UNIVERSIDADE FEDERAL FLUMINENSE FACULDADE DE ODONTOLOGIA
PREVALÊNCIA DO USO DE PROTETORES BUCAIS EM
ESPORTES COLETIVOS: REVISÃO SISTEMÁTICA
Niterói 2018
UNIVERSIDADE FEDERAL FLUMINENSE FACULDADE DE ODONTOLOGIA
PREVALÊNCIA DO USO DE PROTETORES BUCAIS EM
ESPORTES COLETIVOS: REVISÃO SISTEMÁTICA
PROGRAMA DE PÓS-GRADUAÇÃO EM ODONTOLOGIA MESTRADO EM CLÍNICA ODONTOLÓGICA
VICTOR JOSÉ DA ROCHA BOTELHO
Dissertação apresentada à Faculdade de Odontologia da Universidade Federal Fluminense como parte dos requisitos para obtenção do título de Mestre, pelo Programa de Pós-Graduação em Odontologia.
Área de Concentração: Clínica Odontológica
Orientador: Prof. Dr. José de Albuquerque Calasans Maia
Niterói 2018
Prof. José de Albuquerque Calasans Maia Instituição: Universidade Federal Fluminense
Decisão: _________________________Assinatura: ________________________ Prof. Leonardo dos Santos Antunes
Instituição: Universidade Federal Fluminense
Decisão: _________________________Assinatura: ________________________
Prof. Vittorio Moraschini Filho
Instituição: Universidade Salgado de Oliveira
A Deus por ter me dado saúde e força para superar as dificuldades.
A esta universidade, seu corpo docente, direção e administração que oportunizaram a janela que hoje vislumbro um horizonte superior, eivado pela acendrada confiança no mérito e ética aqui presentes.
Ao meu orientador Prof. Dr. José de Albuquerque Calasans Maia, pelo suporte, pela paciência, pelas oportunidades e pelo conhecimento que se propôs a transmitir. Agradeço pela orientação e por não ter desistido de mim em nenhum momento dessa trajetória.
Aos meus pais, pelo amor, incentivo, apoio incondicional e pelo suporte nos momentos mais difíceis dessa caminhada. Agradeço a Deus por ter me colocado nessa família. Sem vocês, não seria nada.
E a todos que direta ou indiretamente fizeram parte da minha formação, o meu muito obrigado.
As lesões dentárias e faciais são comuns nos esportes de contato e, portanto, ganharam atenção e importância na prevenção. Como método de prevenção de traumas na região bucal, a indicação é o uso de protetores bucais. Estes dispositivos protegem os dentes, tecidos moles e outras estruturas amortecendo e distribuindo o impacto. No entanto, em vários esportes, o uso de protetores ainda não é expressivo por atletas profissionais e amadores. O objetivo deste estudo foi verificar a prevalência do uso de protetores bucais em esportes coletivos. Para isso, foi realizada uma revisão sistemática da literatura. Foi realizada uma busca eletrônica nos bancos de dados PubMed, Scopus, Web of Science, Biblioteca Virtual em Saúde, Google Acadêmico e OpenGrey (data final de agosto de 2018); uma busca manual de listas de referência do estudo primário também foi realizada. Os critérios de inclusão abrangeram estudos com questionários e / ou entrevistadores, com a prevalência individual de cada esporte; estudos transversais e de coorte. Além destes, os seguintes esportes cumpriram os mesmos critérios: futebol, basquete, handebol e rugby. Avaliação da qualidade e risco de viés foram aplicados e avalia a qualidade dos estudos elegíveis usando a Newcastle-Ottawa Quality Assessment Scale adaptada para estudos transversais que resultaram em uma média de 66,17% de uso de protetor bucal por atletas de rugby. Os demais esportes apresentaram: handebol, 16,06%; basquete, 12,76%; e futebol, 3,35%. Com base nas evidências encontradas, conclui-se que, apesar da boa média dos atletas de rugby, os demais esportes apresentaram médias baixas no uso de protetores bucais. Acredita-se que mais estudos sejam necessários para evidenciar as razões do não uso e aumentar o conhecimento sobre os benefícios da proteção bucal.
