Orthodontic treatment in traumatized permanent teeth: a systematic review / Tratamento ortodôntico em dentes permanentes traumatizados: uma revisão sistemática

Objective: to analyze, through literature review, the available literature on orthodontic treatment in traumatized permanent teeth. Methods: A literature search was performed in electronic databases (PubMed and SciELO) using the descriptors [tooth injuries] OR [injuries, teeth] OR [injury, teeth] OR [teeth injury] OR [injuries, tooth] OR [injury, tooth] OR [tooth injury] OR [teeth injuries] AND [orthodontics]. Observational studies and clinical trials were included, narrative reviews, laboratory and in vitro studies, case reports and series as well as articles that presented abstracts written in languages other than Portuguese, English and Spanish were excluded from the study. Two reviewers considered the eligibility, the risk of bias of the analyzed data and the qualitative synthesis of the studies included. A total of 1,322 references were found and 4 articles met all inclusion criteria and were included in the qualitative analysis. Some consequences like pulp necrosis and root resorption have been highlighted and trauma severity should be considered when orthodontically intervening in previously traumatized teeth. Final considerations: The traumatized teeth can be orthodontically treated as long as the time of tissue reorganization is respected, and the pull and periodontal conditions are followed up.(AU)

Objetivos: analisar, por meio de revisão de literatura, a respeito do tratamento ortodôntico em dentes permanentes traumatizados. Metodologia: Uma pesquisa bibliográfica foi realizada em bancos de dados eletrônicos (PubMed e SciELO) usando os descritores [tooth injuries] ou [injuries, teeth] ou [injury, teeth] ou [teeth injury] ou [injuries, tooth] ou [injury, tooth] ou [tooth injury] ou [teeth injuries] e [orthodontics]. Foram incluídos estudos observacionais e ensaios clínicos, revisões narrativas, estudos laboratoriais e in vitro, relatos de casos e séries, bem como artigos que apresentassem resumos redigidos em idiomas diferentes do português, inglês e espanhol foram excluídos do estudo. Dois revisores consideraram a elegibilidade, o risco de viés dos dados analisados e a síntese qualitativa dos estudos incluídos. Foram encontradas 1.322 referências e 4 artigos atenderam a todos os critérios de inclusão e foram incluídos na análise qualitativa. Algumas consequências como necrose pulpar e reabsorção radicular têm sido destacadas e a gravidade do trauma deve ser considerada na intervenção ortodôntica em dentes previamente traumatizados. Considerações finais: Os estudos incluídos nesta revisão sugerem que dentes traumatizados podem ser tratados ortodônticamente desde que respeitado o tempo de reorganização tecidual e acompanhadas as condições pulpares e periodontais.(AU)

Combined micro-apical surgery and vital pulp therapy in mandibular second molars with external root resorption caused by impacted teeth / 华西口腔医学杂志

OBJECTIVES@#This study aimed to establish a new treatment of the mandibular second molars with external root resorption caused by impacted teeth to preserve the affected teeth and their vital pulps.@*METHODS@#For mandibular second molars clinically diagnosed as external root resorption caused by impacted teeth, debridement and removal of the root at the resorption site via micro-apical surgery and direct capping of the pulp with bioactive material on the surface of the root amputation via vital pulp therapy were performed immediately after the impacted teeth were extracted.@*RESULTS@#The external root resorption of the affected tooth was ceased. It was asymptomatic with intact crown, normal pulp, periapical alveolar bone reconstruction, normal periodontal ligament, continuous bone sclerosis, and no periapical translucency in radiographic examination at the 1-year postoperative follow-up, thus showing good prognosis.@*CONCLUSIONS@#Simultaneous combination of micro-apical surgery and vital pulp therapy after extraction of impacted teeth could successfully preserve mandibular second molars with ERR caused by impacted teeth and their vital pulps.

Etiology and pathogenesis of internal root resorption / 中华口腔医学杂志

Internal root resorption is a pathologic phenomenon with a characterization of the intraradicular dentin destruction due to the abnormal activities of odontoclasts. With its insidious pathology, internal root resorption can progress to a great extent before its clinical detection. The etiology and natural history of internal root resorption are uncertain and the associated key molecular pathogenesis have not been understood completely. The resorption is usually initiated by a stimulus with the loss of the protective predentin and progressed by the continuous stimuli of pulp infection. Various factors including trauma, chronic inflammation of the pulp, pulpotomy and tooth transplantation have been proposed for the occurrence of internal root resorption. The present paper reviews the etiology and pathogenesis of internal root resorption and provides guidance for the early intervention in the clinical practice.

