Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 681
Filter
1.
Dent. press endod ; 11(1): 63-71, Jan-Apr2021. Tab, Ilus
Article in English | LILACS | ID: biblio-1348216

ABSTRACT

Objetivo: O objetivo do presente trabalho foi avaliar a resistência à fadiga cíclica e torcional de instrumentos rotatórios de níquel-titânio com secções transversais semelhantes e confeccionados com diferentes tipos de tratamentos térmicos: Hyflex CM (HCM 25/.06), Vortex Blue (VB 25/.06), Sequence Rotary File (SRF 25/.06) e EdgeSequel (EDF 25/.06) (n=20). Métodos: O teste de fadiga cíclica avaliou o tempo e o número de ciclos para a fratura (NCF) dos instrumentos em canal artificial com 60° de curvatura e 5mm de raio (n=10). O teste de torção avaliou o torque máximo e a deflexão angular para a fratura dos 3mm da ponta dos instrumentos (n=10). Após o teste de torção e de fadiga cíclica, os instrumentos foram avaliados em microscopia eletrônica de varredura (MEV) (n=10). Os dados foram analisados empregando-se os testes ANOVA e de Tukey, sendo selecionado um nível de significância de 5%. Resultados: HCM apresentou o maior tempo e NCF entre todos os instrumentos avaliados (p<0,05). O SRF apresentou um tempo semelhante (p>0,05) e menor NCF (p<0,05) do que o VB. Em relação ao teste torcional, o HCM apresentou menor valor de torque e maior deflexão angular entre os grupos avaliados (p<0,05). Não houve diferenças significativas entre VB, SRF e EDF em relação à deflexão angular (p>0,05). Conclusão: O HCM apresentou maior resistência à fadiga cíclica e deflexão angular. Entretanto, o VB apresentou maior resistência torcional para a fratura (AU).


Objective: The aim of this study was to evaluate the cyclic and torsional fatigue resistance of Nickel-Titanium rotary instruments with similar cross-sectional design and manufactured by different thermal treatments: Hyflex CM (HCM 25/.06) Vortex Blue (VB 25/.06), Sequence Rotary File (SRF 25/.06) and EdgeSequel (EDF 25/.06) (n=20). Material and Methods: Cyclic fatigue test evaluated the time and number of cycles to failure (NCF) in an artificial stainless steel canal with 60° and 5-mm radius of curvature (n=10). The torsional test (ISO 3630-1) evaluated he maximum torque and distortion angle to failure at 3 mm from the tip (n=10). After the torsional and cyclic fatigue test the instruments were evaluated by scanning electron microscope (SEM). Data were analyzed using one-way ANOVA and Tukey tests, and the level of significance was set at 5%. Results: The HCM presented the longest time and highest NCF to fatigue than all the groups (P<0.05). The SRF presented similar time (P>0.05) and lower NCF (P<0.05) to fatigue than VB. Regarding to the torsional test, HCM presented the lowest torque load and the highest distortion angle of all the groups (P<0.05). No significant difference was found among VB, SRF and EDF regarding the distortion angle (P>0.05). Conclusion: The HCM presented the highest cyclic fatigue resistance and distortion angle to failure. However, the VB showed higher torsional load to failure. (AU).


Subject(s)
Microscopy, Electron, Scanning , Torque , Dental Instruments , Endodontics , Titanium , Analysis of Variance , Fatigue , Nickel
2.
Article in Chinese | WPRIM | ID: wpr-888630

ABSTRACT

This study designed an isokinetic muscle strength rehabilitation training equipment, based on oil resistance. The equipment detected joint angles during movement through displacement sensors to measure the angular velocity in real-time. Then it can achieve flow resistance adjustment and constant velocity movement, based on the flow area of the proportional valve calculated by PID algorithm and the deviation between the set speed and the measured speed. The equipment can also collect muscle strength during exercise through force-sensitive sensors to achieve real-time and accurate assessment of muscle strength. Moreover, the study preliminarily certificated the isokinetic motion the results showed that the mean error of peak torque test is less than 5%, and the correlation is between 0.89 and 0.92 (


Subject(s)
Exercise Therapy , Humans , Movement , Muscle Strength , Muscle, Skeletal , Torque
3.
Clinics ; 76: e2803, 2021. tab, graf
Article in English | LILACS | ID: biblio-1278922

ABSTRACT

OBJECTIVES: To evaluate the clinical characteristics, ground reaction force (GRF), and function of the plantar muscles and dorsiflexors of the ankle in runners with and without Achilles tendinopathy (AT) and in non-runners. METHODS: Seventy-two participants (42 men, 30 women; mean age: 37.3±9.9 years) were enrolled in this cross-sectional study and divided into three groups: AT group (ATG, n=24), healthy runners' group (HRG, n=24), and non-runners' group (NRG, n=24). Both ankles were evaluated in each group. The American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale was used for clinical and functional evaluation. GRF was evaluated using force plates and muscle strength was evaluated using an isokinetic dynamometer. RESULTS: The AOFAS scores were lower in the ATG. The strike impulse was higher in the ATG than in the HRG and NRG. However, GRF was similar among the groups. The ATG exhibited lower total work at 120°/s speed than the HRG. The peak torque in concentric dorsiflexion was lower in the NRG than in the ATG and HRG. The peak torque and total work in concentric plantar flexion were lower in the NRG than in the ATG. The peak torque and total work in eccentric plantar flexion were lower in the NRG than in the ATG and HRG. CONCLUSION: Runners with AT showed higher strike impulse, lower muscle strength of the plantar flexors, and higher clinical and functional damage.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Achilles Tendon , Tendinopathy , Biomechanical Phenomena , Cross-Sectional Studies , Muscle, Skeletal , Torque , Muscle Strength , Ankle , Ankle Joint
4.
Pesqui. bras. odontopediatria clín. integr ; 21(supl.1): e0030, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1346687

