Another cause for the teeth damage could be bruxism (clenching or grinding of the teeth) which may be due to stress. Teens tend to get stressed out because of upcoming exams, etc. Bruxism usually occurs at night while you sleep. When you wake up in the morning, your jaw may feel sore, you may hear a clicking sound when you open or close your mouth or your teeth may become sensitive. Tooth grinding or bruxism could lead to temporomandibular disorder (TMD). Immediately have an appointment with your dentist so that they may fit a night guard for you to wear to protect your teeth.