Clinical Crown Length Changes and Gingival Recessioa Development in Anterior Teeth Associated with Orthodontic Treatment: A Systematic Review and Meta-Analysis

Abstract

The study aims to retrospectively investigate the clinical crown length changes and the development of gingival recession in the labial aspect of the maxillary and mandibular incisors associated with orthodontic treatment and relate them to the observed changes in their sagittal inclination. Eighty-two consecutive subjects, treated by means of fixed orthodontic appliances in both dental arches, with good quality pre- and post-treatment dental casts and lateral cephalometric radiographs, were selected from the archives of a private orthodontic clinic. Incisor clinical crown length before and after orthodontic treatment, as well as the presence or absence of recession, were measured on digitized study models. Sagittal inclination changes were assessed on lateral cephalometric radiographs and categorized as proclination, retroclination or no change (±1°). Spearman’s correlation coefficient, one-way analysis of variance and chi-square tests were used for analysis. The mean change of clinical crown lengths for the maxillary incisors was from -0.24 to 0.01 mm, and for the mandibular, from 0.06 to 0.10 mm. The inclination changes were -1.78° and 1.03°, respectively, but no correlations were observed with changes in clinical crown length. Overall, no statistically significant differences were observed regarding clinical crown length changes and the presence of gingival recession between proclination, retroclination and no change groups. The change of incisor inclination during treatment did not seem to affect labial clinical crown length increases and gingival recession development in this specific sample.