ABSTRACT

ABSTRACT Objective: To obtain reference values for tip, torque and in-out from digital models of Italian and Mozambican subjects in ideal occlusion using a repeatable and validated method and to compare these measurements with previously reported values. Material and Methods: Dental parameters were acquired from digital models of each subject, categorized to one of two groups: Italians (23 males, 27 females; mean age 28.3 years, ±5.7 years) and Mozambicans (14 males, 15 females; mean age, 23.4 years, ±5.9), using VAM software. All subjects had ideal occlusion, permanent dentition and no previous orthodontic treatment, fillings or prostheses. After normality of data was assumed (p<0.05), a paired t-test was performed to detect any statistical differences between the two groups (p<0.05). Then, classical inference (t-test and power analysis) was used to compare our data to those reported by other authors. Results: Mozambicans' incisors were more proclined, while their upper molars appeared to be more prominent regarding Italians'. Italians shown greater tip values, especially at the upper first premolars and lower first molars. In-out values were comparable between the two groups, except for the upper molars (more prominent in Mozambicans) and lower first molar (more prominent in Italians). Unlike other reports, upper second molars displayed negative tip in our samples. Conclusion: Pre-adjusted appliances with standard prescription should not be expected to guarantee optimal outcomes. Prescriptions specific for ethnicities are recommended and reference values should be reconsidered.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Orthodontic Appliances , Dentition, Permanent , Torque , Dental Occlusion , Italy , Mozambique , Orthodontics , Statistics, Nonparametric
5.
Braz. dent. sci ; 24(1): 1-8, 2021. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1145466

ABSTRACT

Objectives: With regard to the prevalence of abutment screw loosening (SL) and bone height reduction, particularly in the posterior regions of the jaws, as well as the contradictory issue of applying short implants instead of surgeries, along with all preparations associated with longer implants, the present study aimed to compare the amount of torque loss in short implants with increased vertical cantilever abutments and standard ones. Material and Methods: In this experimental study, a total number of 20 implants (MegaGen Implant Co., Ltd, South Korea) with 4.5 mm diameter including 10 short implants (7 mm) and 10 standard ones (10 mm) were utilized. Using a surveyor, fixtures were perpendicularly mounted in 13×34 mm resin for short implants and 19×34 mm resin for standard ones. The abutments of the same height but different cuff heights (2.5 mm for the standard implants and 5.5 mm for the short ones) were then tightened with 30 N.cm, via a digital torque meter. To compensate the settling effect, the abutment screw was re-tightened with 30 N.cm after 10 min. Upon applying 500,000 cycles at 75 N.cm and 1 Hz along the longitudinal axis on each sample, blind reverse torque value (RTV) was measured with a digital torque meter. The data were finally analyzed using Student's t-test. Results:Both groups experienced torque loss, but there was no statistically significant difference between the case and control groups in terms of abutment SL (p = 0451). Conclusion: Short implants seem to be a good mechanical alternative in emergencies with respect to torque loss and abutment SL. (AU)


Objetivos: Considerando a prevalência de afrouxamento de parafuso dos pilares, redução da altura óssea especialmente nas regiões posteriores, a questão contraditória da aplicação de implantes curtos em vez de cirurgias e todos os preparos associados a implantes mais longos, este estudo buscou comparar implantes curtos com pilares cantilever verticais aumentados e implantes padrão na quantidade de perda de torque. Material e métodos: Neste estudo experimental, foram utilizados 20 implantes (Megagen, Coreia do Sul) com diâmetro de 4,5 mm, incluindo 10 implantes curtos (7 mm) e 10 implantes padrão (10 mm). A fixação foi realizada perpendicularmente em uma resina 13 × 34 mm para implantes curtos e uma resina 19 × 34 mm para implantes padrão, usando um topógrafo. Os pilares da mesma altura, mas com diferentes comprimentos de manguito (2,5 mm para os implantes padrão e 5,5 mm para os implantes curtos) foram apertados com 30 N, utilizando um torquímetro digital. Para compensar o efeito de sedimentação, o parafuso do pilar foi reapertado com 30 N após 10 min. Depois de aplicar 500.000 ciclos a 75 N e 1 Hz ao longo do eixo longitudinal em cada amostra, o valor de torque reverso cego foi medido com um medidor de torque digital. Os dados foram analisados pelo teste t de Student. Resultados: Todos os grupos tiveram perda de torque, mas não houve diferença estatisticamente significativa entre os grupos caso e controle em termos de afrouxamento do parafuso do pilar (p = 0451). Conclusão: Os implantes curtos parecem ser uma boa alternativa mecânica em emergências em termos de perda de torque e afrouxamento do parafuso do pilar. (AU)


Subject(s)
Bone Screws , Torque , Dental Implantation
6.
Pesqui. bras. odontopediatria clín. integr ; 21(supl.1): e0031, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1340338

ABSTRACT

ABSTRACT Objective: To evaluate the effects of passive self-ligating appliances (PSLAs) and conventional ligating appliances (CLAs) during orthodontic treatment regarding torque, tip, and transversal dental changes. Material and Methods: Dental parameters were digitally acquired from pre- and post-treatment models of each subject belonging to two groups of patients treated with PSLAs (23 patients; 11 females and 12 males with a mean age of 14.2 ± 1.6 years) and CLAs (18 patients; 10 females and 8 males with a mean age of 14.3 ± 1.9 years), respectively. All subjects had Class I or slight Class II malocclusion (= 2mm), permanent dentition and no previous orthodontic treatment. After normality of data was assumed, a paired sample t-test rejected any side differences at T0 and, therefore, the data were grouped by tooth group. Statistical analyses were performed using a linear mixed-effect framework, assuming the appliance, time, and interactions as fixed effects and the tooth type as random effects. Finally, post-hoc effect analysis was used to contrast modeled marginal effects (p<0.05). Results: For both appliances, there is a general increase of both torque and transverse values at T1, especially for PSLAs. Tip shows a general reduction in the lateral sectors for both appliances is registered. The only significant statistical difference referred to appliances' efficacy is located to mandibular intermolar width. Conclusion: Both appliances have an expansive potential for both torque and transverse dental changes. No evident differences are detectable between appliances except for the rate of the mandibular intermolar width increase.


