Changes in the gingival thickness and keratinized gingival width of maxillary and mandibular anterior teeth after orthodontic treatment

Abstract

Objectives To evaluate changes in the gingival thickness (GT) and keratinized gingival width (KGW) of the maxillary and mandibular central and lateral incisors and canines after fixed orthodontic treatment and their association with sagittal tooth movement (STM). Materials and Methods In this study of both arches, 60 periodontally healthy subjects who had completed fixed orthodontic treatment were included. Using pretreatment and posttreatment lateral cephalograms, STM of the maxillary (1-NA angle and distance, and 1-SN angle) and mandibular (1-NB angle and distance, and IMPA angle) incisors were evaluated to divide the subjects into protrusion and retrusion groups. Pretreatment and posttreatment GT was identified via transgingival probing, and KGW was calculated from the free gingival margin to the mucogingival junction. Results The intragroup pretreatment and posttreatment comparison results showed a significant decrease in the GT of the maxillary and mandibular anterior teeth in the protrusion and retrusion groups and a decrease in the KGW of the maxillary lateral incisors in the protrusion group. Pearson correlation coefficient analyses for maxillary and mandibular anterior teeth revealed that the GT changes were not significantly associated with STM. However, a positive correlation existed between the KGW of tooth numbers 13 and 41 and STM. Conclusions STM was not significantly associated with decreased GT of the maxillary and mandibular anterior teeth, but it was positively correlated with the KGW of tooth numbers 13 and 41.

Gingival Margins’ Modifications during Orthodontic Treatment with Invisalign First®: A Preliminary Study

“…A limitation involved in the assessment of gingival margin height is that intraoral photographs did not represent the real size of this variable. Therefore, a lot of studies [ 20 , 23 , 26 ] evaluated gingival modifications including the measurements of clinical crown length (CL) on dental casts. Trentini et al [ 27 ] demonstrated the reliability of photographs and dentals casts for accurate measurements of keratinized tissue width.…”

“…Gingival changes are mainly associated not only with the modifications of teeth bucco-lingual inclinations but also with the derotation and extrusive movements obtained during arch expansion, alignment and leveling of the anterior region. In literature, several studies have assessed gingival margin modifications in permanent dentition before and after fixed appliances revealing that some changes of gingival thickness and keratinized gingival width occurred as a consequence of a better teeth position that allows a different gingival architecture [ 19 , 20 ]. However, to our best knowledge no studies evaluated gingival esthetics in mixed dentition after a Phase 1 interceptive treatment performed only by means of CAT.…”

Long-Term Assessment of Periodontal Tissues after Corticotomy-Assisted Orthodontic Arch Expansion

“…These results seem optimistic compared to those obtained after classical orthodontic treatment. Indeed, a significant reduction in gingival thickness was demonstrated in the region of the maxillary (by 0.15–0.35 mm) and mandibular (by 0.18–0.3 mm) anterior teeth after their displacement in the sagittal plane [ 50 ]. A mean reduction in the KT height of 0.25 mm immediately after conventional treatment has also been reported [ 51 ].…”

“…A mean reduction in the KT height of 0.25 mm immediately after conventional treatment has also been reported [ 51 ]. According to other authors, a significant reduction in KT width occurred only in maxillary lateral incisors after protrusive movement, giving rise to the hypothesis that there is a positive relationship between sagittal tooth displacement and KT width [ 50 ].…”

“…A mean reduction in the KT height of 0.25 mm has also been reported immediately after conventional treatment [ 51 ]. According to other authors, a significant decrease in KT width occurred only with maxillary lateral incisors after protrusive movement, leading to the conclusion that there is a positive relationship between sagittal tooth displacement and KT width [ 50 ]. This thesis was confirmed by Wang et al [ 52 ], who reported that displacement of teeth during orthodontic treatment affects the width of the keratinized gingiva, and an increase in positive torque results in a greater likelihood of reducing the width of the keratinized gingiva.…”