You searched for: “bruxophobia
bruxophobia (s) (noun), bruxophobias (pl)
An abnormal fear of grinding the teeth together because of the damage or pain which excessive teeth grinding or jaw clenching might cause: A bruxophobia occurs when someone is afraid that he or she could have oral health complications; especially, if the teeth grinding causes damage and then other oral health complications which could also take place.

Because grinding often occurs during sleep, most people are unaware that they grind their teeth; however, a dull, constant headache or sore jaw when someone wakes up is a revealing symptom which can cause bruxophobia.