Subject(s)
Humans , Male , Female , Child , Adolescent , Orthodontic Appliances , Orthodontic Brackets , Torsion, Mechanical , Malocclusion/etiology , Malocclusion, Angle Class I/etiology , Retrospective Studies , Data Interpretation, Statistical , Torque , Italy
7.
Dental press j. orthod. (Impr.) ; 26(1): e2119155, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1154069

ABSTRACT

ABSTRACT Introduction: Shorter miniscrew implants (MSIs) are needed to make orthodontics more effective and efficient. Objective: To evaluate the stability, insertion torque, removal torque and pain associated with 3 mm long MSIs placed in humans by a novice clinician. Methods: 82 MSIs were placed in the buccal maxillae of 26 adults. Pairs of adjacent implants were immediately loaded with 100g. Subjects were recalled after 1, 3, 5, and 8 weeks to verify stability and complete questionnaires pertaining to MSI-related pain and discomfort. Results: The overall failure rate was 32.9%. The anterior and posterior MSIs failed 35.7% and 30.0% of the time, respectively. Excluding the 10 MSIs (12.2%) that were traumatically dislodged, the failure rates in the anterior and posterior sites were 30.1% and 15.2%, respectively; the overall primary failure rate was 23.6%. Failures were significantly (p= 0.010) greater (46.3% vs 19.5%) among the first 41 MSIs than the last 41 MSIs that were placed. Excluding the traumatically lost MSIs, the failures occurred on or before day 42. Subjects experienced very low pain (2.2% of maximum) and discomfort (5.5% of maximum) during the first week only. Conclusions: Shorter 3 mm MSIs placed by a novice operator are highly likely to fail. However, failure rates can be substantially decreased over time with the placement of more MSIs. Pain and discomfort experienced after placing 3 mm MSIs is minimal and temporary.


RESUMO Introdução: Mini-implantes (MIs) mais curtos são necessários para uma Ortodontia mais eficiente e efetiva. Objetivo: Avaliar a estabilidade, torque de inserção e de remoção e dor associada a MIs de 3mm instalados em humanos por um ortodontista principiante. Métodos: 82 MIs foram instalados na região vestibular da arcada superior de 26 adultos. Pares de mini-implantes adjacente receberam carga imediata de 100g. Após 1, 3, 5 e 8 semanas, os pacientes foram reavaliados para verificar a estabilidade e preencher um questionário sobre a dor e o desconforto relacionados aos MIs. Resultados: A taxa geral de falhas foi de 32,9%, sendo de 35,7% para os MIs anteriores e 30% para os MIs posteriores. Excluindo os 10 MIs que foram perdidos por trauma (12,2%), a taxa de falha nas regiões anterior e posterior foram de 30,1% e 15,2%, respectivamente e ocorreram no 420 dia ou antes. A taxa geral de falha primária foi de 23,6%. A taxa de falha foi significativamente maior (p=0,010) nos primeiros 41 MIs do que nos 41 últimos (46,3% vs. 19,5%). As experiências relacionadas à dor foram baixas (2,2% máximo), assim como ao desconforto (5,5% máximo) durante a primeira semana. Conclusão: MIs de 3mm instalados por um novato são mais propensos a falhas. Porém, as taxas de falha podem diminuir substancialmente com a instalação de mais MIs com o decorrer do tempo. A dor e o desconforto após a instalação desses dispositivos são mínimos e temporários.


Subject(s)
Humans , Adult , Bone Screws , Dental Implants , Orthodontic Anchorage Procedures , Dental Implants/adverse effects , Feasibility Studies , Dental Prosthesis, Implant-Supported , Torque , Dental Implantation, Endosseous , Maxilla/surgery
8.
Dental press j. orthod. (Impr.) ; 26(1): e211967, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1154066

ABSTRACT

ABSTRACT Objective: Assess the influence of mono- and bicortical anchorage and diameter of mini-implants (MIs) on the primary stability of these devices. Methods: 60 self-drilling MIs were distributed in six groups according to diameter (1.5mm, 1.8mm or 2.0mm) and type of anchorage (monocortical and bicortical) in bovine rib. The primary stability was evaluated by insertion torque, micromobility and pull-out strength tests. ANOVA and/or Tukey analysis were used to conduct intergroup comparisons (p< 0.05). Non-parametric statistics (Kruskal-Wallis and Mann-Whitney) were performed when normality was not found (p< 0.05). Results: MIs with larger diameters and bicortical anchorage showed greater primary stability regarding insertion torque (p< 0.05) and micromobility (p< 0.05). Only MI diameter had an effect on the pull-out strength test. Larger diameter MIs presented better retention in pull-out strength tests (p< 0.001), regardless of mono- or bicortical anchorage. Conclusions: MI primary stability is dependent on its diameter and type of anchorage. Bicortical anchorage showed greater stability when compared with monocortical anchorage, independently of other variables.


RESUMO Objetivo: Avaliar a influência da ancoragem mono e bicortical e do diâmetro dos mini-implantes (MIs) na estabilidade primária desses dispositivos. Métodos: 60 MIs autoperfurantes foram distribuídos em seis grupos, de acordo com o diâmetro (1,5 mm, 1,8 mm ou 2,0 mm) e tipo de ancoragem (monocortical e bicortical), e inseridos em costela bovina. A estabilidade primária foi avaliada pelos testes de torque de inserção, micromobilidade e resistência à tração. ANOVA e/ou análise de Tukey foram usadas para realizar comparações intergrupos (p< 0,05). Estatística não paramétrica (Kruskal-Wallis e Mann-Whitney) foi realizada quando a normalidade não foi encontrada (p< 0,05). Resultados: MIs com diâmetros maiores e ancorados bicorticalmente apresentaram maior estabilidade primária em relação ao torque de inserção (p< 0,05) e micromobilidade (p< 0,05). Apenas o diâmetro do MI influenciou os resultados do teste de resistência à tração. MIs de maior diâmetro apresentaram melhor retenção nos testes de resistência à tração (p< 0,001), independentemente da ancoragem mono ou bicortical. Conclusões: a estabilidade primária do MI é dependente de seu diâmetro e tipo de ancoragem. A ancoragem bicortical apresentou maior estabilidade quando comparada à ancoragem monocortical, independentemente das demais variáveis.


Subject(s)
Humans , Cattle , Dental Implants , Orthodontic Anchorage Procedures , Palate , Palatal Expansion Technique , Torque
9.
Braz. oral res. (Online) ; 35: e021, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1153624

ABSTRACT

Abstrac The aim of the present study was to evaluate the cyclic fatigue, torsional resistance and surface roughness of Reciproc R25 instruments in four different situations, namely as new instruments and as instruments tested after clinical preparation of one, two or three maxillary molars with four root canals. The total time required to perform each root canal preparation was recorded. Cyclic fatigue resistance was determined by the time to fracture using a customized testing device (n = 10 per group). The torsional test evaluated the torque and angle of rotation to failure according to ISO 3630-1 (n = 10 per group). The roughness of the working parts of new and used instruments was evaluated with a profilometer (n = 5 per group). Statistical analysis was performed using one-way ANOVA and Tukey's test. The level of significance was set at 5%. No fractures or deformations were observed after clinical use. Higher preparation time was needed during the third use of the instruments for all root canals (p < 0.05). There were no significant differences among the groups in regard to either cyclic fatigue or torsional resistance (p > 0.05). Regarding the roughness measurements, groove depth was higher on new and one- versus two- or three-maxillary-molar-prepared instruments (p < 0.05). It can be concluded that the clinical use of Reciproc instruments increased preparation time and decreased surface roughness. However, clinical use did not affect the cyclic fatigue or torsional resistance of the Reciproc instruments.


