Your tooth can be sensitive or painful to chewing pressure for many different reasons. Tooth decay can allow foods to contact areas of the tooth that are not supposed to be touched. Gum recession also allows sensitive tooth areas to be exposed.
Structural damage like a dental crack or a loose filling can make it painful to eat.
An abscess is caused by a bacterial infection and results in pockets of pus at the tip of a root or in the gums. Chewing pressure on an abscessed tooth can be very painful
Root canal infections are some of the most common causes of tooth pain while chewing. A root canal infection occurs when the nerve and blood vessels of a person’s tooth are infected causing sometimes severe pain when chewing.

Contact a dentist soon after you discover any sensitivity associated with your teeth while chewing.