Maxillary sinus extraction fistula, refers to the extraction of teeth leading to maxillary sinus fistula, manifested as fluid entering the nose through the mouth, bad taste in the mouth, nasal congestion, runny nose, headache, fever and so on. 1.Maxillary sinus fistula is a more common complication after tooth extraction. After the presence of maxillary sinus fistula, the patient may have secondary bacterial infection, maxillary sinus swelling and pain, orbital and head radiating pain and other symptoms. 2. When the maxillary sinus fistula, the oral cavity will be connected with the maxillary sinus, and when the nose is pinched and puffed, gas can be found flowing out of the wound fossa. In severe cases, there may be a large amount of purulent secretion from the nasal cavity on the side of the mandibular sinus fistula and accompanied by a foul odor. 3. During eating and drinking, food may enter the maxillary sinus through the fistula, forming a foreign body in the maxillary sinus. If the diagnosis of maxillary sinus fistula, should be timely medical treatment, under the guidance of the doctor, do not unauthorized treatment, so as not to delay the condition. Pay attention to rest on weekdays, quit smoking and drinking, and keep a regular routine.