Table 2. Comparison of rugae length among the various shapes within the primary rugae (>5mm) group.

Shape	n	Mean	SD	Curved vs Wavy	Curved vs Straight	Wavy vs Straight
Curved	427	10.04	2.34	<0.001*	0.306	<0.001*
Wavy	389	11.17	2.59
Straight	344	9.75	2.39

*Statistically significant, p<0.01