ABSTRACT Objective: This retrospective study aimed to assess the predictability of Invisalign® aligners regarding rotational, mesio-distal and buccal-lingual tip movements. Methods: Two materials were included in the analysis - EX30, used until 2013; and SmartTrack, in current use. The study comprised 56 adult patients treated with Invisalign Comprehensive. Data sample were assessed on three sets of digital models; model 1 - initial, model 2 - predicted, and model 3 - achieved. Sixty reference points were marked in each dental arch, and two reference planes assisted the superimposition. The degree of rotation, mesio-distal and buccal-lingual tip was obtained via trigonometric calculations, through a previously published validated method. The accuracy of outcomes was compared according to the types of tooth movement and teeth groups,and the influence of predetermined variables on movement accuracy was also investigated. Results: Rotation and mesio-distal tip did not present any significant difference when comparing EX30 and SmartTrack groups. Only buccal-lingual tip presented a significant difference, incisor and canine groups treated with EX30 aligners presented an increase in accuracy (p= 0.007 and p = 0.007, respectively). For each additional degree planned for rotation movements, there was an increase of 0.35° in the discrepancy, and an increase of 0.40° and 0.41° for mesio-distal and buccal-lingual tip, respectively. EX30 and SmartTrack discrepancies were compared by multilevel linear regression. Conclusion: EX30 aligners reached higher accuracy for buccal-lingual tip in anterior teeth. However, for rotation and mesio-distal tip, SmartTrack and EX30 are similarly accurate. The total amount of planned movement has a significant impact on accuracy rates, with a decrease in accuracy for every additional degree. Objective rotational mesiodistal mesio distal buccallingual buccal lingual movements Methods EX 2013 use 5 Comprehensive models initial predicted achieved arch superimposition calculations method groupsand investigated Results EX3 p= (p 0007 0 007 0.00 respectively . respectively) 035 35 0.35 discrepancy 040 40 0.40 041 41 0.41 regression Conclusion However accurate rates 201 000 00 0.0 03 0.3 04 4 0.4 20 0.

RESUMO Objetivo: Esse estudo retrospectivo teve como objetivo aferir a previsibilidade dos alinhadores Invisalign em relação aos movimentos de rotação e inclinações mesiodistal e vestibulolingual. Material e Métodos: Foram incluídos dois materiais nessa análise: EX30®, utilizado até 2013; e SmartTrack®, atualmente em uso. Esse estudo avaliou 56 pacientes tratados com Invisalign Comprehensive. Os dados foram avaliados em três pares de modelos digitais; modelo 1 - inicial, modelo 2 - planejado, e modelo 3 - alcançado. Foram marcados 60 pontos de referência em cada arcada, sendo a sobreposição realizada com auxílio de planos de referência. O grau de rotação e inclinações mesiodistal e vestibulolingual foi obtido por cálculos de trigonometria, usando um método validado publicado anteriormente. Os resultados foram comparados de acordo com os tipos de movimento dentário e grupos de dentes, também foi investigada a influência de variáveis predeterminadas na confiabilidade dos movimentos. Resultados: Os movimentos de rotação e inclinação mesiodistal não apresentaram diferença estatística, quando comparados os grupos EX30® e SmartTrack®. Somente a inclinação vestibulolingual apresentou diferença estatisticamente significativa, sendo que os grupos de incisivos e caninos tratados com alinhadores EX30® apresentaram um aumento na previsibilidade(p= 0,007 e p= 0,007, respectivamente). Para cada grau adicional planejado para movimento de rotação, ocorreu um aumento de 0,35° na discrepância, e aumentos de 0,40° e 0,41° para as inclinações mesiodistal e vestibulolingual, respectivamente. As discrepâncias entre EX30® e SmartTrack® foram comparadas por regressão linear multinível. Conclusão: Os alinhadores EX30® alcançaram maior previsibilidade para a inclinação vestibulolingual em dentes anteriores. No entanto, para rotação e inclinação mesiodistal, SmartTrack® e EX30® apresentaram previsibilidade similar. A quantidade total de movimento planejado apresenta influência significativa nas taxas de previsibilidade, com diminuição na acurácia para cada grau adicional. Objetivo Métodos análise EX30 EX 2013 SmartTrack uso 5 Comprehensive digitais inicial alcançado 6 arcada trigonometria anteriormente Resultados estatística previsibilidadep= previsibilidadep p previsibilidade(p 0007 0 007 0,00 respectivamente . respectivamente) 035 35 0,35 discrepância 040 40 0,40 041 41 0,41 multinível Conclusão anteriores entanto similar EX3 201 000 00 0,0 03 0,3 04 4 0,4 20 0,

ABSTRACT Objective: This bibliometric study aimed to analyze the citation metrics, journal and author characteristics, and subject domains of the 100 top-cited Systematic Reviews (SR) and Meta-Analysis (MA) in orthodontics. Material and Methods: An electronic database search was conducted for SR and MA in the Web of Science on 16th July 2023, without language and time restrictions. Of the 802 hits returned, the 100 top-cited orthodontic articles were shortlisted. They were analyzed for citation metrics, journal characteristics (journal, year of publication, impact factor-IF), author and affiliation characteristics (number, primary and corresponding author’s affiliation, and country), study domain, and keywords. Results: These articles were published from 1996 to 2021 in 20 journals, with an impact factor of 1.9 to 10.5, by 351 researchers affiliated with 104 universities. Their citations ranged from 45 to 344, and 34 poised to be classified as classic (≥ 100 citations). The maximum number of articles was published in the American Journal of Orthodontics and Dentofacial Orthopedics (n=38), the European Journal of Orthodontics (n=18), and the Angle Orthodontist (n=8). The authors for individual papers ranged from 1 to 10, with 5 being the most common (n=58). Europe had the highest contribution regarding the number of corresponding authors, institutions, and citations. Bone anchorage and orthodontic tooth movement/Biomechanics were the most frequently researched domains (n=11 each). The most common keyword used was Orthodontics (n=19), followed by Systematic Review (n=16) and Meta-analysis (n=9). Conclusion: In general, the top cited SR and MA were published in high-impact orthodontic journals, were multi-authored, and reflected the collaborative work from different universities. Objective metrics 10 topcited (SR MetaAnalysis Meta Analysis (MA orthodontics Methods th 2023 restrictions 80 returned shortlisted journal, (journal publication factorIF, factorIF IF , factor-IF) number, (number s country, country country) domain keywords Results 199 202 2 journals 19 9 1. 105 10.5 35 universities 4 344 3 ≥ ( . citations) n=38, n38 n n=38 38 (n=38) n=18, n18 n=18 18 (n=18) n=8. n8 n=8 8 (n=8) n=58. n58 n=58 58 (n=58) institutions movementBiomechanics movement Biomechanics n=11 n11 11 (n=1 each. each each) n=19, n19 n=19 (n=19) n=16 n16 16 (n=16 Metaanalysis analysis n=9. n9 n=9 (n=9) Conclusion general highimpact high multiauthored, multiauthored multi authored, authored multi-authored factor-IF 10. n3 n=3 (n=38 n1 n=1 (n=18 n= (n=8 n5 n=5 (n=58 (n= (n=19 (n=9 (n=3 (n=5 (n

