scholarly journals Relationship between the angulation of temporary anchoring devices and their displacement. Experimental study

2021 ◽  
Vol 31 (1) ◽  
pp. 10-18
Author(s):  
AB Piacenza ◽  
◽  
GD Peralta ◽  
MR Rocamundi ◽  
VB Fumero ◽  
...  
Keyword(s):  
Experimental Study ◽  
Cortical Bone ◽  
Opposite Direction ◽  
Insertion Angle ◽  
Mini Implants ◽  
The Stability ◽  
Micro Implants ◽  
The Sacrifice ◽  
Digital Caliper

The purpose of this study is to assess how the insertion angle influence the stability mini-implant when loaded with 200cNe in this study, 2mini-screws were implanted in male rabbits’ (n=25) tibia in a 6weeks interval between the firstone and the second one. The second mini-implants were placed at different angles with respect to the cortical bone: -20° in the direction of the force e (GroupI), perpendicular to the force (GroupII) and 30° in the opposite direction of the force (GroupIII). These experimental implants were immediately loaded (right tibias). The Tad`s on the left tibias were regarded as control. The animals were sacrificed six weeks after the first surgery. Linear distances between the two Tad`s were measured with a digital caliper at the time of placement, and after the sacrifice, then were compared. The displacements were: GroupI, 2.96mm ±1.05; GroupII, 0.27mm ±0.36; and GroupIII, 0.29 mm ±0.26. The controls remained. The values for the micro-implants of GroupI showed statistically significant differences (p≤0.05) compared to GroupsII y III. Based on these data, we can conclude that mini-implants inclined towards the direction of the force applied induce more displacement than the ones placed perpendicular to theforce or in the opposite direction of the force

scholarly journals An evaluation of insertion sites for mini-implants

2012 ◽  
Vol 83 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Morten G. Laursen ◽  
Birte Melsen ◽  
Paolo M. Cattaneo
Keyword(s):  
Maxillary Sinus ◽  
Cortical Bone ◽  
Cortical Thickness ◽  
Anterior Region ◽  
Lateral Region ◽  
Insertion Angle ◽  
Mini Implants ◽  
Bone To Implant Contact ◽  
Insertion Sites ◽  
The Impact

ABSTRACT Objective: (1) To report the thickness of the cortical bone in insertion sites commonly used for orthodontic mini-implants, (2) to assess the impact of a change in insertion angle on primary cortical bone-to-implant contact, and (3) to evaluate the risk of maxillary sinus perforation. Materials and Methods: At autopsy, 27 human samples containing three to five adjacent teeth were excised and scanned using a table-top micro-computed tomography system. Bone thickness measurements were taken at 45° and 90° to the long the axis of the adjacent teeth, simulating a mini-implant insertion at the mid-root level. Results: In the maxilla, the overall mean cortical thickness at 90° was 0.7 mm buccally in the lateral region, 1.0 mm buccally in the anterior region, and 1.3 mm palatally. In the mandible, the mean cortical thickness was 0.7 mm buccally and 1.8 mm lingually in the anterior region; 1.9 mm buccally and 2.6 mm lingually in the lateral region. Changing the insertion angle from 90° to 45° increased the cortical bone-to-implant contact by an average of 47%. Perpendicular insertion at the mid-root level only rarely interfered with the sinus, whereas apically inclined insertion increased the risk of sinus perforation. Conclusions: Buccally and palatally in the maxilla and buccally in the anterior mandible, the thickness of the alveolar cortical bone is often less than 1 mm. In contrast, the alveolar cortical bone is frequently thicker than 2 mm laterally in the mandible. Changing the insertion angle to 45° will generally enhance implant stability but increase the risk of perforation to the maxillary sinus.

scholarly journals Insertion angle of orthodontic mini-implants and their biomechanical performance: finite element analysis

2015 ◽  
Vol 44 (5) ◽  
pp. 273-279 ◽  
Author(s):  
Vinícius de Oliveira Rossi Arantes ◽  
Cassia Belloto Corrêa ◽  
Nadia Lunardi ◽  
Rodolfo Jorge Boeck Neto ◽  
Rubens Spin-Neto ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
South Korea ◽  
Cortical Bone ◽  
Elastic Deformation ◽  
Cancellous Bone ◽  
Element Analysis ◽  
Insertion Angle ◽  
Mini Implants ◽  
Resistance To Deformation

