The maxillary sinuses are located under the cheekbones. When they become blocked and no longer drain properly, an infection can develop. Often, the sinus opening itself becomes blocked, too. The procedure to clear the sinus opening is called a maxillary antrostomy. The procedure to clear the osteomeatal complex is called an uncinectomy. Usually, both are performed together.
In rare cases, a maxillary antrostomy does not help drain the maxillary sinus completely, or there may be diseased tissue that cannot be removed in this way. If so, the surgeon may need to create a new drainage pathway between the maxillary sinus and the nose (a Caldwell-Luc procedure).
The doctor should be asked for a detailed explanation of the benefits and risks of the procedure, as well as their experience performing this kind of surgery.