Finite Element Method (FEM) Analysis of Dentoskeletal Changes on Temporary Anchorage Device (TAD)-Assisted Mandibular Advancement.

Abstract

Objective: Temporary anchorage devices (TADs) enhance the efficiency of fixed functional appliances (FFAs) by providing stable anchorage, improving skeletal and dental corrections, optimizing vertical control, and enhancing treatment outcomes for Class II and III malocclusions. TADs also help prevent the proclination of the lower incisors and the distalization of the molars, which are commonly observed with FFAs lacking skeletal anchorage. This study aims to analyze the displacement and stress distribution patterns generated in craniofacial structures and dentition using conjoined implants and intermaxillary elastics for growth modification in growing Class II patients.

Methods: Finite element analysis was conducted using cone-beam computed tomography data from an 11-year-old patient with Class II Division 1 malocclusion. Mini-implants and miniplates were designed and assembled in SolidWorks, meshed using HyperMesh, and analyzed in Abaqus 6.14 to evaluate stress and displacement patterns under a 450 g orthopedic force applied via Class II elastics.

Results: In the mandible, the highest principal and von Mises stresses were observed on the posterior surface of the ramus, whereas in the maxilla, stress concentrations were noted lateral to the nasal aperture. Additional stress concentrations were identified in the region posterior to the glenoid fossa. The mandible was displaced anteroinferiorly as a whole, while the maxilla exhibited posterosuperior displacement. Dental movements included maxillary expansion with intrusion of the anterior teeth, and anterior displacement of the mandibular dentition, primarily resulting from bodily movement.

Conclusion: The use of Class II elastics in combination with Temporary Anchorage Devices (TADs) produces greater stress and displacement in skeletal structures compared to the dentition. As a result, this treatment approach is more likely to produce substantial skeletal changes than dental alterations.