Wind-Speed-Adaptive Resonant Piezoelectric Energy Harvester for Offshore Wind Energy Collection.

This paper proposes a wind-speed-adaptive resonant piezoelectric energy harvester for offshore wind energy collection (A-PEH). The device incorporates a coil spring structure, which sets the maximum threshold of the output rotational frequency, allowing the A-PEH to maintain a stable output rotational frequency over a broader range of wind speeds. When the maximum output excitation frequency of the A-PEH falls within the sub-resonant range of the piezoelectric beam, the device becomes wind-speed-adaptive, enabling it to operate in a sub-resonant state over a wider range of wind speeds. Offshore winds exhibit an annual average speed exceeding 5.5 m/s with significant variability. Drawing from the characteristics of offshore winds, a prototype of the A-PEH was fabricated. The experimental findings reveal that in wind speed environments, the device has a startup wind speed of 4 m/s, and operates in a sub-resonant state when the wind speed exceeds 6 m/s. At this point, the A-PEH achieves a maximum open-circuit voltage of 40 V and an average power of 0.64 mW. The wind-speed-adaptive capability of the A-PEH enhances its ability to harness offshore wind energy, showcasing its potential applications in offshore wind environments.

Highly Inductive Coil Spring Strain/Compress Sensors Integrated with Shape Memory Alloy and Shape Memory Polymers-CNTs.

Future wearable electronic gadgets offer great potential for using stretchable, strain-sensitive materials to instantly detect human motion and record physiological information. This paper presens a strain/compress sensor made from a Shape memory alloy (SMA) coil spring covered with silver pastes and the composite of carbon nanotubes and Shape memory polymer (SMP). The combination of the shape memory materials that expand or contract automatically by temperature improved the mechanics of the sensor. First, the proposed sensors showed an excellent ability to broad-range strain of 250% and compress of 50% with a relative inductance (∆L/L0 ) range from -35% to 50%, respectively. Durability during 1000 loading and unloading cycles at 200% strain is included. Secondly, by monitoring changes in resistance, inductance, and time, it is determined how many silver layers appropriate for transformation should be in order to improve the recovery time of the SMA coil spring. Moreover, the presence of CNTs in the composite-covered outer of sensors helps to reduce the influence of the relation between resistance and temperature in the range from 30 °C to 110 °C. Finally, a device is suggested for monitoring arm and triceps brachii muscle movements based on the stretchable area as a key parameter.

Impact and Assessment of Suspension Stiffness on Vibration Propagation into Vehicle.

The impact of transport-induced vibrations on people is a particularly important problem. Sudden or intensifying vibration phenomena of a local nature may compromise safety, especially in transport. The paper addresses the results of research on the impact of spring stiffness parameters on the propagation of vibrations in the vehicle structure using simple amplitude and frequency measures. The use of the developed method of selective multi-criteria analysis of frequency bands made it possible to compare the vibrations recorded in the vehicle with a new or worn coil spring. The results of the present study allow the development of a large data base in which all signals are classified by the exploitation parameters and location of the propagation of vibration in the vehicle. The most important findings and achievements of the presented study are the testing of actual suspension components with real damage under controlled conditions, the identification of the vibration propagation path from the wheel to the driver and passenger feet, the quantitative comparison of vibrations affecting humans in the vehicle (through the feet), and the frequency decomposition of vibration for selected bands. These findings improve the proper interpretation of the developed measures and, as a result, the difficulties in using this knowledge at the engineering level, for example, in the design and construction improvement stage. Therefore, innovation points and engineering significances are a method of selective multi-criteria analysis of frequency bands and have potential applications in diagnostics and the design of suspension systems and in terms of passengers' comfort.

Soft Inductive Coil Spring Strain Sensor Integrated with SMA Spring Bundle Actuator.

This study proposes a soft inductive coil spring (SICS) strain sensor that can measure the strain of soft actuators. The SICS sensor, produced by transforming a shape memory alloy (SMA) wire with the same materials as that of an SMA spring bundle actuator (SSBA) into a coil spring shape, measures inductance changes according to length changes. This study also proposes a manufacturing method, output characteristics of the SICS sensor applicable to the SSBA among soft actuators, and the structure of the SICS sensor-integrated SSBA (SI-SSBA). In the SI-SSBA, the SMA spring bundle and SICS sensor have structures corresponding to the muscle fiber and spindle of the skeletal muscle, respectively. It is demonstrated that when a robotic arm with one degree of freedom is operated by attaching two SI-SSBAs in an antagonistic structure, the displacement of the SSBA can be measured using the proposed strain sensor. The output characteristics of the SICS sensor for the driving speed of the robotic arm were evaluated, and it was experimentally proven that the strain of the SSBA can be stably measured in water under a temperature change of 54 °C from 36 to 90 °C.

