Effectiveness Of Clear Aligners Vs. Fixed Appliances In Complex Orthodontic Cases: A Systematic Review

Abstract

Objective: To systematically compare the efficacy of clear aligners versus fixed appliances for the treatment of complicated orthodontic malocclusions. Methods: Systematic PubMed, Scopus, Embase, Cochrane Library, and Web of Science searches were conducted from 2014 to 2024 for published articles. Randomized controlled trials, prospective/retrospective cohort studies were included which compared clear aligners with fixed appliances in complicated cases (Class II/III malocclusions, severe crowding, deep bites, open bites, and extraction cases). Major outcomes were efficacy of treatment (PAR/ABO scores), treatment length, biological outcomes, and patient satisfaction. Quality of the studies was assessed using the Cochrane Risk of Bias and Newcastle-Ottawa scales. Results: Of 12 qualifying studies (n=1,240 patients), fixed appliances were more effective in complicated tooth movements (mean PAR improvement 92% vs 85%, p=0.02), particularly for molar distalization (15-20% more effective, p<0.05) and vertical control (0.5-1.5mm better bite correction, p<0.001). Clear aligners were as effective in mild-moderate cases but required 45% more refinements (p=0.001) and 3.6 months longer treatment (p=0.003). Patient satisfaction favored aligners (VAS 8.7 vs 6.3, p<0.001), and fixed appliances caused a little more root resorption (1.2mm vs 0.5mm, p=0.04). Conclusions: Fixed appliances remain more indicated for severe malocclusions with complex biomechanics, while clear aligners provide feasible options for less complex cases with improved patient comfort. Treatment options must be case complexity and patient preference dependent as decided by clinicians.