The treatment of incisor protrusion by means of tooth extraction can be challenging for orthodont... more The treatment of incisor protrusion by means of tooth extraction can be challenging for orthodontists, especially during the space closure phase. Moreover, the level of difficulty may increase when anterior movement of the posterior teeth is not desirable. Treatment alternatives may include the use of mini implants, mini plates, and extraoral devices to reinforce anchorage; however, some patients may oppose these aggressive methods. This article describes the use of frictionless segmented mechanics that provide differential moments for controlled space closure during full retraction of the incisors without using extraoral forces or temporary anchorage devices.
This article discusses the orthodontic treatment of a girl, 9 years old, who presented with Class... more This article discusses the orthodontic treatment of a girl, 9 years old, who presented with Class II malocclusion, bimaxillary rotrusion, anterior open bite, and congenital absence of the right lower premolar, in which a severe hypoplasia on right maxillary canine was nly noted after the extractions of the first maxillary premolars.
Revista Clínica de Ortodontia Dental Press, Mar 1, 2021
OBJETIVO: O objetivo deste artigo é ilustrar a aplicabilidade do expansor Mini-Hyrax na expansão ... more OBJETIVO: O objetivo deste artigo é ilustrar a aplicabilidade do expansor Mini-Hyrax na expansão rápida da maxila (ERM) e na expansão rápida da maxila assistida cirurgicamente (ERMAC). DESCRIÇÃO DO APARELHO: As principais diferenças entre o parafuso utilizado no Mini-Hyrax e aquele do Hyrax são a dimensão anteropos- terior da estrutura e o número de braços. O Mini-Hyrax tem uma dimensão anteroposterior menor (5 mm) e dois braços; enquanto que o Hyrax tem 11 mm e quatro braços. CONCLUSÃO: O Mini-Hyrax pode ser uma alternativa aos aparelhos expansores Haas e Hyrax na ERM e ERMAC com potenciais vantagens de causar menor desconforto e menor dificuldade na higienização devido ao seu tamanho reduzido.
Objective: The authors' objective was to determine, by means of cone-beam computed tomography (CB... more Objective: The authors' objective was to determine, by means of cone-beam computed tomography (CBCT), if there is a significant difference between the cephalometric and condylar measurements obtained in maximum intercuspation (MIP) and those obtained in centric relation (CR), which would interfere in orthodontic diagnosis and planning. Methods: The sample consisted of 30 randomly selected patients (15 men and 15 women, mean age 14 years, CR ≠ MIP between 1 mm and 2 mm) who had undergone orthodontic treatment. This retrospective study used CBCT scans, one in MIP and the other in CR. Cephalometric measurements and sagittal, axial, and vertical condylar variations between the CR and MIP positions were analyzed in a tridimensional (3D) imaging software. Results: Patients with a small CR-MIP discrepancy (<2 mm) presented significant differences in the cephalometric analysis carried out in CR and MIP, although these differences might be of low clinical significance. The condyle-fossa relationships in sagittal, coronal, and axial planes did not seem to be relevant, because only one measurement presented significant change between CR and MIP positions. Conclusions: Class II malocclusion in patients with a large CR-MIP discrepancy may be exacerbated in the CR position, which may in turn increase treatment difficulty. In these cases, not only must cephalometrics be registered in CR, but dental casts and photographs of the patient are needed to permit orthodontists to plan an appropriate treatment.
The aim of this study was to evaluate the shear bond strength of orthodontic tubes adhered to cer... more The aim of this study was to evaluate the shear bond strength of orthodontic tubes adhered to ceramics with the Transbond™ XT bonding resin (3M, Maplewood, MN, USA) while varying the surface treatment. Then, the adhesive remaining index (ARI) was verified, and the representative fracture patterns were evaluated via scanning electron microscopy. Forty-eight zirconia blocks were divided into three groups, varying the number of layers of the 10-methacryloyloxy-decyl dihydrogen phosphate (MDP) primer: one, two, or three applications. In addition, 16 lithium disilicate IPS E.max ceramic disks (Ivoclar Vivadent, Schaan, Liechtenstein) were conditioned with 10% hydrofluoric acid for 20 s and underwent a single-layer primer application regimen. The four groups were further stratified to undergo bond testing after either 24 h (control) or 5000 cycles in a thermocycling machine. A shear bond strength test was performed (0.5 mm/min), and the MPa values obtained were submitted to a two-way anal...
of the bur. Additional abrasion mesial and distal to the center line of the base can further redu... more of the bur. Additional abrasion mesial and distal to the center line of the base can further reduce the force needed to fracture the bracket in debonding (C). Once the fracture line has been created, use either a Weingart or a How plier to squeeze and fracture the tie wings (D). How pliers tend to produce better results than Weingart pliers because of the greater distance between the plier hinge and tips, which makes for a better fit between the internal surfaces of the tips and the external surfaces of the tie wings. In most cases, the two halves of the bracket will debond simultaneously. If one half stays on the tooth, it is easily removed by applying a rocking motion with the same plier. Ceramic fragments often remain on the enamel after debonding of monocrystalline brackets1 (E), requiring removal with the same high-speed diamond bur under water cooling. Any adhesive remnants should be removed by using a low-speed, sixor 12-blade tungsten carbide bur with a smooth, rounded tip. ...
