Long term dental transversal stability of Class II division 1 treated with cervical headgear.

INTRODUCTION: In several conditions, outcome stability is a great challenge for Orthodontics. Previous studies have reported that relapse commonly occurs along the years after orthodontic treatment finishing. OBJECTIVE: The aim of the present study was to evaluate in the long-term transversal dental arch changes of Class II division 1 patients treated with cervical headgear and fixed appliance. METHODS: Plaster study casts of 20 patients treated with cervical headgear without dental extractions were 3D-scanned and evaluated in three distinct times: initial (T1), immediate post-treatment (T2) and long-term retention (T3 - minimum 20 years). Transversal teeth distance of maxillary and mandibular canines, premolars and first molars were measured. RESULTS: A statistically significant increase during treatment was observed for all maxillary teeth transversal distances (p< 0.05). In turn, a significant reduction was observed in the long term (p< 0.05). For the mandibular teeth, canine transversal distance presented statistically significant constriction in the retention period (p< 0.05). Mandibular first molars distance was significantly expanded by treatment (p< 0.05) and remained stable in the long term. The changes observed for the other teeth or other times were considered not statistically relevant. CONCLUSIONS: For the accessed sample, transversal changes occurred during treatment and retention phases in Class II division 1 patients treated with cervical headgear and fixed appliance. Relapse was considered statistically relevant, even with the institution of a retention protocol.

Long term dental transversal stability of Class II division 1 treated with cervical headgear

ABSTRACT Introduction: In several conditions, outcome stability is a great challenge for Orthodontics. Previous studies have reported that relapse commonly occurs along the years after orthodontic treatment finishing. Objective: The aim of the present study was to evaluate in the long-term transversal dental arch changes of Class II division 1 patients treated with cervical headgear and fixed appliance. Methods: Plaster study casts of 20 patients treated with cervical headgear without dental extractions were 3D-scanned and evaluated in three distinct times: initial (T1), immediate post-treatment (T2) and long-term retention (T3 - minimum 20 years). Transversal teeth distance of maxillary and mandibular canines, premolars and first molars were measured. Results: A statistically significant increase during treatment was observed for all maxillary teeth transversal distances (p< 0.05). In turn, a significant reduction was observed in the long term (p<0.05). For the mandibular teeth, canine transversal distance presented statistically significant constriction in the retention period (p<0.05). Mandibular first molars distance was significantly expanded by treatment (p<0.05) and remained stable in the long term. The changes observed for the other teeth or other times were considered not statistically relevant. Conclusions: For the accessed sample, transversal changes occurred during treatment and retention phases in Class II division 1 patients treated with cervical headgear and fixed appliance. Relapse was considered statistically relevant, even with the institution of a retention protocol.

RESUMO Introdução: Em várias condições, a estabilidade dos resultados é um grande desafio para a Ortodontia. Estudos prévios relataram que a recidiva ocorre, comumente, ao longo dos anos, após o término do tratamento ortodôntico. Objetivo: O objetivo da presente pesquisa foi avaliar as alterações transversais da arcada dentária em longo prazo de pacientes Classe II, divisão 1, tratados com aparelho extrabucal cervical e aparelho fixo. Métodos: Modelos de gesso de 20 pacientes tratados com AEB cervical, sem extrações dentárias, foram escaneados e avaliados em três momentos distintos: inicial (T1), pós-tratamento imediato (T2) e acompanhamento de longo prazo (T3, mínimo de 20 anos). A distância transversal entre os caninos superiores e inferiores, pré-molares e primeiros molares foi medida. Resultados: Foi observado aumento estatisticamente significativo durante o tratamento para todas as distâncias transversais dos dentes superiores (p < 0,05). Por sua vez, foi observada redução significativa em longo prazo (p < 0,05). Para os dentes inferiores, a distância transversal intercaninos apresentou constrição estatisticamente significativa no período de contenção (p < 0,05). A distância dos primeiros molares inferiores aumentou significativamente com o tratamento (p < 0,05) e permaneceu estável em longo prazo. As alterações observadas para os outros dentes ou outros tempos foram consideradas sem significância estatística. Conclusões: Para a amostra estudada, as alterações transversais ocorreram durante as fases de tratamento e contenção em pacientes Classe II, divisão 1, tratados com aparelho extrabucal de tração cervical e aparelho fixo. A recidiva foi considerada estatisticamente significativa, mesmo com a instituição de um protocolo de contenção.

Effect of Orthodontic Treatment on Tooth Autotransplantation: Systematic Review of Controlled Clinical Trials.