ABSTRACT
Dental and facial injuries are common in contact sports and therefore have gained attention and importance in prevention. As a method of prevention for traumas in the buccal region, the indication is the use of mouth guards. These devices protect teeth, soft tissues and other structures by cushioning and distributing the impact. However, in several sports, the use of protectors is still not expressive by professional and amateur athletes. The objective of this study was to verify the prevalence of the use of mouth guards in collective sports. For this, a systematic review of the literature was carried out. An electronic search was performed in the PubMed, Scopus, Web of Science, Virtual Health Library, Google Scholar and OpenGrey databases (end date August 2018); a hand-search of primary study reference lists was also conducted. The inclusion criteria covered studies with questionnaires and/or interviewers, with the individual prevalence of each sport; cross-sectional and cohort studies. In addition to these, the following sports met the same criteria: soccer, basketball, handball and rugby. Quality assessment and risk of bias were applied and evaluates the quality of eligible studies using the Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies which resulted in an average of 66.17% of buccal protector use by rugby athletes. The other sports presented: handball, 16.06%; basketball, 12.76%; and football, 3.35%. Based on the evidence found, it is concluded that, despite the good average of the rugby athletes, the other sports presented low averages in the use of mouth guards. It is believed that more studies are needed to evidence the reasons for non-use and to increase knowledge about the benefits of oral protection.
1 - INTRODUÇÃO
Os níveis de competitividade no esporte aumentam cada vez mais com o objetivo de se atingir a vitória. Com isso, maior exigência no desempenho físico, técnico e mental dos esportistas, os expondo a risco de lesões traumáticas, principalmente, em esportes coletivos.1
Injúrias bucofaciais e traumatismos dentários são frequentemente vistos em esportes coletivos e podem causar problemas estéticos, funcionais e psicológicos.2 As lesões traumáticas nos esportes podem atingir alto índice de incidência, variando de acordo com o esporte praticado.3
Foi demonstrado que a prática desportiva aumenta o risco de lesões, tais como o traumatismo dentário4 e a sua prevalência varia dependendo do tipo de esporte. Dos diferentes esportes, o judô, basquete, handebol e futebol são os esportes mais relacionados a traumas.5,6,7 Nos esportes coletivos, a face torna-se a parte do corpo mais exposta e suscetível a traumas e, portanto, as lesões nos tecidos moles ocorrem mais frequentemente, tendo como exemplos as abrasões, contusões e lacerações. Todas elas devem ser avaliadas para descartar fraturas e/ou lesões significativas.8
Os protetores bucais provaram reduzir o número e a severidade das lesões traumáticas bucais que acometem atletas de esportes de contato.9 Eles protegem os dentes, tecidos moles e outras estruturas adjacentes, amortecendo e distribuindo o impacto. No arco superior protegem os tecidos moles e dentes anteriores, e, no arco inferior, além de protegerem os tecidos moles e dentes, evitam deslocamentos e traumas na articulação temporomandibular.10
A concussão cerebral é o grau mais suave do traumatismo craniano. A literatura médica relata evidência de que o protetor bucal favorece a proteção, não só da cavidade bucal, mas também de estruturas cranianas.11
O mecanismo de ação dos protetores bucais funciona como amortecedor do trauma, distribuindo as forças durante o impacto contra os dentes, prevenindo a laceração e equimose dos lábios e bochechas, e, evitando também que os dentes do arco oposto estejam sujeitos a contatos traumáticos fortes, que poderiam gerar fraturas nos dentes e estruturas de suporte.12
A recomendação na fabricação dos protetores bucais segue os seguintes critérios: adaptação, retenção e estabilidade do material. O protetor deve interferir o mínimo possível na fala e na respiração, deve ser resistente e confortável, sem produzir odor e gosto e ter excelente retenção e ajuste nos arcos dentários.13