RESUMO Objetivo: Este estudo bibliométrico teve como objetivo analisar as métricas de citação, as características dos periódicos e dos autores, e os domínios temáticos das 100 Revisões Sistemáticas (RS) e Meta-Análises (MA) mais citadas em Ortodontia. Material e Métodos: Uma pesquisa em banco de dados eletrônico foi realizada para RS e MA na Web of Science no dia 16 de julho de 2023, sem restrições de idioma e data de publicação. Dos 802 resultados encontrados, foram selecionados os 100 artigos ortodônticos mais citados. Eles foram analisados quanto a métricas de citação, características do periódico (revista, ano de publicação e fator de impacto [FI]), características dos autores e afiliação (quantidade, afiliação dos autores principal e correspondente, e país), domínio do estudo e palavras-chave. Resultados: Esses artigos foram publicados entre 1996 e 2021 em 20 periódicos com fator de impacto de 1,9 a 10,5, por 351 pesquisadores afiliados a 104 universidades. Suas citações variaram de 45 a 344, com 34 prestes a serem classificados como clássicos (≥ 100 citações). A maior quantidade de artigos foi publicada na American Journal of Orthodontics and Dentofacial Orthopedics (n=38), na European Journal of Orthodontics (n=18), e no The Angle Orthodontist (n=8). A quantidade de autores por artigo variou de 1 a 10, sendo 5 o mais frequente (n=58). A Europa teve a maior contribuição em relação ao número de autores correspondentes, instituições e citações. Ancoragem óssea e movimentação dentária ortodôntica/Biomecânica foram os domínios mais abordados (n=11 cada). A palavra-chave mais utilizada foi Ortodontia (n=19), seguida de Revisão Sistemática (n=16) e Meta-análise (n=9). Conclusão: No geral, as RS e MA mais citadas foram publicadas em revistas ortodônticas de alto impacto, eram de autoria múltipla e refletiam o trabalho colaborativo de diferentes universidades. Objetivo citação 10 (RS MetaAnálises Meta Análises (MA Métodos 2023 80 encontrados citados revista, revista (revista FI, FI , [FI]) quantidade, (quantidade correspondente país, país país) palavraschave. palavraschave palavras chave. chave palavras-chave Resultados 199 202 2 19 9 1, 105 10,5 35 universidades 4 344 3 ≥ ( . citações) n=38, n38 n n=38 38 (n=38) n=18, n18 n=18 18 (n=18) n=8. n8 n=8 8 (n=8) n=58. n58 n=58 58 (n=58) correspondentes ortodônticaBiomecânica ortodôntica Biomecânica n=11 n11 11 (n=1 cada. cada cada) palavrachave palavra n=19, n19 n=19 (n=19) n=16 n16 (n=16 Metaanálise análise n=9. n9 n=9 (n=9) Conclusão geral [FI] n3 n=3 (n=38 n1 n=1 (n=18 n= (n=8 n5 n=5 (n=58 (n= (n=19 (n=9 [FI (n=3 (n=5 (n

ABSTRACT Objective: The purpose of this retrospective study was to compare accuracy of arch expansion using two different thermoplastic materials in Invisalign aligners: EX30® (Polyethylene Terephthalate Glycol, or PETG) and SmartTrack® (polyurethane). Methods: The study sample comprised 65 adult patients consecutively treated with Invisalign from two private practices: group 1 - treated with EX30® (358 teeth) and group 2 - treated with SmartTrack® (888 teeth). Six hundred and twenty-three measurements were assessed in three digital models throughout treatment: model 1 - initial, model 2 - predicted tooth position, and model 3 - achieved position. Sixteen reference points per arch were marked and, after best alignment, 2 points per tooth were copied from one digital model to another. Linear values of both arches were measured for canines, premolars, and first molars: on lingual gingival margins and cusp tips of every tooth. Comparisons were performed by Wilcoxon and Mann-Whitney test. Results: Both termoplastic materials presented significant differences between predicted and achieved values for all measurements, except for the lower molar cusp tip in the SmartTrack® group. There is no statistical difference in the accuracy of transverse expansion between these two materials. Overall accuracy for EX30® aligners in maxilla and mandible were found to be 37 and 38%, respectively; and Smarttrack® presented an overall accuracy of 56.62% in the maxilla and 68.72% in the mandible. Conclusions: It is not possible to affirm one material expands better than the other. Further controlled clinical studies should be conducted comparing SmartTrack® and EX30® under similar conditions. Objective EX30 EX Polyethylene Glycol PETG SmartTrack polyurethane. polyurethane . (polyurethane) Methods 6 practices 358 (35 teeth 888 (88 teeth. twentythree twenty treatment initial position alignment another canines premolars molars MannWhitney Mann Whitney test Results 38 38% respectively Smarttrack 5662 56 62 56.62 6872 68 72 68.72 Conclusions other conditions EX3 (polyurethane 35 (3 88 (8 566 5 56.6 687 7 68.7 ( 8 56. 68.