This systematic review was focused on evaluating tooth autotransplantation, considering its impacts on the teeth, bone, soft tissues, and aesthetics in orthodontic patients. A bibliographic search was conducted without limitations on year of publication or language in the databases of PubMed, Web of Science, Scopus, Medline Complete, Cochrane, Clinical Trials, and Trials Central. For triage of articles, indications, surgical planning, orthodontic movement, risk factors for treatment, and long-term follow-ups were considered. For outcomes, the results with reference to teeth, alveolar bone, periodontal tissues, and esthetic satisfaction were considered. Risk of bias was evaluated using the methodological index for nonrandomized studies-MINORS. The results showed 10 controlled clinical trials, and no randomized clinical trials were found. The selected studies included 715 patients and 934 autotransplanted teeth among which there were premolars, molars, and anterior teeth evaluated in the long term, indicating that orthodontics associated with autotransplantation indicated a result that was generally clinically acceptable. The quality of the set of evidence was considered medium due to the presence of different methodological problems, risk of bias, and significant heterogeneity in the evaluated studies. There was a sufficient body of evidence that justified autotransplantation in patients who needed orthodontic movement. In teeth, there was an increase in root resorption influenced by orthodontics, but without impacting on the general clinical result in the long term. Bone and periodontal tissue do not appear to be affected by orthodontics. The patient's aesthetic satisfaction was not considered in the studies.

Current status of low intensity pulsed ultrasound for dental purposes.

Over the past few years, tissue engineering applied to the dental field has achieved relevant results. Tissue engineering can be described by actions taken to improve biological functions. Several methods have been described to enhance cellular performance and low intensity pulsed ultrasound (LIPUS) has shown to play an important role in cell metabolism. The present article provides an overview about the current status of LIPUS as a tissue engineering tool to be used to enhance tooth and periodontal regeneration.

Effect of PGE2 induced by compressive and tensile stresses on cementoblast differentiation in vitro.

OBJECTIVE: The aim of the study was to clarify the mechanisms underlying orthodontically induced root resorption by characterizing the role of PGE(2) induced by compressive stress (CS) and tensile stress (TS) on cementoblast metabolism in vitro. DESIGN: Mouse cementoblast cell line OCCM-30 was continuously stimulated with 0.2 KPa CS or 5.0 KPa TS. COX-2 mRNA expression and PGE(2) production were thus quantified. In addition, cells were treated with COX-2 inhibitor and the role of PGE(2) induced by CS or TS on the expression of genes related to cementoblast differentiation was examined. PGE(2) receptors mRNA expression induced by CS or TS was also evaluated. Moreover, cells were treated with exogenous PGE(2) and the role of PGE(2) concentration on matrix mineralization was verified. RESULTS: CS and TS enhanced COX-2 mRNA expression and PGE(2) production. PGE(2) synthesis, however, was markedly induced by CS. Gene expression of bone morphogenetic protein 2 (BMP-2), osteocalcin (OCN) and receptor activator for nuclear factor kappaB ligand (RANKL) was enhanced by CS on an endogenous PGE(2)-mediated manner. Osteoprotegerin (OPG) expression was not affected by CS. Meanwhile, TS up-regulated the expression of BMP-2 and alkaline phosphatase (ALP) on an endogenous PGE(2)-mediated manner. TS down-regulated RANKL mRNA expression, whilst OPG expression was not affected. Moreover, EP4 mRNA expression was considerably enhanced by TS. Regarding PGE(2) concentration, only cells treated with low concentration presented anabolic response. CONCLUSIONS: Gene expression was differentially regulated according to the type of mechanical stimulation applied to cementoblasts. In addition, it is shown that PGE(2) plays an important role on mediating cementoblast mechanosensitivity.

Ultrasound stimulation induces PGE(2) synthesis promoting cementoblastic differentiation through EP2/EP4 receptor pathway.

The present study aims to provide insights into how ultrasound treatment (US) can affect the regenerative response of cementum by evaluating the role of prostaglandin E(2) induced by ultrasound stimulation on cementoblastic differentiation. The mouse cementoblast cell line OCCM-30 was exposed to low-intensity ultrasound and the cyclooxygenase-2 (COX-2) mRNA expression and prostaglandin E(2) (PGE(2)) production were quantified. The role of the US-induced PGE(2) in mineralization was examined using COX-2 inhibitor and prostaglandin receptors (EP-receptors) agonists and antagonists. In addition, gene expression of differentiation markers related to mineral metabolism was evaluated. Ultrasound significantly enhanced COX-2 mRNA expression and PGE(2) production. PGE(2) induced by US mediated mineral nodule formation, whereas COX-2 inhibitor treatment eliminated the enhancement of mineralization induced by US stimulation. Mineral deposition was also inhibited by treatment with EP2 or EP4 antagonist. Moreover, up-regulation of differentiation markers induced by US was suppressed by treatment with COX-2 inhibitor. The present findings provide evidence that US stimulation has a positive effect on mineralization ability of cementoblasts through the activation of EP2/EP4 pathway, suggesting that US can be a promising therapeutic tool for cementum repair.