Dentro dessas características, existem 3 tipos de protetores bucais: os de estoque (stock), os feitos na boca ou pré-fabricados (mouth-formed) e os customizados ou feitos sob medida (custom-made).14
Os universais ou de estoque são destinados a se adaptar em qualquer boca. Não tem uma boa adaptação e é comum relatos, pelos usuários, de que eles ficam soltos, pesados, dificultam a fala e a respiração. Além disso, necessitam que o atleta fique de boca fechada. São muito grossos nas superfícies oclusais e finos na parte labial.15 Tem como vantagens o baixo custo e a facilidade na aquisição.10
O segundo tipo inclui aqueles que são adaptados diretamente na boca, sendo pré-fabricados. São melhores na adaptação dos que os de estoque, mas piores do que os feitos sob-medida.15 São mais encontrados na versão termoplástica (boil and
bite), que são feitos a partir de uma moldeira termoplástica pré-formada de copolímero
de PVAc – PE (EVA), ou PVC que quando colocada em água quente fica plastificada e então moldada na boca.10
Os feitos sob medida são produzidos a partir de uma moldagem das arcadas feita pelo cirurgião-dentista. Independentemente do material utilizado na fabricação, estes apresentam melhor adaptação, volume e espessura.15 Geralmente, após obtenção do modelo em gesso da arcada superior do paciente, é produzido os protetores através de um aparelho a vácuo, sendo que os materiais mais usados são as placas de vinil termoplásticas. Esse tipo de material é mais confortável, pois se adapta bem a superfície dos dentes e estruturas adjacentes, tem boa retenção e distribui melhor as forças de impacto, dando maior segurança ao usuário.10 São os mais indicados e utilizados por pacientes que usam aparelhos ortodônticos fixos.16
Os protetores bucais entregam alto grau de proteção aos dentes e estruturas de suporte, com isso devem ser utilizados como material de proteção pelos atletas. As associações esportivas deveriam conter ao menos um cirurgião-dentista em sua equipe para prevenir lesões bucais (com protetores bucais) e atuar no caso de urgência e tratamento das lesões ocorridas.16
Considerando as especificações, as qualidades, os benefícios e o conhecimento maior sobre protetores bucais, o presente estudo tem como objetivo, avaliar, através de uma revisão sistemática da literatura, a prevalência do uso de protetores bucais por atletas, em diferentes esportes coletivos (futebol, basquete, rúgbi e handebol).
2 – METODOLOGIA
Neste estudo foi realizado uma revisão sistemática da literatura, seguindo, com algumas alterações, a metodologia de delineamento proposta pelo Centro de Colaboração Cochrane17 e a recomendação Prisma18 para revisões sistemáticas: a) Formulação da questão pergunta; b) Definição da estratégia de busca dos artigos; c) Seleção dos estudos (aplicação dos critérios de inclusão e exclusão); d) Avaliação crítica da evidência disponível; e) Sintetização e definição da força da evidência científica (Ranqueamento); f) Coleta e análise dos dados; g) Interpretação e recomendações.
2.1 - Formulação da pergunta
Qual a prevalência estimada da utilização de protetores bucais entre esportistas profissionais e amadores em diferentes esportes coletivos?
2.2 – Definição da estratégia de busca
Uma pesquisa bibliográfica foi realizada de janeiro de 2018 a agosto de 2018 e foi conduzida usando as seguintes bases de dados eletrônicas: PubMed, Scopus, Web of Science e Biblioteca Virtual de Saúde – BVS (Medline, SciELO, LILACS, BBO). Além desses, foram realizadas buscas no Google Acadêmico e literatura cinza. Os bancos de dados eletrônicos foram explorados tendo, cada um deles, uma forma de combinar os seguintes termos:
Termo MeSH: athletes
Termos livres athletes, athlete, sportsathletes, sportsathlete, sportsman, sportsmen, sportswoman, sportswomen, players, player, practitioners, practitioner
Termo MeSH: Sports
Termos livres: Sports, Sport, Athletics, Athletic
Term MeSH: Prevalence
