tonic bite reflex

ton·ic bite re·flex

(ton'ik bīt rē'fleks)
An atypical oral motor pattern seen when a person bites down and cannot release the position, often accompanied by increased tension throughout the face, head, and neck, which can result in shortening of muscles and connective tissue that prevents full jaw opening.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012