PAX9 and tooth agenesis: According to Yu, et al.52(2019) more than 91.9% of non-syndromic tooth agenesis cases are caused by seven pathogenic genes (PAX9,53-55 AXIN2,56EDA,57LRP6,58,59MSX1,54,60-62WNT10A,59,63-65andWNT10B12,66,67).