Abstract Objective: The purpose of this study was to histologically evaluate pulp and dentin under induced tooth movement (ITM) with different types of forces. Material and Methods: The maxillary right first molars of rats were submitted to movement with continuous (CF), continuous interrupted (CIF) and intermittent (IF) forces during 5, 7 and 9 days with nickel-titanium (NiTi) closed-coil springs exerting 50cN force magnitude. The groups were histologically evaluated as for cellularity pattern, presence of dystrophic, hemodynamic alterations in the pulp as well dentin alterations. The main observed alterations were related to hemodynamic pulp characteristics, such as presence of thrombosis, vascular congestion and hemorrhages. The hemodynamic alterations were statistically evaluated by Shapiro-Wilk normality test and analysis of variance by the Kruskall-Wallis test. Results: There was no significant differences observed between groups in the different types of applied forces and duration of ITM (vascular congestion, p=1.000; hemorrhage, p=0.305; thrombosis, p=1.000). Conclusions: Pulp tissue alterations resulting from ITM were limited to hemodynamic events, without progressing to irreversible degeneration, regardless of the type of force applied.

OBJETIVO: avaliar as alterações histológicas ocorridas na área periodontal de molares de ratos submetidos à movimentação dentária induzida (MDI), logo após um trauma intencional (subluxação). MÉTODOS: quarenta ratos Wistar machos adultos (Rattus norvegicus albinus) foram selecionados. Os animais foram divididos em oito grupos (n = 5), de acordo com a combinação das variáveis: Grupo 1 - controle (sem trauma e sem MDI); Grupo 2 - MDI; Grupos 3, 4, 5 e 6 - grupos de trauma dentoalveolar correspondendo, respectivamente, para 1, 3, 8 e 10 dias após o trauma; Grupos 7 e 8 - os molares murinos foram submetidos a um impacto de 900cN e, de um e três dias após o evento trauma, o movimento do dente foi induzido. Os primeiros molares superiores dos animais foram movidos mesialmente durante sete dias, com uma mola fechada (50cN). Após período experimental de cada grupo, os animais foram sacrificados por overdose anestésica e as maxilas direitas foram removidas e processadas para análise histológica qualitativa. RESULTADOS: nos animais dos grupos 3, 4, 5 e 6, as alterações histológicas não foram muito significativas. Consequentemente, o efeito do movimento dentário induzido logo após um evento de subluxação (grupos 7 e 8) foi muito semelhante ao descrito para o grupo 2. CONCLUSÃO: não houve diferença na qualidade do reparo periodontal quando a MDI foi aplicada aos dentes que sofreram um trauma de subluxação.

OBJECTIVE: The objective of this study was to assess the histological alterations that occurred in the periodontal area of rat molars submitted to induced tooth movement (ITM) right after an intentional trauma (subluxation). METHODS: Forty adult male Wistar rats (Rattus norvegicus albinus) were selected. The animals were divided into eight groups (n = 5), according to the combination of variables: Group 1 - control (neither trauma nor ITM); Group 2 - ITM; Groups 3, 4, 5 and 6 - dentoalveolar trauma groups corresponding, respectively, to 1, 3, 8 and 10 days after trauma; Groups 7 and 8 - the animals' molars were subjected to a 900 cN impact and, one and three days after the trauma event, tooth movement was induced. The rats' maxillary first molars were mesially moved during seven days with a closed coil (50 cN). After the experimental period of each group, the animals were sacrificed by anesthetic overdose and the right maxillas were removed and processed for histological analysis under light microscopy. RESULTS: In the animals of group 3, 4, 5 and 6, the histological alterations were not very significant. Consequently, the effect of induced tooth movement right after a subluxation event (groups 7 and 8) was very similar to those described for Group 2. CONCLUSION: There was no difference in the quality of periodontal repair when ITM was applied to teeth that had suffered a subluxation trauma.