Termos livres: Prevalence, Prevalences
Termo MeSH: mouth protectors
Termos livres: mouth protectors, mouth protector, protective mouthpiece, protective mouthpieces, mouth guards, mouth guard, mouthguard, mouthguards
PubMed
((((Athletes[MeSH Terms] OR Athletes[Title/Abstract] OR Sportsathlete[Title/Abstract] OR Sportsathletes[Title/Abstract] OR Sportsman[Title/Abstract] OR Sportswoman[Title/Abstract] OR Sportswomen[Title/Abstract] OR Players[Title/Abstract] OR Player[Title/Abstract] OR Practitioner[Title/Abstract] OR Practitioners[Title/Abstract])) AND (Sports[MeSH Terms] OR Sports[Title/Abstract] OR Sport[Title/Abstract] OR Athletics[Title/Abstract] OR Athletic[Title/Abstract])) AND
(Prevalence[MeSH Terms] OR Prevalence[Title/Abstract] OR
Prevalences[Title/Abstract])) AND (Mouth protectors[MeSH Terms] OR Mouth protectors[Title/Abstract] OR Mouth protector[Title/Abstract] OR Protective mouthpiece[Title/Abstract] OR Protective mouthpieces[Title/Abstract] OR Mouth guards[Title/Abstract] OR Mouth guard[Title/Abstract] OR Mouthguard[Title/Abstract] OR Mouthguards[Title/Abstract])
Scopus
((TITLE-ABS-KEY (Athletes) OR TITLE-ABS-KEY (Athlete) OR TITLE-ABS-KEY (Sportsathlete) OR TITLE-ABS-KEY (Sportsathletes) OR TITLE-ABS-KEY (Sportsman) OR TITLE-ABS-KEY (Sportsmen) OR TITLE-ABS-KEY (Sportswoman) OR KEY (Sportswomen) OR KEY (Players) OR
TITLE-ABS-KEY (Player) OR TITLE-ABS-TITLE-ABS-KEY (Practitioner) OR TITLE-ABS-TITLE-ABS-KEY (Practitioners))) AND ((TITLE-ABS-KEY (Sports) OR TITLE-ABS-KEY (Sport) OR TITLE-ABS-KEY (Athletics) OR TITLE-ABS-KEY (Athletic))) AND ((TITLE-ABS-KEY (Prevalence) OR TITLE-ABS-KEY (Prevalences))) AND ((TITLE-ABS-KEY (“Mouth protectors”) OR TITLE-ABS-KEY (“Mouth protector”) OR TITLE-ABS-KEY (“Protective mouthpiece”) OR TITLE-ABS-KEY (“Protective mouthpieces”) OR TITLE-ABS-KEY (“Mouth guards”) OR TITLE-ABS-KEY (“Mouth guard”) OR TITLE-ABS-KEY (Mouthguard) OR TITLE-ABS-KEY (Mouthguards)))
BVS
(tw:(Protetores bucais)) AND (tw:(Esportes)) AND (tw:(Atletas)) AND (tw:(Prevalência))
Web of Science
Cada variável foi pesquisada individualmente com os termos livres, aplicando a palavra OR. Após isso, juntou-se todas utilizando #1 AND #2 AND #3 AND #4.
#1
(((((((((((TÓPICO:(athletes) OR TÓPICO: (athlete)) ORTÓPICO: (sportsathletes)) OR TÓPICO:(sportsathlete)) OR TÓPICO:(sportsman)) OR TÓPICO: (sportsmen))OR T ÓPICO: (sportswoman)) ORTÓPICO: (sportswomen)) OR TÓPICO:(players)) OR TÓ PICO: (player)) ORTÓPICO: (practitioners)) OR TÓPICO:(practitioner))
#2
TÓPICO:(Sports) OR TÓPICO: (Sport) ORTÓPICO: (Athletics) OR TÓPICO:(Athletic )
#3
TÓPICO:(Prevalence) OR TÓPICO:(Prevalences) #4
TÓPICO:(mouth protectors) OR TÓPICO:(mouth protector) OR TÓPICO:(protective
mouthpiece) OR TÓPICO:(protective mouthpieces) OR TÓPICO:(mouth
guards) OR TÓPICO: (mouth guard) OR TÓPICO: (mouthguard) OR
TÓPICO: (mouthguards)
Google Scholar
Prevalence AND "Mouth protectors" OR "Mouthguards" AND Athletes OR Players AND Sports
Os artigos selecionados foram agrupados por ano de publicação. O formulário de extração de dados foi realizado de forma independente por dois avaliadores (VJRB e JACM) avaliando-se o perfil metodológico das publicações, considerando autor e ano de publicação, o tipo de estudo, local, faixa etária, amostra do estudo, tipo de protetor bucal e esporte.
2.3 – Seleção dos estudos
A fim de selecionar artigos potencialmente relevantes, foi realizada avaliação dos títulos e resumos de cada artigo especificamente, a partir de leitura cuidadosa, permanecendo somente aqueles que preencheram os critérios estabelecidos, e retirando-se os repetidos por bases de dados considerando apenas um, seguindo as etapas apresentadas no diagrama de fluxo de acordo com as diretrizes PRISMA.18
Nos casos em que os títulos e os resumos não foram esclarecedores, o artigo foi acessado na íntegra. Em seguida, os estudos selecionados foram confrontados e, quando houvesse discordâncias, estas foram discutidas buscando-se um consenso entre dois avaliadores (VJRB e JACM). Para avaliar a concordância entre os autores foi utilizado o índice Kappa.