Effect of corticotomy techniques accelerating orthodontic tooth movement on root resorption / 北京大学学报(医学版)

In recent years, developing new methods to accelerate orthodontic tooth movement (OTM) has attracted extensive attention in the field of orthodontic clinical and scientific research. It reduces orthodontic treatment time and risks. Over the past, various approaches have been done to accelerate orthodontic tooth movement. Several forms of corticotomy techniques have been effective in inducing rapid tooth movement. These techniques activate regional acceleratory phenomenon and create a favorable microenvironment for accelerating tooth movement. Root resorption is one of most common side effects of orthodontic treatment. It affects the long-term viability and health of teeth. However, the effect of corticotomy techniques accelerating orthodontic tooth movement on root resorption still remains unclear. Accelerating tooth movement may have two-side effects on root resorption. Through shortening the treatment period and removing the hyalinized tissues, the acceleration of orthodontic tooth movement could reduce root resorption. The increase of root resorption might be due to the local inflammation and function of cementoclasts/odontoclasts. In this paper, we reviewed the effects of different corticotomy techniques accelerating orthodontic tooth movement on root resorption. Corticotomy techniques deal with mucoperio-steal flaps and bone tissues differently and develop towards minimally invasive. Previous studies on root resorption use two-dimensional images, including apical films and panoramic tomography, to evaluate the degree of root resorption. In recent years, researches measure the volume of root resorption accurately using cone-beam computed tomography (CBCT) and micro-CT. Most studies suggest that the root resorption during acceleration of orthodontic tooth movement through corticotomy techniques is not statistically different from that of traditional orthodontic treatment. Some studies using micro-CT have shown that the root resorption in the groups of corticotomy techniques increases compared with the control group without surgery. Because of the short duration of these studies, the clinical significance is controversial on the overall impact of corticotomy techniques on orthodontic treatment. Accelerating orthodontic tooth movement is still at its emerging phase and need further research in the form of clinical trials to illustrate the effect of corticotomy techniques accelerating orthodontic tooth movement on root resorption.

Alteraciones dentarias en piezas sometidas a fuerzas de ortodoncia con técnica de Arco Recto / Dental alterations in pieces subjected to orthodontic forces with the straight wire technique

El objetivo fue evaluar radiográficamente las alteraciones dentarias en piezas sometidas a fuerzas ortodóncicas. Se analizaron 2871 piezas dentarias por observación radiográfica pre y post tratamiento. Variables registradas: sexo, edad, tipo de alteración, pieza dentaria y grado de reabsorción. Se calcularon intervalos de confianza 95% por método score de Wilson. Se utilizó prueba de bondad de ajuste Chi cuadrado, comparando frecuencias observadas con frecuencias esperadas bajo independencia. Se utilizó prueba de diferencia de proporciones, estadístico de Fisher y prueba Chi-cuadrado de asociación. Se concluyó que las alteraciones dentarias post tratamiento de ortodoncia son frecuentes y se originan en factores biológicos y mecánicos. La mayor tasa de prevalencia son las reabsorciones radiculares. Es responsabilidad del ortodoncista conocer todos los factores de riesgo con el fin de prevenirlas o detenerlas a tiempo (AU)

The correlation between external apical root resorption and electric pulp test responses: a prospective clinical trial

ABSTRACT Objective: The current study investigated the correlation between pulpal sensitivity to the electric pulp tester (EPT) and external apical root resorption (EARR) in four types of maxillary anterior teeth of fixed orthodontic treatment patients. Methods: In this prospective cohort study, 232 anterior teeth of 58 patients (mean age 18.96 ± 6.13 years) treated with fixed orthodontic treatment were examined. The EPT readings were recorded at twelve time points immediately before archwire insertion. Root resorption of four maxillary incisors were measured by means of parallel periapical radiographs at three time intervals (six months interval from the start) through design-to-purpose software to optimize data collection. A multiple linear regression model and Pearson correlation coefficient were used to assess the association of EPT values and observed EARR (p< 0.05). Results: The highest level of EPT measurement was recorded at initial visit, and then there was a decreasing trend in EPT level during treatment for the next six and twelve months. There was another increasing trend after six months till the finishing time of the treatment. There was a significant correlation between changes in root length and time of recording the root length (p< 0.001). There was significant positive correlation between changes in EPT level and amount of observed root resorption (p< 0.001). Conclusion: The relative decrease in electric pulp test level could be a diagnostic sign of root resorption during orthodontic treatment. Further studies with longer follow up are needed to confirm the current results.