RESUMO Objetivo: O objetivo deste estudo retrospectivo foi comparar a acurácia na expansão da arcada utilizando alinhadores Invisalign com dois tipos de material termoplástico: EX30® (Polietileno Tereftalato Glicol, ou PETG) e SmartTrack® (poliuretano). Método: A amostra desse estudo incluiu 65 pacientes adultos tratados consecutivamente em dois consultórios particulares: grupo 1 - tratado com EX30® (358 dentes), e grupo 2 - tratado com SmartTrack® (888 dentes). Foram avaliadas 623 medidas em três pares de modelos digitais, ao longo do tratamento: modelo 1 - inicial, modelo 2 - posição dentária planejada, modelo 3 - posição alcançada. Foram marcados 16 pontos de referência por arcada e, após o bestfit, 2 pontos por arcada foram copiados de um modelo digital para o outro. Medidas lineares de ambas as arcadas foram aferidas para caninos, pré-molares e primeiros molares, localizadas na margem gengival lingual e ponta de cúspide de todos os dentes. Foram realizadas comparações usando os testes Wilcoxon e Mann-Whitney. Resultados: Ambos os materiais termoplásticos apresentaram diferenças significativas entre os valores planejados e alcançados em todas as medidas, exceto na ponta de cúspide dos primeiros molares inferiores do grupo SmartTrack®. Não houve diferença estatística entre esses dois materiais quanto à acurácia da expansão transversa. Em termos gerais, a acurácia dos alinhadores EX30® na maxila e mandíbula foi de 37% e 38%, respectivamente. O grupo SmartTrack® apresentou acurácia de 56,62% e 68,72% na maxila e mandíbula, respectivamente. Conclusões: Não foi possível afirmar que um material expande melhor que o outro. Estudos clínicos controlados futuros devem ser conduzidos comparando SmartTrack® e EX30® sob condições similares. Objetivo termoplástico EX30 EX Polietileno Glicol PETG SmartTrack poliuretano. poliuretano . (poliuretano) Método 6 particulares 358 (35 dentes, dentes , dentes) 888 (88 62 digitais tratamento inicial planejada alcançada bestfit outro caninos prémolares pré MannWhitney. MannWhitney Mann Whitney. Whitney Mann-Whitney Resultados transversa gerais 37 38 38% respectivamente 5662 56 56,62 6872 68 72 68,72 Conclusões similares EX3 (poliuretano 35 (3 88 (8 566 5 56,6 687 7 68,7 ( 8 56, 68,

ABSTRACT Objective: This study aimed to analyze the scientific production of genetic polymorphisms and external apical root resorption (EARR) to establish main findings, geographic trends, and research gaps for possible future investigations. Methods: Unrestricted publications were searched using the Scopus database (March 2023) to include studies that addressed the association between genetic polymorphisms and EARR. Case-control, cohort, cross-sectional, and review studies were considered eligible. The softwares VOS viewer™ and Bibliometrix were used for data analysis. Results: Of the 44 studies analyzed, “Iglesias-Linares A” was the most cited author. The University of Seville (Spain) conducted the most research on this topic. Brazil, Spain, and the USA were the leading countries in terms of citations. The most frequent term in the co-occurrence of keywords was “EARR.” The journal American Journal of Orthodontics and Dentofacial Orthopedics presented a great relevance in the area, demonstrating a high number of publications. Several genetic polymorphisms have been investigated, with interleukins being the most studied. Conclusion: Endodontics is an area of research that should focus more on root resorption and genetic polymorphisms, as it still underexplored, compared to orthodontics. Polymorphisms have been studied as possible predictors of EARR caused by orthodontic tooth movement. However, the gap in the research indicates a need to search for new genes associated with EARR. Objective (EARR findings trends investigations Methods March 2023 Casecontrol, Casecontrol Case control, control Case-control cohort crosssectional, crosssectional cross sectional, sectional cross-sectional eligible viewer analysis Results 4 analyzed IglesiasLinares Iglesias Linares A author Spain (Spain topic Brazil citations cooccurrence co occurrence “EARR. investigated Conclusion underexplored orthodontics movement However 202 “EARR 20 2

RESUMO Objetivo: Este estudo objetivou analisar a produção científica sobre polimorfismo genético e reabsorção radicular apical externa (external apical root resorption, EARR) para estabelecer os principais achados, tendências geográficas e lacunas de pesquisa, para possíveis investigações futuras. Métodos: Foram pesquisadas publicações na base de dados Scopus (março de 2023) para incluir estudos que abordassem a associação entre polimorfismos genéticos e EARR. Foram considerados elegíveis estudos de caso-controle, relatos de caso, coorte, transversais e revisões. Para análise dos dados, foram utilizados os softwares VOS viewer® e Bibliometrix. Resultados: Dos 44 estudos incluídos, Iglesias-Linares A foi o autor mais citado. A Universidade de Sevilha (Espanha) foi a instituição que mais pesquisou o tema. Brasil, Espanha e EUA foram os principais países em termos de citações. O termo mais frequente na coocorrência das palavras-chave foi EARR. O periódico American Journal of Orthodontics and Dentofacial Orthopedics apresentou grande relevância na área, com vários artigos publicados. Vários polimorfismos genéticos foram investigados, sendo as interleucinas as mais estudadas. Conclusão: Endodontia é uma área de pesquisa que poderia focar mais no tema reabsorção radicular e polimorfismos genéticos, por ser um assunto ainda pouco explorado, em comparação à Ortodontia. Polimorfismos têm sido estudados como possíveis genes preditores de EARR como consequência da movimentação dentária ortodôntica. No entanto, ainda existe uma lacuna na investigação, indicando a necessidade de procurar novos genes associados à EARR. Objetivo external resorption achados futuras Métodos março 2023 casocontrole, casocontrole caso controle, controle caso-controle coorte revisões viewer Bibliometrix Resultados 4 incluídos IglesiasLinares Iglesias Linares citado (Espanha Brasil citações palavraschave palavras chave publicados investigados estudadas Conclusão explorado Ortodontia ortodôntica entanto investigação 202 20 2

