Validation of three-dimensional digital model superimpositions based on palatal structures in patients with maximum anterior tooth retraction following premolar extraction

Analysis of Three-Dimensional Tooth Movement: A Comparative Study Between Digital Dental Models and Craniofacial Models

OBJECTIVE

This study aims to validate the efficacy of using a digital dental model (DM) with reference to the palatal region of interest (PROI) for assessing orthodontic tooth movement (TM) by comparing it with the analysis of a computed tomography (CT) model with reference to the cranial region of interest (CROI).

MATERIALS AND METHODS

Thirty-four patients (mean age: 21 years and 11 months) with jaw deformities underwent DM and CT scans before and after presurgical orthognathic treatment. Linear and angular measurements during TM were conducted in three dimensions using both DM and CT to assess reliability.

RESULTS

DM analysis with PROI registration exhibited high levels of reproducibility, with minimal standard errors in X, Y, and Z displacements (<0.15 mm) and 0.43 degrees in angular change. CT analysis with CROI registration demonstrates similarly high reproducibility, with standard errors inferior to DM analysis (<0.20 mm). Bland-Altman analysis indicated agreement in linear changes of each X, Y, and Z displacement between DM and CT measurements, with limits of agreement (LOA) below 0.91 mm.

CONCLUSIONS

The results of this study suggest that the PROI, focusing on the third palatal rugae and the horizontal part of the palatal vault, serves as a reliable reference region for evaluating three-dimensional (3D) tooth movement.

CLINICAL SIGNIFICANCE

Digital dental models offer distinct advantages including the absence of X-ray exposure, no metal artifacts, and the ability to generate high-resolution 3D models. The methodology demonstrated high precision and reproducibility, supporting its potential clinical utility in orthodontic treatment planning and assessment.

Superimposition of virtual models using palatal rugae and maximum habitual intercuspation

INTRODUCTION

The superimposition of 3 dimensions (3D) digital models has been increasingly used for evaluating dental changes resulting from orthodontic treatment, and different superimposition techniques have been described. Although the maxilla has areas with greater stability for superimposition, such as the palatal rugae, there is still no reliable method for superimposing models of the lower arch.

OBJECTIVE

Therefore, this article aims to describe a technique for superimposing virtual models.

METHODS

To evaluate pre- and post-orthodontic treatment changes, the Geomagic Qualify 2013 software (3D Systems®, Rock Hill, South Carolina, USA) was used, with reference points in the maxilla, including the rugae and a reference area in the palate and midpalatal raphe. The lower arch was superimposed using the maximum habitual intercuspation (MHI) model as reference.

RESULTS AND CONCLUSION

3D models superimposition using palatal rugae and MHI occlusion seems to offer satisfactory results in the interpretation of clinical changes at different follow-up moments in terms of development and/or orthodontic treatment.

Accuracy and reliability of mandibular digital model superimposition based on the morphological characteristics of vessels in extraction adult patients

BACKGROUND

This study aimed to validate the availability of superimposing full-color mandibular digital models (DMs) by the morphological characteristics of vessels in extraction adult patients.

METHODS

Twenty-eight adult patients were included, and their DMs were superimposed with pre- and posttreatment cone beam computed tomography (CBCT) and the morphological characteristics of lingual vessels. The measurements of each tooth were compared under the same coordinate system.

RESULTS

The ICC results displayed exceptional agreement in intra- and interrater assessments, with scores exceeding 0.891 in the crown for intrarater agreement and scores surpassing 0.888 in the crown for interrater agreement. Furthermore, no statistically significant differences were found in the 2 superimposition methods (P > 0.05).

CONCLUSION

The morphological characteristics of vessels under the mucogingival junction in the lingual side of mandible of are stable enough for the superimposition of mandibular DMs in the adult patients undergo orthodontic treatment with premolars extraction.

Comparison between 2D cephalometric and 3D digital model superimpositions in patients with lateral incisor agenesis treated by canine substitution

INTRODUCTION

This study aimed to assess the reliability of measurements obtained after superimposing 3-dimensional (3D) digital models by comparing them with those obtained from lateral cephalometric radiographs in patients with lateral agenesis space closure by mesialization.

METHODS

Data were collected from premaxillary and postmaxillary dental casts and lateral cephalometric radiographs of 26 patients presenting lateral incisor agenesis and treated with rapid maxillary expanders and space closure by mesialization of the lateral sectors. Sagittal and vertical movements of the incisors and the maxillary molars were evaluated with lateral cephalometric radiographs and digitized 3D models superimposed on the palatal area. Paired sample t tests were used to determine if any significant difference existed between the 2 measuring techniques and between 2 different localizations of superimpositions.

RESULTS

Cephalograms and 3D digital model measurements were statistically similar in molars and incisor movements according to anteroposterior and vertical planes. Regarding incisor movements in the anteroposterior plane, measurements derived from second ruga 3D models were significantly greater than those derived from third ruga 3D digital models.

CONCLUSIONS

The 3D model superimposition method using the palate as a reference area is clinically reliable for assessing anteroposterior and vertical tooth movement as cephalometric superimposition in patients treated with rapid maxillary expanders and space closure by mesialization.