RESUMO Objetivo: O presente estudo investigou a correlação entre a sensibilidade pulpar ao teste pulpar elétrico (TPE) e a reabsorção radicular apical externa (RRAE) nos quatro dentes anteriores superiores de pacientes em tratamento ortodôntico com aparelho fixo. Métodos: Nesse estudo de coorte prospectivo, foram avaliados 232 dentes anteriores de 58 pacientes (idade média 18,96 ± 6,13 anos) tratados com aparelho ortodôntico fixo. As leituras do TPE foram registradas em doze tempos de avaliação, imediatamente antes da inserção dos arcos. As reabsorções radiculares dos quatro incisivos superiores foram aferidas por meio da média das radiografias periapicais, em três intervalos de tempo (em intervalos de seis meses desde o início) por um software desenvolvido para essa finalidade, com o intuito de otimizar a coleta de dados. Para aferir a associação entre os valores de TPE e as RRAE observadas (p< 0,05), foram utilizados o modelo de regressão linear múltiplo e o coeficiente de correlação de Pearson. Resultados: O nível mais alto das medidas do TPE foi registrado na primeira visita e, daí em diante, houve uma tendência de diminuição no nível do TPE durante o tratamento, nos seis a doze meses seguintes. Houve, também, outra tendência de aumento após os seis meses até o término do tratamento, além de uma correlação significativa entre as mudanças no comprimento radicular e o tempo de registro do comprimento radicular (p< 0,001), bem como uma correlação positiva significativa entre as mudanças no nível do TPE e a quantidade de reabsorção radicular observada (p< 0,001). Conclusão: Uma diminuição relativa no nível de sensibilidade ao teste pulpar elétrico pode ser um sinal diagnóstico de reabsorção radicular durante o tratamento ortodôntico. Estudos futuros com acompanhamentos mais longos são necessários para confirmar os presentes resultados.

Invasive cervical resorption of central incisor during orthodontic treatment

ABSTRACT Introduction: Invasive cervical resorption (ICR) is a relatively rare type of ERR (External Root Resorption), in which a localized resorption begins in the cervical area of the tooth, below the epithelial junction and above the ridge crest. Objective: Describe the clinical case of an 11-year-old boy with no dental trauma history, presenting moderate crowding and ectopic eruption of the maxillary right central incisor. He had been undergoing orthodontic treatment elsewhere, and his family was dissatisfied with the results. Description: A new treatment was indicated, which included rapid maxillary expansion followed by extraction of four premolars. During routine panoramic evaluation, a radiolucid image was detected and a periapical radiograph was requested. At this point, an ICR of the maxillary right central incisor was found. The treatment was cautiously finalized and despite the use of light forces, central incisor was severally compromised by ICR and was therefore extracted. Conclusion: This clinical example discusses the importance of routine radiographs for the early diagnoses of ICR.

RESUMO Introdução: A reabsorção cervical invasiva (RCI) é um tipo relativamente raro de reabsorção radicular externa (RRE), no qual uma reabsorção localizada começa na região cervical do dente, abaixo da junção epitelial e acima da crista marginal. Objetivo: Descrever o caso clínico de um menino com 11 anos de idade, sem histórico de trauma dentário, apresentando apinhamento moderado e erupção ectópica do incisivo central superior. Ele realizava tratamento ortodôntico em outro local, mas sua família estava insatisfeita com os resultados. Descrição: Foi iniciado um novo tratamento, que incluiu a expansão rápida da maxila, seguida pela extração de quatro pré-molares. Durante a avaliação de rotina da radiografia panorâmica, uma imagem radiolúcida foi detectada, e uma radiografia periapical da região foi solicitada, sendo encontrada uma RCI no incisivo central superior direito. O tratamento foi finalizado com cautela e, apesar do uso de forças leves, o incisivo central estava seriamente comprometido pela RCI e, portanto, precisou ser extraído. Conclusão: Esse exemplo clínico discute a importância das radiografias de rotina para o diagnóstico precoce da RCI.

Lateral and apical root resorption in teeth orthodontically moved into edentulous ridge areas

ABSTRACT Objective: The present study aimed at comparing the external lateral root resorption (ELRR) and external apical root resorption (EARR) between teeth moved through the atrophic edentulous ridge and those undergoing the usual orthodontic movement. Methods: Fifty-four premolars were evaluated, where 27 of them had been moved toward the edentulous ridge (Group 1) and 27 from the same patient, had not been translated, which comprised the control group (Group 2). ELRR was evaluated by 0-3 scores and EARR was evaluated by 0-4 scores, before and after movement. Measurements were compared by Kruskal-Wallis and Student-Newman-Keuls tests. Results: ELRR increased statistically only in the Group 1 (p< 0.05). After orthodontic treatment, it was observed that almost 56% (n = 15) of teeth in Group 1 presented scores 2 and 3, while Group 2 presented scores 2 and 3 in about 11% (n= 3) of the teeth. EARR increased in both groups after orthodontic movement, however, statistically analyses showed no significant differences between groups (p> 0.05). Conclusions: Orthodontic movement into the atrophic edentulous ridge is subject to a greater lateral external root resorption.