Since no recent study has been done about Afrikaans Fisher language the aim of this article is to give an updated linguistic description of this variety.1 Heiberg (1957) conducted a previous study. Varieties change all the time (D'Arcy, 2015:484) and Afrikaans Fisher language is no exception. Due to Covid-19 the researchers were unable to focus exclusively on subsistence fisher communities. Covid anxiousness led to the fact that many fishers did not want to take part in this qualitative study, in which, inter alia, questionnaires and interviews were used (Blume, 2023:35). All fishers indicating their willingness to participate were chosen as respondents if they were between 18 and 75 years of age. The sample of forty fishers is therefore small but is supplemented by various other sources. The areas covered were the coastal areas of the Eastern, Southwestern and Western Cape (Blume, 2023:35). Afrikaans Fisher language has been influenced by different languages, especially Dutch, Portuguese, Malay and English and is recognised as a variety due to several unique words and expressions. Stell, Luffin and Rakiep (2008:293) indicate that the initial Malay and Creole Portuguese of the 20th century led to the development of Muslim Afrikaans. Heiberg (1957:96) explains that the names of certain types offish have an Eastern origin and that they most probably show Malay or Portuguese influence, for example: daeraad: Portuguese, dorado, English dageraad (Blume, 2023:80). Dutch words like dòòdstròòm, kabbelau, omweer/onweer, platvisch (to mention a few) show remarkable similarities with Afrikaans (see Overdiep, 1940; Blume, 2023:108). The list below indicates examples of English influence: bait: something to lure the fish with bait caster: somebody who uses live bait to catch fish beaut: (noun) - a big or pretty fish beautiful: to describe a fish that is big or pretty bottom feeders: Amongst others steenbras, kapenaars, Rooi Roman, Miss Lucy, etcetera cast: fishing method using a hook, line, sinker and bait catch and release: catch fish and throw them back into the water chum, chumming: use bait to get a lot of fish in one place coffee grinder: a type of pulley drag, smooth drag: the breaks on the pulley - "die drag is smooth". dropshot: hook made of steel with a built-in sinker and bait which is used to catch fish edge - "daai edge gee": have a better chance of a catch happy days: exclamation of joy hook-up, double hook-up: when fish bite or when more than one fish is caught on one hook live bait: bait that is alive pink prawn: type of sand or mud prawn popper: artificial bait in the form of small fish pull: when you can see that a fish bites because of the movement of the line rocket: used to describe a fast fish - "Hy swem soos 'n rocket." run: when thefish bit but try to swim away with the hook and bait. The Afrikaans equivalents loop and hardloop are also used. single: when only one hook is used size: when a fish is legally big enough spinner: type of bait made of metal which turns around in the water tentacle: a type of bait, specifically octopus tentacle tooth wire: strong line used to catch fish trawl: method of pulling bait behind a boat trigger: "hongerkliertjie trigger": stimulation of the glands on certain types offish, usually when the chum method is used try wind: used instead of probeer inkatrol unbelievable: emotional exclamation wangle: manipulate tools to function as they should Hybrid (English and Afrikaans) forms are frequently used: The following English fish names are used: banded galjoen: also known as bastard galjoen, demba. belman: other names are baardman, belvis, tasselfish. bronze bream: alternative names are hottentot, das, Jan Bruin, John Brown, fat fish, copper bream, Nyizala, butterfish, etcetera. bronzy: variant of bronze bream. cob: kabeljou flatty: frequently used in the Eastern Cape instead of Kaapse stompneus. garrick: also called leervis, leerfish grunter: instead of knorhaan gruntertjie: instead of knorhaan Miss Lucy: instead of rooistompneus pig/pig nose: instead of witneussteenbras pyltail (stingray): instead of pylstert, skerpneuspylstert, blou pylstert, vlinderrog raggie: from ragged toothed shark instead of yellow shark, brown shark shad: (Afrikaans: elf) swart musselcracker: (Afrikaans: poenskop). This fish is also known as black biskop, witbek, black steenbras, saqomolo, swartbiskop. Most fishers use either musselcracker or poenskop. tiger: instead of tiger shark wit musselcracker: Also known as brusher, mussel crusher, silver steenbras, white biskop. Most fishers use musselcracker instead of biskop. yellowtail: Seriola lalandi (Blume, 2023:155-157). Fisher language differs in terms of degrees of standardisation as certain words also occur in the general vocabulary, as indicated in the latest Handwoordeboek van die Afrikaanse Taal (HAT). Some words are not standardised as they are English words, for example shad (instead of elf) or they consist of hybrid forms, containing English and Afrikaans elements, like raggie for a specific type of shark. Other words and expressions are not included in the HAT, probably as they are not so well-known or frequently used in the general lexicon, for example bonnie/ bonnietjie instead of bonito. Stylistic variation is evident in the usage of the frequently used informal word flattie instead of stompneus. The degree of education can also lead to variation, as in skuide for skuite and kiewe for kieue. Certain meaning distinctions relating to Fisher language do not occur in the HAT, for example mas used as a verb and the meaning distinction "small boat" at the lemma bakkie.

Afrikaanse visserstaal is deur verskillende tale beïnvloed, waaronder veral Nederlands, Portugees, Maleis en Engels en word as variëteit onderskei op grond van heelwat unieke woorde en uitdrukkings. Daar is min geografiese differensiasie tussen Oos-Kaapse en Wes-Kaapse visserstaal as gevolg van die dialekkontinuum (Blume, 2023). Woorde in Afrikaanse visserstaal verskil ten opsigte van gestandaardiseerdheid deurdat sommige woorde ook in die algemene woordeskat voorkom, soos in die nuutste HAT aangedui. Sommige woorde is nie gestandaardiseer nie aangesien hulle Engelse woorde is, byvoorbeeld shad, of 'n hibridiese vorm van Engels en Afrikaans is, byvoorbeeld raggie. Ander woorde en uitdrukkings is nie in die HAT opgeneem nie, waarskynlik omdat hulle nie so bekend/gebruiklik is in die algemene leksikon nie, byvoorbeeld bonnie/bonnietjie in plaas van die standaardwoord bonito. Stylvlakverskille kom voor by die Standaardafrikaanse woord stompneus teenoorflatty (informeel). Laasgenoemde word eerder onder die vissers gebruik. Dit geld ook vir die gebruik van visserman teenoor visterman. Enkele woorde in HAT6 bevat nie die visserstaal-betekenisonderskeiding nie, byvoorbeeld bakkie en mas as werkwoord.

RESUMEN; Introducción: Existen procedimientos quirúrgicos que pueden generar una disminución en la duración de los tratamientos de ortodoncia (TO) mediante una aceleración del movimiento dental. La técnica más estudiada corresponde a la corticotomía clásica, la cual muchas veces es desechada por los pacientes debido a su invasividad. Es por esto que nacen las intervenciones quirúrgicas mínimamente invasivas (IQMI), tales como las micro osteoperforaciones (MOP) y la piezocisión, que buscan el mismo resultado, pero sin realizar colgajos de espesor total, otorgándole al paciente nuevas alternativas terapéuticas para acortar el tratamiento de ortodoncia. La evidencia al respecto aún es controversial, debido a que la certeza de la evidencia es baja o muy baja con relación a estos procedimientos. Métodos: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metaanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. Resultados y conclusiones: Identificamos 39 revisiones sistemáticas que en conjunto incluyeron 43 estudios primarios, de los cuales, 31 corresponden a ensayos aleatorizados. Concluimos que las intervenciones quirúrgicas mínimamente invasivas podrían aumentar la tasa de movimiento dental a las 12 semanas, la distancia total acumulada, la tasa de movimiento dental y reducir la duración total de tratamiento, pero la certeza de la evidencia es incierta. Además, podrían resultar en poca o ninguna diferencia sobre el índice gingival, la profundidad de sondaje y el índice de placa.

