Effects of crown movement on periodontal biotype: a digital analysis

Abstract

Orthodontic treatment has important correlations with periodontal changes. Various mechanical and biological factors are involved in determining such changes, but anatomical and morphological variables, generally addressed as periodontal biotype, play a key role. In measurement of such modifications, digital and non-contact reverse engineering technologies may be of tremendous advantage. The aim of this study is to retrospectively evaluate, in a series of digitized dental casts, some of the parameters addressing periodontal biotype and correlate them to extent and direction of tooth movement. Pre- (T0) and post-treatment (T1) dental casts of 22 patients were scanned by 3Shape TRIOS 3® scanner. A number of variables (crown ratio, gingival margin position, gingival contour, papillae position, gingival scallop) were investigated and their variations calculated after digital measurements on single casts at T0 and T1, or after direct measurement (T1 vs T0) on the superimposition and alignment of digital models. Univariate and multivariate statistics were then performed. No significant correlation was detected between the sagittal or vertical movement of dental crown and displacement of the gingival margin. On the other hand, vestibular gingival contour resulted significantly altered by vestibular and extrusion movements. Further studies are needed to ascertain the differential effect of bone and soft tissue on such modifications. The relationship between orthodontic treatment and the periodontium overcomes the consideration of gingival recession and includes all the concepts of periodontal biotype with its characteristics. Digital technologies and non-contact reverse engineering techniques now available have the potential to allow a more precise definition of such a relationship.

The Influence of Orthodontic Treatment on Periodontal Health between Challenge and Synergy: A Narrative Review

“…In addition, other studies have shown that the antioxidant n acetyl cysteine (NAC) reduces pro-inflammatory cytokine generation in gingival fibroblasts when exposed to lipopolysaccharide, while NAC reduces alveolar bone loss in experimental periodontitis [112,113].…”

Impact of orthodontic correction of dental crowding with pre-molar extraction in the anterior mandible evaluated by cone-beam computed tomography

“…The present study identified that there was a significant increase in the L-CEJ-MBC distance and no significant change in the F-CEJ-MBC distance, illustrating the development of bone dehiscence on the lingual side during the retraction and retroclination movements of the mandibular incisors [ Table 5 ]. Prior studies have also evaluated the effect of the increase in the proclination of the mandibular incisor and the formation of bone dehiscence[ 18 19 20 ]; however, few studies have evaluated the effect of the retroclination of the mandibular incisors in cases treated orthodontically with the extraction of premolars. [ 6 7 ]…”

Effect of gingival biotype on orthodontic treatment-induced periodontal complications: A systematic review

“…Similar to biotype, different methods have been used to evaluate gingival recession. The measurement of the gingival recession on dental casts 29 , 53 could be misleading due to factors, such as extrusion, crown fracture, attrition, or restoration. 54 , 55 Crown length measurement for indirect estimation of gingival recession 8 is also not reliable, as the tooth length might be affected by different factors, such as gingival hyperplasia.…”