Subject(s)
Titanium , Root Canal Preparation , Stress, Mechanical , Materials Testing , Torque , Dental Instruments , Equipment Design
10.
Rev. Ciênc. Méd. Biol. (Impr.) ; 19(3): 472-484, dez 5, 2020. fig
Article in Portuguese | LILACS | ID: biblio-1358017

ABSTRACT

Introdução: o aprimoramento do processo de osseointegração faz com que os investimentos em pesquisa e o desenvolvimento de novos materiais e tratamentos de superfície sejam despendidos para promover a relação entre osso e implante. Uma das condições para o sucesso é a ausência de micromovimentos ou estabilidade primária da peça implantada, fato esse que leva alguns cirurgiões a aplicar torques excessivos sobre o implante, podendo resultar em danos ao tratamento aplicado à superfície externa do mesmo. Objetivo: o presente trabalho investigou possíveis níveis de deformação do preparo de superfície conforme diferentes valores de torque foram aplicados à dois sistemas de implantes para avaliar os possíveis danos causados. Metodologia: foram instalados 5 implantes do sistema Dérig e 5 implantes do sistema Straumann em um bloco de poliuretano, para posterior remoção com contra-torque e avaliação da superfície sob o Microscópio Eletrônico de Varredura (MEV). Resultados: nos resultados obtidos, no grupo de implantes Dérig não foi possível constatar evidências que comprovem que a elevação dos valores de torque aplicados aos implantes até 95 Ncm danifiquem ou alterem a estrutura do preparo de superfície externa dos implantes, contudo, no grupo Straumann, verificamos danos e alterações no preparo de superfície com torque progressivo a partir de 50 Ncm. Conclusão: possíveis alterações e danos ao preparo de superfície de implantes que apresentem rugosidade de superfície aumentada por jateamento podem ocorrer em torques acima de 50 Ncm empregados com o objetivo de aumentar sua estabilidade primária.


Introduction: improving the osseointegration process means that investments in research and development of new materials and surface treatments are expended to promote the relationship between bone and implant. One of the conditions for success is the absence of micromovements or primary stability of the implanted part. This fact causes some surgeons to apply excessive torque to the implant, which may result in damage to the treatment applied to the external surface of the implant. Objective: The present work investigated possible surface preparation deformation levels as different torque values were applied to two implant systems to evaluate the possible damage caused. Methodology: ive Dérig system implants and five Straumann system implants were installed in a polyurethane block for subsequent counter-torque removal and surface evaluation under the Scanning Electron Microscope (SEM). Results: Iin the obtained results, in the Dérig implant group it was not possible to verify evidences that the increase of the torque values applied to the implants up to 95 Ncm could damage or alter the structure of the external surface preparation of the implants, however, in the Straumann group we verified damage and changes in surface preparation with progressive torque from 50 Ncm. Conclusion: possible alterations and damages to the surface preparation of implants that present increased surface roughness by blasting can occur in torques above 50 Ncm employed in order to increase their primary stability.


Subject(s)
Torque , Dental Implantation , Tooth Wear , Polyurethanes , Bone and Bones
11.
Int. j. odontostomatol. (Print) ; 14(2): 230-235, June 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1090679

ABSTRACT

La estabilidad primaria es un requisito importante para la supervivencia y éxito de los implantes durante la osteointegración. En los últimos años, los implantes inmediatos postextracción han demostrado ser una opción de tratamiento exitosa y predecible para la reposición de dientes con mal pronóstico, pero surge la duda de si dichos implantes alcanzan valores de estabilidad primaria comparables a aquellos colocados en hueso maduro. Comparar la estabilidad primaria de implantes inmediatos colocados en alveolos postextracción con la de implantes colocados en hueso maduro. Se llevó a cabo un estudio clínico retrospectivo, con los datos recogidos sobre 175 implantes, colocados en 175 pacientes. Todos los implantes colocados pertenecían al modelo Essential Cone (Klockner Implant System) y se dividieron en dos grupos: implantes inmediatos (Grupo A, n=31) e implantes colocados en hueso maduro (Grupo B, n=144). La estabilidad primaria de todos los implantes se midió mediante torque de inserción y análisis de frecuencia de resonancia con Osstell ISQ. No se encontraron diferencias estadísticamente significativas respecto a la estabilidad medida a través del torque de inserción (26,29+10,07 Vs 25,76+9,72 N/cm) pero sí que se encontraron diferencias significativas en la medida de la estabilidad primaria mediante AFR, siendo inferiores los valores correspondientes a los implantes colocados en los alveolos post exodoncia (60,74 ± 6,17 en sentido VL y 62,19 ± 7.64 en sentido MD frente a 68,34 ± 6.26 en sentido VL y 69,29 ± 7.98 en sentido MD obtenidos en los implantes colocados en hueso maduro). El torque de inserción de los implantes inmediatos es similar al de los implantes colocados en hueso maduro, pero sus valores ISQ son significativamente inferiores, lo que demuestra un mayor grado de micromovimiento, y por consiguiente, un mayor riesgo de fracaso durante el período de osteointegración.


