Accuracy of Orthodontic Force and Tooth Movement Measurements

1996 ◽  
Vol 23 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Dan Lundgren ◽  
Py Owman-Moll ◽  
Jüri Kurol ◽  
Birgit Mårtensson
Keyword(s):  
Tooth Movement ◽  
Mean Value ◽  
Measurement Methods ◽  
Calibration Data ◽  
Force Measurements ◽  
Accuracy Of Measurement ◽  
Measuring Machine ◽  
Initial Force ◽  
Level Of Agreement

This study was designed to test the accuracy of measurement methods for assessment of force and tooth movement in orthodontic procedures. Daily in vivo measurements of the force produced by activated archwires showed that the initial force declined substantially (by 20 per cent of mean value) within 3 days. Both the ‘trueness’ (validity) and precision of the force measurements, obtained with a strain gauge, were found to be high (SD values were 1·0 cN and 0·4 cN, respectively). Horizontal tooth movements were measured with three different instruments: a slide calliper, a co-ordinate measuring machine, and laser measuring equipment based on holograms. There was a good level of agreement between these methods. This was also confirmed by calibration data. The precision of the methods was (SD values) 0·06, 0·07, and 0·13 mm, respectively. The benefits of the use of the co-ordinate measuring machine are obvious, since it can measure tooth movements in relation to reference planes in all directions.

Reliability of a Single β-Thromboglobulin Measurement in a Diabetic Population : Importance of PGE1 in Anticoagulant Mixture

1987 ◽  
Vol 57 (02) ◽  
pp. 201-204 ◽  
Author(s):  
P Y Scarabin ◽  
L Strain ◽  
C A Ludlam ◽  
J Jones ◽  
E M Kohner
Keyword(s):  
In Vitro Release ◽  
Mean Value ◽  
Reliable Estimate ◽  
Diabetic Patients ◽  
Single Measurement ◽  
Diabetic Population ◽  
The Difference ◽  
Vitro Release

SummaryDuring the collection of samples for plasma β-thromboglobulin (β-TG) determination, it is well established that artificially high values can be observed due to in-vitro release. To estimate the reliability of a single β-TG measurement, blood samples were collected simultaneously from both arms on two separate occasions in 56 diabetic patients selected for a clinical trial. From each arm, blood was taken into two tubes containing an anticoagulant mixture with (tube A) and without (tube B) PGE!. The overall mean value of B-TG in tube B was 1.14 times higher than in tube A (p <0.01). The markedly large between-arms variation accounted for the most part of within-subject variation in both tubes and was significantly greater in tube B than in tube A. Based on the difference between B-TG values from both arms, the number of subjects with artifically high B-TG values was significantly higher in tube B than in tube A on each occasion (overall rate: 28% and 14% respectively). Estimate of between-occasions variation showed that B-TG levels were relatively stable for each subject between two occasions in each tube. It is concluded that the use of PGEi decreases falsely high B-TG levels, but a single measurement of B-TG does not provide a reliable estimate of the true B-TG value in vivo.

scholarly journals In vivo calibration of the T2* cardiovascular magnetic resonance method at 1.5 T for estimation of cardiac iron in a minipig model of transfusional iron overload

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Peter Diedrich Jensen ◽  
Asbjørn Haaning Nielsen ◽  
Carsten Wiberg Simonsen ◽  
Ulrik Thorngren Baandrup ◽  
Svend Eggert Jensen ◽  
...  
Keyword(s):  
Rank Correlation ◽  
Calibration Data ◽  
Iron Loading ◽  
Spearman Rank Correlation ◽  
Calibration Equation ◽  
Spearman Rank ◽  
Cardiac Iron ◽  
In Vivo Calibration ◽  
Spearman Rank Correlation Coefficient

