A study of the Australian Aborigines (native Australians) showed that most of them had straight teeth. This was due to the fact that their diet consisted largely of gritty roots which constantly wore down their teeth and therefore prevented them from crowding.
Jan 13, 2019
From Champlain Orthodontics...
Your teeth will shift throughout your life, regardless of whether you've worn braces before. To ensure your teeth stay straight, wear your retainer as often as possible.