Root resorption is a variable to be considered in induced tooth movement (ITM). It is related to root morphology and alveolar bone crest, and also to the types of forces exerted by mechanotherapy. This histometric study evaluated the predominance of root resorption among roots of different dimensions, following ITM with different types of forces and at different time intervals. The study was conducted on 54 rats divided into three groups, according to the type of force: continuous (CF), continuous interrupted (CIF) and intermittent (IF), at periods of 5, 7 and 9 days. The percentage of resorption between mesiobuccal roots of larger dimension and intermediate roots of smaller dimension was assessed. The evaluations were performed on the AxioVision software, and the non-parametric analysis of variance for repeated measures in independent groups was further applied, consisting of a scheme of two factors, and complemented by the Dunn test at a significance level of 5%. The intermediate roots presented a higher percentage of resorption, which was gradual at the periods evaluated for the three types of forces, but mainly for CF. Comparing the intermediate roots with the mesiobuccal roots, there was a statistically significant difference (p < 0.05) in the CF group at day 7 and day 9, and in the FI group, at day 9. The intragroup analysis evidenced a statistically significant difference (p < 0.05) between the 5th and the 9th day for the intermediate root in the CF group. The intergroup analysis did not reveal any statistically significant difference (p > 0.05) in individually analyzed roots.

Manufacturers offer various prescriptions of preadjusted brackets for use in the “straight-wire” orthodontic technique. However, the need to incorporate bends in the rectangular wires during orthodontic finishing has led to concerns regarding the type of prescription chosen and the credibility of information provided by the manufacturer. The aim of this study was to compare the slot angulations of Roth prescription preadjusted metallic brackets for the maxillary left central incisor and maxillary left canine. For each tooth type, 10 brackets of three commercial brands (GAC, Forestadent and Morelli) were selected. Two individual metal matrices for brackets and tooth positioning were made for each group of teeth. Captured images were obtained by standardized ortho-radial photography with a digital camera. Images were exported and analyzed with the Image J software package. One-way ANOVA and Tukey statistical analyses were performed at the 5% significance level. For brackets of the maxillary left central incisor, differences in mean angulation were observed between the Morelli and GAC groups (p < 0.01) and between the Forestadent and GAC groups (p < 0.01). For brackets of the maxillary left canine, differences in mean angulation were found between the Morelli and GAC groups (p < 0.01) and between the Morelli and Forestadent groups (p < 0.05). In conclusion, despite their same prescription name, the different brands exhibited significantly different angulation measurements.

Dentre os traumatismos dento-alveolares, a avulsão dentária é a mais severa por causar danos em muitas estruturas e por consistir num deslocamento total do dente de seu alvéolo ósseo. O tratamento ideal é o reimplante dentário imediatamente após avulsão, pois o tempo extra-bucal é fator determinante para um bom prognóstico e o sucesso do tratamento. Infelizmente, isto nem sempre é possível. O sucesso do reimplante depende de muitos fatores que podem acelerar ou retardar a reabsorção radicular ou mesmo a anquilose e entre eles estão o tipo e as características do meio de armazenamento no qual esse dente foi mantido entre a avulsão e o reimplante. Manter o dente num meio úmido adequado que possa preservar pelo maior tempo possível a vitalidade das células do ligamento periodontal na superfície radicular é o elemento-chave do reimplante bem sucedido. Pesquisas recentes levaram ao desenvolvimento de meios de armazenamento que tem condições muito próximas às do alvéolo dental, possuindo osmolalidade (pressão celular) adequada, pH, metabólitos nutrientes e glicose. Embora estes meios de armazenamento possam ser adquiridos comercialmente, a situação mais comum é que o produto não esteja facilmente acessível no momento do acidente. Frente a isto, o objetivo deste artigo é apresentar uma revisão da literatura sobre diversos meios de armazenamento para dentes avulsionados, considerando suas características, efetividade e acessibilidade. Para isto, foi realizada uma busca de artigos nas bases de dados PubMed/Medline, Lilacs, BBO e Scielo por meio das palavras-chave: ‘storage media’, ‘tooth replantation’, ‘tooth avulsion’, ‘milk’ e ‘propolis’. Após a avaliação dentro dos critérios de inclusão e exclusão, 39 artigos foram selecionados e os meios de armazenamento neles descritos foram criteriosamente estudados quanto às suas características, efetividade e acessibilidade. A revisão da literatura revelou uma grande variedade de meios úmidos de estocagem avaliada em estudos laboratoriais e casos clínicos, incluindo soluções para cultura de células e tecidos, como a Hank's Balanced Salt Solution (HBSS); produtos médico-hospitalares desenvolvidos especificamente para armazenamento de órgãos, como Viaspan® e Euro-Collins®; meios de cultura como o Meio Mínimo Essencial (MEM); solução fisiológica; produtos naturais, como água, saliva, leite bovino em suas diferentes apresentações, própolis, chá verde, Morus rubra, clara de ovo e água de coco; produtos reidratantes como Gatorade® e Ricetral, até mesmo soluções para lentes de contato. Com base na literatura, pode-se afirmar que até agora, com exceção das soluções específicas para armazenamento e culturas, o leite pasteurizado integral é o mais indicado e o que tem o melhor prognóstico dentre as substâncias que estejam mais provavelmente disponíveis no local do acidente, como água, solução fisiológica ou saliva. Suas vantagens são a grande disponibilidade, fácil acesso, pH fisiologicamente compatível e osmolalidade (pressão do líquido) com as células do ligamento periodontal aderidas à superfície radicular, presença de nutrientes e fatores de crescimento. Apesar disso, o fato é que não se tem um produto que preencha todos os requisitos para ser considerado ideal para o armazenamento temporário de dentes avulsionados e as pesquisas para tanto devem prosseguir.

