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

	Mandibular molars WT	Mandibular molars Mutants 3M	Mandibular molars Mutants 4M	Maxillary molars WT	Maxillary molars Mutants 3M	Maxillary molars Mutants 4M
Mean ST			0.59			0.76
STD			0.09			0.04
Mean M1	0.79	0.77	0.82	1.04	1.01	1.06
STD	0.02	0.04	0.03	0.05	0.05	0.02
p-value		0.19	0.12		0.19	0.56
Mean M2	0.85	0.85	0.81	0.90	0.86	0.86
STD	0.02	0.02	0.03	0.02	0.05	0.03
p-value		0.89	0.02		0.03	0.02
Mean M3	0.60	0.57	0.58	0.61	0.58	0.54
STD	0.02	0.02	0.05	0.03	0.02	0.04
p-value		0.006	0.06		0.02	0.01

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.