Some “discovery”. They were making note of this years ago when they studied Egyptian mummies — their bread and whatnot contained sand and it affected their teeth.
That is what I was going to say! This “discovery” has been common knowledge for many decades.
This provides some background regarding dental anthropology beginning in the 1920's.
Traditionally, dental anthropology also categorizes dental wear according to the agent causing the wear. Attrition and abrasion are identified as the two main components in dental wear. The former is caused by tooth-on-tooth contact, whereas the latter is the result of contact with foreign materials (e.g. food, abrasives in food, other objects held in the mouth).The number of studies and papers on the subject of the dentition of prehistoric and ‘primitive’ populations increased greatly in the 1920s. In this period and the years after there were great advances in the knowledge about dental structures, hominid dental evolution,dental morphology, dental pathology, and dental wear (both abrasion and attrition).A.A. Dahlberg is most often considered to be the ‘father of dental anthropology’ as it was his early work in the 1930’s and 1940’s which laid the very important foundations for further research in the field.