The average maximal load generated in the oral cavity is around 700 N. The incisors carry loads of 100 - 200 N, the canines 300 N, the premolars 400 - 500 N, and the molars 600 - 700 N. Within the incisor group, the central incisors carry 200 N and the laterals 100 N, and within the molar group the first molars carry 700 N and the second molars 600 N.
There are large individual variations, but as a general rule, females generate slightly lower force levels than the ones presented above. Under normal mastication, the force levels are much lower than presented above. The are often in the Newton range.
If the contacting areas during chewing are small, very large stresses can be introduced in the contact regions. For example, imagine that a fine sand particle is in the food and that its contact area is only 1 square micron wwhen a chewing fforce of 1 N is used. Under this condition, a 1000000 MPa compressive stress is produced locally when the sand particle is pressed against the tooth surface.