RESUMO Objetivo: O presente estudo teve como objetivo comparar a reabsorção radicular lateral externa (RRLE) e a reabsorção radicular apical externa (RRAE) em dentes movimentados sobre o rebordo edêntulo atrófico e naqueles submetidos à movimentação ortodôntica usual. Métodos: Foram avaliados 54 pré-molares, sendo 27 deles movimentados em direção ao rebordo edêntulo (Grupo 1) e 27 (dos mesmos pacientes) não transladados, que compuseram o grupo controle (Grupo 2). A RRLE foi avaliada por meio de escores de 0 a 3, e a RRAE foi avaliada por meio de escores de 0 a 4, antes e depois do tratamento. As medidas foram comparadas por meio dos testes de Kruskal-Wallis e de Student-Newman-Keuls. Resultados: O escore da RRLE aumentou estatisticamente apenas no Grupo 1 (p< 0,05). Após o tratamento ortodôntico, observou-se que quase 56% (n = 15) dos dentes do Grupo 1 apresentaram escores 2 e 3, enquanto o Grupo 2 apresentou escores 2 e 3 em cerca de 11% (n = 3) dos dentes. O escore da RRAE aumentou em ambos os grupos após a movimentação ortodôntica; entretanto, as análises estatísticas não mostraram diferenças significativas entre os grupos (p> 0,05). Conclusões: Dentes submetidos à movimentação ortodôntica sobre rebordo edêntulo atrófico estão sujeitos a uma maior reabsorção radicular externa lateral.

Negligible tooth resorptions after anterior open bite treatment using skeletal anchorage with miniplates

ABSTRACT Introduction: When miniplates are used as anchoring for orthodontic mechanics for anterior open bite correction by retraction of anterior teeth and posterior teeth intrusion and retraction, orthodontically induced inflammatory external apical root resorption is clinically negligible. Methods: A homogeneous sample of 32 patients was used, and the roots of the teeth were compared on CT scans performed before and after orthodontic treatment. Results: The observed root resorption was minimal, and this can be explained by the uniform distribution of forces in several teeth, simultaneously, in the set of the dental arch and in the bone that supports the teeth. Conclusion: The most important thing to prevent root resorption in orthodontic practice, besides being concerned with the intensity of the applied forces, is to be careful with its distribution along the roots of each tooth, in the dental arch and in the bone that supports the teeth.

RESUMO Introdução: Quando são utilizadas miniplacas como ancoragem para a mecânica ortodôntica de correção da mordida aberta anterior por meio da retração dos dentes anteriores e intrusão e retração dos dentes posteriores, as reabsorções radiculares apicais externas inflamatórias induzidas ortodonticamente são clinicamente irrelevantes. Métodos: Usou-se uma amostra homogênea de 32 pacientes, e comparou-se as raízes dos dentes em tomografias realizadas antes e depois do tratamento ortodôntico. Resultados: As reabsorções radiculares observadas foram mínimas, e isso pode ser explicado pela distribuição uniforme das forças em vários dentes, simultaneamente, no conjunto da arcada dentária e no osso que suporta os dentes. Conclusão: O mais importante para se prevenir as reabsorções radiculares na prática ortodôntica, além de se preocupar com a intensidade das forças aplicadas, é tomar cuidado com a sua distribuição ao longo das raízes de cada dente, na arcada dentária e no osso que suporta os dentes.

Effects of low-level laser on the repair of orthodontically induced inflammatory root resorption: a systematic review of studies in rats / Efectos del láser de bajo nivel en la reparación de la reabsorción radicular inflamatoria inducida por ortodoncia: una revisión sistemática de estudios en ratas

Orthodontically induced inflammatory root resorption (OIIRR) is a complication of dental treatment which consists of the degradation of local tissue due to an inflammatory reaction provoked by inappropriate orthodontic stimulus. The aim of the present systematic review was to assess the effectiveness of low-level laser therapy (LLLT) in reducing orthodontically induced inflammatory root resorption (OIIRR) in animal models. A systematic review was carried out in the MEDLINE, EMBASE and LILACS databases. Studies of interventions in animals were selected which analysed the effect of LLLT on OIIRR repair. The risk of bias was analysed through the 10 domains of the SYRCLE RoB tool for animal studies. Seventy-one studies were found; 27 were eliminated as duplicates and 44 titles/abstracts were analysed. Of these, 38 were excluded, and five studies were included for qualitative analysis. In 66.6 % of the studies included, the authors state that LLLT was effective in the inhibition/repair of OIIRR. In histological analysis it was observed that root resorption was significantly less in animals treated with laser as compared to the control. Furthermore, LLLT accelerated cicatrization after OIIRR. Laser proved effective in reducing root resorption lacunae and shortening the inflammatory process induced by the application of orthodontic force.

La resorción radicular inflamatoria inducida por tratamiento ortodontico (RRIITO) es una complicación del tratamiento odontológico que consiste en la degradación del tejido local debido a una reacción inflamación provocada por un estímulo ortodóntico inadecuado. El objetivo fue analizar la efectividad de la terapia láser de baja intensidad (LBI) en la disminución de RRIITO en ratas. Se realizó una revisión sistemática en las bases MEDLINE, EMBASE y LILACS. Fueron utilizados los términos 'resorción radicular', 'láser de baja intensidad', 'fototerapia', 'tratamiento ortodóntico', 'movimiento dental'. Fueron seleccionados estudios de intervención en animales, que analizaron el efecto del LBI en la reparación de la RRIITO. Los riesgos de sesgos fueron analizados mediante los 10 domínios de la herramienta SYRCLE RoB para estudios en animales. 71 estudios fueron encontrados, siendo eliminados 27 duplicados, y analizados 44 títulos/abstracts; de estos, fueron incluídos 5 estudios para análisis cualitativa. El 66,6 % de los estudios incluidos afirman que el LBI fue efectivo em reparar la RRIITO. En el análisis histológico se observó que la RRIITO fue significativamente menor en animales tratados con láser en comparación con el control. Además de eso, el LBI aceleró el proceso de cicatrización de la RRIITO. El láser se mostró efectivo en reducir las lagunas de resorción radicular y acortar el proceso inflamatorio inducido por la aplicación de fuerzas ortodonticas.

