Document Detail


M/F ratios of four different closing loops: 3D analysis using the finite element method (FEM).
MedLine Citation:
PMID:  17203575     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: It has been claimed that the opus loop is capable of delivering a constant and optimum M/F ratio without the need for gable bends.
OBJECTIVE: To compare the forces, moments and moment/force (M/F) ratios of the opus loop, L-loop, T-loop and vertical helical closing loop (VHC loop) in a segmented arch with the finite element method (FEM).
METHODS: The FEM was used to compare 3D models of closing loops in rectangular (0.016 x 0.022 inch) stainless steel wire. The L-, T- and VHC loops were designed with and without preactivation bends. The opus loop had no preactivation bends. The T-Loops were 10 mm in height and 10 mm in length. The horizontal and vertical forces, the moments and the M/F ratios at the alpha and beta ends were recorded at 0, 0. 1, 0.4, 0.7 and 1 mm intervals.
RESULTS: The highest horizontal and vertical forces were produced by the L-loop (with and without preactivation bends) and in most cases the lowest forces were produced by the VHC loop. Loops with preactivation bends produced marked changes in the M/F ratio and loops without preactivation bends low, but relatively constant, M/F ratios over the full range of activation. Of the loops modelled without preactivation bends the opus and T-loop had the highest M/F ratios (7.20 - 7.67 mm at the anterior ends).
CONCLUSION: Stainless steel opus and T-loops without preactivation bends had constant M/F ratios, but both loops failed to deliver the optimum M/F ratio of 10:1.
Authors:
Mohammad Reza Safavi; Allahyar Geramy; Amir Kamyar Khezri
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Australian orthodontic journal     Volume:  22     ISSN:  0587-3908     ISO Abbreviation:  Aust Orthod J     Publication Date:  2006 Nov 
Date Detail:
Created Date:  2007-01-05     Completed Date:  2007-03-01     Revised Date:  2014-06-27    
Medline Journal Info:
Nlm Unique ID:  1260462     Medline TA:  Aust Orthod J     Country:  Australia    
Other Details:
Languages:  eng     Pagination:  121-6     Citation Subset:  D    
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MeSH Terms
Descriptor/Qualifier:
Biomechanical Phenomena
Computer Simulation
Dental Alloys
Finite Element Analysis*
Humans
Imaging, Three-Dimensional*
Models, Biological
Orthodontic Appliance Design*
Orthodontic Wires*
Stainless Steel
Stress, Mechanical
Surface Properties
Chemical
Reg. No./Substance:
0/Dental Alloys; 12597-68-1/Stainless Steel
Comments/Corrections
Comment In:
Aust Orthod J. 2014 May;30(1):90-1   [PMID:  24968652 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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