ABSTRACT: Introduction: There are surgical procedures that can generate a decrease in the orthodontic (OT) treatments duration through a Acceleration of tooth movement. The most studied technique corresponds to classical corticotomy, which is often discarded by patients due to its invasiveness. This is why minimally invasive surgical interventions (MISI) are born, such as micro osteoperforations (MOP) and piezocision, which seek the same result, but without making total thickness flaps, giving the patient new therapeutic alternatives to shorten orthodontic treatment. The evidence on this is still controversial, because the certainty of the evidence is low or very low in relation to these procedures. Methods: A search was performed using Epistemonikos, the biggest database for systematic reviews in health, which is maintained by screening of multiple sources of information, including MEDLINE, EMBASE, Cochrane, among others. Data from systematic reviews were extracted, and analysis of the primary studies was performed, including a meta-analysis and a summary of findings table using GRADE approach. Results and conclusions: We identified 39 systematic reviews that together included 43 primary studies, of which 31 correspond to randomized clinical trials. We conclude that minimally invasive surgical interventions could increase the rate of tooth movement at 12 weeks, distance total accumulated, the rate of tooth movement and reduce the total duration of treatment, but the certainty of the evidence is uncertain. In addition, they could result in little or no difference in gingival index, probing depth and plaque index.

ABSTRACT: Several methods have been described to shorten orthodontic treatments, but the main disadvantage is their invasiveness. Animal studies have shown that piezopuncture can accelerate the rate of tooth movement without causing collateral damage. Objective: To evaluate the clinical outcome, in terms of safety and efficacy, of a flapless piezopuncture on maxillary canine distalization. Methods: A split-mouth randomized clinical trial was carried out on five patients. Piezopuncture was performed on a random side of the maxillary arch to assess the rate of canine movement on the stimulated side, compared to the non-stimulated control side after 15 (T1), 30 (T2), and 60 (T3) days. Also, immediate side effects and changes in buccal bone thickness after one year were assessed. Results: Distalization on the intervention versus control side at T1 was 1.24±0.21mm versus 0.64±0.33mm (p=0.005); at T2 it was 2.00±0.28mm versus 1.36±0.49mm (p=0.046); and at T3 it was 4.28±0.66mm versus 3.65±0.88mm (p=0.102). No adverse effects related to the surgical procedure were observed or reported by patients. The thickness of the buccal bone plate showed no significant changes. Conclusions: Flapless piezopuncture accelerates the rate of tooth movement in orthodontic patients over the first 15 days and its effect declines over the next 45 days.

INTRODUCTION: Supernumerary teeth (SNT) are often associated with malocclusions. Data on SNT in the South African population are not well documented OBJECTIVE: To determine the prevalence, distribution of characteristics and any associated complications of SNT in a South African sample of dental patients DESIGN: The study was retrospective, cross-sectional and descriptive METHOD: Orthopantomographs of 12,005 dental patients were reviewed for the presence of SNT. The number, morphology, location, eruption status and orientation of SNT were assessed. Associated orthodontic problems were noted RESULTS: The prevalence rate was 2.48%. No sexual dimorphism in the distribution of SNT was noted. Types of SNT tabulated were: supplementary, conical, tuberculate and odontoma. Maxilla demonstrated a higher predilection for SNT. Variation in the distribution of SNT in the anterior, premolar and molar regions in each jaw and across jaws was statistically significant. Relationship of eruption status to the morphology and orientation of SNT was of significance. Malocclusions noted were displacement and impaction of adjacent teeth CONCLUSION: From an orthodontic perspective, presence of SNT may compromise tooth movement and space closure in patients. Additionally, as majority of SNT in this population were in the maxillary molar and mandibular premolar regions, caution is advised when planning the placement of orthodontic implants in these regions

Abstract Objective Many genes and signaling molecules are involved in orthodontic tooth movement, with mechanically and hypoxically stabilized HIF-1α having been shown to play a decisive role in periodontal ligament signaling during orthodontic tooth movement. Thus, this in vitro study aimed to investigate if genetic polymorphisms in HIF1A (Hypoxia-inducible factor α-subunits) influence the expression pattern of HIF-1α protein during simulated orthodontic compressive pressure. Methodology Samples from human periodontal ligament fibroblasts were used and their DNA was genotyped using real time Polymerase chain reaction for the genetic polymorphisms rs2301113 and rs2057482 in HIF1A . For cell culture and protein expression experiments, six human periodontal ligament fibroblast cell lines were selected based on the patients’ genotype. To simulate orthodontic compressive pressure in fibroblasts, a 2 g/cm2 force was applied under cell culture conditions for 48 hours. Protein expression was evaluated by Western Blot. Paired t-tests were used to compare HIF-1α expression with and without compressive pressure application and unpaired t-tests were used to compare expression between the genotypes in rs2057482 and rs2301113 (p<0.05). Results The expression of HIF-1α protein was significantly enhanced by compressive pressure application regardless of the genotype (p<0.0001). The genotypes in the genetic polymorphisms rs2301113 and rs2057482 were not associated with HIF-1α protein expression (p>0.05). Conclusions Our study confirms that compressive pressure application enhances HIF-1α protein expression. We could not prove that the genetic polymorphisms in HIF1A affect HIF-1α protein expression by periodontal ligament fibroblasts during simulated orthodontic compressive force. movement HIF1α HIFα HIF 1α α Thus HIFA A Hypoxiainducible Hypoxia inducible αsubunits subunits α-subunits rs rs230111 rs205748 experiments patients gcm2 gcm g cm2 cm g/cm 4 hours Blot ttests t tests p<0.05. p005 p p<0.05 0 05 (p<0.05) p<0.0001. p00001 p<0.0001 0001 (p<0.0001) p>0.05. p>0.05 (p>0.05) rs23011 rs20574 p00 p<0.0 (p<0.05 p0000 p<0.000 000 (p<0.0001 p>0.0 (p>0.05 rs2301 rs2057 p0 p<0. (p<0.0 p000 p<0.00 00 (p<0.000 p>0. (p>0.0 rs230 rs205 p<0 (p<0. (p<0.00 p>0 (p>0. rs23 rs20 p< (p<0 p> (p>0 rs2 (p< (p> (p