Abordagem quanto ao diagnóstico e ao tratamento da avulsão dentária: uma revisão de literatura / Approach to diagnosis and treatment of dental avulsion: a literature review

Objetivo: descrever uma revisão da literatura que apresente as principais consequências que podem ocorrer quando o dente avulsionado é reimplantado de forma tardia, proporcionando um prognóstico desfavorável. Revisão de literatura: a avulsão dental é uma lesão traumática que se caracteriza pelo completo deslocamento do dente de seu alvéolo, acarretando danos tanto às estruturas de suporte do elemento dental quanto às estruturas pulpares. A permanência extraoral do elemento dental avulsionado por períodos longos ou em meios de armazenamento inadequados pode provocar danos adicionais. Considerações finais: as lesões de inserções são as principais consequências da pós-avulsão dentária, isso devido a uma ruptura do ligamento periodontal, com uma secagem excessiva antes do reimplante, danificando as células do ligamento periodontal, o que, por sua vez, provoca uma resposta inflamatória exacerbada em uma ampla área da superfície radicular. (AU)

Objective: to describe a literature review, which presents the main consequences of late reimplantation of the avulsed tooth, providing an unfavorable prognosis. Literature review: tooth avulsion is a traumatic lesion characterized by the complete displacement of the tooth from the socket, causing damage to the support structures of the dental element as well as to pulp structures. The long extraoral time of the avulsed tooth or the time in inadequate storage may cause additional trauma. Final considerations: insertion lesions are the main consequences of tooth post-avulsion due to a rupture in the periodontal ligament, with an excessive drying prior to reimplantation, which damages the periodontal ligament cells and causes an exacerbated inflammatory response in a large root surface area. (AU)

Tooth resorptions are not hereditary

ABSTRACT Root resorptions caused by orthodontic movement are not supported by consistent scientific evidence that correlate them with heredity, individual predisposition and genetic or familial susceptibility. Current studies are undermined by methodological and interpretative errors, especially regarding the diagnosis and measurements of root resorption from orthopantomographs and cephalograms. Samples are heterogeneous insofar as they comprise different clinical operators, varied types of planning, and in insufficient number, in view of the prevalence of tooth resorptions in the population. Nearly all biological events are coded and managed through genes, but this does not mean tooth resorptions are inherited, which can be demonstrated in heredograms and other methods of family studies. In orthodontic root resorption, one cannot possibly determine percentages of how much would be due to heredity or genetics, environmental factors and unknown factors. There is no need to lay the blame of tooth resorptions on events taking place outside the orthodontic realm since in the vast majority of cases, resorptions are not iatrogenic. In orthodontic practice, when all teeth are analyzed and planned using periapical radiography or computerized tomography, and when considering all predictive factors, tooth resorptions are not iatrogenic in nature and should be considered as one of the clinical events inherent in the treatment applied.

RESUMO As reabsorções radiculares decorrentes da movimentação ortodôntica não têm evidência científica consistente que as correlacione com a hereditariedade, predisposição e suscetibilidade genética ou familiar. Os trabalhos sobre esse tema apresentam erros metodológicos e interpretativos, em especial quanto ao diagnóstico e à mensuração das reabsorções radiculares a partir de ortopantomografias e cefalogramas. As amostras são heterogêneas - quanto aos operadores clínicos e tipos de planejamentos aplicados - e em número muito pequeno, considerando-se a prevalência das reabsorções dentárias na população. Quase todos os eventos biológicos são codificados e gerenciados a partir dos genes, mas não por isso as reabsorções dentárias são hereditárias, o que seria demonstrado em heredogramas e outras formas de estudos familiares. Nas reabsorções radiculares em Ortodontia, não é possível determinar percentuais de quanto seria decorrente da hereditariedade ou da genética, de fatores ambientais e de fatores desconhecidos. Não se faz necessário transferir a "culpa" das reabsorções dentárias para eventos externos à Ortodontia pois, na grande maioria dos casos, elas não são iatrogênicas. Na prática ortodôntica, quando se faz a análise de todos os dentes e o planejamento, via radiografia periapical ou tomografia computadorizada, e quando se leva em consideração os fatores preditivos, as reabsorções dentárias não serão de natureza iatrogênica, e devem ser encaradas como uma das intercorrências clínicas do tratamento aplicado.

