Early versus late intermaxillary elastics in patients with Class II malocclusion: a randomized clinical trial.

Objectives: To compare efficacy and treatment duration of early versus late Class II elastics in patients with Class II malocclusion. Material and Methods: Forty patients were randomized into two groups based on the timing of elastics use: early and late. In the early group, light short elastics were used from the day of placement of fixed preadjusted edgewise appliances. In the late group, elastics were inserted once 0.016 × 0.022-inch stainless steel archwires were in place. Lateral cephalograms and standardized smile photographs were taken before treatment and after achieving a Class I buccal segment relationship. Treatment duration, dental, skeletal, and soft tissue measurements were then compared between the two groups. Results: Maxillary central incisors were retroclined relative to the SN plane (95% confidence interval (CI): 3.75°-11.99° and 3.96°-9.18° in the early and late groups, respectively) with clockwise rotation of the occlusal plane (95% CI: 3.75°-11.99° and 3.96°-9.18° in the early and late groups, respectively). Treatment duration to level and align and reach Class I buccal occlusion was significantly less in the early group (95% CI: 4.74-10.8 months). Comparison between groups revealed no significant differences for all measurements except MP/SN and PP/SN angles (P < .05). Conclusions: Class II elastics were equally effective and more efficient in the early group with significantly less time needed to level and align and reach Class I buccal occlusion compared to the late group.