Primary stability is an important requirement for the survival and success of implants during osseointegration. In recent years, immediate post-extraction implants have proven to be a successful and predictable treatment option for the replacement of teeth with a poor prognosis, but the question arises as to whether these implants reach primary stability values comparable to those placed in mature bone. The objective of the study was to compare the primary stability of immediate implants placed in post-extraction alveoli with that of implants placed in mature bone. A retrospective clinical study was carried out, with data collected on 175 implants, placed in 175 patients. All implants placed belonged to the Essential Cone model (Klockner Implant System) and were divided into two groups: immediate implants (Group A, n = 31) and implants placed in mature bone (Group B, n = 144). The primary stability of all implants was measured by insertion torque and resonance frequency analysis with Osstell ISQ. No statistically significant differences were found regarding the stability measured through the insertion torque (26.29 + 10.07 Vs 25.76 + 9.72 N / cm) but significant differences were found in the measurement of primary stability by means of AFR, the values corresponding to implants placed in the post-exodontic alveoli being lower (60.74 ± 6.17 in the VL direction and 62.19 ± 7.64 in the MD direction versus 68.34 ± 6.26 in the VL direction and 69.29 ± 7.98 in the MD direction obtained in implants placed in mature bone). The insertion torque of immediate implants is similar to that of implants placed in mature bone, but their ISQ values are significantly lower, which demonstrates a higher degree of micromotion, and therefore, a greater risk of failure during the period of osseointegration.


Subject(s)
Dental Prosthesis Retention , Dental Implantation, Endosseous/methods , Tooth Extraction , Vibration , Case-Control Studies , Retrospective Studies , Osseointegration , Torque , Immediate Dental Implant Loading , Resonance Frequency Analysis
12.
Rev. Ateneo Argent. Odontol ; 62(1): 40-51, jun. 2020. ilus, tab, graf
Article in Spanish | LILACS | ID: biblio-1148184

ABSTRACT

La incorporación de los microimplantes a la ortodoncia revoluciona la mecánica de cierre de espacios por deslizamiento, ya que mejora sus dos puntos "débiles": el anclaje y el control dentario tridimensional. El propósito de este trabajo es determinar los vectores de fuerza y el tipo de movimiento generado en la retrusión en masa del sector anterosuperior, según las distintas ubicaciones de los microtornillos y la altura del brazo de la palanca anterior. Las nuevas tendencias de utilización de microimplantes para la retrusión producen vectores de fuerza horizontales y verticales y momentos según su ubicación y según el punto de aplicación de la fuerza. Debido a esto último, el conocimiento de la biomecánica adquiere especial importancia para un correcto resultado final en el tratamiento ortodóncico. Un diagnóstico certero, un objetivo de tratamiento claro y realista y la elección de la aparatología correcta se verán frustrados una y otra vez de no contar con un correcto conocimiento de las reacciones biológicas ante las fuerzas ejercidas (AU)


The incorporation of miniscrew into orthodontics revolutionizes the mechanics of sliding closure spaces, since it improves its two "weak" points: anchoring and three-dimensional dental control. The purpose of this work is to determine the force vectors and the type of movement generated in the mass retrusion of the anterior superior sector according to the different miniscrew´s locations and the anterior lever arm´s height. The new trends in the use of miniscrews for retrusion produce horizontal and vertical force vectors and moments according to their location and the point of application. In consequence, the knowledge of biomechanics acquires special importance to get a correct final result in orthodontic treatment. Not having a detailed knowledge of the biological reactions on the forces exerted will cause that the accurate diagnosis, the clear and realistic treatment objective, and the choice of the correct appliances to be frustrated over and over (AU)


Subject(s)
Humans , Tooth Movement Techniques , Biomechanical Phenomena , Dental Implants , Orthodontic Space Closure/methods , Torque , Imaging, Three-Dimensional , Orthodontic Anchorage Procedures
13.
Article in English | WPRIM | ID: wpr-811257

ABSTRACT

PURPOSE: A stability-measuring device that utilizes damping capacity analysis (DCA) has recently been introduced in the field of dental implantology. This study aimed to evaluate the sensitivity and reliability of this device by measuring the implant stability of ex vivo samples in comparison with a resonance frequency analysis (RFA) device.METHODS: Six implant beds were prepared in porcine ribs using 3 different drilling protocols to simulate various implant stability conditions. Thirty-six pork ribs and 216 bone-level implants measuring 10 mm in height were used. The implant beds were prepared using 1 of the following 3 drilling protocols: 10-mm drilling depth with a 3.5-mm-diameter twist drill, 5-mm drilling depth with a 4.0-mm-diameter twist drill, and 10-mm drilling depth with a 4.0-mm-diameter twist drill. The first 108 implants were external-connection implants 4.0 mm in diameter, while the other 108 implants were internal-connection implants 4.3 mm in diameter. The peak insertion torque (PIT) during implant placement, the stability values obtained with DCA and RFA devices after implant placement, and the peak removal torque (PRT) during implant removal were measured.RESULTS: The intraclass correlation coefficients (ICCs) of the implant stability quotient (ISQ) results obtained using the RFA device at the medial, distal, ventral, and dorsal points were 0.997, 0.994, 0.994, and 0.998, respectively. The ICCs of the implant stability test (IST) results obtained using the DCA device at the corresponding locations were 0.972, 0.975, 0.974, and 0.976, respectively. Logarithmic relationships between PIT and IST, PIT and ISQ, PRT and IST, and PRT and ISQ were observed. The mean absolute difference between the ISQ and IST values on a Bland-Altman plot was −6.76 (−25.05 to 11.53, P<0.05).CONCLUSIONS: Within the limits of ex vivo studies, measurements made using the RFA and DCA devices were found to be correlated under a variety of stability conditions.


Subject(s)
Dental Implants , Diagnostic Techniques and Procedures , In Vitro Techniques , Osseointegration , Red Meat , Ribs , Torque
14.
Rev. odontol. UNESP (Online) ; 49: e20200047, 2020. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1156802

ABSTRACT

Introduction: The cantilever length of implant-supported fixed prosthesis metal structure has been considered an important factor to transfer occlusion forces to the dental implant. Objective: This study evaluated the influence of different extensions of cantilevers of Branemark protocol implant prosthesis when submitted to mechanical thermocycling by screw loosening evaluation. Material and method: The groups G10 (n = 5), G15 (n = 5) and G20 (n = 5) were formed according to the distance in millimeters between the force application site in the cantilever and the center of the last implant. All metal structures (n = 15) were submitted to a 120 N cyclic vertical load in a chewing simulation machine (MSM-Elquip, São Carlos-SP, Brazil) under controlled temperature and moisture conditions. Two hundred and fifty thousand mechanical cycles were performed with a frequency of 2 Hz that simulates a masticatory activity similar to 3 months. To compare the data obtained regarding the loosening of the metal structure screws, implant position and sites of load application, the analysis of variance with two factors and the Tukey test were performed. Result: Statistical analysis showed that the G10 group presented greater torque loss, statistically different from G15 (p = 0.001) and G20 (p = 0.002), and there was no significant difference between groups G15 and G20. Conclusion: It can be concluded from the results that all the screws presented torque loss after simulation of 3 month masticatory activity, suggesting the need for periodical evaluation to prevent failures in the treatment.