Shear bond strength of metallic brackets photo-activated with light-emitting diode (LED) at different exposure times

The purpose of this study was to compare the shear bond strength of orthodontic metallic brackets photo-activated with two different light-curing sources at different exposure times: halogen light (XL 1500, 3M ESPE) and LED light (Ortholux, 3M Unitek). Sixty bovine permanent lower incisors were inserted into PVC tubes containing plaster. The buccal surfaces were cleaned with pumice and water, and then etched with 37 percent phosphoric acid gel. The XT Primer bonding agent (3M Unitek) was applied to the enamel surfaces and the metallic pre-coated brackets (Transbond APC II system, 3M Unitek) were attached to upper central incisors. The teeth were randomly divided into four groups (n=15). In Group I (Control), halogen light was used for 40 seconds, while in Groups II, III, and IV were light-cured with LED light unit for 40, 10, and 5 seconds, respectively. The teeth were stored in distilled water at 37°C for 24 hours. The brackets were submitted to shear bond strength test in universal testing machine (Instron) at a crosshead speed of 0.5 mm/minute. Shear bond strength means (MPa) were 4.87 for Group I; 5.89 for Group II; 4.83 for Group III, and 4.39 for Group IV. Tukey's test detected no statistically significant differences among the groups regarding the shear bond strength (p>0.05). Neither of the types of light-curing sources or exposure times influenced the shear bond strength of metallic brackets.

Shear bond strength of metallic brackets photo-activated with light-emitting diode (LED) at different exposure times.

The purpose of this study was to compare the shear bond strength of orthodontic metallic brackets photo-activated with two different light-curing sources at different exposure times: halogen light (XL 1500, 3M ESPE) and LED light (Ortholux, 3M Unitek). Sixty bovine permanent lower incisors were inserted into PVC tubes containing plaster. The buccal surfaces were cleaned with pumice and water, and then etched with 37% phosphoric acid gel. The XT Primer bonding agent (3M Unitek) was applied to the enamel surfaces and the metallic pre-coated brackets (Transbond APC II system, 3M Unitek) were attached to upper central incisors. The teeth were randomly divided into four groups (n=15). In Group I (Control), halogen light was used for 40 seconds, while in Groups II, III, and IV were light-cured with LED light unit for 40, 10, and 5 seconds, respectively. The teeth were stored in distilled water at 37 degrees C for 24 hours. The brackets were submitted to shear bond strength test in universal testing machine (Instron) at a crosshead speed of 0.5 mm/minute. Shear bond strength means (MPa) were 4.87 for Group I; 5.89 for Group II; 4.83 for Group III, and 4.39 for Group IV. Tukey's test detected no statistically significant differences among the groups regarding the shear bond strength (p>0.05). Neither of the types of light-curing sources or exposure times influenced the shear bond strength of metallic brackets.

Avaliação do índice de Peck Peck em pacientes portadores de maloclusão Classe I e Classe II, primeira divisão de Angle / Evaluation of Peck and Peck index in patients with Angle Class I and Class II division 1 malocclusions

Alterações no tamanho mésio-distal e vestibulo-lingual dos dentes podem significar dificuldade no correto posicionamento dos incisivos na arcada. Este estudo propôs avaliar o equilíbrio dentário através do índice de PECK PECK (1975) em pacientes leucodermas portadores de maloclusão Classe I e Classe II, 1ª divisão de Angle. Foram selecionados 100 modelos de gesso da arcada inferior com apinhamento anterior em graus variados de pacientes não tratados ortodonticamente. As dimensões mésio-distal e véstibulo-lingual dos incisivos inferiores foram mensuradas com auxílio de paquímetro digital com graduação 0,01mm. Os resultados mostraram que o Grupo I apresentou discrepância nos incisivos centrais e laterais esquerdos em 86,67 por cento dos casos, os incisivos centrais direitos apresentaram discrepância em 82,23 por cento e os incisivos laterais direitos em 84,45 por cento dos casos. O Grupo II, 1 apresentou discrepância nos incisivos centrais esquerdos em 89,10 por cento e os incisivos centrais direitos em 87,28 por cento dos casos, os incisivos laterais esquerdos apresentaram discrepância em 83,64 por cento dos casos, uma incidência menor que os incisivos laterais direitos, com 85,46 por cento. Pode-se concluir que os incisivos laterais e centrais esquerdos apresentaram maior incidência de discrepância dentária para a maioria dos casos, quando comparados aos homólogos em ambos os grupos, e houve ausência de correlação total entre homólogos em ambos os grupos.