The Role of The Bite in TMJ Disorders

ADJUSTING BITES
There are many ways to eliminate bite strain.  Teeth can be drilled down, built up, and/or moved orthodontically.  The choice depends on your dental needs, your finances, and your face height.  People with excessively long faces can most benefit from reducing high spots to make them shorter, and people with excessively short faces can most benefit from building up teeth to make them taller.
 
REDUCING high spots involves accurately locating them with little blue carbon paper and then reducing them with a high speed drill in a process known as equilibration.  Equilibration does not harm teeth or make them more susceptible to developing cavities.  In fact, until MRI became popular and made us realize that the vast majority of TMJ disorder patients have a dislocated TMJ disk, equilibration was the primary means used by dentists to treat TMJ problems, and the largest TMJ professional organization in the world is still the American Equilibration Society.  Equilibration is especially useful in people with steeply interdigitating tooth inclines which restrict the range of motion of the lower jawbone.   It enables longer smoother chewing strokes.
 
BUILDING UP low spots usually just involves bonding tooth colored filling material directly to the tops of the teeth.  The process can significantly reinforce teeth that already have fillings, because material bonds to enamel with incredible strength.  Also the material is versatile, because it can be easily ground down or added to itself later. The primary disadvantage of using composite resin for building up teeth is that the material tends to wear down.  Teeth were designed to wear down slowly and steadily over time, so such wear of composite resin may not be a problem. However, in people who have strong jaws and vigorous tooth grinding habits, wear of the composite resin may occur rapidly enough to destabilize the bite, so more longlasting materials like gold or porcelain is required – especially on the molars which receive most of the bite force.  
 
WEAKENED TEETH due to the presence of cavities or previous fillings will require gold or porcelain onlays or crowns eventually anyway, and that permanent dental work can be very helpful in recreating a healthy bite.   Filling materials prevent food from collecting in a defect in a tooth, but they do little to reinforce the tooth structurally.  As teeth become more brittle with age, they tend to crack or chip from around the filling.  Thus, a tooth with a filling will eventually need to be covered by a solid piece of gold or porcelain such as a crown or onlay so that no part of the natural tooth structure surrounding the filling can fracture. 
 
GOLD is the ideal material for reconstructing bite surfaces.  It is extremely accurate and biocompatible.  It has a hardness very similar to natural tooth structure – which minimizes wear.   In addition gold is strong even when thin, and it can be bonded to enamel with impressive strength.   Gold tooth build-ups usually don't require novocaine.
 
PORCELAIN has excellent esthetics, however it also has disadvantages.  Porcelain needs bulk for strength, so the tooth preparation process requires significant reduction of tooth structure, which increases the chance of the tooth later needing a root canal.  It’s also difficult to create an accurate bite with porcelain, because porcelain cannot be simply cast to fit the bite but instead must be initially built too high and then ground down in the dental lab until it fits.  Finally, porcelain is so much harder than natural teeth that, insead of wearing down itself, it tends to wear away the opposing natural teeth.