Dentists say they're seeing more patients who grind or clench their teeth. Also known as bruxism, the condition happens unconsciously, usually when people are asleep, and can lead to teeth being ground-down, nerves exposed, as well as jaw and headaches. So what is the main cause and how can bruxism be treated? Susie speaks with Dr Mo Amso, a dentist and Chief Executive of the New Zealand Dental Association and Wellingtonian Olivia Hope-Simcock who has experienced bruxism for the last few years.