Abstract Background Non-invasive estimation of the cardiac iron concentration (CIC) by T2* cardiovascular magnetic resonance (CMR) has been validated repeatedly and is in widespread clinical use. However, calibration data are limited, and mostly from post-mortem studies. In the present study, we performed an in vivo calibration in a dextran-iron loaded minipig model. Methods R2* (= 1/T2*) was assessed in vivo by 1.5 T CMR in the cardiac septum. Chemical CIC was assessed by inductively coupled plasma-optical emission spectroscopy in endomyocardial catheter biopsies (EMBs) from cardiac septum taken during follow up of 11 minipigs on dextran-iron loading, and also in full-wall biopsies from cardiac septum, taken post-mortem in another 16  minipigs, after completed iron loading. Results A strong correlation could be demonstrated between chemical CIC in 55 EMBs and parallel cardiac T2* (Spearman rank correlation coefficient 0.72, P < 0.001). Regression analysis led to [CIC] = (R2* − 17.16)/41.12 for the calibration equation with CIC in mg/g dry weight and R2* in Hz. An even stronger correlation was found, when chemical CIC was measured by full-wall biopsies from cardiac septum, taken immediately after euthanasia, in connection with the last CMR session after finished iron loading (Spearman rank correlation coefficient 0.95 (P < 0.001). Regression analysis led to the calibration equation [CIC] = (R2* − 17.2)/31.8. Conclusions Calibration of cardiac T2* by EMBs is possible in the minipig model but is less accurate than by full-wall biopsies. Likely explanations are sampling error, variable content of non-iron containing tissue and smaller biopsies, when using catheter biopsies. The results further validate the CMR T2* technique for estimation of cardiac iron in conditions with iron overload and add to the limited calibration data published earlier.

scholarly journals Interaction of periodontitis and orthodontic tooth movement—an in vitro and in vivo study

2021 ◽  
Author(s):  
Birgit Rath-Deschner ◽  
Andressa V. B. Nogueira ◽  
Svenja Beisel-Memmert ◽  
Marjan Nokhbehsaim ◽  
Sigrun Eick ◽  
...  
Keyword(s):  
Alveolar Bone ◽  
Tooth Movement ◽  
Mechanical Strain ◽  
Orthodontic Tooth Movement ◽  
Fusobacterium Nucleatum ◽  
In Vivo Study ◽  
Rt Pcr ◽  
Periodontal Inflammation

Abstract Objectives The aim of this in vitro and in vivo study was to investigate the interaction of periodontitis and orthodontic tooth movement on interleukin (IL)-6 and C-X-C motif chemokine 2 (CXCL2). Materials and methods The effect of periodontitis and/or orthodontic tooth movement (OTM) on alveolar bone and gingival IL-6 and CXCL2 expressions was studied in rats by histology and RT-PCR, respectively. The animals were assigned to four groups (control, periodontitis, OTM, and combination of periodontitis and OTM). The IL-6 and CXCL2 levels were also studied in human gingival biopsies from periodontally healthy and periodontitis subjects by RT-PCR and immunohistochemistry. Additionally, the synthesis of IL-6 and CXCL2 in response to the periodontopathogen Fusobacterium nucleatum and/or mechanical strain was studied in periodontal fibroblasts by RT-PCR and ELISA. Results Periodontitis caused an increase in gingival levels of IL-6 and CXCL2 in the animal model. Moreover, orthodontic tooth movement further enhanced the bacteria-induced periodontal destruction and gingival IL-6 gene expression. Elevated IL-6 and CXCL2 gingival levels were also found in human periodontitis. Furthermore, mechanical strain increased the stimulatory effect of F. nucleatum on IL-6 protein in vitro. Conclusions Our study suggests that orthodontic tooth movement can enhance bacteria-induced periodontal inflammation and thus destruction and that IL-6 may play a pivotal role in this process. Clinical relevance Orthodontic tooth movement should only be performed after periodontal therapy. In case of periodontitis relapse, orthodontic therapy should be suspended until the periodontal inflammation has been successfully treated and thus the periodontal disease is controlled again.

scholarly journals An In Vivo 3D Micro-CT Evaluation of Tooth Movement After the Application of Different Force Magnitudes in Rat Molar

2009 ◽  
Vol 79 (4) ◽  
pp. 703-714 ◽  
Author(s):  
Carmen Gonzales ◽  
Hitoshi Hotokezaka ◽  
Yoshinori Arai ◽  
Tadashi Ninomiya ◽  
Junya Tominaga ◽  
...  
Keyword(s):  
Tooth Movement ◽  
Three Dimensional ◽  
Element Model ◽  
Longitudinal Change ◽  
Micro Ct ◽  
Linear Measurements ◽  
Center Of Rotation ◽  
Ct Evaluation ◽  
Space Width

Abstract Objective: To investigate the precise longitudinal change in the periodontal ligament (PDL) space width and three-dimensional tooth movement with continuous-force magnitudes in living rats. Materials and Methods: Using nickel-titanium closed-coil springs for 28 days, 10-, 25-, 50-, and 100-g mesial force was applied to the maxillary left first molars. Micro-CT was taken in the same rat at 0, 1, 2, 3, 10, 14, and 28 days. The width of the PDL was measured in the pressure and tension sides from 0 to 3 days. Angular and linear measurements were used to evaluate molar position at day 0, 10, 14, and 28. The finite element model (FEM) was constructed to evaluate the initial stress distribution, molar displacement, and center of rotation of the molar. Results: The initial evaluation of PDL width showed no statistical differences among different force magnitudes. Tooth movement was registered 1 hour after force application and gradually increased with time. From day 10, greater tooth movement was observed when 10 g of force was applied. The FEM showed that the center of rotation in the molar is located in the center of five roots at the apical third of the molar roots. Conclusion: The rat's molar movement mainly consists of mesial tipping, extrusion of distal roots, intrusion of mesial root, palatal inclination, and mesial rotation. Although the initial tooth movement after the application of different force magnitudes until day 3 was not remarkably different, 10 g of force produced more tooth movement compared with heavier forces at day 28.

3-D in vivo force measurements on mandibular implants supporting overdentures. A comparative study.

1996 ◽  
Vol 7 (4) ◽  
pp. 387-396 ◽  
Author(s):  
R. Mericske-stern ◽  
M. Piotti ◽  
G. Sirtes
Keyword(s):  
Comparative Study ◽  
Force Measurements

scholarly journals Hemodynamic forces can be accurately measured in vivo with optical tweezers

2017 ◽  
Author(s):  
Sébastien Harlepp ◽  
Fabrice Thalmann ◽  
Gautier Follain ◽  
Jacky G. Goetz
Keyword(s):  
Optical Tweezers ◽  
Cell Biology ◽  
Accurate Determination ◽  
Force Measurements ◽  
Hemodynamic Forces ◽  
Non Invasive ◽  
Drag Forces ◽  
Measured Flow ◽  
Living Organisms

AbstractForce sensing and generation at the tissular and cellular scale is central to many biological events. There is a growing interest in modern cell biology for methods enabling force measurements in vivo. Optical trapping allows non-invasive probing of pico-Newton forces and thus emerged as a promising mean for assessing biomechanics in vivo. Nevertheless, the main obstacles rely in the accurate determination of the trap stiffness in heterogeneous living organisms, at any position where the trap is used. A proper calibration of the trap stiffness is thus required for performing accurate and reliable force measurements in vivo. Here, we introduce a method that overcomes these difficulties by accurately measuring hemodynamic profiles in order to calibrate the trap stiffness. Doing so, and using numerical methods to assess the accuracy of the experimental data, we measured flow profiles and drag forces imposed to trapped red blood cells of living zebrafish embryos. Using treatments enabling blood flow tuning, we demonstrated that such method is powerful in measuring hemodynamic forces in vivo with accuracy and confidence. Altogether, this study demonstrates the power of optical tweezing in measuring low range hemodynamic forces in vivo and offers an unprecedented tool in both cell and developmental biology.

scholarly journals Rational design of protein-specific folding modifiers

2020 ◽  
Author(s):  
Anirban Das ◽  
Anju Yadav ◽  
Mona Gupta ◽  
R Purushotham ◽  
Vishram L. Terse ◽  
...  
Keyword(s):  
Single Molecule ◽  
Rational Design ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Force Measurements ◽  
Folding Nucleus ◽  
Dynamics Simulations ◽  
General Method

AbstractProtein folding can go wrong in vivo and in vitro, with significant consequences for the living cell and the pharmaceutical industry, respectively. Here we propose a general design principle for constructing small peptide-based protein-specific folding modifiers. We construct a ‘xenonucleus’, which is a pre-folded peptide that resembles the folding nucleus of a protein, and demonstrate its activity on the folding of ubiquitin. Using stopped-flow kinetics, NMR spectroscopy, Förster Resonance Energy transfer, single-molecule force measurements, and molecular dynamics simulations, we show that the ubiquitin xenonucleus can act as an effective decoy for the native folding nucleus. It can make the refolding faster by 33 ± 5% at 3 M GdnHCl. In principle, our approach provides a general method for constructing specific, genetically encodable, folding modifiers for any protein which has a well-defined contiguous folding nucleus.

An analysis of in vivo cell migration during teleost fin morphogenesis

1984 ◽  
Vol 66 (1) ◽  
pp. 205-222
Author(s):  
A. Wood ◽  
P. Thorogood
Keyword(s):  
Close Association ◽  
Video Recording ◽  
Time Lapse ◽  
Mesenchymal Cells ◽  
Mean Value ◽  
Distal Margin ◽  
Cellular Processes ◽  
Interference Contrast Microscopy ◽  
Time Lapse Video

In the teleost embryo the pectoral fin bud initially displays an apical ectodermal ridge along its entire distal margin. The ridge subsequently becomes transformed into an apical fold as the distal ectodermal epithelium grows and folds to enclose an extracellular space between the apposed basal surfaces of the epithelium. Collagen fibrils up to 2 micron in diameter, termed ‘actinotrichia’, are deposited along the proximo-distal axis in two (dorsal and ventral) arrays. The actinotrichia are aligned parallel to one another with a regular spacing along the greater part of their length. Mesenchymal cells migrating distally from the base of the fin bud encounter the dorsal and ventral arrays of actinotrichia and move between them apparently using the fibrils as a substratum. The entire structure is transparent and, using the killifish Aphyosemion scheeli, we have investigated the migration of the mesenchymal cells between 135 and 220 h of development, using Nomarski interference contrast microscopy and time-lapse video recording. The number of cellular processes per cell increased significantly during the period of observation. These processes could be graded according to their diameters. Processes of diameter greater than 2 micron were not usually aligned along actinotrichia and arose at any aspect of the cell body. In contrast, processes with diameters less than 2 micron appeared to be confined to the distal aspects of the migrating cells and showed an increasing tendency to become aligned as development progressed. Time-lapse video recordings revealed that such aligned processes move faster (mean speed 17.98 (+/− 2.25) micron/h) than non-aligned processes (mean speed 4.66 (+/− 0.67) micron/h). Whole cell translocation was generally slower than rates of process movement: the lowest mean value (1.52(+/− 0.36) micron/h) was recorded between 135 and 160 h of development rising to a maximum mean rate (4.72(+/− 0.42) micron/h) between 195 and 220 h; the period of the fastest rate of cell translocation correlated with maximum process alignment along actinotrichia. Thin 1 micron plastic sections revealed that, generally, aligned processes were in close association with the surface of the actinotrichial fibrils and not the spaces between them.

scholarly journals Leptin levels in gingival crevicular fluid during canine retraction: in vivo comparative study

2019 ◽  
Vol 46 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Sanjit Kumar Sar ◽  
Divya Shetty ◽  
Piush Kumar ◽  
Saurabh Juneja ◽  
Payal Sharma
Keyword(s):  
Tooth Movement ◽  
Gingival Crevicular Fluid ◽  
Nickel Titanium ◽  
Coil Spring ◽  
Canine Retraction ◽  
Space Closure ◽  
Significant Difference ◽  
Elisa Technique ◽  
Crevicular Fluid

Objective: To evaluate and compare the leptin levels in gingival crevicular fluid (GCF) and rate of canine retraction using an elastomeric chain and nickel–titanium (NiTi) closed coil spring. Design: In vivo, clinical study. Setting: Orthodontic department at ITS Centre for Dental Studies and Research, Ghaziabad, India. Participants: Twenty-seven patients reported to the Department of Orthodontics at ITS Centre for Dental Studies and Research. Methods: Twenty-seven patients were included in the study in which canine retraction was carried out with an elastomeric chain and NiTi closed coil spring on either side of the arch applying 150 g of force on both sides. GCF samples were collected before the commencement of canine retraction, on the first, seventh and 21st day after application of force and were analysed for leptin levels by the ELISA technique. Impressions for the study model were taken at baseline and after 21 days to measure the rate of tooth movement bilaterally with an electronic digital calliper. Results: The results obtained within both groups showed a significant decrease in leptin levels from baseline to 21 days ( P = 0.0001). There was no significant difference in leptin levels between both groups, but leptin levels decreased more in the NiTi closed coil spring group. The rate of tooth movement is not significantly different between both groups, but space closure is faster in the NiTi closed coil spring group. Conclusions: Leptin levels in GCF showed a significant decrease during canine retraction using an elastomeric chain and NiTi coil spring; there was no significant difference in the rate of tooth movement between both the groups.

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