Dental avulsion is the most severe type of traumatic tooth injuries because it causes damage to several structures and results in the complete displacement of the tooth from its socket in the alveolar bone. The ideal situation is to replant an exarticulated tooth immediately after avulsion because the extraoral time is a determinant factor for treatment success and for a good prognosis. However, it is not always possible. The success of replantation depends on a number of factors that may contribute to accelerate or minimize the occurrence of root resorption or ankylosis, among which is the type and characteristics of the medium used for temporary storage during the time elapsed between avulsion and replantation. Maintaining the tooth in an adequate wet medium that can preserve, as longer as possible, the vitality of the periodontal ligament cells that remain on root surface is the key to success of replantation. Recent research has led to the development of storage media that produce conditions that closely resemble the original socket environment, with adequate osmolality (cell pressure), pH, nutritional metabolites and glucose, and thus create the best possible conditions for storage. Although these storage media can now be purchased in the form of retail products, the most common scenario is that such a product will not be readily available at the moment of the accident This paper reviews the literature on the different storage media that have been investigated for avulsed teeth based on full-length papers retrieved from PubMed/Medline, Lilacs, BBO and SciELO electronic databases using the key words ‘storage medium’, ‘transportation medium’, ‘avulsion’, ‘tooth avulsion’, ‘replantation’, ‘tooth replantation’, ‘milk’ and ‘propolis’. After application of inclusion and exclusion criteria, 39 papers were selected and critically reviewed with respect to the characteristics, efficacy and ease of access of the storage medium. The review of the literature showed that a wide array of types of wet storage media have been evaluated in laboratory studies and clinical reports, including cell and tissue culture solutions like Hank's Balanced Salt Solution (HBSS); medical/hospital products developed specifically for organ storage purposes, such as Viaspan® and Euro-Collins®; culture media, like Minimum Essential Medium (MEM); saline; natural products like water, saliva, bovine milk and its variations, propolis, green tea, Morus rubra (red mulberry), egg white and coconut water; rehydrating solutions, like Gatorade® and Ricetral, and even contact lens solutions. Based on the literature, it could be stated that, so far, apart from Based on the literature, it could be stated that, so far, apart from solutions designed specifically for storage and culture purposes, regular pasteurized whole milk is the most frequently recommended and with the best prognosis among other solutions that are likely to be available at the scene of an accident, such as water, saline or saliva. Its advantages include its high availability, ready accessibility, physiologically compatible pH and osmolality (fluid pressure) with the root-surface adhered PDL cells, presence of nutrients and growth factors. However, there is not yet a single solution that fulfills all requirements to be considered as the ideal medium for temporary storage of avulsed teeth, and research on this field should carry on.

