Three-dimensional evaluation of the root resorption of maxillary incisors after the orthodontic traction of bicortically impacted canines: case reports

Luis Ernesto Arriola-Guillén,Juan Schilling,Yalil Augusto Rodríguez-Cárdenas,Aron Aliaga-Del Castillo,Heraldo Luis Dias-Da Silveira,Gustavo Armando Ruíz-Mora

doi:10.1186/s40510-019-0267-z

Abstract

BackgroundThe root resorption of the maxillary incisors after the orthodontic traction of impacted canines is a concern for clinicians. The aim of this case series report was to evaluate the root resorption of the maxillary incisors after traction until the occlusal plane of the bicortically impacted canines (placed between the two cortical bones in the middle of the alveolar process) located in a complex position using three-dimensional superimposition. This case series report describes the root resorption of the maxillary incisors after orthodontic traction with NiTi closed coil springs and a heavy anchorage appliance in three cases of bilateral impacted canines located in a complex position (bicortically) near to midline. Cone-beam computed tomographies (CBCTs) were obtained before and after traction. Root resorption in all root surfaces of the maxillary incisors was evaluated with color-coded maps using the ITK-SNAP and the 3D Slicer software to indicate loss of the root surface (in red) or gain of the surface (in blue) and was quantified in millimeters by the superimposition method.ResultsThe root changes mainly occurred in the apical third of the maxillary incisor root and did not exceed 2 mm.ConclusionsRoot resorption of the maxillary incisors after the traction of bicortically impacted canines located in a complex position was observed mainly in the apex region, and the amount of root resorption was smaller than 2 mm in all root surfaces.

Highlights

The root resorption of the maxillary incisors after the orthodontic traction of impacted canines is a concern for clinicians
The root resorption of the maxillary incisors prior to orthodontic treatment can be observed in some cases with impacted canines [11] but is more frequent in this type of impaction because of its unfavorable eruption trajectory compared to that of buccal or palatal impactions [7]
Among the different analyses that can be performed with three-dimensional superimpositions, color-coded maps permit an interactive visual analytic evaluation of surface displacements [22, 24, 27,28,29]. These maps can be applied to evaluate root resorption after the orthodontic traction of impacted canines. The purpose of this case series report was to evaluate the root resorption of maxillary incisors after the traction of bicortically impacted canines located in a complex position through the use of three-dimensional superimposition and color-coded surface maps

Summary

Introduction

The root resorption of the maxillary incisors after the orthodontic traction of impacted canines is a concern for clinicians The aim of this case series report was to evaluate the root resorption of the maxillary incisors after traction until the occlusal plane of the bicortically impacted canines (placed between the two cortical bones in the middle of the alveolar process) located in a complex position using three-dimensional superimposition. The root resorption of the maxillary incisors prior to orthodontic treatment can be observed in some cases with impacted canines [11] but is more frequent in this type of impaction because of its unfavorable eruption trajectory compared to that of buccal or palatal impactions [7]. The prognosis of these maxillary incisors is reserved, keeping them in the mouth may be preferred to preserve the alveolar bone ridge, especially in younger patients [13,14,15,16]

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