Displacement and stress distribution of Kilroy spring and nickel-titanium closed-coil spring during traction of palatally impacted canine: A 3-dimensional finite element analysis.

OBJECTIVE: To compare the stress distribution and initial displacements during traction of palatally impacted canine between Kilroy and nickel-titanium (NiTi) closed-coil springs by means of the finite element analysis. SETTING AND SAMPLE POPULATION: A finite element method analysis of two traction methods for a maxillary impacted canine. MATERIALS AND METHODS: The corresponding periodontal ligaments (PDLs), brackets, molar tubes and a 0.019 × 0.025-in base stainless-steel (SS) wire were modelled and imported to ANSYS SpaceClaim version 2020 R1. Traction was simulated under two different set-ups with equal force magnitude (60 g); (1) the Kilroy spring, which is made of 0.016-inch SS, and (2) the NiTi closed -coil spring. Von Mises stress distributions and initial displacements of the maxillary teeth were analysed. RESULTS: In both mechanics, while the highest stress was seen on the impacted canine (Kilroy, 10.41 kPa; NiTi closed-coil, 5.27 kPa), the stress distribution decreased as the distance from the impacted canine increased. The Kilroy spring showed a greater total displacement (465.60 µm) on the impacted canine. The higher stresses on the adjacent lateral (5.29 kPa) and premolar (6.41 kPa) occurred with the Kilroy spring. CONCLUSIONS: The Kilroy spring yielded higher stresses than the NiTi closed-coil spring on the impacted canine and the adjacent teeth. The difference between distribution of the stresses over the impacted canine induced greater displacement with the Kilroy spring, particularly in the vertical direction.

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

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.

Dynamics and observations of long-term orthodontic tooth movement and subsequent relapse in C57BL/6 mice.

The risk of relapse associated with orthodontic treatment is a major problem. Despite extensive research and discussion regarding the risk of orthodontic relapse, the underlying mechanisms remain to be elucidated. This study aimed to evaluate relapse following orthodontic treatment in mice (C57BL/6) tested via the coil spring method based on tooth movement at 21 days and mechanical retention at 7 days after completion of the procedure. During the experiment, relapse was observed and evaluated over 7 days. At the end of orthodontic tooth movement, the average distance was 259.6 (± 10.9) µm, and tooth movement was observed in all mice. No significant differences in distance were observed at the end of the experimental treatment period or after 7 days of mechanical retention. The distance at the start of observation was 258.6 (± 10.4) µm, whereas that at the end was 155.4 (± 12.4) µm, indicating that the distance had decreased significantly. Relative to the total relapse distance over the 7-day period, 45.7 (± 4.3)% of the relapse was observed on Day 0-1. The mouse model established in the current study provides an effective and reproducible method for the optimal evaluation of relapse. Our findings clarified that most of the relapse occurs within 7 days during the initial observation stage.

Evaluation of the force degradation and deformation of the open-closed and open springs of NiTi: An in vitro study.

OBJECTIVE: The aim of this study was to evaluate the force degradation and deformation over time of an open-closed and open coil spring. MATERIAL AND METHODS: 40 NiTi springs were divided into 2 groups according to the manufacturer (20 specimens per group): Morelli™ (Sorocaba, SP, Brazil) and Orthopli™ (Philadelphia, PA, USA). Then, they were subdivided into 2 groups according to the type of spring (n=10): open spring and open-closed spring. The springs were submitted to the initial compression test in a Universal Test Machine (Instron) in 43.3% of the initial length and analyzed in 3 points (0.5mm, 3.25mm and 6.5mm). After this, the springs were activated with a 240 gf and those maintained for 4 weeks in artificial saliva in the oven at 37°C, and analyzed by a new compression test with the same initial parameters. Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy (SEM/EDS) analyzed the spring's morphology. Two-way repeated measures Analysis of Variance was applied for each brand and extension of compression. Student t-test with correction of Bonferroni was used to compare open spring vs open-closed springs and pairwise t-test was used to compare initial vs final period. The level of significance was set at 95% in all tests. The most representative images were selected (SEM/EDS). RESULTS: The Orthopli™ open-closed spring showed a statistically higher deformation (14.52±0.37) in relation to open spring (14.85±0.19) after 4 weeks (P<0.05). No statistical difference was observed between the types of Morelli™ springs (P>0.05). Orthopli™ open-closed spring showed force values statistically higher than the open spring in the initial and final time (P<0.05). Regardless of the type of spring, the initial force was significantly higher than the final force (P<0.05). CONCLUSIONS: The orthodontist should not rely on the indicated force range without considering the type of spring (open or open-closed), the manufacturer and the amount of compression of the spring.