This study evaluated whether periodontal ligament (PL) thickness varied with root size and examined the possible influence of this variation on orthodontic mechanics. Measurements were taken of the maxillary left first molar in 54 male Wistar rats. Mean mesial and distal PL thicknesses were compared between the intermediate buccal and mesiobuccal roots using paired Student's t-tests with a 5% significance level. Mean values differed significantly between roots (p < 2.2 × 10-16). PL thickness in rats is directly proportional to root dimensions.

OBJECTIVE: The purpose of this study was to evaluate the thickness of the periodontal ligament of rat molars during orthodontic tooth movement (OTM). METHODS: Thirty Wistar rats were divided into three groups of 10 animals each: GI, GII and GIII and the mice were euthanized at 7, 14 and 21 days, respectively. Experimental subjects were compared to their respective controls by the Mann-Whitney test. Comparison of values between compression and tension sides were performed during the same and different time periods through Analysis of Variance (ANOVA), Kruskal-Wallis test and, subsequently, Tukey's test. RESULTS: Groups GI and GII showed decreased PDL size in the apical regions of the mesiobuccal root and in the cervical region of the distobuccal root. There was also an increased PDL in the cervical regions of the mesiobuccal root, apical region of the distobuccal root and middle region of both roots. CONCLUSION: The reduction and increase in PDL size were seen in the same root, which characterizes tooth inclination. The apical, middle and cervical regions were compared with one another in each time period and at three times: 7, 14 and 21 days. They were also compared in each region, confirming a tipping movement in GI and GII and a gradual decreased intensity between GI to GII, reaching normal dimension in GIII.

This study evaluated the effect of heat treatment on CrNi stainless steel orthodontic archwires. Half of forty archwires of each thickness - 0.014" (0.35 mm), 0.016" (0.40 mm), 0.018" (0.45 mm) and 0.020" (0.50 mm) (totalling 160 archwires) - were subjected to heat treatment while the remainder were not. All of the archwires had their individual thickness measured in the anterior and posterior regions using AutoCad 2000 software before and after compressive and tensile strength testing. The data was statistically analysed utilising multivariance ANOVA at a 5% significance level. All archwires without heat treatment that were subjected to tensile strength testing presented with anterior opening, which was more accentuated in the 0.020" archwires. In the posterior region, the opening produced by the tensile force was more accentuated in the archwires without heat treatment. There was greater stability in the thermally treated archwires, especially those subjected to tensile strength testing, which indicates that the heat treatment of orthodontic archwires establishes a favourable and indispensable condition to preserve the intercanine width.

The objective of this work was to assess the knowledge about orthodontic tooth movement and dental trauma held by a group of orthodontists in specific areas of Brazil. For this purpose, 166 questionnaires with 15 objective questions about this subject were distributed. One hundred and five questionnaires were properly filled and collected after 30 days. It was concluded that, except for avulsion, the knowledge on dental injuries held by the professionals interviewed was considered unsatisfactory, and about 40% of them were not acquainted with the recommendations for the orthodontic movement of traumatized teeth.

OBJETIVOS: comparar os valores médios normais das angulações mesiodistais dentárias, propostos por Ursi, em 1989, com as angulações mesiodistais de caninos, pré-molares e molares inferiores em indivíduos com e sem a presença dos terceiros molares inferiores e idades entre 18 e 25 anos. Além disso, foram comparados os valores das angulações mesiodistais desses dentes nessas duas situações. MÉTODOS: foram utilizadas 40 radiografias ortopantomográficas de indivíduos, de ambos os gêneros, que não receberam tratamento ortodôntico, divididos em dois grupos: Grupo I, constituído por 20 radiografias que não apresentavam os terceiros molares inferiores; e Grupo II, formado por 20 radiografias com os terceiros molares inferiores presentes. RESULTADOS E CONCLUSÕES: a análise dos resultados e a análise estatística permitiram concluir que ambos os grupos exibiram pré-molares e molares inferiores mais angulados em sentido mesial, quando comparados à oclusão normal. Por outro lado, a angulação mesiodistal de caninos inferiores mostrou-se semelhante àquela apresentada em casos de oclusão normal. Os dois grupos, quando comparados entre si, exibiram semelhantes valores angulares dos caninos, pré-molares e molares inferiores, de modo que a presença dos terceiros molares não exerceu influência sobre essas angulações mesiodistais dentárias.

