Generally speaking, it is possible to use an oral device over an existing denture provided that the denture is stable and not loose. However, it is more favorable to have at least six teeth to retain an oral device. Every patient is different and has a unique oral condition. The best way to determine if you’re a candidate for oral appliance therapy is to come in to see the dentist for an evaluation. There are many options out there and the dentist can help determine which option is best.