Table 1. Average AA midpoint diameter (±SD) for all four possible AA present at stage 21.

AA	Midpoint diameter (±SD) (mm)
	R		L
II	0.109	(0.009)	0.110	(0.024)
	n  =	9	n  =	8
III	0.125	(0.020)	0.114	(0.019)*
	n  =	39	n  =	27
IV	0.123	(0.021)	0.115	(0.021)†
	n  =	49	n  =	28
VI	0.118	(0.026)	0.094	(0.027)*,†
	n  =	41	n  =	14

^*,† indicate a statistically significant difference (p<0.05) between AA diameters.