Intrusion of overerupted periodontally compromised posterior teeth using orthodontic mini implants: A mechanobiological finite element study.

Autor: Ugarte OM; School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil., Cattaneo PM; Melbourne Dental School, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia., Roscoe MG; School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil., Gialain IO; School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil., Dominguez GC; School of Dentistry, Department of Orthodontics and Pediatric Dentistry, University of São Paulo, São Paulo, Brazil., Ballester RY; School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil., Meira JBC; School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil.
Jazyk: angličtina
Zdroj: Orthodontics & craniofacial research [Orthod Craniofac Res] 2023 May; Vol. 26 (2), pp. 239-247. Date of Electronic Publication: 2022 Sep 08.
DOI: 10.1111/ocr.12606
Abstrakt: Introduction: The intrusion of posterior teeth had been considered challenging up to the development of orthodontic mini implants. In periodontally compromised teeth, the challenge is even greater, because of the root resorption risk due to periodontal ligament over-compression. Still, the precise strategy to determine the force reduction level remains uncertain.
Objective: The objective of the study was to determine, by a finite element analysis (FEA), the force reduction needed to avoid root resorption and maintain the efficiency of orthodontic mechanics of periodontally compromised teeth similar to the sound one.
Methods: An anatomical model was constructed representing a premolar inserted into a maxillary bone. Based on the initial model (R0), three bone height loss conditions were simulated (R2 = 2 mm, R4 = 4 mm, and R6 = 6 mm). Two intrusive movements were simulated: pure intrusion (bilateral mini implant) and uncontrolled-tipping intrusion (buccal mini implant). The hydrostatic stress at the periodontal ligament was used to evaluate the risk of root resorption due to over-compression.
Results: For bilateral mini implant intrusion, the force had to be decreased by 16%, 32% and 48% for R2, R4 and R6, respectively. For buccal mini implant intrusion, the required reductions were higher (20%, 36% and 56%). A linear relationship between the intrusive force reduction and the alveolar bone height loss was observed in both intrusion mechanics.
Conclusions: According to the FE results, 8% or 9.3% of force reduction for each millimetre of bone height loss is suggested for intrusion with bilateral or buccal mini implant, respectively. The buccal mini implant anchorage must be associated with a supplemental strategy to avoid buccal crown tipping.
(© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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