Abstract The aim of this study was to quantify the force exerted by tandem archwires in a specific system of passive self-ligating bracket. Forty-eight thermo-activated nickel-titanium orthodontic archwires were separated into four groups (n = 12): G1 – two .014” + .014” round archwires; G2 – two .014” + .016” round archwires; G3 – .014” x .025” rectangular archwire; and. G4 – .016” x .022” rectangular archwire. Brackets were fixed onto teeth 1.5 to 2.5 using a device that represented the upper teeth, maintaining an interbracket distance of 6.0 mm. The deflection tests were performed using the structure representative of tooth 1.1 as support on the Instron testing machine at a speed of 2.0 mm/min. The archwires were evaluated at deflections of 0.5 mm, 1.0 mm, and 1.5 mm. The data were analyzed by a generalized linear model, considering values at different deflections as repeated measurements in the same experimental unit (α = 0.5%). At 0.5 mm, higher forces were observed in G2 and G3, which did not differ significantly (p > 0.05). The lowest force was observed in G4 (p < 0.05). At 1.0 mm and 1.5 mm, the highest force was observed in G3, followed by G4 and G2 (p < 0.05). The lowest force was observed in G1 (p < 0.05). In general, tandem archwires (same or different calibers) in a specific passive self-ligating bracket exerted lower force when compared with rectangular archwires. selfligating self ligating Fortyeight Forty eight thermoactivated thermo activated nickeltitanium nickel titanium n 12 12) G .014 014 .016 016 .025 025 archwire .022 022 15 1 5 1. 25 2 2. 60 6 0 6. 11 20 mmmin min mm/min 05 0. 10 model α 0.5%. 0.5% . 0.5%) p 0.05. 005 0.05 0.05) general calibers .01 01 .02 02 00 0.0 .0

ABSTRACT Objective: To investigate the effects of orthodontic tooth movement on clinical attachment level (CAL) changes in treated periodontitis in adult patients with malocclusion. Material and Methods: Present study is based on PRISMA guidelines; all articles published in international databases such as PubMed, Scopus, Science Direct, and Embase between 2012 to May 2022 are included. 95% confidence interval (CI) for mean difference with fixed effect modal and inverse-variance were calculated. Data analysis was performed using STATA.V16 software. Results: In the initial review, duplicate studies were eliminated, abstracts of 175 studies were reviewed, two authors reviewed the full text of 21 studies, and finally, eleven studies were selected. The mean of CAL gain was 2.29 mm (MD, 95% CI -2.47 mm, -2.12 mm; p=0.00) (I2=91.81%; p=0.00; high heterogeneity). The mean difference of PPD changes was -1.93 mm (MD, 95% CI -2.07 mm, -1.80 mm; p=0.00) (I2=98.52%; p=0.00; high heterogeneity). Conclusion: Due to the limitations of the study and based on the meta-analysis, it is observed that orthodontic treatment is performed with higher success after reconstructive surgery with periodontal improvement. Objective (CAL malocclusion Methods guidelines PubMed Scopus Direct 201 202 included 95 (CI inversevariance inverse variance calculated STATAV16 STATAV STATA V16 V STATA.V1 software Results review eliminated 17 2 finally selected 229 29 2.2 MD, MD (MD 2.47 247 47 -2.4 2.12 212 12 -2.1 p=0.00 p000 p 0 00 I2=91.81% I29181 I I2 91 81 (I2=91.81% heterogeneity. heterogeneity . heterogeneity) 1.93 193 1 93 -1.9 2.07 207 07 -2.0 1.80 180 80 -1.8 I2=98.52% I29852 98 52 (I2=98.52% Conclusion metaanalysis, metaanalysis meta analysis, meta-analysis improvement 20 9 STATAV1 V1 STATA.V 22 2. 2.4 24 4 -2. 2.1 p=0.0 p00 I2=91.81 I2918 8 (I2=91.81 1.9 19 -1. 2.0 1.8 18 I2=98.52 I2985 5 (I2=98.52 -2 p=0. p0 I2=91.8 I291 (I2=91.8 1. -1 I2=98.5 I298 (I2=98.5 - p=0 I2=91. I29 (I2=91. I2=98. (I2=98. p= I2=91 (I2=91 I2=98 (I2=98 I2=9 (I2=9 I2= (I2= (I2 (I

ABSTRACT Introduction: Superposing 3D models is an imminent need. However, current methods rely on marking multiple points on the maxilla and mandible, which could increase point marking and overlapping errors. Objective: This study aimed at developing a method for superimposing 3D models of the maxillary and mandibular arches with Autodesk Inventor® engineering software, using a single universal coordinate system (UCS) point superposition. Methods: A total of 104 STL (stereolithography) models of the maxillary and mandibular arches exported from My iTero® platform were retrospectively selected, in which T0 and T1 were the initial and refinement periods, respectively (n=26 per group). The X, Y, and Z coordinates associated with a single point in each arch were inserted into the models with SlicerCMF® software for model orientation. The arch models with UCS registration were transferred to Autodesk Inventor® for superimposition and to measure tooth movements performed during Invisalign® treatment. Arch expansion, intrusion and rotation were analyzed by two examiners. The statistics were performed using intraclass correlation coefficients (ICC), Dahlberg’s formula, and t-test (p<0.05). Results: A reliable method of superimposing 3D digital models using a single UCS point in the maxilla and mandible was developed. ICC showed excellent intra- and inter-examiner correlation (ICC>0.90). A systematic error was not found concerning linear and angular measurements (<1mm and <1.5°, respectively). Digital dental movements could be analyzed, including arch expansion, dental intrusion, and tooth rotation. Conclusions: The developed method was proven reliable and reproducible for superimposing 3D models of the maxillary and mandibular arches by using UCS system. Introduction D need However errors Objective Inventor (UCS superposition Methods 10 stereolithography (stereolithography iTero selected T periods n=26 n26 n 26 (n=2 group. group . group) X Y SlicerCMF orientation Invisalign treatment expansion examiners ICC, , (ICC) Dahlbergs Dahlberg s formula ttest t test p<0.05. p005 p p<0.05 0 05 (p<0.05) Results intra interexaminer inter examiner ICC>0.90. ICC090 ICC>0.90 90 (ICC>0.90) <1mm 1mm mm 15 1 5 <1.5° respectively. respectively) Conclusions n=2 n2 2 (n= (ICC p00 p<0.0 (p<0.05 ICC09 ICC>0.9 9 (ICC>0.90 <1.5 n= (n p0 p<0. (p<0.0 ICC0 ICC>0. (ICC>0.9 <1. p<0 (p<0. ICC>0 (ICC>0. <1 p< (p<0 ICC> (ICC>0 < (p< (ICC> (p