Root length and alveolar bone level of impacted canines and adjacent teeth after orthodontic traction: a long-term evaluation

Abstract Objective The aim of this retrospective study was to evaluate the long-term effects of orthodontic traction on root length and alveolar bone level in impacted canines and adjacent teeth. Material and Methods Sample consisted of 16 patients (nine males and seven females), mean initial age 11 years and 8 months presenting with unilaterally maxillary impacted canines, palatally displaced, treated with the same surgical and orthodontic approach. Teeth from the impacted-canine side were assigned as Group I (GI), and contralateral teeth as control, Group II (GII). The mean age of patients at the end of orthodontic treatment was 14 years and 2 months and the mean post-treatment time was 5 years and 11 months. Both contralateral erupted maxillary canines and adjacent teeth served as control. Root length and alveolar bone level (buccal and palatal) were evaluated on cone-beam computed tomography (CBCT) images. The comparison of root length and alveolar bone level changes between groups were assessed by applying paired t-test, at a significance level of 5% (p<0.05). Results There were no statistically significant differences in root length and buccal and palatal bone levels of canines and adjacent teeth among groups. Conclusions Impacted canine treatment by closed-eruption technique associated with canine crown perforation, has a minimal effect on root length and buccal and palatal alveolar bone level in both canine and adjacent teeth, demonstrating that this treatment protocol has a good long-term prognosis.

Why not to treat the tooth canal to solve external root resorptions? Here are the principles!

ABSTRACT This paper aims at exposing the foundations or reasons why, in cases of external tooth resorption, including those of orthodontic origin, one should not perform a root canal to treat it. That should be done only to teeth with contamination or pulp necrosis, to remove the periapical inflammation induced by microbial products. When facing cases of external tooth resorption, one's conduct must always respect the following sequence of steps: first of all, identifying the cause accurately; then, planning the therapeutic approach and, finally, adopting the conducts in a very well-founded way. The situations in which endodontic treatment is recommended for tooth resorptions are those when there are: a) pulp necrosis with microbial contamination, b) aseptic pulp necrosis, c) developing calcific metamorphosis of the pulp and d) diagnosis of internal resorption. It is not possible, through the pulp, to control the resorption process that is taking place in the external part, after all, the causes are acting in the periodontal ligament. There is no evidence that justifies applying endodontic treatment, by means of root canal, to control external resorption processes, when the pulp shows vitality.

RESUMO Este artigo tem por objetivo principal expor os fundamentos ou razões pelas quais, em casos de dentes com reabsorção dentária externa, incluindo as de origem ortodôntica, não se deve fazer o canal para tratá-la. Isso se faz apenas nos dentes com contaminação ou necrose pulpar, para remover a inflamação periapical induzida pelos produtos microbianos. Frente a casos de reabsorção dentária externa, as condutas devem premiar sempre a seguinte sequência: primeiro, identificar a causa com precisão; depois, planejar a forma de abordagem terapêutica e, por fim, adotar as condutas de forma muito bem fundamentada. As situações em que o tratamento endodôntico está indicado na terapêutica das reabsorções dentárias são quando houver: a) necrose pulpar por contaminação microbiana, b) necrose pulpar asséptica, c) metamorfose cálcica da polpa inicial e d) diagnóstico de reabsorção interna. Não se consegue, por via pulpar, controlar o processo reabsortivo que está ocorrendo na parte externa; afinal, as causas estão atuando no ligamento periodontal. Não há qualquer evidência que justifique fazer o tratamento endodôntico, via canal, para controlar processos reabsortivos externos, quando a polpa está com vitalidade.

Reabsorção dentária externa: não se faz o canal para tratá-la! / External root resorption: root canal treatment is not recommended

O presente artigo visa fundamentar as razões pelas quais, em casos de dentes com reabsorção dentária externa, não se deve fazer o canal para tratá-la. Isso se faz apenas nos dentes com contaminação ou necrose pulpar, para remover a inflamação periapical induzida pelos produtos microbianos. Frente a casos de reabsorção dentária externa, as condutas devem priorizar sempre a seguinte sequência: primeiro, identificar precisamente a causa; depois, planejar a forma de abordagem terapêutica e, por fim, adotar as condutas de forma muito bem fundamentada. Não se consegue controlar o processo reabsortivo que está ocorrendo na parte externa por via pulpar; afinal, as causas estão atuando no ligamento periodontal. Não se tem qualquer evidência que justifique fazer o tratamento endodôntico, via canal, para controlar processos reabsortivos externos quando a polpa está com vitalidade.

