Periodontal status of mandibular central incisors after orthodontic proclination in adults

Abstract

Introduction: Some animal and human studies showed that periodontal recession occurs after incisor proclination, but other authors disagree. The purpose of this study was to assess the periodontal status of mandibular central incisors that were proclined during orthodontic treatment.

Methods: The sample comprised 34 adults who had completed treatment over periods of 7 months to 3 years 11 months. The proclination and vertical movement of these teeth were analyzed by 6 measurements from lateral cephalometric radiographs taken before and after treatment. The thickness and height of the symphysis were recorded from pretreatment lateral cephalometric films. Crowding was determined based on the irregularity index from the initial cast. The following periodontal clinical parameters were assessed: plaque and gingival bleeding indexes, probing pocket depth, clinical levels of attachment, and recession of selected teeth and of the mandibular central incisors. The height of the keratinized tissue and the thickness of the facial gingival margin of these incisors were also measured. The Pearson and Spearman correlation analyses, the Fisher exact test, and the Kruskal-Wallis test were applied.

Results: Statistical analyses showed no correlation between recession and the plaque and gingival bleeding indexes, probing pocket depth, and total quantity of labial movement (P >.05). Recession was negatively correlated with keratinized gingival height and thickness of the facial gingival margin on the mandibular central incisors.

Conclusions: Final inclination (>95 degrees ) and free gingival-margin thickness (>0.5 mm) showed greater and more severe recession on the mandibular central incisors. Nevertheless, when comparing thickness to the final inclination, thickness had greater relevance to recession.