Mechanical responses of maxillary canine and surrounding tissues under orthodontic loading: a non-linear three-dimensional finite element analysis

Choi

J of Oral Rehabilitation

et al. 2018

Section: Methodsmentioning

confidence: 99%

Biomechanical effect of mandibular advancement device with different protrusion positions for treatment of obstructive sleep apnoea on tooth and facial bone: A finite element study

Choi

J of Oral Rehabilitation

et al. 2018

“…At the same time, a hyperelastic law was used to simulate large non-linear strains associated with the non-linear nature of PDLs [42]. A 2nd-order Ogden model was used to define the strain energy function [43][44][45]. The parameter values listed in Table 2 were obtained through the fitting of uniaxial experimental data by Natali et al [46].…”

Section: Methodsmentioning

confidence: 99%

Comparison of the Effects Caused by Three Different Mandibular Advancement Devices on the Periodontal Ligaments and Teeth for the Treatment of Osa: A Finite Element Model Study

et al. 2020

AIM: The purpose of this study is to compare the stress effects developed on the periodontal ligaments and teeth by three different types of mandibular advancement devices (MADs) using a finite element method (FEM) analysis. Introduction: Obstructive sleep apnea (OSA) is a disease with a high prevalence and, in recent years, the use of MADs as an alternative or support treatment to the continuous positive airway pressure (CPAP) has spread. Their use finds relative contraindications in the case of partial edentulism and severe periodontal disease. Given the widespread of periodontal problems, it is essential to know the effects that these devices cause on the periodontal ligament of the teeth. Materials and methods: Starting from the computed tomography (CT) scan of a patient’s skull, 3D reconstructions of the maxilla and mandible were implemented. Three different MADs were prepared for the patient, then 3D scanned, and lastly, coupled with the 3D models of the jaws. The devices have two different mechanics: One has a front reverse connecting rod (OrthoapneaTM), and two have lateral propulsion (SomnodentTM and HerbstTM). A FEM analysis was performed to calculate the stress applied on periodontal ligaments, on every single tooth and the displacement vectors that are generated by applying an advancement force on the mandible. Results: HerbstTM and SomnodentTM devices present very similar stress values, mainly concentrated on lateral teeth, but in general, the forces are very mild and distributed. The maximum stresses values are 3.27 kPa on periodontal ligaments and 287 kPa on teeth for SomnodentTM and 3.56 kPa on periodontal ligaments and 302 kPa on teeth for HerbstTM. OrthoapneaTM has, instead, higher and concentrated stress values, especially in the anterior maxillary and mandibular area with 4.26 kPa and 600 kPa as maximum stress values, respectively, on periodontal ligaments and teeth. Conclusions: From the results, it is concluded that devices with a bilateral mechanism generate less and more distributed stress than an anterior connecting rod mechanism. Therefore, they may be advisable to patients with compromised periodontal conditions in the anterior area.

European J Oral Sciences

“…The tooth movement induced using the method described by King et al . results in a tipping motion, which makes it more difficult to identify the tension and compressive sides . In addition, the rat M1 contains five roots, which complicates the identification of the same locations across all the samples.…”

Section: Methodsmentioning

confidence: 99%

Stress overload‐induced periodontal remodelling coupled with changes in high mobility group protein B1 during tooth movement: an in‐vivo study

Zou

Lin

2019

High mobility group protein B1 (HMGB1), a bone‐active cytokine and an osteocyte alarmin, might have dual functions in bone metabolism that could benefit bone formation and accelerate osteoclastogenic activity. High mobility group protein B1 was recently shown to be involved in tooth movement. Here, we investigated the expression of HMGB1, which remains poorly elucidated, under stress overload‐induced periodontal remodelling conditions in vivo. Thirty‐six Sprague‐Dawley rats (male, 180–200 g) were randomly divided into three groups: two experimental groups, in which 50 or 100 g of force was applied to the first molars for 7 d to induce movement; and one control group, in which no force was applied. These stresses induced tooth movement over significantly different distances, and marked morphological changes were consistently observed in the periodontal tissues of the experimental rats, as demonstrated by histological staining. A real‐time PCR analysis showed upregulation of the receptor activator of nuclear factor‐kappaB ligand‐to‐osteoprotegerin ratio and downregulation of the Hmgb1 gene. Changes in both location and expression of the HMGB1 were observed through immunofluorescence analysis. Our data suggest that HMGB1 expression during orthodontic tooth movement might be regulated in a time‐ and force‐dependent manner that is substantially more complex than anticipated.