Table 1. .

Descriptive Statistics. Evaluated Arches (n), Sex and the Presence of Third Molars. Mean and Standard Deviation (SD) for Age, Follow-Up Time, Years Without Retention, Overbite, Overjet, Intercanine Width (ICW), Little's Index (LI), and Posttreatment Changes (LI T2–T1)^a

Sample (F/M)	Mean Age in Years (±SD)	Follow-Up Period in Years (±SD)	Years Without Upper Hawley Retainer (±SD)	Years Without Lower 3X3 Retainer (±SD)
Upper arch: 35 (25/10); Lower arch: 38 (26/12).	T0: 13.63 (±6.74)	7.68 (±1.89)	7.39 (±1.96)	7.19 (±1.66)
	T1: 15.97 (±6.63)
	T2: 23.64 (±6.65)

^a F indicates female; m, male.