Polimorfismo (+3954c>T) del gen IL-1B y su asociación con la resorción radicular apical externa post-tratamiento ortodóntico / IL-1B (+3954c>T) gene polymorphism and its association with external root resorption after orthodontic treatment

El objetivo fue determinar la presencia del polimorfismo rs1143634 (+3954C>T) del gen Interleuquina 1 Beta (IL-1B) y su asociación con la resorción radicular apical externa (RRE) post-tratamiento ortodóntico. Se realizó un estudio piloto de individuos tratados con aparatología ortodontica, 13 (casos) presentaron RRE posterior al tratamiento ortodóntico y 22 (controles) estaban clínicamente sanos. A partir de muestras de células epiteliales de mucosa bucal se extrajo ADN y se genotipificó el polimorfismo rs1143634 (+3954C>T) del gen IL-1B mediante la reacción en cadena de la polimerasa y digestión del producto con la enzima de restricción TaqI. Se estimaron las frecuencias alélicas y genotípicas del rs1143634; además, se evaluó la desviación del equilibrio de Hardy-Weinberg. Las frecuencias alélicas y genotípicas se compararon mediante la prueba de c2 con razón deverosimilitud (p <0,05). El promedio de edad de los participantes fue 28,1 (DE=11,5) años y el 68,6 % era mujeres. Al comparar la distribución de los genotipos del polimorfismo IL-1B (+3954C>T) entre grupos no se encontró una diferencia estadísticamente significativa (p=0,0926). Sin embargo, se observó una diferencia significativa en la distribución de alelos (p= 0,035), siendo el alelo T (alelo 2) más prevalente en el grupo control. El polimorfismo IL-1B (+3954C>T) se encontró presente en la población de estudio. Aunque no existieron diferencias en la distribución de los genotipos que apoyara una asociación entre este polimorfismo y la RRE, si hubo una diferencia en la distribución de los alelos, sugiriendo que el alelo T posiblemente actúa como factor protector contra el desarrollo de la RRE.

The objective of this study was to determine the presence of Interleukin 1 beta (IL-1B) rs1143634 (+3954C>T) gene polymorphism and its association with external apical root resorption (ERR) after orthodontic treatment. We conducted a pilot study of individuals treated with orthodontic treatment, 13 (cases) had ERR after orthodontic treatment and 22 (controls) were clinically healthy. DNA was extracted from samples of epithelial cells from the oral cavity and IL-1B rs1143634 (+3954C>T) gene polymorphism was genotyped by polymerase chain reaction and digestion product through the TaqI restriction enzyme. Genotype and allele frequencies of rs1143634 were estimated; in addition, the deviation from Hardy-Weinberg equilibrium was assessed. Allele and genotype frequencies were compared using the c2 test with likelihood ratio (p <0.05). The mean age of participants was 28.6 (SD= 11.5) years and 68.6 % were females. No statistically significant association was found between the genotypes distribution of IL-1B (+3954C>T) polymorphism with ERR (p= 0.0926). However, a significant difference in the alleles distribution (p= 0.035) was observed, where the allele T (allele 2) was more prevalent in the control group. IL-1B (+3954C>T) polymorphism was present in the study population. Although there were no differences in the genotypes distribution to support an association between this polymorphism with ERR, there was a difference in the alleles distribution, suggesting that the allele T possibly acts as a protective factor against the development of ERR.

Evaluation of the Impact of Alveolar Bone Resorption on the Root Formation of Molars in Transgenic Mice with RANK Over-expression / Evaluación del Imapacto de la Resorción Ósea Alveolar sobre la Formación Radicular de Molares en Ratones Transgénicos con Sobreexpresión de RANK

Alterations in the balance of the osteoblastic-osteoclastic activity (osteopetrosis, osteolysis) have an impact on the dental development. The over activation of the osteoclastogenesis pathway RANK/RANKL/OPG in RANKTg mice produces an acceleration of tooth eruption and root elongation, suggesting this pathway could control the speed of tooth formation. Evaluate the effect of osteoclastic hyperactivity on the root formation of molars in RANKTg mice. Histologic study both descriptive and comparative of the impact of hyper-resorption of the alveolar bone in Hertwig's epithelial root sheath (HERS) of molars in both RANKTg mice and controls. This is done through the immuno-detection of matrical, epithelial and cellular proliferation proteins with histological, histoenzymology and inmunohistochemical techniques. Osteoclastic hiperactivity in alveolar bone does not alter the root structure and integrity of molars in RANKTg mice; the acceleration in root formation does not alter the HERS integrity. An area of cellular hyper-proliferation in the apical follicular tissue of HERS was found, which could regulate root growth in response to osteoclastic activity. The overexpressed RANK produces an inhibition of amelogenin expression at 5 days of age, suggesting an indirect regulation of these cells by RANK/RANKL. Exploring other molecular factors expressed in HERS, and the related engram, would make possible the use of new therapies for the control of osseous and inflammatory pathologies during root formation.

