We also looked up the top SNP from each of the 15 genome-wide significant loci in a previous analysis of secondary dentition and found that 7 were at least nominally associated (P < 0.05) with the number of permanent teeth between 6 and 14 years old (Supplementary Material, Table S4) (7). For the three loci (i.e. HMGA2, BMP4, MSRB3) associated with ‘age at first tooth’ at genome-wide significance, the allele associated with earlier primary tooth eruption was also associated with a greater number of permanent teeth. Furthermore at the four loci (ADK/VCL/AP3M1, 2q35, CACNB2, 6q21) associated with ‘number of primary teeth’, the allele associated with a greater number of teeth at 1 year was also the allele associated with greater number of permanent teeth (6–14 years).