Effects of reversing the coiling direction on the force-deflection characteristics of nickel-titanium closed-coil springs.

OBJECTIVE: To investigate the effects of reversing the coiling direction of nickeltitanium closed-coil springs (NiTi-CCSs) on the force-deflection characteristics. METHODS: The samples consisted of two commercially available conventional NiTi-CCS groups and two reverse-wound NiTi-CCS groups (Ormco-Conventional vs. Ormco-Reverse; GAC-Conventional vs. GAC-Reverse; n = 20 per group). The reverse-wound NiTi-CCSs were directly made from the corresponding conventional NiTi-CCSs by reversing the coiling direction. Tensile tests were performed for each group in a temperature-controlled acrylic chamber (37 ± 1℃). After measuring the force level, the range of the deactivation force plateau (DFP) and the amount of mechanical hysteresis (MH), statistical analyses were performed. RESULTS: The Ormco-Reverse group exhibited a significant shift of the DFP end point toward the origin point (2.3 to 0.6 mm), an increase in the force level (1.2 to 1.3 N) and amount of MH (1.0 to 1.5 N) compared to the Ormco-Conventional group (all p < 0.001), which indicated that force could be constantly maintained until the end of the deactivation curve. In contrast, the GAC-Reverse group exhibited a significant shift of the DFP-end point away from the origin point (0.2 to 3.3 mm), a decrease in the force level (1.1 to 0.9 N) and amount of MH (0.6 to 0.4 N) compared to the GAC-Conventional group (all p < 0.001), which may hinder the maintenance of force until the end of the deactivation curve. CONCLUSIONS: The two commercially available NiTi-CCS groups exhibited different patterns of change in the force-deflection characteristics when the coiling direction was reversed.

Evaluating the Amount of Tooth Movement and Root Resorption during Canine Retraction with Friction versus Frictionless Mechanics Using Cone Beam Computed Tomography.

BACKGROUND: The current study was carried out to compare the amount of tooth movement during canine retraction comparing two different retraction mechanics; friction mechanics represented by a NiTi closed coil spring versus frictionless mechanics represented by T - loop, and their effect on root resorption using Cone Beam Computed Tomography (CBCT). METHOD: Ten patients were selected in a split-mouth study design that had a malocclusion that necessitates the extraction of maxillary first premolars and retraction of maxillary canines. The right maxillary canines were retracted using T - loops fabricated from 0.017 X 0.025 TMA wires. The left maxillary canines received NiTi coil spring with 150 gm of retraction force. Pre retraction and post retraction Cone Beam Computed Tomography were taken to evaluate the amount of tooth movement and root resorption using three-dimensional planes. RESULTS: T - loop side showed statistically significant higher mean anteroposterior measurement than NiTi coil spring side, indicating a lower amount of canine movement pre and post a canine retraction. Concerning the root resorption, there was no statistically significant change in the mean measurements of canine root length post retraction. CONCLUSION: The NiTi coil spring side showed more distal movement more than the T-loop side. Both retraction mechanics with controlled retraction force, do not cause root resorption.

Effects of Orthokin, Sensikin and Persica mouth rinses on the force degradation of elastic chains and NiTi coil springs.