Las alteraciones en el balance de la actividad osteoblástica-osteoclástica (osteopetrosis, osteolisis) tienen un impacto en el desarrollo dental. La activación de la vía sobre la osteoclastogénesis RANK/RANKL/OPG en ratones RANKTg produce una aceleración de la erupción de los dientes y elongación de las raíces, lo que sugiere que esta vía podría controlar la velocidad de formación de los dientes. El objetivo de este estudio consiste en evaluar el efecto de la hiperactividad osteoclástica en la formación de las raíces de los molares en ratones RANKTg. Se realizó un estudio histológico descriptivo y comparativo del impacto de la hiper-reabsorción del hueso alveolar sobre la vaina epitelial radicular (de Hertwig - HERS) de molares en ratones RANKTg y controles. Se realizó la inmuno-detección de la proliferación matricial, epitelial y celular de proteínas, combinada con técnicas histológicas, inmunohistoquímicas e histoenzimológicas. La hiperactividad osteoclástica en el hueso alveolar no altera la estructura de la raíz dentaria y la integridad de los molares en ratones RANKTg; la aceleración de la formación de la raíz no altera la integridad de la misma. Se encontró un área de hiper-proliferación celular en el tejido folicular apical del HERS, que podría regular el crecimiento de la raíz en respuesta a la actividad osteoclástica. La sobreexpresión en los RANK produce una inhibición de la expresión de amelogenina a los 5 días de edad, lo que sugiere una regulación indirecta de estas células por RANK/RANKL. La exploración de otros factores moleculares expresados en HERS, y el engrama relacionado, haría posible el uso de nuevas terapias para el control de patologías óseas e inflamatorias durante la formación de la raíz dentaria.

Cone beam computed tomography study of apical root resorption induced by Herbst appliance

Objective This study evaluated the frequency of root resorption during the orthodontic treatment with Herbst appliance by Cone Beam Computed Tomography (CBCT).Material and Methods The sample comprised 23 patients (11 men, 12 women; mean ages 15.76±1.75 years) with Class II division 1 malocclusion, treated with Herbst appliance. CBCT was obtained before treatment (T0) and after Herbst treatment (T1). All the dental roots, except third molars, were evaluated, and apical root resorption was determined using the axial guided navigation method. Paired t-tests and Wilcoxon T Test were used to compare the dependent samples in parametric and nonparametric cases, respectively. Chi-Square Test with Yates’ correction was used to evaluate the relationship between apical root resorption and gender. Results were considered at a significance level of 5%.Results Apical resorption was detected by CBCT in 57.96% of 980 roots that underwent Herbst appliance treatment. All patients had minimal resorption and there was no statistical significance between the genders.Conclusion CBCT three-dimensional evaluation showed association between Herbst appliance and minimal apical root resorption, mostly in the anchoring teeth, without clinical significance.

Anti-dentine Salivary SIgA in young adults with a history of dental trauma in deciduous teeth

Anti-dentin autoantibodies are associated with inflammatory root resorption in permanent teeth and are modulated by dental trauma and orthodontic force. However, it is not known whether deciduous tooth trauma can stimulate the development of a humoral immune response against dentin. The aim of this study was to evaluate the levels of salivary SIgA reactivity against human dentin extract in young adults with a history of trauma in the primary dentition. A sample of 78 patients, aged 18 to 25, who had completed an early childhood (0 to 5 years old) caries prevention program years earlier at the Universidade Estadual de LondrinaPediatric Clinic, underwent radiographic examination and salivary sampling. Anti-dentin SIgA levels were analyzed by immunoenzymatic assay and Western blotting. Although dental trauma to deciduous teeth had occurred in 34 (43.6%) of the patients, no differences in SIgA levels were detected between individuals who had experienced trauma and those who had not (p > 0.05). Multivariate regression analysis showed no association between dental trauma and SIgA levels (p > 0.05). Patients with a history of deciduous trauma presented low levels of anti-dentin antibodies, associated with orthodontic root resorption (p < 0.05). Western blot analysis showed that salivary antibodies recognized a single band of approximately 45 kDa in dentin extract. We concluded that salivary SIgA recognizes a specific component of the dentin matrix and that anti-dentin antibodies were not triggered by trauma to primary teeth. However, trauma to deciduous teeth may down-modulate SIgA in response to orthodontic root response.

Extreme root resorption associated with induced tooth movement: A protocol for clinical management

Cases in which teeth have only the cervical third remaining from orthodontically induced external root resorption, cast the following doubts: 1) What care should be taken to keep these teeth in mouth with the least risk possible? 2) What care should be taken with regards to reading of imaging exams, particularly in terms of accurately determining cervical root and bone loss? 3) Why is not endodontic treatment recommended in these cases? The present study aims at shedding light on the aforementioned topics so as to induce new insights into the theme.

Nos casos em que os dentes têm apenas o terço cervical remanescente de uma reabsorção radicular externa induzida ortodonticamente: 1) Quais seriam os cuidados para que permaneçam na boca, com o menor risco possível de perda? 2) Quais seriam os cuidados na interpretação imaginológica desses casos, quanto à determinação precisa da perda radicular e óssea cervical? 3) Por que o tratamento endodôntico não estaria indicado? No presente trabalho, procura-se esclarecer esses pontos e respondendo os questionamentos, para induzir novos insights sobre o assunto.