Introdução: O comprimento do cantilever da infraestrutura de prótese implanto-suportada tem sido considerado um importante fator de transferência de força de oclusão para o implante dentário. Objetivo: Esse trabalho avaliou a influência das diferentes extensões do cantilever da prótese sobre implantes tipo protocolo de Branemark submetidas à termociclagem mecânica pela avaliação dos afrouxamentos dos parafusos de fixação. Material e método: Os grupos G10 (n=5), G15 (n=5) e G20 (n=5) foram formados de acordo com a distância, em milímetros, entre o local de aplicação de força no cantilever e o centro do último implante. Todas as barras (n=15) foram submetidas a carga vertical cíclica de 120 N em uma máquina de simulação de mastigação (MSM-Elquip, São Carlos/SP, Brasil), em condições de temperatura e umidade controladas. Foram realizados 250 mil ciclos mecânicos com frequência de 2 Hz que simulou uma atividade mastigatória correspondente a 3 meses. Para comparar os dados obtidos quanto à soltura dos parafusos da barra, a posição dos implantes e os locais de aplicação de carga, foi realizada a análise de variância com dois fatores e o teste de Tukey. Resultado: A análise estatística mostrou que o grupo G10 apresentou maior perda de torque, diferente estatisticamente de G15 (p=0,001) e G20 (p=0,002) e que não houve diferença significante entre os grupos G15 e G20. Conclusão: Pode-se concluir que todos os parafusos apresentaram perda de torque após o ensaio simulando uma atividade mastigatória de 3 meses, sugerindo a necessidade de avaliação clínica periódica afim de prevenir fracasso no tratamento.


Subject(s)
Prostheses and Implants , Bite Force , Dental Implants , Torque , Mastication
15.
ABCD arq. bras. cir. dig ; 33(1): e1487, 2020. tab, graf
Article in English | LILACS | ID: biblio-1130500

ABSTRACT

ABSTRACT Background: Restoring the contractile function to the abdominal wall is a major goal in hernia repair. However, the core understanding is required when choosing the method for outcome assessment. Aim: To assess the role of the anterolateral abdominal muscles on abdominal wall function in patients undergoing hernia repair by analysis of correlation between the surface electromyography activation signal of these muscles and torque produced during validated strength tests. Methods: Activation of the rectus abdominis, external oblique, and internal oblique/transverse abdominis muscles was evaluated by surface electromyography during two validated tests: Step: 1-A, isometric contraction in dorsal decubitus; 1-B, isometric contraction in lateral decubitus; 2-A, isokinetic Biodex testing; and 2-B, isometric Biodex testing. Results: Twenty healthy volunteers were evaluated. The linear correlation coefficient between root mean square/peak data obtained from surface electromyography signal analysis for each muscle and the peak torque variable was always <0.2 and statistically non-significant (p<0.05). The agonist/antagonist ratio showed a positive, significant, weak-to-moderate correlation in the external oblique (Peak, p=0.027; root mean square, 0.564). Surface electromyography results correlated positively among different abdominal contraction protocols, as well as with a daily physical activity questionnaire. Conclusions: There was no correlation between surface electromyography examination of the anterolateral abdominal wall muscles and torque measured by a validated instrument, except in a variable that does not directly represent torque generation.


RESUMO Racional: A devolução da funcionalidade contrátil da parede abdominal é uma das metas no reparo das hérnias abdominais. Contudo, o entendimento do core deve necessariamente fazer parte na escolha do método de avaliação desse desfecho. Objetivo: Avaliar o papel dos músculos da parede anterolateral na função da parede abdominal com base na correlação entre o sinal de ativação muscular obtido na eletromiografia de superfície e torque produzido durante testes de força validados. Métodos: A ativação dos músculos reto abdominal, oblíquo externo, e oblíquo interno e transverso foi avaliada por eletromiografia de superfície durante dois testes validados. Etapa: 1-A, contração isométrica em decúbito dorsal; 1-B, contração isométrica em decúbito lateral; 2-A, teste isocinético no Biodex; e 2-B, teste isométrico no Biodex. Resultados: Foram avaliados 20 voluntários saudáveis. O coeficiente de correlação linear entre os dados de valor quadrático médio/Pico obtidos análise do sinal da eletromiografia de superfície para cada músculo e o Pico de torque foram sempre <0,2 e estatisticamente insignificantes (p<0.05). A relação agonista/antagonista demonstrou correlação positiva, significativa e de fraca a moderada no músculo externo oblíquo (Pico, p=0,027; valor quadrático médio, 0,564). Os resultados eletromiografia de superfície estiveram positivamente correlacionados nos diferentes protocolos de contração abdominal e também com um questionário de atividade física diária. Conclusões: Não houve correlação entre o exame de eletromiografia de superfície e o torque mensurado por um instrumento validado, exceto em uma variável que não representa diretamente a geração de torque.


Subject(s)
Humans , Abdominal Wall , Abdominal Muscles , Torque , Electromyography , Isometric Contraction
16.
Einstein (Säo Paulo) ; 18: e0AO5052, 2020. graf
Article in English | LILACS | ID: biblio-1090065

ABSTRACT

ABSTRACT Objective To compare screw fixation strength for subtalar arthrodesis. Methods Eight matched pairs of cadaver feet underwent subtalar joint arthrodesis with two 7.3mm cannulated screws. Randomization was used to assign screw orientation, such that one foot in each pair was assigned dorsal to plantar screw orientation (DP Group), and the other foot, plantar to dorsal orientation (PD Group). Standard surgical technique with fluoroscopy was used for each approach. Following fixation, each specimen was loaded to failure with a Bionix ® 858 MTS device, applying a downward axial force at a distance to create torque. Torque to failure was compared between DP and PD Groups using Student's t test, with p=0.05 used to determine statistical significance. Results Statistical analysis demonstrated that the mean torque to failure slightly favored the DP Group (37.3Nm) to the PD Group (32.2Nm). However, the difference between the two groups was not statistically significant (p=0.55). Conclusion In subtalar arthrodesis, there is no significant difference in construct strength between dorsal-to-plantar and plantar-to-dorsal screw orientation. The approach chosen by the surgeon should be based on factors other than the biomechanical strength of the screw orientation.