AIM: To compare the normal mean values of the mesiodistal axial angulation, proposed by Ursi in 1989, with the mesiodistal axial angulation of canine teeth, premolar and inferior molars in individuals with and without the presence of the third inferior molars and ages between 18 and 25 years. Besides, the values of the mesiodistal axial angulation of these teeth were compared in these two situations. METHODS: Forty panoramic x-rays were used from individuals of both genders that didn't receive orthodontic treatment, divided in two groups: Group I, constituted by 20 x-rays that didn't present the third inferior molars, and Group II, formed by 20 x-rays with the presence of the third inferior molars. RESULTS AND CONCLUSIONS: The results analysis and the statistical analysis allowed to conclude that both Groups exhibited inferior premolar and molars more angled in mesial direction when compared to the normal occlusion. On the other hand, the mesiodistal axial angulation of inferior canine teeth was similar to the presented in cases of normal occlusion. The two groups, when compared amongst themselves, exhibited similar angular values of the canine teeth, premolar and inferior molars, so that the presence of the third molars didn't exercise influence on these dental angulations.

The aim of this study was to evaluate the occurence of compensation in mesiodistal axial inclinations of canines in skeletal malocclusions patients. The sample consisted of 25 Angle Class II, division 1 malocclusion (group 1) and 19 Angle Class III malocclusion patients (group 2). After measurement of dental angulations through a method that associates plaster model photography and AutoCad software, comparisons between the groups were performed by T-test for independent samples. Results showed that there was no statistically significant difference (p < 0.05) between groups, when maxillary canine angulations were compared. Regarding the mandibular canines, there was a statistically significant difference in dental angulation, expressed by 3.2° for group 1 and 0.15° for group 2. An upright position tendency for mandibular canines was observed in the Angle Class III sample. This configures a pattern of compensatory coronary positioning, since the angulation of these teeth makes them occupy less space in the dental arch and consequently mandibular incisors can be in a more retracted position in the sagittal plane.

OBJETIVO: avaliar o efeito da retração anterior sobre o ponto A sagital e verticalmente, bem como a correlação e a previsibilidade do comportamento dessas estruturas. METODOLOGIA: sessenta telerradiografias em norma lateral foram usadas, tomadas no início e no final do tratamento ortodôntico corretivo, a partir de 30 pacientes (22 feminino e 8 masculino) com idade entre 10 e 17 anos antes do tratamento, com má oclusão de Classe II, divisão 1 ou Classe I, que foram submetidos às extrações dos quatro primeiros pré-molares ou somente dois primeiros pré-molares superiores. Além das variáveis .1NA,1-NA, 1.PP e 1-A, mensurações lineares horizontais e verticais foram feitas em relação a uma linha de referência construída a partir da linha SN menos 7º e uma linha perpendicular a ela. Todos os dados foram mensurados duas vezes, e as médias foram submetidas ao teste t emparelhado, de correlação linear e de regressão. RESULTADOS: em média, o ponto A retraiu 0,71mm e movimentou para baixo 2,38mm, seguindo 1,03mm e 4,13mm de retração, respectivamente, do ápice radicular e da borda incisal, e 2,35mm de extrusão dentária. A retração do ponto A apresentou correlação positiva em relação ao ápice radicular (r = 0,75; alfa < 0,0001) e em relação à retração da borda incisal (r = 0,70; alfa < 0,0001), mostrando um comportamento ântero-posterior previsível. CONCLUSÕES: concluiu-se que o ponto A retraiu-se e movimentou-se para baixo seguindo o dente, e a retração do ponto A em relação aos incisivos foi previsível.