Background. Elastomeric chains and NiTi coil springs are two major traction aids in orthodontic tooth movements. Force degradation occurs over time in both groups, with higher percentages in elastic chains. The effects of environmental factors and some mouth rinses on this force decay have been previously studied. No study has been performed to evaluate the effect of current popular mouth rinses such as Orthokin, Sensikin and Persica on this force degradation. Methods . Forty pieces of elastic chains consisting of 5 loops (Ortho Technology, USA) and 40 NiTi closed coil springs (3M Unitek, Germany) were divided into 4 groups: control (artificial saliva), Orthokin mouthwash, Sensikin mouthwash and Persica mouthwash. All the groups were kept in an incubator at 37°C for 3 weeks. In the test groups, the samples were immersed in mouthwash twice a day. Force degradation was measured at 5 time intervals: baseline, 1 hour, 24 hours, 1 week and 3 weeks, using a digital force gauge. Repeated-measures ANOVA and one-way ANOVA were used for statistical analysis. Results. Force decay occurred over time in both elastic chainand coil spring groups. In elastic chain group, after 3 weeks, Orthokin mouth rinse had significantly lower force degradation compared to other groups (P < 0.05) and in coil spring group there were no statistically significant differences in force degradation after 3 weeks between the subgroups (P > 0.05). Conclusion. Based the results of this study, these three mouthwashes did not increase the force degradation of orthodontic traction aids under study.

Modified differential evolution algorithm with onlooker bee operator for mixed discrete-continuous optimization.

For solving non-linear programming problems containing discrete and continuous variables, this article suggests two modified algorithms based on differential evolution (DE). The two proposed algorithms incorporate a novel random search strategy into DE/best/1 and DE/cur-to-best/1 respectively. Inspired by the artificial bee colony algorithm, the random search strategy overcomes the searching unbalance of DE/best/1 and DE/cur-to-best/1 by enhancing the global exploration capability of promising individuals. Two numerical experiments are given to test the two modified algorithms. Experiment 1 is conducted on the benchmark function set of CEC2005 in order to verify the effectiveness of the improved strategy. Experiment 2 is designed to optimize two mixed discrete-continuous problems to illustrate the competitiveness and the practicality of the proposed algorithms. In particular, the modified DE/cur-to-best/1 finds the new optima of two engineering optimization problems.

Comparative evaluation of pentraxin 3 levels in GCF during canine retraction with active tieback and NiTi coil spring: An in vivo study.

OBJECTIVES: To compare the levels of pentraxin 3 (PTX-3) in gingival crevicular fluid (GCF) in patients undergoing orthodontic canine retraction with active tieback and nickel titanium (NiTi) coil spring. MATERIALS AND METHODS: Fifteen patients of the age group 15-25 years with first premolar extraction undergoing canine retraction were selected. One month after placement of 0.019" × 0.025" stainless steel wire, canine retraction was started with active tieback (150 g force) on upper right quadrant and NiTi coil spring (150 g force) on upper left quadrant. GCF samples were collected 1 h before commencement of canine retraction and thereafter at intervals of 1 h, 1 day, 1 week, and 2 weeks after application of force. The collected GCF was eluted from the microcapillary pipette in 100 µl phosphate-buffered saline (pH 5-7.2). The samples were analyzed for PTX-3 levels by the ELISA technique. RESULTS: The mean levels of PTX-3 at 1 h before canine retraction (baseline) was 1.30 ± 0.22 ng/ml and at 1 h 1.66 ± 0.33 ng/ml, 1 day 2.65 ± 0.09 ng/ml, 1 week 1.96 ± 0.15 ng/ml, and 2 weeks 1.37 ± 0.18 ng/ml in active tieback group. The mean levels of PTX-3 at 1 h before canine retraction was 1.32 ± 0.30 ng/ml, and at 1 h 1.71 ± 0.39 ng/ml, 1 day 2.78 ± 0.12 ng/ml, 1 week 2.52 ± 0.18 ng/ml, and 2 weeks 2.12 ± 0.17 ng/ml in NiTi coil spring group. A significant difference of P < 0.001 was found in PTX-3 levels in GCF during canine retraction between active tieback and NiTi coil spring at 1 day, 1 week, and 2 weeks. CONCLUSION: The results showed that PTX-3 levels increased from 1 h after application of orthodontic force and reached peak at 1 day, followed by a gradual decrease at 1 week and 2 weeks in both active tie back and NiTi coil spring groups.

A Novel Approach to Regain Anterior Space Using Modified 2 by 3 Fixed Appliance: A Report of Two Cases.

