Sinus Expansion
The maxilary sinus is prevented from destroying bones by the presence of teeth.
Missing top teeth gives the sinus the opportunity to expand.
The maxilary sinus contains slight pressure, which causes it to expand into the edentulous area, subsequently causing bone atrophy.
With the loss of teeth, the sinuses expand and destroy bone in the area. The bottom teeth continue to erupt and traumatize soft tissue.Cross Section view of sinus expansion
In this cross-section view, we can see bone loss from two different directions. Due to the sinus expansion, atrophy from both the tooth side and the sinus side sometimes leave only a paper thin sheet of bone between the maxilary sinus and the inside of the mouth.
Sinus expansion due to tooth loss sometimes leaves only a paper thin sheet of bone between the sinus and the inside of the mouth
