Teeth grinding can be a strange condition because it is often done unconsciously and people are not aware they are physically grinding their teeth.
Teeth grinding (also known as bruxism or jaw clenching,) is a complaint whereby people grind the top half of their teeth over or backwards and forwards of the lower set of teeth. The condition is often said to be related to stress or anxiety and is a way of people controlling it. As mentioned, most people do not realise they are doing it and will often know nothing about it until any problems arise. Most likely, teeth are grinded during sleep, when under a period of stress or when concentrating intensely.