She was unaware her flatmate Jelle Kouwenhoven (22) was a tooth grinder until his girlfriend dobbed him in.
"I haven't heard him. We're separated by two doors, a hallway and a bathroom. But some people grind their teeth so loudly they can be heard outside a closed door," Ms Po (21) said yesterday.
An estimated 8% of men and women across all ethnic groups ground or clenched their teeth, she said. No-one was quite sure why, and most grinders only found out they did so when told by their bed-mates they were "bugging them".
"People who grind their teeth at night usually do so very intensively, so it's a really odd noise and can be very loud and annoying."
There could be physical and psychological consequences, including worn teeth, headaches, a painful jaw, sore face muscles and pain in the temporomandicular joint, the points just in front of the ears where the jawbone attaches to the rest of the skull.
The fifth-year student decided to study tooth grinders and record electronic patterns of their overnight habits after completing a project over the summer recording people eating food.
For the summer project, participants were hooked up to a small portable electron micrograph machine to record the sound of their chewing. The sounds were turned into digital patterns using a data processing algorithm designed by her supervisor, Prof Mauro Farella.
The recording process is the same for the teeth grinders, who wear the machine over two nights while eating their evening meal and sleeping.
As well as producing attractive and unique patterns, her research was showing obvious differences between normal tooth activity such as eating and night-time grinding or clenching, Ms Po said.
So far, Ms Po has analysed 10 teeth grinders but would like more - as many more as she can get. Anyone willing to participate can contact her at jessica.po@otago.ac.nz