AbstractObjectiveThe aim of this study was to assess the stresses and strains generated after the application of two types of forces (traction of 200 gf and torsion of 20 N.cm) in two types of orthodontic mini-implants inserted at different (45° and 90° to the cortical bone) angles.Material and methodthree-dimensional models of two brands of mini-implant (SIN – Sao Paulo, Brazil, and RMO – South Korea) were exported and analyzed by finite element analysis (FEA). Analyses were performed on simulations of cortical bone, cancellous bone and the screw.ResultFEA analysis showed that RMO mini-implants had greater elastic deformation when subjected to tensile and torsional forces when compared with SIN mini-implants. For both trademarks and insertion angles tested, there was greater cortical bone deformation, but with the greatest strain located on the mini-implant. Tension on the mini-implant was located in its transmucosal profile region.ConclusionWhen comparing the two brands of mini-implants by FEA, it is fair to conclude that that the larger number of threads and their greater angle of inclination resulted in less resistance to deformation and induced a higher level of tension in the mini-implant and cortical bone when subjected to forces, especially when inserted at an angle of 45º to the cortical bone.

scholarly journals Effect of insertion angle on the stability of orthodontic mini‑implants in a rabbit tibia model: A finite element analysis

2019 ◽  
Vol 87 (2) ◽  
Author(s):  
Víctor M. Araujo-Monsalvo ◽  
Mercy G. González-Aréas ◽  
Elisa Martínez-Coria ◽  
Enrique Flores-Cuamatzi ◽  
Benjamín Araujo-Monsalvo ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Analysis ◽  
Insertion Angle ◽  
Mini Implants ◽  
Rabbit Tibia ◽  
The Stability

scholarly journals Influence of the growth pattern on cortical bone thickness and mini-implant stability

2020 ◽  
Vol 25 (6) ◽  
pp. 33-42
Author(s):  
Carolina Carmo de Menezes ◽  
Sérgio Estelita Barros ◽  
Diego Luiz Tonello ◽  
Aron Aliaga-Del Castillo ◽  
Daniela Garib ◽  
...  
Keyword(s):  
Success Rate ◽  
Cortical Bone ◽  
Cortical Thickness ◽  
Growth Pattern ◽  
Alveolar Bone ◽  
Insertion Site ◽  
Bone Thickness ◽  
Cortical Bone Thickness ◽  
Mini Implants ◽  
The Stability

ABSTRACT Introduction: Controversial reports suggest a relationship between growth pattern and cortical alveolar bone thickness, and its effect in the use of mini-implants. Objective: The main purpose of this study was to assess the influence of the growth pattern on the cortical alveolar bone thickness and on the stability and success rate of mini-implants. Methods: Fifty-six mini-implants were inserted in the buccal region of the maxilla of 30 patients. These patients were allocated into two groups, based on their growth pattern (horizontal group [HG] and vertical group [VG]). Cortical thickness was measured using Cone Beam Computed Tomography. Stability of mini-implants, soft tissue in the insertion site, sensitivity during loading and plaque around the mini-implants were evaluated once a month. Intergroup comparisons were performed using t tests, Mann-Whitney tests, and Fisher exact tests. Correlations were evaluated with Pearson’s correlation coefficient. Results: The cortical bone thickness was significantly greater in the HG at the maxillary labial anterior region and at the mandibular buccal posterior and labial anterior regions. There was a significant negative correlation between Frankfort-mandibular plane angle (FMA) and the labial cortical thickness of the maxilla, and with the labial and lingual cortical bone thicknesses of the mandible. No significant intergroup difference was found for mini-implant mobility and success rate. No associated factor influenced stability of the mini-implants. Conclusions: Growth pattern affects the alveolar bone cortical thickness in specific areas of the maxilla and mandible, with horizontal patients presenting greater cortical bone thickness. However, this fact may have no influence on the stability and success rate of mini-implants in the maxillary buccal posterior region.

Effect of cortical bone thickness and density on pullout strength of mini-implants: An experimental study

2020 ◽  
Vol 157 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Fatma Kübra Erbay Elibol ◽  
Emre Oflaz ◽  
Emine Buğra ◽  
Metin Orhan ◽  
Teyfik Demir
Keyword(s):  
Experimental Study ◽  
Cortical Bone ◽  
Pullout Strength ◽  
Bone Thickness ◽  
Cortical Bone Thickness ◽  
Mini Implants

A simulation apparatus for the experimental study of batch reactor control methods

1986 ◽  
Vol 51 (6) ◽  
pp. 1259-1267
Author(s):  
Josef Horák ◽  
Petr Beránek
Keyword(s):  
Experimental Study ◽  
Closed Loop ◽  
Dynamic Properties ◽  
Batch Reactor ◽  
Exothermic Reaction ◽  
Electric Heating ◽  
Batch Reactors ◽  
Exchange Area ◽  
The Stability ◽  
Methods Of Control

A simulation apparatus for the experimental study of the methods of control of batch reactors is devised. In this apparatus, the production of heat by an exothermic reaction is replaced by electric heating controlled by a computer in a closed loop; the reactor is cooled with an external cooler whose dynamic properties can be varied while keeping the heat exchange area constant. The effect of the cooler geometry on its dynamic properties is investigated and the effect of the cooler inertia on the stability and safety of the on-off temperature control in the unstable pseudostationary state is examined.

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