Changes in clinical crown length and the development of gingival recession associated with orthodontic treatment-induced incisor inclination changes: a retrospective cohort study

Abstract

Background/Objectives: Gingival recession results from the displacement of the gingival margin apically to the cementoenamel junction. There is unclear evidence regarding the impact of orthodontic treatment on the development of gingival recessions. The aim of this study was to investigate the changes in clinical crown length and the development of gingival recession on the labial aspect of the maxillary and mandibular incisors associated with orthodontic treatment and relate these changes to the observed variations in their sagittal inclination.

Materials/Methods: Eighty-two consecutive subjects treated with fixed orthodontic appliances in both dental arches, possessing high-quality pre- and post-treatment dental casts and lateral cephalometric radiographs, were selected from the archives of a private orthodontic clinic. Incisor clinical crown lengths before and after orthodontic treatment, as well as the presence or absence of recession, were measured using digitized study models. Changes in sagittal inclination were assessed from 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 utilized for analysis.

Results: The mean change in clinical crown lengths for the maxillary incisors ranged from -0.24 to 0.01 mm, while for the mandibular incisors, it varied from 0.06 to 0.10 mm. The inclination changes were -1.78° and 1.03°, respectively, but no correlations were found between these inclination changes and the clinical crown length alterations. Overall, no statistically significant differences were observed in clinical crown length changes concerning the presence of gingival recession among the proclination, retroclination, and no change groups.

Limitations: The sample of this study was retrospective and assessments were carried out immediately post-treatment.

Conclusions/Implications: The alteration of incisor inclination during treatment did not appear to impact the changes in labial clinical crown length and the development of gingival recession in this specific sample.