Objective:

The objective of this study was to evaluate the effects of the four first premolars extraction compared with a non-extraction treated control group on the lower anterior facial height.

Methods:

Electronic search was conducted on PubMed, Cochrane, Scopus, Lilacs, Scielo, clinical trials, and opengrey.eu databases; only article published in English were included. The eligibility criteria were extraction of four first premolars compared with a non-extraction control group treated with fixed mechanotherapy. Anterior Nasal Spine to Menton (ANS-Me) (mm) was taken as the primary outcome; Frankfurt mandibular plane angle (FMA) and Nasion to Menton (N-Me) were selected as secondary outcomes. Non-randomized Studies-of Intervention (ROBINS-I) tool was used for the quality assessment and risk of bias. Heterogeneity was analyzed using statistical tests, including chi-squared-based Q-statistic, tau-square, and I-squared statistics. Review Manager was used for quantitative assessment and meta-analysis.

Results:

Five retrospective studies were included for quantitative assessment and three were included in the meta-analysis due to certain missing data. Extraction of four first premolars did not affect both primary and secondary outcomes with P = .65, P = .93, and P = .91, respectively, for ANS-Me, FMA, and N-Me.

Conclusion:

This review and meta-analysis concluded that there was no statistically significant effect of extraction of four first premolars on lower anterior facial height.

Search results

Evaluating the Lower Anterior Facial Height in Patients Treated with Extraction Versus Non-extraction Fixed Mechanotherapy: “A Systematic Review and Meta-analysis”