OBJECTIVE: it was aimed to evaluate the effect of retraction of anterior teeth on the point A sagittally and vertically, as well as the correlation and the predictability of the behavior of these structures. METHODS: sixty lateral cephalograms were used, which were taken at the beginning and at the end of fixed appliance orthodontic treatment, from thirty patients (22 female and 8 male) aging from 10 to 17 years at baseline, with Class II, Division 1 or Class I malocclusion, who underwent four first premolars extractions or maxillary first premolars extractions only. Besides the variables 1.NA, 1-NA, U1/PP and U1<FONT FACE=Symbol>«</FONT>AVERT, horizontal and vertical linear measurements were made in relation to a horizontal reference line constructed from the S-N plane minus 7º and its perpendicular. As distributed normally, all the data were measured twice, and the mean values were submitted to paired t test, linear correlation and regression tests. RESULTS: in average, point A retracted 0.71mm and moved 2.38mm downwardly, following 1.03mm of root apex and 4.13mm of incisal edge retraction, and 2.35mm of tooth extrusion. The retraction of point A was positively correlated with root apex (r = 0.75; p < 0.0001) and with incisal edge retraction (r = 0.70; p < 0.0001), showing a predictable sagittal behavior. CONCLUSIONS: it was concluded that point A retracted and moved downwardly following the tooth, and the retraction of point A in relation to the incisors was predictable.

OBJETIVO: o presente trabalho objetivou avaliar as alterações ocorridas nas posições dos terceiros molares inferiores em pacientes tratados ortodonticamente com extrações dos primeiros pré-molares. METODOLOGIA: utilizou-se 80 ortopantomografias, obtidas no pré e pós-tratamento ortodôntico corretivo de 40 pacientes, divididos em dois grupos. O grupo 1 constou de 20 pacientes (13 femininos e 7 masculinos) que se submeteram a tratamento ortodôntico com extrações de primeiros pré-molares. O grupo 2 foi constituído por 20 pacientes (13 femininos e 7 masculinos) tratados ortodonticamente sem extrações. Foram estabelecidas medidas angulares, com o objetivo de avaliar as inclinações e medidas lineares, para analisar as modificações no sentido vertical dos terceiros molares. Todos os dados foram mensurados duas vezes, cujos valores médios foram submetidos dos testes t emparelhado e teste t independente. RESULTADOS: os resultados mostraram diferenças estatisticamente significantes (p<0,01) entre as medidas angulares finais e iniciais do grupo 1. CONCLUSÕES: concluiu-se que os deslocamentos verticais dos terceiros molares inferiores são semelhantes nos casos tratados ortodonticamente com e sem extrações e que estes elementos dentários tornam-se mais verticalizados ao final da terapia realizada com extrações de primeiros pré-molares inferiores.

AIM: The aim of this study is to evaluate the positional changes occurred with lower third molars in patients treated orthodontically with extractions of first premolars. METHODS: A total of 80 panoramic radiographs obtained at pre and post-treatment periods from 40 patients, were divided into 2 groups: group 1 were composed by 20 patients (13 female and 7 male) that were submitted to orthodontic treatment with extraction of first premolars; group 2 were composed by 20 patients (13 female and 7 male) that were submitted to orthodontic treatment without extractions. Angular measurements were established to evaluate the tipping and linear measurements were established to analyze the vertical changes of the lower third molars. All data were measured twice and averaged, then submitted to paired and unpaired test. RESULTS: Significant differences were found between the initial and final angular measurements of group 1 (p<0.01). CONCLUSIONS: It was concluded that similar vertical changes of lower third molars occurred when extraction and non-extraction cases were compared, and third lower molars became less tipped with the extractions of lower first premolars.

INTRODUÇÃO: o alinhamento dentário correto, bem como sua estabilidade, representam objetivos importantes do tratamento ortodôntico. O apinhamento na região anterior é uma anomalia de posição dentária comum e para obter sua correção as opções clínicas disponíveis para o ortodontista são as extrações dentárias, a expansão do arco dentário ou os desgastes interproximais. Os desgastes freqüentemente são indicados, mas existem questionamentos quanto às indicações, técnicas e condições pré e pós-tratamento. OBJETIVO: o objetivo deste artigo é apresentar uma discussão, embasada na literatura pertinente, dos principais fatores envolvidos com este procedimento clínico.

BACKGROUND: A dental alignment and its stability are important objectives of the orthodontic treatment. The crowding in the anterior area is a common anomaly tooth position problem and, to obtain its correction, the clinical options to the orthodontist are extractions, expansion of dental arch, and dental stripping. Stripping are usually used but it is frequently questioned for the indications, techniques and conditions pre and post-treatment. OBJECTIVE: The purpose of this article is to present a discussion, based in the pertinent literature, of the main factors related to this clinical procedure.