A inclusão dos estudos sem restrição de idioma foi baseada na estratégia PICOS ou PECOS (Patient or problem - Paciente ou problema em questão ou diagnóstico; Intervention – Intervenção de interesse ou exposição de interesse; Comparison - Comparação de intervenção; Outcomes - desfechos; Studies - tipos de estudo) conforme abaixo:
Participantes: Esportistas profissionais e amadores (incluindo crianças e adolescentes)
Intervenção / Exposição: Utilização de protetores bucais Comparação: Não realizado
Desfecho: Prevenção de traumatismo dentário.
Tipos de estudo: Transversais e de coorte (retrospectivo e prospectivo).
Foram excluídos artigos com as seguintes características: i) com informação insuficiente.
Os critérios de inclusão para a realização do estudo foram: estudos com questionários e/ou entrevistadores, com a prevalência individual de cada esporte; estudos transversais e coorte. Além desses, os seguintes esportes entraram nos mesmos critérios: futebol, basquete, handebol e rúgbi. Foram selecionados esses esportes por serem os mais semelhantes possíveis: esportes coletivos, contato é permitido até certo ponto, a maioria dos contatos é com um adversário e não apresentam regras sobre proteção bucal.
Como critérios de exclusão, os seguintes dados foram selecionados: esportes que apresentassem equipamentos auxiliares para a sua prática, tais como: taco, capacete, armadura, bicicleta; que não identificassem uma prevalência individualizada (quando mencionados mais de um esporte); revisões de literatura, revisões sistemáticas, caso-controle, estudos clínicos randomizados; esportes de contato direto, tais como lutas.
2.5 – Análise Qualitativa dos estudos
Após a seleção e tendo o número final de estudos, dois investigadores independentes (VJRB e JACM) avaliaram a qualidade dos estudos elegíveis usando a Escala de Avaliação da Qualidade de Newcastle-Ottawa adaptada para estudos transversais.19 Originalmente, esta ferramenta foi desenvolvida para estudos de
coorte e caso-controle. Essa adaptação, contém 7 itens, divididos em três categorias: seleção de participantes (seleção), comparabilidade de grupos de estudo (comparabilidade) e avaliação de exposição (resultado). Um estudo foi classificado com uma estrela para cada item, exceto nos itens “determinação da exposição” e “avaliação do resultado” que podem receber até 2 estrelas, onde mostra uma alta qualidade. Para nosso estudo, a seguinte categoria “comparabilidade de grupos de estudo” foi descartada, uma vez que o foco dos estudos é no percentual dos que usam protetor bucal. Dessa forma, um estudo pode conter no máximo 8 estrelas. Foi adotado como um artigo de boa qualidade aquele que obteve, no mínimo, 5 estrelas.
2.6 – Coleta e análise dos dados
Os dados relevantes da metodologia dos artigos selecionados, foram extraídos e apresentados de forma detalhada.
Os artigos selecionados foram agrupados por ano de publicação. O formulário de extração de dados foi feito de forma independente avaliando-se o perfil metodológico das publicações, considerando autor e ano de publicação, esporte, métodos de medição (exemplo: questionário), amostra do estudo (por esporte), local, gênero, nível de competição, faixa etária e/ou média etária e prevalência.
2.7 – Análise Estatística
A prevalência média do uso de protetor bucal global e de cada esporte foi calculado pela soma de todas as prevalências dadas pelos estudos e dividindo pela quantidade total e, por esporte, desses estudos.
Para realização da estatística descritiva, o programa StatPlus LE (Windows, versão 6.5.0.0) foi utilizado.
Prevalence of the use of mouthguards in collective sports: systematic review
ACKNOWLEDGMENTS
This study was conducted during the master's degree in dental clinic of Victor José da Rocha Botelho, under supervision of the Prof. José de Albuquerque Calasans Maia. It was supported by the post-graduation program of Universidade Federal Fluminense.
CONFLIT OF INTEREST
This paper do not have any conflict of interest.
ABSTRACT
The objective of this study was to verify the prevalence of the use of mouth guards in collective sports. For this, a systematic review of the literature was carried out. An electronic search was performed in the PubMed, Scopus, Web of Science, Virtual Health Library, Google Scholar and OpenGrey databases (end date August 2018); a hand-search of primary study reference lists was also conducted. The inclusion criteria covered studies with questionnaires and/or interviewers, with the individual prevalence of each sport; cross-sectional and cohort studies. In addition to these, the following sports met the same criteria: soccer, basketball, handball and rugby. Quality assessment and risk of bias were applied and evaluates the quality of eligible studies using the Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies which resulted in an average of 66.17% of buccal protector use by rugby athletes. The other sports presented: handball, 16.06%; basketball, 12.76%; and football, 3.35%. Based on the evidence found, it is concluded that, despite the good average of the rugby athletes, the other sports presented low averages in the use of mouth guards. It is believed that more studies are
needed to evidence the reasons for non-use and to increase knowledge about the benefits of oral protection.