Early loss of permanent anterior teeth in growing children has a psychological impact on the child. Anterior teeth are important both aesthetically and functionally. When a permanent tooth is lost, the teeth adjacent to the created space tend to migrate into the space resulting in the space loss. Management of regaining space with the removable appliance always depends on child cooperation for using the appliance as well as for the recall visits. The advantages of fixed appliances over the removable appliances are minimal discomfort, reduced need for patient cooperation and increased control of tooth movements in all three directions of space. Thus, a short course of fixed appliance like the modified 2 by 3 fixed appliance followed by fixed functional space maintainer could be an ideal treatment option for such cases.

The effect of different environmental factors on force degradation of three common systems of orthodontic space closure.

BACKGROUND: Different environmental conditions, such as high temperature or exposure to some chemical agents, may affect the force decay of different methods of space closure during orthodontic treatment. The aim of this in vitro study was to evaluate the force decay pattern in the presence of tea as a popular drink in some parts of the world and two mouthwashes that are usually prescribed by the orthodontist once the treatment is in progress. MATERIALS AND METHODS: Elastic chain (EC), nickel-titanium (Ni-Ti) closed coil spring and tie-back (TB) method were used as the means of space closure. The specimens were placed in five different media: Hot tea, hot water (65°), chlorhexidine mouthwash, fluoride mouthwash and the control group (water at 37°). The specimens were stretched 25 mm and the elastic force of three systems was measured at the beginning of the study, after 24 h, after 1 week and after 3 weeks. One-way ANOVA was used to compare the results between the groups and Duncan test was carried out to compare the sets of means in different groups (P ≤ 0.05). RESULTS: Tea increases the force decay in the EC and TB groups. Oral mouthwashes also resulted in more rapid force decay than the control group. EC and Ni-Ti groups were not much affected in the presence of oral mouthwashes. CONCLUSION: Regarding the immersion media, TB method showed the biggest variation in different media and Ni-Ti coil spring was least affected by the type of media.

To lower elongation molar with micro implant anchorage nail and Ni-Ti coil spring: a clinical study / 口腔疾病防治

Objective @# To investigate the clinical effects of micro implant anchorage nail and Ni-Ti coilspring to lower the elongation molar. @*Methods@#60 patients with the first maxillary molar elongation were divided into 2 groups. 30 of them were treated with micro implant anchorage nail and Ni-Ticoil spring to lower the molar (observation group), and the other 30 patients were treated with segmental arch to lower the molar (control group). The average lowering time, depth and pain degree of the 2 groups were compared. @*Results@#The average lowering time was faster and the overage lowering depth was greater in the observation group than that in the control group; the slight pain rate in the observation group was significantly higher than that in the control group (P<0.05), while the ratio of moderate pain and severe pain was significantly lower than that in the control group (P<0.05).@*Conclusion@# To lower the elongation molar with micro implant anchorage nail and Ni-Ti coilspring might have shorter course and less pain.

Load-deflection characteristics and plastic deformation of NiTi closed coil springs / 대한치과교정학회지

OBJECTIVE: NiTi closed coil springs were reported to have relatively constant unloading forces. However, the characteristics of NiTi closed coil springs from various manufacturers have not been elucidated. The purpose of this study was to compare load-deflection characteristics of various NiTi closed coil springs and to find out the optimal range of extension. METHODS: Seven kinds of NiTi closed coil springs from five manufacturers were tested. Load deflection curves were obtained at extension ranges from 2 mm to 30 mm. Also, springs were kept extended during a 4 week period, and then load deflection curves were obtained again. RESULTS: Sentalloy (Tomy) and Jinsung blue (Jinsung) showed superelasticity in every extension ranges tested and showed plastic deformation of less than 1 mm. Ni-Ti (Ormco) showed superelasticity only after the springs were extended at or more than 10 mm, thereby meaning that clinicians should extend these springs at or more than 10 mm to utilize the superelasticity. Orthonol (RMO) and Nitanium (Ortho Organizers) did not show superelasticity. After 4 weeks of extension, all springs showed plastic deformation less than 1 mm when the extension was at or under 25 mm. CONCLUSIONS: The superelastic behavior of NiTi closed springs were different among various NiTi spring products, and some NiTi closed springs failed to show superelasticity.

