Chewing System

What does it mean to have an Unstable Chewing System?

The three reasons people lose their teeth are dental decay, gum disease and an unstable chewing system. Your chewing system consists of how your teeth fit together when your chewing muscles move your lower jaw up and down.  An unstable chewing system, if not discovered and addressed, can cause excessive tooth wear; cracked or loose teeth; sensitive teeth; jaw joint disorders and early tooth loss.

An unstable chewing system is an often overlooked and sometimes “silent” oral disease that many people dismiss as “natural aging or wearing” of teeth. In much the same way a set of tires that are not aligned properly wear faster and do not perform optimally, an unbalanced bite can lead to excessive or abnormally accelerated tooth wear.

Unstable: jaw joint not in socket where teeth fit

Stable: jaw joint in socket where teeth fit

What are the signs and symptoms?

You may have an unstable chewing system if you have one or more of the following signs and symptoms:

  • Worn down, chipped, cracked or broken teeth
  • Teeth that are sensitive to hot, cold and/or biting
  • Multiple “root canals”
  • Mobile or loosening teeth
  • Clenching/grinding of your teeth
  • Abfractions or wedge-shaped notches in the teeth at the gum line;
  • Gum recession
  • Severe localized bone loss around teeth
  • Pain in the teeth and/or TMJ when you chew
  • Headaches and facial muscle pain
  • Teeth or dental work that fracture or break

On your back teeth, you will notice that there are points (cusps) and valleys (fossae). In a healthy bite, the cusps of your back teeth fit tightly into the fossae of your opposing teeth while the two jaw joints (TMJ’s) seat completely in their sockets. This is the least stressful and least destructive bite relationship for your teeth, bone, gums, TMJ’s, jaw muscles, and your existing dental work. The human bite is capable of generating forces measuring up to 900 pounds per square inch – so when your bite does not line up correctly, damage can and will occur.

In addition, a healthy bite has of the proper amount of overlap of the upper front teeth over the lower front teeth to guide our side to side chewing motion (think of guardrails on a roadway).  The front teeth protect the back teeth by limiting excess stress during chewing.  When the front teeth are not aligned properly or are worn down, they are unable to provide this protective function, damaging the front and back teeth, bone, gums, TMJ’s and jaw muscles.

A simple way to demonstrate this “protective” function is by placing your hand on the side of your jaw and clenching fully on your back teeth. Can you feel how forcefully your muscles contract? Now, assuming that the upper and lower back teeth can separate from each other when your front teeth are edge-to-edge or canine-to-canine, try clenching with just your front teeth or canines. Can you feel how much less force is created by the muscles?

How is bite disease treated?

If your long-term goal is good dental health, you may choose to learn more about your unstable chewing system. We will recommend a detailed evaluation of your bite, which includes mounted study models, digital images and detailed records of your current condition. In many cases, bite splint therapy will be required to relax overworked chewing muscles and allow your jaw joint to properly seat in the jaw socket; years of an unstable bite can create chewing muscle imbalance and/or a TMJ disorder.  Once your jaw joint is seated in the socket, a diagnosis of how your upper and lower teeth fit together is made to consider the most conservative option to stabilize your bite.