Keywords: Mouth guards, Sports, Dental injuries
INTRODUCTION
The levels of competitiveness in the sport are increasing more and more in order to achieve victory. With this, greater demands on the physical, technical and mental performance of athletes, exposing them to the risk of traumatic injuries, mainly in collective sports.1
Bucofacials injuries and dental trauma are often seen in collective sports and can cause aesthetic, functional and psychological problems.2 Traumatic injuries in sports can reach a high incidence rate, varying according to the sport practiced.3
Mouth guards have proven to reduce the number and severity of traumatic injuries to the mouth of contact sports athletes.4 They protect teeth, soft tissues and other adjacent structures by cushioning and distributing the impact.
The recommendation in the manufacture of mouthguards follows the following criteria: adaptation, retention and stability of the material. The protector should interfere as little as possible in speech and breathing, must be sturdy and comfortable, without producing odor and taste, and have excellent retention and adjustment in the dental arches.5
The mouth guards deliver a high degree of protection to the teeth and support structures, so they should be used as protective material by the athletes. Sports associations should contain at least one dental surgeon in their team to prevent oral lesions (with mouth guards) and to act in case of urgency and treatment of the injuries that occurred.6
Considering the specifications, qualities, benefits and greater knowledge about mouth guards, the present study aims to evaluate, through a systematic review of the literature, the
prevalence of the use of mouth guards by athletes in different collective sports (soccer, basketball, rugby and handball).
MATERIAL AND METHODS
This systematic was undertaken in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta -Analyses (PRISMA) statement.7 The review protocol is registered in the PROSPERO database (CRDxxxxxxxxxxx; http://www.crd.york.ac.uk/PROSPERO).
Electronic databases were searched from January 2018 to August 2018: PubMed, Scopus, BVS (Medline, SciELO, Lilacs, BBO), Web of Science, Google Scholar and OpenGrey databases. An additional manual search was also conducted of the reference lists of all primary studies to identify addicional relevant publications; the related studies linked to each primary study in the PubMed database were also considerer. The search strategy used MeSH terms and synonyms in order not to impose any restrictions, and to maximise the search for articles in this research phase. The search strategy was adapted for each database, with no language or date restrictions.
The eligibility criteria were based on a research question, defined in the PECO format, which was as follows: cross-sectional and cohort studies (retrospective and prospective) that included professional and / or amateur athletes (P) with or without use of mouth guards (E) to determine the prevalence of wearing mouth guards in different collective sports (O) were included.
To identify this, the studies went through inclusion criteria: studies with questionnaires and / or interviewers, with the individual prevalence of each sport; cross-sectional studies and cohort studies. In addition to these, the following sports entered the same criteria: soccer, basketball, handball and rugby; and exclusion: sports that present auxiliary equipment for their
practice, such as: club, helmet, armor, bicycle; that identify a global prevalence (when more than one sport is mentioned); literature reviews, systematic reviews, case-control, randomized clinical trials; direct contact sports such as fights.
Two reviewers (VJRB and JACM) performed the search strategy, in order to identify eligible studies and independently evaluate the titles and abstracts of all studies identified from the electronic databases. Full-text copies were retrieved from studies that met the inclusion criteria, or for which there were insufficient data in the title and abstract to make a clear decision. These copies were assessed independently. Any disagreements on the eligibility of included studies, at any point in the process, were resolved through consensus.
Quality assessment and risk of bias were applied and evaluated the quality of eligible studies using the Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies described by Modesti et al.8 Originally, this tool was developed for cohort and case-control studies. This adaptation contains 7 items, divided into three categories: selection of participants (selection), comparability of study groups (comparability) and evaluation of exposure (outcome). One study was rated one star for each item, except for the items "exposure determination" and "outcome assessment" that can receive up to 2 stars, where it shows a high quality. For our study, the following category "comparability of study groups" was discarded, since the focus of the studies is on the percentage of those who wear a mouthguard. In this way, a study can contain at most 8 stars. It was adopted as a good quality article that obtained at least 5 stars.
