantral fistula can be done using the following procedures: The choice of method depends on the size and position of fistula.
 * 1) Palatal pedical flap operation
 * 2) Buccal sliding flap operation
 * 3) combination technique

Palatal pedical flap repair
This method is most commonly used and is performed under local anesthesia. The advantages of this method are firstly it produced thick, strong repair due to thickness of the flap. Secondly there is rapid healing due to high vascularity and also sufficient amount of tissue is available.

Buccal flap operation
It is a simple procedure to close chronic oroantral fistulas. This procedure is combined with Caldwell-Luc operation to clear the antrum of any pathology. The flap may break down due to due to any infection, poor vascularity or excessive tension on the sutures. In such a case, antrum must be carefully examined and cleared of infection before attempting second surgery.

Combination technique
Here both buccal and palatal flaps are together used as a double layer to close the fistula. This process is seldom required and is only indicated in cases of long standing, very large oroantral fistulas.

Other techniques
Materials like preserved cartilage, 24 carat gold discs or tentalum gauze can be used to fill the defect before surgery. Buccal pad of fat can also be used for closure of oroantal fistula.

Post Operative Care
Following all the methods of oroantral fistula closure, the patients are advised against creating suction in mouth or producing pressure in nose. Drinking with straw, smoking, blowing nose or sneezing is to be avoided during 1st 10 postoperative days, as it may increase pressure in antrum and disrupt the healing of tissues. Following surgery, nasal decongestants and prophylactic antibiotics are prescribed to facilitate antral drainage and prevent infection.