RESUMO Objetivo Comparar a força de fixação dos parafusos para artrodese subtalar. Métodos Oito pares de pés de cadáveres frescos foram submetidos à artrodese da articulação subtalar com dois parafusos canulados de 7,3mm. A randomização foi usada para atribuir a orientação do parafuso, de modo que um pé em cada par foi designado com orientação de dorsal para plantar (Grupo DP), e o outro pé com orientação de plantar para dorsal (Grupo PD). Técnica cirúrgica padrão com radioscopia foi usada para os procedimentos. Após a fixação, cada amostra foi testada até a falha com um dispositivo Bionix®858 MTS, aplicando força axial descendente a uma distância para criar torque. O torque de falha foi comparado entre os Grupos DP e PD, usando o teste t de Student, com p=0,05 usado para determinar significância estatística. Resultados A análise estatística demonstrou que a média do torque até a falha favoreceu ligeiramente o Grupo DP (37,3Nm) em relação ao PD (32,2Nm). No entanto, a diferença entre os dois grupos não foi estatisticamente significativa (p=0,55). Conclusão Na artrodese subtalar, não há diferença significativa na força de compressão entre as orientações dos parafusos dorsal-plantar e plantar-dorsal. A abordagem escolhida pelo cirurgião deve ser baseada em outros fatores, sem preocupação com a força biomecânica da orientação dos parafusos.


Subject(s)
Humans , Arthrodesis/methods , Bone Screws , Subtalar Joint/surgery , Arthrodesis/instrumentation , Biomechanical Phenomena , Cadaver , Calcaneus/surgery , Talus/surgery , Reproducibility of Results , Treatment Failure , Torque
17.
Article in English | LILACS, BBO | ID: biblio-1135548

ABSTRACT

Abstract Objective: To evaluate the difference in torsional resistance, angular deflection and fragment length between two new rotary instruments: AF Blue S4 and S-One. These files share all features except cross-sectional design. Material and Methods: A total of 40 new Nickel-Titanium instruments of 25 mm in length were tested in this study and divided in two groups: 20 AF Blue S4, tip 25 and constant 6% taper and 20 AF-Blue S4 tip 25 and constant 6% taper. The torsional test was performed by the use of a torque recording endodontic motor (KaVo, Biberac, Germany). Torque to Fracture (TtF), Angular Deflection (AD) and Fragment Length (FL) was recorded for each instrument. To ensure an immovable block at 3mm of the instrument tip, an auto-polymerizing resin (DuraLay; Reliance Dental Mfg Co, Worth, IL) was used. Each file was rotated clockwise at a speed of 300 rpm until fracture occurred. Results: Group A (AF Blue S4) showed higher TtF and AD than Group B (S-One), and statistical analysis found significant differences between the two instruments (p<0.05). The mean values for FL showed no significant differences (p>0.05) between the two instruments. Conclusion: The AF Blue S4 seems to have a higher resistance to torsional stress in vitro. Clinically, the use of AF Blue S4 could be safer in narrow canals.


Subject(s)
Tensile Strength , In Vitro Techniques , Torque , Dental Alloys , Torsion, Mechanical , Titanium , Data Interpretation, Statistical , Dental Instruments , Endodontics/instrumentation , Italy/epidemiology , Nickel
18.
Rev. cient. odontol ; 7(2): 75-85, jul.-dic. 2019. ilus
Article in Spanish | LIPECS, LILACS, LIPECS | ID: biblio-1046731

ABSTRACT

Esta investigación realizó una revisión sobre la colocación de implantes dentales en pacientes con osteoesclerosis idiopática, para lo cual algunos investigadores proponen que se debe tener en cuenta un protocolo específico, el cual habla de un fresado con irrigación externa con suero fisiológico a 5 °C. La estabilidad del implante dental es importante para una buena osteointegración, la cual depende de la calidad ósea, la técnica quirúrgica y la superficie de contacto entre hueso e implante. La fuerza de torque para una buena estabilidad primaria, según una revisión sistemática, es de 20 Ncm a 45 Ncm. Para el éxito de la colocación de implantes dentales, se debe tener un buen diagnóstico de la zona edéntula y una correcta osteointegración. La identificación correcta de los hallazgos clínicos, como la osteoesclerosis idiopática, es importante para diferenciarla de otras patologías óseas benignas y malignas. La osteoesclerosis idiopática se caracteriza por ser asintomática, no tener etiología conocida y no tener tratamiento indicado. El lugar más común donde se presenta esta patología ósea es en el maxilar superior y la zona más prevalente es la zona premolar, aunque algunos autores han reportado la zona molar como la más prevalente para esta condensación ósea. En la actualidad, no existe suficiente investigación sobre la colocación de implantes dentales en pacientes con osteoesclerosis idiopática para determinar la fuerza de torque de inserción con la que se deberían colocar los implantes para una buena estabilidad primaria en una zona con condensación ósea. (AU)


The present review is on the placement of dental implants in patients with idiopathic osteoesclerosis. Some studies have proposed the need for a specific protocol which involves milling with external irrigation with physiological serum at 5 degrees Celsius. The stability of the dental implant is important for good osseointegration, which depends on bone quality, surgical technique and contact surface between the bone and the implant. According to a systematic review, the torque force for good primary stability is 20 to 45 Ncm. Successful placement of dental implants requires accurate diagnosis of the edentulous area and correct osseointegration. It is important to differentiate clinical findings such as idiopathic osteoesclerosis from other benign and malignant bone pathologies. Idiopathic osteosclerosis is characterized as being asymptomatic, having no known etiology, and having no indicated treatment. The most common localization of this bone pathology is in the upper jaw, with the most prevalent area being the premolar area, while some authors have reported the molar area as the most prevalent for this bone condensation. At present, there are few studies on to the force of the insertion torque with which implants should be made to achieve good primary stability in an area with bone condensation in patients with idiopathic osteosclerosis. (AU)


Subject(s)
Humans , Male , Female , Osteosclerosis , Dental Implants , Osseointegration , Torque , Diagnosis, Differential
19.
Fisioter. Pesqui. (Online) ; 26(3): 298-303, jul.-set. 2019. tab, graf
Article in Portuguese | LILACS | ID: biblio-1039893

