Comparative Analysis of Skeletal Changes, Occlusal Changes, and Palatal Morphology in Children with Mild Class III Malocclusion Treated with Elastodontic Appliances and Bimaxillary Plates

Abstract

Background: The aim of the present study was to compare the changes observed in children after the early treatment of mild class III malocclusion using bimaxillary removable plates supported by class III elastics and elastodontic devices.

Methods: Twenty children (mean age 7.6 ± 1.1 years) with signs of class III malocclusion were treated using by-maxillary plates (PG group) with class III elastics (10 subjects = mean age 7.9 ± 1.3 years) or using class III elastodontic devices (EG group) (10 subjects = mean age 7.4 ± 0.8 years). Digital models and lateral cephalograms were obtained before treatment (T0) and at the end of treatment (T1). The digital models were analyzed to assess occlusal changes and maxillary morphology using the surface-to-surface matching technique. Changes in cephalometric parameters were also analyzed. The data outcomes were statistically analyzed using the paired Student's t test for inter-timing assessments and the independent Student's t test for inter-group assessments.

Results: Both groups showed correction of class III malocclusions, with a significant increase in the ANB angle and the overjet (p < 0.05). Subjects in the PG group exhibited a greater reduction in the inter-incisal angle compared to the EG group (p < 0.05). The children in the EG group had a significantly lower percentage of palatal morphology matching between T0 and T1 compared to the PG group (p < 0.05), suggesting greater morphological changes in the palate.

Conclusions: Elastodontic appliances (EAs) and bi-maxillary plates successfully correct class III malocclusions in children. However, elastodontic devices significantly improved the morphology of the palate, both in the transverse and anteroposterior directions.

Keywords: children; class III malocclusion; digital orthodontics; early treatment; interceptive orthodontics.

Figure 1

Appliances tested for the purpose of the present study. (A) Bi-maxillary plates with class III elastics and (B) the class III elastodontic device.

Figure 2

The digital models were imported into 3-Matic software to perform linear occlusal measurements: (A) overjet calculation and (B) overbite calculation.

Figure 3

Digital process involved for the surface analysis of the palate. (A) T0 (gray) and T1 (light blue) maxillary models (3-Matic software); (B) generation of the median palatal plane (MPP) using two points respectively located on the median palatal raphe adjacent to the second ruga and 1 cm distal to the first point (3-Matic software); (C) superimposition between T0m and T1 maxillary models using MPP as reference plane (3-Matic software); (D) segmentation of the palate excluding dentition (MeshMixer software version 3.5); (E) final digital palatal model (MeshMixer software).

Figure 4

Deviation analysis and calculation of the percentage of matching between T0 and T1 maxillary models for both PG and EG groups. The RGB colored scale bar (millimeters) is shown on the right: the upper (red) and lower (blue) parts of the scale indicate the maximum positive and negative deviations. Green indicates the tolerance range, set to 0.5 mm.

Figure 5

Example of analysis of sagittal discrepancy. (A) Cephalometric examination analysis performed on a latero-lateral cephalogram and (B) extra-oral right profile photograph.