Comparison of each molar width (vestibulolingual dimension) between wild-type and <i>Rsk2-/Y</i> mutant mice with 3 or 4 molars.

In mutants the width of M1 was not modified. The width of the maxillary M2 and M3 was reduced. In the mandible the width of M2 was lower only when 4 molars were present, and the width of M3 was lower only in mutants with 3 molars (all distances in millimeters; significant p-values in bold). M1 : molar 1; M2 : molar 2; M3 : molar 3; ST : supplementary tooth in front of M1; STD : standard deviation; Mutant 3M : mutant with 3 molars; Mutant 4M : mutant with 4 molars.