Educate your teeth!
Dentures are removable prosthesis that require stability. A pivot or fulcrum point may place undue stress on the denture base. Dentures may pivot if they are ill-fitting or if a tooth root or bony protuberance causes rocking of the denture.
Some people are capable of exerting tremendous chewing forces during normal function. Small cracks can begin and propagate to the point of splitting the denture base.
Your dentist may attempt to repair the dentures reinforcing the middle portion. A reline or remake may be recommended to increase denture stability. Removal of the tooth root or bony protuberance may also be recommended. If standard denture acrylic is incapable of tolerating strong chewing forces, dentures can also be made using a metal base.