RESUMO Introdução: A sobreposição de modelos 3D é uma necessidade iminente. No entanto, os métodos atuais dependem da marcação de múltiplos pontos na maxila e na mandíbula, o que pode aumentar a incorporação de erros no processo de sobreposição. Objetivo: O objetivo desse estudo foi desenvolver um método para sobrepor modelos 3D das arcadas superior e inferior utilizando o software de engenharia Autodesk Inventor®, por meio da marcação de um único ponto em cada arcada, usando o sistema de coordenadas universal (UCS). Métodos: No total, 104 modelos STL das arcadas superior e inferior exportados da plataforma My iTero® foram selecionados retrospectivamente, onde T0 foi o período inicial e T1, o de refinamento (n=26 por grupo). As coordenadas X, Y e Z associadas a um único ponto em cada arcada foram inseridas nos modelos usando o software SlicerCMF®. Os modelos com os pontos UCS demarcados foram transferidos para o software Autodesk Inventor® para realizar a sobreposição e medir os movimentos dentários realizados durante o tratamento com Invisalign®. Os movimentos de expansão, intrusão e rotação foram analisados por dois examinadores. A análise estatística foi realizada usando os coeficientes de correlação intra-classe (ICC), fórmula de Dahlberg e teste t (p<0,05). Resultados: Foi desenvolvido um método confiável de sobreposição de modelos digitais 3D usando um único ponto UCS na maxila e mandíbula. O ICC apresentou excelente correlação intra e inter-avaliadores (ICC>0,90). Não foi encontrado erro sistemático nas medidas lineares e angulares (<1mm e <1,5°, respectivamente). Os movimentos dentários puderam ser analisados por meio do método proposto, incluindo expansão da arcada, intrusão e rotação dentária. Conclusão: O método desenvolvido provou ser confiável e reprodutível para sobreposição de modelos 3D das arcadas superior e inferior usando o sistema UCS com marcação de ponto único. Introdução D iminente entanto mandíbula Objetivo Inventor UCS. . (UCS) Métodos total 10 iTero retrospectivamente T T1 n=26 n26 n 26 (n=2 grupo. grupo grupo) X SlicerCMF SlicerCMF® Invisalign Invisalign® examinadores intraclasse classe ICC, , (ICC) p<0,05. p005 p p<0,05 0 05 (p<0,05) Resultados interavaliadores inter avaliadores ICC>0,90. ICC090 ICC>0,90 90 (ICC>0,90) <1mm 1mm mm 15 1 5 <1,5° respectivamente. respectivamente respectivamente) proposto dentária Conclusão (UCS n=2 n2 2 (n= (ICC p00 p<0,0 (p<0,05 ICC09 ICC>0,9 9 (ICC>0,90 <1,5 n= (n p0 p<0, (p<0,0 ICC0 ICC>0, (ICC>0,9 <1, p<0 (p<0, ICC>0 (ICC>0, <1 p< (p<0 ICC> (ICC>0 < (p< (ICC> (p

ABSTRACT Objective: This study was designed to analyze and compare the cusp and apex movements of the maxillary canines and first molars during canine retraction in the first step of extraction space closure, and to evaluate if these teeth follow a curvilinear (acceleration and/or deceleration) movement rate. Material and Methods: Twenty-five patients (23.3 ± 5.1 years of age) were enrolled. The retraction of the maxillary canines was accomplished using nickel-titanium closed coil springs (100gf) on 0.020-in stainless steel archwire. Oblique cephalograms were traced and superimposed on the anatomic best fit of the maxilla (before the retraction [T0], and after one month [T1], three [T3], five [T5] and seven [T7] months). Statistics was based in a normally distributed data. Multilevel procedures were used to derive polynomials for each of the measurements. Student’s t-test and one-way repeated measures ANOVA were conducted. The level of significance of 5% was adopted. Results: Canine cusps and apexes did not follow a quadratic curve regarding horizontal movement (neither accelerate nor decelerate). Canine and molar cusps showed more horizontal movement than apexes (4.80 mm vs. 2.78 mm, and 2.64 mm vs. 2.17 mm, respectively). Conclusions: Canine did not accelerate or decelerate overtime horizontally; the cusps and apexes of the canines and molars showed more horizontal movement and larger rate at the beginning of canine retraction, followed by significantly smaller and constant movement rate after the first month. Objective closure acceleration andor deceleration Methods Twentyfive Twenty 23.3 233 23 3 (23. 51 5 1 5. age enrolled nickeltitanium nickel titanium 100gf gf (100gf 0.020in 0020in 0.020 0 020 archwire before T0, T0 T , [T0] T1, T1 [T1] T3, T3 [T3] T5 [T5 T7 [T7 months. months . months) data measurements Students Student s ttest t test oneway way conducted adopted Results neither decelerate. decelerate) 4.80 480 4 80 (4.8 vs 278 2 78 2.7 264 64 2.6 217 17 2.1 respectively. respectively respectively) Conclusions horizontally 23. (23 020in 0020 0.02 02 [T0 [T1 [T3 [T 4.8 48 8 (4. 27 7 2. 26 6 21 (2 002 0.0 4. (4 ( 00 0.

RESUMO Objetivo: O objetivo deste estudo foi analisar a movimentação das cúspides e dos ápices de caninos e primeiros molares superiores durante a retração de caninos na primeira fase do fechamento do espaço pós-extração, e avaliar se esses dentes apresentam mudança na taxa de movimentação (aceleração e/ou desaceleração). Material e Métodos: Vinte e cinco pacientes (idade = 23,3 ± 5,1 anos) foram incluídos. A retração dos caninos superiores foi realizada com molas helicoidais fechadas de níquel-titânio (100gf) em arco 0,020” de aço inoxidável. Foram feitos traçados cefalométricos de telerradiografias oblíquas e sobrepostos ao melhor ajuste anatômico da maxila (antes da retração [T0]; após um mês [T1], três meses [T3], cinco meses [T5] e sete meses [T7]). A estatística foi baseada em dados com distribuição normal. Procedimentos multiníveis foram usados para derivar polinômios para cada uma das medidas. Teste t de Student e ANOVA de uma via para medidas repetidas foram realizados, adotando-se um nível de significância de 5%. Resultados: As cúspides e os ápices dos caninos não seguiram uma curva quadrática em relação ao movimento horizontal (sem aceleração ou desaceleração). As cúspides dos caninos e molares apresentaram mais movimento horizontal do que os ápices (4,80 mm vs. 2,78 mm e 2,64 mm vs. 2,17mm, respectivamente). Conclusões: A movimentação horizontal dos caninos não acelerou ou desacelerou ao longo do tempo; as cúspides e os ápices dos caninos e molares apresentaram maior movimento horizontal e maior taxa de movimentação no início da retração dos caninos, seguida por uma taxa de movimentação significativamente menor e constante após o primeiro mês. Objetivo pósextração, pósextração pós extração, extração pós-extração eou desaceleração. desaceleração . desaceleração) Métodos idade 233 23 3 23, 51 5 1 5, anos incluídos níqueltitânio níquel titânio 100gf gf (100gf 0,020 0020 0 020 inoxidável antes T0 T [T0] T1, T1 , [T1] T3, T3 [T3] T5 [T5 T7. T7 [T7]) normal realizados adotandose adotando 5% Resultados sem 4,80 480 4 80 (4,8 vs 278 2 78 2,7 264 64 2,6 217mm 17mm 2,17mm respectivamente. respectivamente respectivamente) Conclusões tempo 0,02 002 02 [T0 [T1 [T3 [T [T7] 4,8 48 8 (4, 27 7 2, 26 6 0,0 00 [T7 4, (4 0, (

