Back in the days of university, when I studied dental medicine (1994–2000) the phenomenon was already known and addressed to us students how to treat it. But it was taught like something not so common, and yes, in the early years of my practice I treated people with Bruxism around once in two or three months.
These days there is not one single day where I don´t treat tendomandibular disorders and the easiest form: Bruxism.
There are more people grinding than not grinding.
A significant peak is found in Women: Most of grinders are women between 25–50 years old. Nearly no woman at that age doesn´t grind or press their teeth.