Anchorage methods and treatment outcomes in the treatment of bimaxillary protrusion: a systematic review and meta-analysis

Aim: This systematic review aimed to identify the most effective anchorage methods producing better skeletal, dental, aesthetic and patient experience outcomes in the treatment of bimaxillary protrusion.

Methods: Electronic databases (Pubmed, Medline, Scopus, and Cochrane library) were searched without language restrictions. Unpublished studies were searched for on clinicaltrials.gov. Search terms included bimaxillary proclination, bimaxillary dentoalveolar protrusion, biprotrusion, bimaxillary prognathism, bimaxillary protrusion, and bidental. Treatment studies on patients with bimaxillary protrusion were included. Relevant articles were assessed for quality according to Cochrane guidelines and the data extracted for statistical analysis. Using predefined forms two authors assessed eligibility for inclusion in the study and any disagreement was discussed. Cochrane Risk of Bias tool was used for quality assessment and GRADE was used to assess the quality of the evidence.

Results: Four studies met the inclusion criteria, while 32 were excluded based on study design and/or no outcome of interest reported. Only three studies were included in the random-effects meta-analysis. There was some evidence to suggest that the use of TADs resulted in less anchorage loss than traditional anchorage techniques (mean difference 2.38 mm; 95% CI, −3.89 to −0.88; P = 0.002). There was a significant difference in treatment duration with use of TADs (mean difference 0.92 months; 95% CI −1.64 to- 0.21; P = 0.01).

Conclusion: There is very low-quality evidence to suggest TADs provide better anchorage and shorter treatment duration in the orthodontic treatment of bimaxillary protrusion.