ABSTRACT Objective: To study the effect of using a combination of Channa Striata gel and hyperbaric oxygen therapy on pressure areas during orthodontic treatment. Material and Methods: The study was conducted using the ARRIVE Essential 10 guidelines. In this study, 35 3-4 months male guinea pigs (Cavia Cobaya) weighing 300-400 grams were used and divided into 5 groups (n=7). Decalcification was performed to dissolve the dental calcium and jawbone to cut the tissue properly. The decalcification was performed for 30 days. Then preparations were made with HE (Hematoxylin Eosin), observed using a microscope, and counted the number of osteoclasts and macrophages on a light microscope with 400 times magnification. The results of the preparations were analyzed using the SPSS program. Results: The Kruskal-Wallis test of macrophage cells and the ANOVA test of osteoclast cells showed significant results between all groups (p<0.05). Conclusion: The effect of hyperbaric oxygen therapy 2,4 ATA administered on days 8-14 and Channa Striata extract gel administered on days 3-14 can increase the number of macrophages in the periodontal ligament and osteoclasts in the alveolar bone in the pressure area during orthodontic tooth movement. Objective treatment Methods 1 guidelines 3 34 4 3- Cavia Cobaya 300400 300 300-40 n=7. n7 n n=7 . 7 (n=7) properly Hematoxylin Eosin, Eosin , Eosin) 40 magnification program Results KruskalWallis Kruskal Wallis p<0.05. p005 p p<0.05 0 05 (p<0.05) Conclusion 24 2 2, 814 8 14 8-1 314 3-1 movement 30040 300-4 n= (n=7 p00 p<0.0 (p<0.05 81 8- 31 3004 300- (n= p0 p<0. (p<0.0 (n p<0 (p<0. p< (p<0 (p< (p

ABSTRACT Introduction: Orthodontists attempt to maximize treatment efficiency regarding time, tooth position and adverse effects. A new approach, not yet explored, is the activation frequency. Objective: The aim of this split-mouth randomized controlled trial was to evaluate the effect of reactivation intervals on the efficiency of tooth movement. Methods: Thirty eight patients having a Class I malocclusion with bimaxillary dentoalveolar protrusion or severe crowding, Class II with mandibular deficiency or Class III, requiring first premolar extraction and canine retraction were recruited. Elastomeric chains producing 150g were replaced every two, four, six or eight weeks. There were 36, 37, 36, and 36 quadrants randomly allocated to these groups, respectively. The canine retraction rate was the primary outcome. Canine tipping, rotation, and root resorption and pain were the secondary outcomes. Only the outcome assessors were blinded to group assignment. Results: The average total movement for the 6 months was 5.14, 5.31, 2.79 and 3.85 mm for the two-week, four-week, six-week and eight-week reactivation intervals, respectively. Root resorption was significantly higher in the two-week and four-week groups. No adverse events were observed. Conclusion: The canine retraction rate, tipping, rotation and pain were similar in 2, 4, 6 and 8-week activation intervals groups. Longer reactivation intervals show less root resorption. The trial protocol was not pre-registered. The study was self-funded. Introduction time effects approach explored frequency Objective splitmouth split mouth Methods crowding III recruited g two four weeks 37 3 groups respectively tipping outcomes assignment Results 514 5 14 5.14 531 31 5.31 279 2 79 2.7 385 85 3.8 twoweek, twoweek week, week fourweek, fourweek sixweek eightweek observed Conclusion 4 8week 8 preregistered. preregistered pre registered. registered pre-registered selffunded. selffunded self funded. funded self-funded 51 1 5.1 53 5.3 27 7 2. 38 3. 5.

RESUMO Introdução: Os ortodontistas buscam otimizar a eficiência do tratamento quanto ao tempo de duração, à posição dos dentes e aos efeitos adversos. Um aspecto ainda não avaliado são os diferentes intervalos entre as ativações. Objetivo: O objetivo desse estudo controlado e randomizado de boca dividida foi avaliar a influência de diferentes intervalos de reativação na eficiência da movimentação dentária. Métodos: Foram recrutados 38 pacientes com má oclusão de Classe I com biprotrusão dentoalveolar ou apinhamento severo, Classe II com deficiência mandibular ou Classe III, que necessitavam de extração do primeiro pré-molar e retração do canino. As cadeias elastoméricas gerando 150 g foram substituídas a cada duas, quatro, seis ou oito semanas, constando 36, 37, 36 e 36 quadrantes alocados aleatoriamente nesses grupos, respectivamente. O desfecho primário foi a taxa de retração do canino. Os desfechos secundários foram a inclinação, a rotação e a reabsorção radicular do canino, e a dor. Somente os avaliadores dos resultados não tinham conhecimento da alocação nos grupos. Resultados: O movimento total médio para os seis meses foi de 5,14; 5,31; 2,79 e 3,85 mm para os intervalos de reativação de duas semanas, quatro semanas, seis semanas e oito semanas, respectivamente. A reabsorção radicular foi significativamente maior nos grupos de duas e quatro semanas. Não foram observados eventos adversos. Conclusão: A taxa de retração, a inclinação e a rotação do canino e a dor foram semelhantes nos grupos com intervalos de ativação de duas, quatro, seis e oito semanas. Intervalos de reativação mais longos mostram menos reabsorção radicular. O protocolo do estudo não foi pré-registrado. O estudo foi autofinanciado. Introdução duração adversos ativações Objetivo dentária Métodos 3 severo III prémolar pré molar 15 37 respectivamente Resultados 5,14 514 5 14 5,31 531 31 279 2 79 2,7 385 85 3,8 Conclusão préregistrado. préregistrado registrado. registrado pré-registrado autofinanciado 1 5,1 51 5,3 53 27 7 2, 8 3, 5,