One phase or two phase orthodontic treatment for Class II division 1 malocclusion ?

Area of Science:

• Orthodontics and Dental Research
• Craniofacial Development and Malocclusion Studies

Background:

• Class II malocclusion, characterized by prominent upper front teeth, affects children and adolescents.
• Treatment timing (early vs. late) for Class II malocclusion is a critical consideration in orthodontic practice.
• The efficacy of different orthodontic appliances and treatment phases requires systematic evaluation.

Purpose of the Study:

• To systematically review randomized clinical trials comparing early (two-phase) versus late (one-phase) orthodontic treatment for Class II malocclusion in children and adolescents.
• To assess the impact of treatment timing and appliance type on outcomes such as overjet, ANB angle, and incisal trauma.
• To compare orthodontic interventions against no treatment or alternative appliance types.

Main Methods:

• Systematic review of randomized clinical trials sourced from multiple electronic databases (Cochrane, MEDLINE, Embase, ClinicalTrials.gov, WHO ICTRP).
• Inclusion criteria focused on children/adolescents with Class II malocclusion, comparing early vs. late treatment, or active treatment vs. no treatment/other appliances.
• Data extraction and synthesis involved independent assessment of bias, using odds ratios (ORs) for dichotomous outcomes (incisal trauma) and mean differences (MDs) for continuous outcomes (overjet, ANB angle).

Main Results:

• Early two-phase treatment with functional appliances or headgear significantly reduced the incidence of incisal trauma compared to late one-phase treatment (OR 0.56, 95% CI 0.33-0.95; OR 0.45, 95% CI 0.25-0.80, respectively).
• While early treatment initially improved overjet and ANB angle, final cephalometric outcomes showed no statistically significant difference between early and late treatment groups.
• Late orthodontic treatment with functional appliances demonstrated effectiveness in reducing overjet (MD -5.46 mm) and ANB angle (MD -2.37°) compared to no treatment.

Conclusions:

• Low to moderate quality evidence suggests early orthodontic treatment (two-phase) is more effective in reducing incisal trauma for prominent front teeth than a single late treatment phase.
• No significant additional benefits were observed for early treatment regarding final overjet or cephalometric measurements compared to late treatment.
• Late adolescent treatment utilizing functional appliances is effective in correcting prominent upper front teeth when compared to no intervention.