El Trípode en la distalización unilateral de molares superiores: cambios oclusales / The tripod in the unilateral distalization of superior molars: occlusal changes

Aumentar los conocimientos en los tratamientos distalizadores, se realizó este estudio con una técnica distalizadora novedosa: el Trípode. El estudio incluyó 6 pacientes con clase II de Angle por mesogresión de los molares superiores y con ausencia clínica del segundo molar superior. Se evaluaron las modificaciones a nivel dental producidas por el trípode. Los primeros molares superiores se distalizaron (3.36 mm), además, el molar sufrió una inclinación distal; las segundas bicúspides siguieron al molar en su movimiento distal, mientras que, la primera bicúspide del lado de la distalización se mesializó; los incisivos resultaron vestibularizados y la anchura transversal, medida a nivel de los primeros molares y primeras bicúspides, disminuyó, mientras que, en las segundas bicúspides aumentó. Los cambios producidos con esta aparatología a nivel dental han sido: distalización de los primeros molares superiores (3.36 mm), además, el molar sufrió una inclinación distal; las segundas bicúspides siguieron al primer molar en su movimiento distal, mientras que, la primera bicúspide del lado de la distalización se mesializó; los incisivos resultaron vestibularizados; la anchura transversal medida a nivel de los primeros molares y primeras bicúspides disminuyó, mientras que, en las segundas bicúspides aumentó(AU)

To enhance the knowledge of the distalizing treatments, a study was conducted with a distalizing novel technique: the tripod. The study included 6 patients with Angle class II due to mesogression of the superior molars and with clinical absence of the second superior molar. The modifications produced by the tripod at the dental level were evaluated. The first superior molars were distalized (3.36 mm). The molar also suffered a distal inclination, the second bicuspids followed the molar in its distal movement, whereas the first bicuspid of the side of the distalization was mesialized. The incisive were vestibularized and the cross-sectional width measured at the level of the first molars and the first bicuspids decreased, while in the second bicuspids increased. The changes caused by this apparatology at the dental level were the following: distalization of the first superior molars (3.36 mm); besides, the molar suffered a distal inclination; the second bicuspids followed the first molar in its distal movement, whereas the first bicuspid of the side of the distalization was mesialized; the incisives were vestibularized; the cross-sectional width measured at the level of the first molars and first bicuspids decreased, but in the second bicuspids it increased(AU)

El Trípode en la distalización unilateral de molares superiores: cambios oclusales / The tripod in the unilateral distalization of superior molars: occlusal changes

Aumentar los conocimientos en los tratamientos distalizadores, se realizó este estudio con una técnica distalizadora novedosa: el Trípode. El estudio incluyó 6 pacientes con clase II de Angle por mesogresión de los molares superiores y con ausencia clínica del segundo molar superior. Se evaluaron las modificaciones a nivel dental producidas por el trípode. Los primeros molares superiores se distalizaron (3.36 mm), además, el molar sufrió una inclinación distal; las segundas bicúspides siguieron al molar en su movimiento distal, mientras que, la primera bicúspide del lado de la distalización se mesializó; los incisivos resultaron vestibularizados y la anchura transversal, medida a nivel de los primeros molares y primeras bicúspides, disminuyó, mientras que, en las segundas bicúspides aumentó. Los cambios producidos con esta aparatología a nivel dental han sido: distalización de los primeros molares superiores (3.36 mm), además, el molar sufrió una inclinación distal; las segundas bicúspides siguieron al primer molar en su movimiento distal, mientras que, la primera bicúspide del lado de la distalización se mesializó; los incisivos resultaron vestibularizados; la anchura transversal medida a nivel de los primeros molares y primeras bicúspides disminuyó, mientras que, en las segundas bicúspides aumentó(AU)

To enhance the knowledge of the distalizing treatments, a study was conducted with a distalizing novel technique: the tripod. The study included 6 patients with Angle class II due to mesogression of the superior molars and with clinical absence of the second superior molar. The modifications produced by the tripod at the dental level were evaluated. The first superior molars were distalized (3.36 mm). The molar also suffered a distal inclination, the second bicuspids followed the molar in its distal movement, whereas the first bicuspid of the side of the distalization was mesialized. The incisive were vestibularized and the cross-sectional width measured at the level of the first molars and the first bicuspids decreased, while in the second bicuspids increased. The changes caused by this apparatology at the dental level were the following: distalization of the first superior molars (3.36 mm); besides, the molar suffered a distal inclination; the second bicuspids followed the first molar in its distal movement, whereas the first bicuspid of the side of the distalization was mesialized; the incisives were vestibularized; the cross-sectional width measured at the level of the first molars and first bicuspids decreased, but in the second bicuspids it increased(AU)