Sinus is located in the upper jaw bone.
When is sinus closure necessary?
The opening of sinus is the most common intergrowth of the extraction of the small or big upper molar. It may occur if the dental root grows into the sinus, however, it sometimes cannot be seen on X-ray images.
After tooth extraction a so-called nose blowing test is done to check whether the sinus closure was successful. If not, the sinus has to be closed immediately with using local anaesthesia. The dentist creates a gingival flap, that is used for closing the cavity, and fixes it to the mucosal of the roof of the mouth with sutures.