Oroantral communication is pathological communication between maxillary sinus and oral cavity. It usually appears as a complication upon the extraction of maxillary molars and premolars. Pneumatisation of sinuses, long and divergent roots and a rough extraction technique are amongst the main predisposing factors for the occurrence of oroantral communication. In order to prevent this type of complication, it is necessary to adjust the extraction technique. Even when all the precautions have been taken, oroantral communication may occur. If that is the case, it is important to diagnose and treat communication in order to prevent more serious complications. The most frequently used method for diagnosing it is blowing the nose test, also patients may complain of the passage of liquids and food from the oral cavity to the nose. If oroantral communication is not treated, it will result in oroantral fistula. This type of persistent communication makes it possible for food and pathogenic factors to enter the maxillary sinus and cause maxillary sinusitis. The treatment of oroantral communication needs to be performed as soon as possible. A broad range of treatment procedures are available, the decision is made based on the size of an oroantral communication, the time that has passed from its occurrence to the diagnosis and the presence of an infection in maxillary sinus. The treatment of a small-opening oroantral communication is based on helping to create and maintain a blood clot in the alveolus, while the treatment of a large-opening oroantral communication is based on surgical treatment.