If you end up with an opening between your oral cavity and your sinus from a maxillary surgery on your palate, there are few great surgical or grafting solutions to close it. So an obturator is a prosthetic solution which is usually a combination plastic and silicone piece, that is removable for cleaning, that fits in the roof of your mouth to close things up and reduce debris getting where it shouldn't, infections, and so much more. It also makes nasal breathing so much easier for people with this kind of situation. If you don't have any upper/maxillary teeth left (or not many) the obturator can actually be on the underside (tissue side) of an upper denture, giving your mouth when you smile or open it, a more natural appearance.

Brian, stage 4 oral cancer survivor. OCF Founder and Director. The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant.