scholarly journals Accuracy and Reliability of AG501 Articulograph for Mandibular Movement Analysis: A Quantitative Descriptive Study

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6324
Author(s):  
María Florencia Lezcano ◽  
Fernando Dias ◽  
Alain Arias ◽  
Ramón Fuentes

Electromagnetic articulography (EMA) have been mostly employed to study articulatory movements of speech. This technology appears to be very promising for studying mandibular movements within the field of dentistry. However, there are no studies reporting the validity of EMA for such purpose. The aim of this study is to assess accuracy and reliability of Carstens three-dimensional EMA AG501 in order to validate its use for mandibular movement analysis in dentistry. A set of tests was conducted attaching 16 sensors to a rotating rigid structure placed inside the measurement area. Another set of tests were conducted using a mouth anatomical model with human-like articulatory behaviour. A function of the EMA system called “head correction” was applied to normalize the data of every recording. The system reliability was higher at the centre of the measurement area and decreased toward the edges. Dispersion was greater for raw data than for normalized data. Bland-Altman analysis of agreement between the AG501 and a millimetre ruler used to measure the distance between the sensors revealed limits of agreement between 0.5 mm and −0.9 mm. The results suggest that EMA AG501 is valid for three-dimensional analysis of mandibular biomechanics allowing natural movements.

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Ramón Fuentes ◽  
Alain Arias ◽  
María Florencia Lezcano ◽  
Diego Saravia ◽  
Gisaku Kuramochi ◽  
...  

The aim of this study was to analyze the general, geometric, and kinematic characteristics of the masticatory cycle’s movements in a tridimensional way, using a method developed by our study group to provide a new insight into the analysis of mandibular movements due to advancement in the potential of computational analysis. Ten individuals (20.1 ± 2.69 years), molar class I, without mandibular movement problems participated in this study. The movements of the masticatory cycles, frontal and sagittal mandibular border movements, were recorded using 3D electromagnetic articulography and processed with computational scripts developed by our research group. The number of chewing cycles, frequency (cycles/s), chewing cycle areas/mandibular border movements areas ratios, and the mouth opening and closing speeds on the 3D trajectory of the chewing cycle were compared. The cycles were divided and analyzed in thirds. The masticatory cycles showed high variation among the individuals (21.6 ± 9.4 cycles); the frequency (1.46 ± 0.21 cycles/s) revealed a moderate positive correlation (R = 0.52) with the number of cycles. The frontal area ratios between the cycle area and the mandibular border movement presented higher values in the first third (6.65%) of the masticatory cycles, and the ratios of sagittal areas were higher and more variable (first, 7.67%; second, 8.06%; and third, 10.04%) than the frontal view. The opening and closing mouth speeds were greater in the second third of the masticatory cycles (OS, 57.82 mm/s; CS, 58.34 mm/s) without a significant difference between the opening and closing movements when the same thirds were evaluated. Further studies are necessary to improve the understanding of the masticatory cycles regarding the standardization of parameters and their values.


2017 ◽  
Vol 6 (2) ◽  
pp. 84-94
Author(s):  
Swati Ahuja ◽  
Mark Scarbecz ◽  
Heath Balch ◽  
David R Cagna

ABSTRACT Aims and objectives To determine the accuracy of an opto-electronic pantograph (Freecorder Bluefox, Dentron) in locating a known transverse horizontal axis (THA); To determine the accuracy of the opto-electronic pantograph and the mechano-electronic pantograph (Cadiax Compact 2, Whip Mix Corp) in recording preset condylar control values; and additionally, compare the accuracy of the opto-electronic and mechano-electronic pantographs with each other. Materials and methods A fully adjustable articulator (Denar D5A, Whip Mix Corp) was employed as a mock patient. True condylar control settings and condylar control values determined by each recording device were documented and statistically analyzed using 2-sample independent t-tests (p < 0.05). Results Statistical data analysis indicated that (1) the opto-electronic pantograph did not accurately locate the known THA; (2) the condylar control values registered by opto-electronic and the mechano-electronic pantographs were statistically different from the preset condylar control values; and (3) different degrees of accuracy existed between the opto-electronic pantograph and mechano-electronic pantograph. Conclusion Errors up to 5 mm in the location of the THA may not have much clinical significance. The majority of articulator condylar control settings predicted by the opto-electronic and mechano-electronic pantographs investigated in this study were statistically different. Clinically, the predicted mean values for the lateral condylar inclination (LCI) and progressive mandibular lateral translation (PMLT) were within 5° of the known mock patient settings. However, the medial wall angulation and immediate side shift values obtained from the opto-electronic instrument suffered from large errors. Clinical implication Practical goals for complex restorative dentistry often include attaining accurate occlusal relationships, simulating the patient's mandibular movements in the laboratory using three-dimensional instrumentation and achieving desired occlusal contacts and relationships. Clinicians may rely on mandibular motion-recording devices to render accurate and useful information. Cost of purchase of electronic mandibular motion-recording devices (opto-electronic and mechano-electronic recorders), their accuracy, and time required for training should be compared with the use of conventional pantographs. The use of electronic pantograph may lead to savings in time and efforts over conventional pantograph and interocclusal records. How to cite this article Balch H, Cagna DR, Ahuja S, Scarbecz M. Verification of the Accuracy of Electronic Mandibular Movement-recording Devices: An in vitro Investigation. Int J Experiment Dent Sci 2017;6(2):84-94.


2019 ◽  
Author(s):  
Florencia Lezcano ◽  
Fernando Jose Dias ◽  
Constanza Farfán ◽  
María Cristina Manzanares Céspedes ◽  
Ramon Fuentes

Abstract Background. The aim of this study was to propose and establish the proof of concept of an approach to synchronize 3D Electromagnetic Articulography (3D-EMA) with Surface Electromyography (SEMG) systems based on the standard components of these equipment. Methods. Initially it was planned and obtained the required equipment with the appropriate characteristics required, and them it was created the proper conditions to register the synchronized signals provided by both systems. Thus, we selected a SEMG with a switch module incorporated to be able to achieve synchronization of signals. After the system setup was stablished, chewing tasks were recorded on a healthy volunteer, collecting a proof-of-concept database. The variability among recordings of the database were analyzed in order to detect possible interferences. Results. The analysis of the chewing task recordings obtained with the synchronized 3D EMA and SEMG signals in the present study did not reveal significant distortions, all values were within the informed by the manufacturers of both systems. The method presented the advantage of using only components that are already included with the equipment employed.Conclusion. The method of analysis described in this paper is an effective tool that facilitates the investigation of mandibular movements synchronized in two domains: articulatory movements and electromyographic activity. Thus, it is promising to be applied in different clinical situations to improve the analysis of the complexity of masticatory activity, in addition being able to generate new insights on this topic.


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4580
Author(s):  
Francesco Crenna ◽  
Giovanni Battista Rossi ◽  
Marta Berardengo

Biomechanical analysis of human movement is based on dynamic measurements of reference points on the subject’s body and orientation measurements of body segments. Collected data include positions’ measurement, in a three-dimensional space. Signal enhancement by proper filtering is often recommended. Velocity and acceleration signal must be obtained from position/angular measurement records, needing numerical processing effort. In this paper, we propose a comparative filtering method study procedure, based on measurement uncertainty related parameters’ set, based upon simulated and experimental signals. The final aim is to propose guidelines to optimize dynamic biomechanical measurement, considering the measurement uncertainty contribution due to the processing method. Performance of the considered methods are examined and compared with an analytical signal, considering both stationary and transient conditions. Finally, four experimental test cases are evaluated at best filtering conditions for measurement uncertainty contributions.


2007 ◽  
Vol 44 (3) ◽  
pp. 278-285 ◽  
Author(s):  
Virgilio F. Ferrario ◽  
Fabrizio Mian ◽  
Redento Peretta ◽  
Riccardo Rosati ◽  
Chiarella Sforza

Objective: To compare three-dimensional nasal measurements directly made on subjects to those made on plaster casts, and nasal dimensions obtained with a surface-based approach to values obtained with a landmark representation. Methods: Soft-tissue nasal landmarks were directly digitized on 20 healthy adults. Stone casts of their noses were digitized and mathematically reconstructed using nonuniform rational B-splines (NURBS) curves. Linear distances, angles, volumes and surface areas were computed using facial landmarks and NURBS-reconstructed models (surface-based approach). Results: Measurements on the stone casts were somewhat smaller than values obtained directly from subjects (differences between −0.05 and −1.58 mm). Dahlberg's statistic ranged between 0.73 and 1.47 mm. Significant (p < .05) t values were found for 4 of 15 measurements. The surface-based approach gave values 3.5 (volumes) and 2.1 (surface area) times larger than those computed with the landmark-based method. The two values were significantly related (volume, r = 0.881; surface, r = 0.924; p < .001), the resulting equations estimated actual values well (mean difference, volume −0.01 mm3, SD 1.47, area 0.05 cm2, SD 1.44); limits of agreement between −2.89 and 2.87 mm3 (volume); −2.88 and 2.78 cm2 (area). Conclusions: Considering the characteristics of the two methods, and for practical purposes, nasal distances and angles obtained on plaster models were comparable to digital data obtained directly from subjects. Surface areas and volumes were best obtained using a surface-based approach, but could be estimated using data provided by the landmark representation.


2004 ◽  
Vol 12 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Leonardo Rigoldi Bonjardim ◽  
Maria Beatriz Duarte Gavião ◽  
Luciano José Pereira ◽  
Paula Midori Castelo

This research aimed to evaluate mandibular movements in children with and without signs and symptoms of temporomandibular dysfunction. The sample taken consisted of 99 children aged 3 to 5 years distributed in two groups: I - Absence of signs and/or symptoms of TMD (25 girls/40 boys); II - Presence of signs and symptoms of TMD (16 girls/18 boys). The symptoms were evaluated through an anamnesis questionnaire answered by the child's parents/caretakers. The clinical signs were evaluated through intra- and extraoral examination. Maximum mouth opening and left/right lateral movements were measured using a digital caliper. The maximum protrusive movement was measured using a millimeter ruler. The means and standard deviations for maximum mouth opening in Group I and Group II were 40.82mm±4.18 and 40.46mm±6.66, respectively. The values found for the left lateral movement were 6.96mm±1.66 for Group I and 6.74mm±1.55 for Group II, while for the right lateral movement they were 6.46mm±1.53 and 6.74mm±1.77. The maximum protrusion movements were 5.67mm±1.76 and 6.12mm±1.92, in Groups I and II, respectively. The mandibular movement ranges neither differed statistically between groups nor between genders. FAPESP Process 96/0714-6.


2001 ◽  
Vol 90 (1) ◽  
pp. 205-215 ◽  
Author(s):  
Guido Baroni ◽  
Alessandra Pedrocchi ◽  
Giancarlo Ferrigno ◽  
Jean Massion ◽  
Antonio Pedotti

The adaptation of dynamic movement-posture coordination during forward trunk bending was investigated in long-term weightlessness. Three-dimensional movement analysis was carried out in two astronauts during a 4-mo microgravity exposure. The principal component analysis was applied to joint-angle kinematics for the assessment of angular synergies. The anteroposterior center of mass (CM) displacement accompanying trunk flexion was also quantified. The results reveal that subjects kept typically terrestrial strategies of movement-posture coordination. The temporary disruption of joint-angular synergies observed at subjects' first in-flight session was promptly recovered when repetitive sessions in flight were analyzed. The CM anteroposterior shift was consistently <3–4 cm, suggesting that subjects could dynamically control the CM position throughout the whole flight. This is in contrast to the observed profound microgravity-induced disruption of the quasi-static body orientation and initial CM positioning. Although this study was based on only two subjects, evidence is provided that static and dynamic postural control might be under two separate mechanisms, adapting with their specific time course to the constraints of microgravity.


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