The Need to Chew

Chewing tough food (whole-grain bread, raw fruit and vegetables, nuts, etc.) is an ideal massage for our gums and enhances the resistance and elasticity of gingival tissues, thus preventing pyorrhea (inflammation of the sockets of the teeth) and paradontosis (inflammation of the gums).
If we do not use our teeth for what they were intended, they may well fall out prematurely and decay.
Both soft food that does not require chewing and sweets weaken the gums and the teeth.
Chewing cleans the teeth and corrects their position, activates the blood flow inside the tooth from the root and preserves it.

Schneider, Ernst, Healthy by Nature, 2 vols., Madrid, Spain: Editorial Safeliz, 2008, vol. 1, p. 200.