ABSTRACT

RESUMO O medo de quedas pode fazer com que o idoso desenvolva estratégias que alteram o equilíbrio semiestático e dinâmico, predispondo-o a um risco aumentado de cair. A função muscular dos abdutores e adutores de quadril tem importante papel na manutenção da estabilidade postural. Entretanto, não se sabe se idosos com medo de cair apresentam maior comprometimento na função muscular do quadril. Assim, o objetivo foi comparar o pico de torque (PT) isométrico dos músculos abdutores e adutores de quadril entre idosos com e sem medo de quedas. Os participantes foram divididos em dois grupos: com (n=81) e sem (n=81) medo de quedas. O PT dos abdutores e adutores de quadril foi obtido com dinamômetro isocinético (System 4 Pro, Biodex, Nova York, EUA). A comparação do PT dos grupos foi realizada por meio de modelo linear geral univariado, ajustado pelas covariáveis idade, sexo, índice de massa corporal, nível de atividade física e histórico de quedas, utilizando o software SPSS 17.0, com nível de significância de 5%. Não houve diferença do PT abdutor e adutor do quadril entre os grupos após análise univariada com ajustamento. Observou-se que idosos com medo de quedas não apresentam prejuízos na função muscular dos estabilizadores de quadril quando comparados a idosos sem medo de quedas.


RESUMEN El miedo a caerse puede hacer que los ancianos desarrollen estrategias de alteración del equilibrio semiestático y dinámico, predisponiéndolos a un mayor riesgo de caídas. La función muscular de los abductores y de los aductores de cadera juega un papel importante en el mantenimiento de la estabilidad postural. Sin embargo, no se sabe si los ancianos con miedo a caerse tienen un mayor deterioro en la función muscular de la cadera. Por lo tanto, el objetivo fue comparar el torque máximo (TM) isométrico de los músculos abductores y aductores de cadera entre los ancianos con miedo y sin miedo a caerse. Los participantes se dividieron en dos grupos: con miedo a caerse (n=81) y sin (n=81) miedo a caerse. El TM de los abductores y aductores de cadera se obtuvo mediante la utilización del dinamómetro isocinético (System 4 Pro, Biodex, Nueva York, EE.UU.). La comparación del TM de los grupos se realizó mediante un modelo lineal general univariado, ajustado por covariables edad, género, índice de masa corporal, nivel de actividad física e historial de caídas, utilizando el software SPSS 17.0, con nivel de significancia del 5%. No hubo diferencias entre el TM del abductor y del aductor de cadera entre los grupos tras el análisis univariado con ajuste. Se observó que los ancianos con miedo a caerse no presentaron daños en la función muscular de los estabilizadores de la cadera en comparación con los ancianos sin miedo a caerse.


ABSTRACT The fear of falling can cause older adults to develop strategies that alter the semi-static and dynamic balance, predisposing them to increased risk of falling. The muscular function of abductors and adductors plays an important role in maintaining postural stability. However, it is unknown whether older people with fear of falling have greater impairment in hip muscular function. Thus, the objective was to compare the isometric peak torque (PT) of hip abductor and adductor muscles among older adults with and without fear of falling. Participants were divided into two groups: with (n=81) and without (n=81) fear of falling. The PT of hip abductors and adductors was obtained with isokinetic dynamometer (System 4 Pro, Biodex, New York, USA). The PT groups were compared using general linear model univariate, adjusted for covariates age, sex, body mass index, physical activity level and history of falls, using the SPSS 17.0 software, with a significance level of 5%. No difference was found between the PT of hip abductor and adductor and the groups after univariate analysis with adjustment. We observed that older people with fear of falling have no muscle function loss of the hip stabilizers when compared with subjects without fear of falling.


Subject(s)
Humans , Male , Female , Middle Aged , Aged , Torque , Muscle Strength/physiology , Hip/physiology , Accidental Falls , Cross-Sectional Studies , Postural Balance/physiology , Muscle Strength Dynamometer , Fear/physiology
20.
Rev. ADM ; 76(4): 219-228, jul.-ago 2019. ilus
Article in Spanish | LILACS | ID: biblio-1023759

ABSTRACT

El quad-hélix (QH) es un aparato de expansión maxilar, fabricado con alambre de acero inoxidable soldado a bandas en molares, que dispone de espirales o hélices que aumentan la longitud de alambre del aparato, lo que lo hace muy elástico y aligera la magnitud de la fuerza sobre los dientes, es ampliamente usado tanto en dentición mixta como en permanente temprana, fácil de fabricar, higiénico y bien tolerado por los pacientes. Su principal acción es mover hacia vestibular los procesos dentoalveolares de la arcada maxilar, influyendo secundariamente en la expansión de la sutura palatina media en pacientes con dentición mixta o permanente temprana. El QH es muy práctico y tiene muchos usos y adaptaciones y se puede utilizar como auxiliar en el tratamiento de problemas de hábito de dedo o lengua, para abrir mordida, rotar y dar torque a molares permanentes o para mover sólo un diente en particular. En este artículo describimos una nueva aplicación del QH que consiste en la tracción, de dientes anteriores superiores permanentes retenidos, después del abordaje quirúrgico para localizarlos. También revisaremos las indicaciones, contraindicaciones, ventajas y desventajas del aparato QH soldado a bandas en molares así como su elaboración, variantes y forma de activación (AU)


The quad-helix (QH) is a maxillary expansion appliance, manufactured with stainless steel wire welded to bands in molars, which has spirals or helix to increase the length of wire of the device, which makes it very elastic and lightens the magnitude of the force on the teeth, is widely used both in mixed and in early permanent dentition, is easy to manufacture, hygienic and well tolerated by patients. Its major action is to move towards the dentoalveolar process of the maxillary arcade, secondarily influencing the expansion of the middle palatal suture in young patients with mixed or permanent early dentition. The QH is very practical and has many uses and adaptations as an aid in the treatment of problem of thumb sucking or tongue habit, to open bite, to rotate and torque permanent molars or to move only one particular tooth. In this article we describe a new application of the QH that consist of the traction or retained permanent upper teeth, after surgical approach to locate them. We will also review the indications, contraindications, advantages and disadvantages of the QH welded to molar bands, as well as its construction, variants and activation form (AU)


Subject(s)
Humans , Child, Preschool , Child , Palatal Expansion Technique , Malocclusion/therapy , Orthodontic Wires , Tongue Habits , Dentition, Permanent , Torque , Dentition, Mixed
SELECTION OF CITATIONS
SEARCH DETAIL