Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Feb;159(2):175-183.e3.
doi: 10.1016/j.ajodo.2019.12.020. Epub 2020 Dec 31.

Three-dimensional evaluation of dental decompensation and mandibular symphysis remodeling on orthodontic-surgical treatment of Class III malocclusion

Michelle Sendyk  1 , Lucia Helena Soares Cevidanes  2 , Antonio Carlos de Oliveira Ruellas  2 , Liana Fattori  3 , Fausto Medeiros Mendes  4 , João Batista de Paiva  3 , José Rino Neto  3
Affiliations

Three-dimensional evaluation of dental decompensation and mandibular symphysis remodeling on orthodontic-surgical treatment of Class III malocclusion

Michelle Sendyk et al. Am J Orthod Dentofacial Orthop. 2021 Feb.

Abstract

Introduction: The purposes of this research were to identify the buccolingual inclinations of the mandibular teeth and the mandibular symphysis remodeling that result from the orthodontic decompensation movement.

Methods: The sample consisted of 30 adults with Class III dentofacial deformity, who had presurgical orthodontic treatment. Three-dimensional images were generated by cone-beam computed tomography scans at 2 different times (initial and before orthognathic surgery). Three-dimensional virtual models were obtained and superimposed using automated voxel-based registration at the mandible to evaluate B-point displacement, mandibular molar and incisor decompensation movement, and symphysis inclination and thickness. The 3-dimensional displacements of landmarks at the symphysis were quantified and visualized with color-coded maps using 3D Slicer (version 4.0; www.slicer.org) software.

Results: The measurements showed high reproducibility. The patients presented mandibular incisor proclination, which was consistent with the movement of tooth decompensation caused by the presurgical orthodontic treatment. Statistically significant correlations were found between the inclination of the mandibular incisors, symphysis inclination, and B-point displacement. Regarding the thickness of the symphysis and the inclination of the incisors, no statistically significant correlation was found.

Conclusions: The buccolingual orthodontic movement of the mandibular incisors with presurgical leveling is correlated with the inclination of the mandibular symphysis and repositioning of the B-point but not correlated to the thickness of the symphysis.

PubMed Disclaimer

Conflict of interest statement

All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest, and none were reported.

Figures

Fig 1.
Fig 1.
Color maps of distances of the T1 and T2 models for a patient that represents this study data. The color map scale is set from −3 to +13 mm. Green color indicates no displacement between models. Red represents the anterior displacement of T2 relative to the T1 model: A, sagittal view; B, coronal view.
Fig 2.
Fig 2.
Image of the mandibular incisor and corresponding alveolar socket.
See this image and copyright information in PMC

References

    1. Pereira-Stabile CL, Ochs MW, de Moraes M, Moreira RW. Preoperative incisor inclination in patients with Class III dentofacial deformities treated with orthognathic surgery. Br J Oral Maxillofac Surg 2012;50:533–6. - PubMed
    1. Sperry TP, Speidel TM, Isaacson RJ, Worms FW. The role of dental compensations in the orthodontic treatment of mandibular prognathism. Angle Orthod 1977;47:293–9. - PubMed
    1. Guedes FP, Capelozza Filho L, Garib DG, Nary Filho H, Borgo EJ, Cardoso Mde A. Impact of orthodontic decompensation on bone insertion. Case Rep Dent 2014;2014:341752. - PMC - PubMed
    1. Molina-Berlanga N, Llopis-Perez J, Flores-Mir C, Puigdollers A. Lower incisor dentoalveolar compensation and symphysis dimensions among Class I and III malocclusion patients with different facial vertical skeletal patterns. Angle Orthod 2013;83:948–55. - PMC - PubMed
    1. McNeil C, McIntyre GT, Laverick S. How much incisor decompensation is achieved prior to orthognathic surgery? J Clin Exp Dent 2014;6:e225–9. - PMC - PubMed