From: Does fixed retention prevent overeruption of unopposed mandibular second molars in maxillary first molar extraction cases?
Retention group (n=30)
Non-retention group (n=35)
Males
18
19
Females
12
16
Age at T1 (years)
15.2 (1.6)
16.2 (1.7)
Age at T2 (years)
17.6 (1.7)
18.6 (2.0)
T2-T1 interval (years)
2.4 (0.8)
2.4 (0.9)