For this systematic review, which was registered beforehand in PROSPERO (CRD42016053492), we synthesized evidence from existing randomized clinical trals on humans to see which treatment is most effective for the esthetic rehabilitation of dental fluorosis, the prevalence of which is seeing a worldwide steady increase. We found that resin infiltration seems to be the most effective treatment approach for lesions of mild to moderate severity, followed by bleaching, and finally microabrasion. Our study's strengths are its a priori registration, wide search, quality check according to Cochrane guidelines, and the use of a new robust analytic method to provide valid clinical recommendations according to the principles of evidence-based medicine.

Purpose Orthodontic treatment involving premolar extractions might improve the angulation of lower third molars, which are the teeth most often impacted. This study analyzes the impact of first/second lower premolar extraction during orthodontic therapy on the angulation of mandibular third molars. Methods A total of 120 patients treated non-extraction (n = 40), with extraction of first (n = 40), or second lower premolars (n = 40) were included. The mesiodistal angulation of lower third molars relative to the adjacent tooth and their developmental stage were evaluated from posttreatment orthopantomograms. Between-group differences were statistically evaluated at a significance level of 0.05. Results The orthopantomograms of 120 patients (51% female) with a median age of 15.2 years at the time of debonding were evaluated after a mean treatment duration time of 2.9 years. No difference (P > 0.05) was seen between the average angulation of the lower third molars of the right (mean = 24.4°, standard deviation [SD] 13.6°) and the left side (mean = 23.6°, SD 14.1°). No differences in the angulation of the lower third molar were found between the non-extraction and extraction groups for the right (P = 0.44) or the left side (P = 0.22). Likewise, no differences were found when comparing the first and second premolars for the right (P = 0.26) or the left side (P = 0.10). Premolar extraction was associated with an advanced root development stage of the right third molar (odds ratio 7.1; 95% confidence interval 1.1–48.1; P = 0.04), with no differences between extraction of the first or second premolar (P = 0.10). Conclusion Orthodontic treatment involving premolars extractions might be associated with a small acceleration in root development, but not with the angulation, of lower third molars.