OPN3 and tooth agenesis: Earlier, traditional research on non-syndromic hypodontia focused on finding variants in candidate genes, but current trends using WES have revealed new mutated genes for non-syndromic hypodontia (Zeng et al., 2017; Dinckan et al., 2018; Zhang et al., 2019), including OPN3, which was previously thought to be irrelevant to tooth development (Inagaki et al., 2021).