Aim: The aim is to systematically review existing evidence from patient records who underwent orthodontic treatment and to compare whether there is a difference in treatment outcome with aligners to fixed mechanotherapy for comprehensive orthodontic treatment. Methods: PRISMA guidelines were used, and PROSPERO (CRD42022365558) registration was done. Four electronic databases (Pubmed, Medline, Scopus and Google Scholar) were searched up to 2020. There were no restrictions on year and publication status. Randomized clinical trials (RCTs) and Cohort study comparing treatment outcomes with aligners and with Fixed mechanotherapy using ABO-OGS parameters were included. Risk of bias was done by Cochrane risk of bias (ROB) -2 and graph was plotted using RevMan software version 5.3. The standardized mean difference (SDM) was used for an overall pooled estimate. Results: Out of initially identified 2277 searches, twelve studies were included in review. Four studies were included for meta-analysis. Based on standard mean difference for objective grading system (OGS) and discrepancy index (DI) the treatment outcome is more favourable for fixed mechanotherapy, and difference is statistically significant (p >0.05). Though the appointment and repair are less for aligners the stability of treatment is satisfactory for fixed mechanotherapy. Conclusions: Treatment outcomes are better in fixed mechanotherapy as compared to clear aligners. ABO DI showed results in favour of aligners in parameters like crowding, buccal posterior crossbites and cephalometric. Whereas majority of parameters favoured ABO OGS score in favour of fixed mechanotherapy except for overjet. However, the treatment duration is more or less same in both the appliances. Clinical Significance: Aligner system has revolutionised dentistry thus the present meta