Hagurumanstyle is a Sanrio universe introduced in 2015, based on tooth characters.
The Hagurumanstyle characters appear when people clench their teeth together to persevere and support their dreams.
According to the Hagurumanstyle character page on the Japanese Sanrio website, it is said that they help with "mental care" (which distinguished on from "dental care").
The teeth in Hagurumanstyle work hard in people's mouths to "make the world go round". Using "teeth" terms, they are able to express themselves about difficult situations.