Nighttime Clenching & Grinding of Teeth:

It is my own observation that nowadays about 85% of all adults clench and grind their teeth in their sleep.  One may not think about the deleterious effects of this phenomenon until he realizes what the consequences are on the masticatory apparatus (teeth, muscles and jaw joint).

Normal chewing places about 68 lbs/sq inch of pressure on the back teeth. If you intentionally clench your teeth you may increase that force to about 150 lbs/sq inch.

However, an individual who clenches and grinds their teeth subconsciously at night can exert pressures of upwards of 1200 lbs/sq inch momentarily. That is equal to an industrial grinding machine!  This sudden spike in the amount of pressure can fracture teeth and damage the jaw joint (TMJ) over time.  The continuous working of the muscles of the jaw and face results in their hypertrophy (increase in size as result of exercise). 

Another less significant but noticeable side effect of clenching and grinding is localized growth of bone on the sides of the jaw and middle of the palate.  These bone growth which are referred to as Tori (plural for Torus) are benign in nature, but they can grow to a considerable size, interfere with eating and irritate the overlying gums.

Finally let us mention that one of the causes of having sensitive teeth is para functional clenching and grinding.  Here is the mechanism:  When you grind your teeth while they are locked into each other, you start bending and flexing them right at the gum line (point of their exit from anchoring bone).  Since our teeth are not very flexible they start breaking down and losing small bits of tooth substance (enamel & dentin) from their necks.  This erosion and loss of protective enamel can render teeth sensitive to cold and brushing.  If erosion continues untreated for a long time, it can also impinge on the pulp chamber (nerve) in the tooth and cause its demise, requiring root canal therapy. 

The most common treatment offered by dental professionals for night time clenching and grinding of teeth is an appliance called Night Guard.  Night Guard is a horseshoe shaped piece if acrylic that covers the surface of the teeth and separates them during grinding.  Therefore it prevents teeth from rubbing against each other.  It also protects the jaw joint (TMJ) by repositioning it and also by stretching the muscles therefore decreasing the amount of force that they can generate. 

Author: Syamack Ganjavian, DDS

Reference: www.crescentdentalde.com