The treatment of incisor protrusion by means of tooth extraction can be challenging for orthodont... more The treatment of incisor protrusion by means of tooth extraction can be challenging for orthodontists, especially during the space closure phase. Moreover, the level of difficulty may increase when anterior movement of the posterior teeth is not desirable. Treatment alternatives may include the use of mini implants, mini plates, and extraoral devices to reinforce anchorage; however, some patients may oppose these aggressive methods. This article describes the use of frictionless segmented mechanics that provide differential moments for controlled space closure during full retraction of the incisors without using extraoral forces or temporary anchorage devices.
This article discusses the orthodontic treatment of a girl, 9 years old, who presented with Class... more This article discusses the orthodontic treatment of a girl, 9 years old, who presented with Class II malocclusion, bimaxillary rotrusion, anterior open bite, and congenital absence of the right lower premolar, in which a severe hypoplasia on right maxillary canine was nly noted after the extractions of the first maxillary premolars.
Revista Clínica de Ortodontia Dental Press, Mar 1, 2021
OBJETIVO: O objetivo deste artigo é ilustrar a aplicabilidade do expansor Mini-Hyrax na expansão ... more OBJETIVO: O objetivo deste artigo é ilustrar a aplicabilidade do expansor Mini-Hyrax na expansão rápida da maxila (ERM) e na expansão rápida da maxila assistida cirurgicamente (ERMAC). DESCRIÇÃO DO APARELHO: As principais diferenças entre o parafuso utilizado no Mini-Hyrax e aquele do Hyrax são a dimensão anteropos- terior da estrutura e o número de braços. O Mini-Hyrax tem uma dimensão anteroposterior menor (5 mm) e dois braços; enquanto que o Hyrax tem 11 mm e quatro braços. CONCLUSÃO: O Mini-Hyrax pode ser uma alternativa aos aparelhos expansores Haas e Hyrax na ERM e ERMAC com potenciais vantagens de causar menor desconforto e menor dificuldade na higienização devido ao seu tamanho reduzido.
Objective: The authors' objective was to determine, by means of cone-beam computed tomography (CB... more Objective: The authors' objective was to determine, by means of cone-beam computed tomography (CBCT), if there is a significant difference between the cephalometric and condylar measurements obtained in maximum intercuspation (MIP) and those obtained in centric relation (CR), which would interfere in orthodontic diagnosis and planning. Methods: The sample consisted of 30 randomly selected patients (15 men and 15 women, mean age 14 years, CR ≠ MIP between 1 mm and 2 mm) who had undergone orthodontic treatment. This retrospective study used CBCT scans, one in MIP and the other in CR. Cephalometric measurements and sagittal, axial, and vertical condylar variations between the CR and MIP positions were analyzed in a tridimensional (3D) imaging software. Results: Patients with a small CR-MIP discrepancy (<2 mm) presented significant differences in the cephalometric analysis carried out in CR and MIP, although these differences might be of low clinical significance. The condyle-fossa relationships in sagittal, coronal, and axial planes did not seem to be relevant, because only one measurement presented significant change between CR and MIP positions. Conclusions: Class II malocclusion in patients with a large CR-MIP discrepancy may be exacerbated in the CR position, which may in turn increase treatment difficulty. In these cases, not only must cephalometrics be registered in CR, but dental casts and photographs of the patient are needed to permit orthodontists to plan an appropriate treatment.
The aim of this study was to evaluate the shear bond strength of orthodontic tubes adhered to cer... more The aim of this study was to evaluate the shear bond strength of orthodontic tubes adhered to ceramics with the Transbond™ XT bonding resin (3M, Maplewood, MN, USA) while varying the surface treatment. Then, the adhesive remaining index (ARI) was verified, and the representative fracture patterns were evaluated via scanning electron microscopy. Forty-eight zirconia blocks were divided into three groups, varying the number of layers of the 10-methacryloyloxy-decyl dihydrogen phosphate (MDP) primer: one, two, or three applications. In addition, 16 lithium disilicate IPS E.max ceramic disks (Ivoclar Vivadent, Schaan, Liechtenstein) were conditioned with 10% hydrofluoric acid for 20 s and underwent a single-layer primer application regimen. The four groups were further stratified to undergo bond testing after either 24 h (control) or 5000 cycles in a thermocycling machine. A shear bond strength test was performed (0.5 mm/min), and the MPa values obtained were submitted to a two-way anal...
of the bur. Additional abrasion mesial and distal to the center line of the base can further redu... more of the bur. Additional abrasion mesial and distal to the center line of the base can further reduce the force needed to fracture the bracket in debonding (C). Once the fracture line has been created, use either a Weingart or a How plier to squeeze and fracture the tie wings (D). How pliers tend to produce better results than Weingart pliers because of the greater distance between the plier hinge and tips, which makes for a better fit between the internal surfaces of the tips and the external surfaces of the tie wings. In most cases, the two halves of the bracket will debond simultaneously. If one half stays on the tooth, it is easily removed by applying a rocking motion with the same plier. Ceramic fragments often remain on the enamel after debonding of monocrystalline brackets1 (E), requiring removal with the same high-speed diamond bur under water cooling. Any adhesive remnants should be removed by using a low-speed, sixor 12-blade tungsten carbide bur with a smooth, rounded tip. ...
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