The mean prevalence of global buccal protector use and of each sport was calculated by summing all the prevalences given by the studies and dividing by the total amount and by sport of these studies. For the descriptive statistics, the program StatPlus LE (Windows, version 6.5.0.0) was used.
RESULTS
Studies selection
The selection process of studies for this systematic review is presented in Figure 1. The initial search resulted in 103 MEDLINE / PubMed titles, 101 titles in the Virtual Health Library, 96 titles in Scopus, 42 titles in the Web of Science and 569 in other sources (Hand-search, OpenGrey literature and Google Scholar), totaling 911 records. After performing the removal of duplicates, 494 articles remained. After applying exclusion and inclusion criteria (eligibility), there were 49 articles that went through the quality evaluation process, thus remaining 17 articles for inclusion in the systematic review.
Study characteristics
The characteristics of the 17 studies included in this systematic review are given in Table 1. Of these 17 included studies, 3 were performed with handball athletes9,10,13, 4 of soccer16,17,19,22, 3 of basketball11,20,25 and 7 of rugby12,14,15,18,21,23,24. The studies included: 662
handball athletes9,10,13, 1746 soccer16,17,19,22, 1235 basketball11,20,25 and 2792 athletes of rugby12,14,15,18,21,23,24. Most of the studies were performed in Europe (n = 8), followed by Australia (n = 4), North America (n = 3)19,22,23, Brazil (n = 2)17,20 and Malaysia (n = 1)15, observing that a study was performed in 2 different places. The gender of the athletes was divided as follows: male (n = 9)10,12,14,15,16,17,18,20,21, both (n = 6)9,11,13,15,19,22 and female (n = 1)23,
and one article does not report. The age range found in the analysis was 5 years to 52 years. The athletes' level of competition ranged from amateurs (children and adults) to professionals. The level of competition related to each sport was as follows: handball (1 study with amateurs and 2 with professionals); basketball (3 studies with a mix between professionals and amateurs); rugby (4 studies with amateurs, 1 with professionals and 2 did not mention); and football (3 articles with amateurs only).
Prevalence of the use of mouthguards by sports
The average prevalence of use of a mouthguard for sports is shown in Graphic 1. It is observed that the sport with the highest percentage of mouthguard use is rugby, with 66.17% (standard deviation 29.63%, minimum 9.21%, maximum 100%); followed by: handball 16.06% of mean (standard deviation 11.23%, minimum 5.7%, maximum 28%), basketball 12.76% (standard deviation 10.60%, minimum 6.3%, maximum 25 %) and soccer, with a mean of 3.35% (standard deviation 3.38%, minimum 0.29%, maximum 8%).
The average prevalence of mouthguard use for all sports is 33.12% (standard deviation 34.54%, minimum 0.29%, maximum 100%).
Assessments of the risk of bias and quality
Thirty-two studies presented scores below 5 points, showing potential risk of bias and, therefore, were excluded from the systematic review. No article scored the highest score (Tables 2 and 3). The maximum number of points obtained was 6 and six studies obtained this score.12,14,15,19,23,2
DISCUSSION
Summary of evidence
Considering that mouthguards are devices that reduce the risk of orofacial lesions, protecting soft tissues and teeth, it becomes questionable that their use is not widespread, especially in contact sports. The objective of this systematic review was to investigate the prevalence of mouthguard use in different collective sports and with relative contact.
A comprehensive survey of studies including electronic search, manual search and grey literature was conducted. There was no restriction of date of publication and language, thus reducing the risk of bias.
The research determined that the search would be for similar, collective sports, where the rules do not prohibit contact, most of contacts are against the opponent and that there is no compulsory use of mouthguards. Thus, the sports chosen for the systematic review were: basketball, soccer, handball and rugby.
For this systematic review, the NOS (Newcastle-Ottawa Scale) quality analysis was applied in modified form. Therefore, the selection of studies for inclusion in this review was done so that articles with less than 5 stars were excluded. Those who were rated with 5 stars or more were included in this study. Thus, of the 49 articles that passed the eligibility criteria, 17 were included after the quality analysis. It should be noted that none of the articles reached the maximum score.
Most of the studies presented only amateur players (children, adolescents and/or recreation).9,14,16,18,19,21,22 Those who selected only professional players for their research, match only 3 studies.10,13,24 Other studies, had as a mixture in the samples according to level of competition.11,12,17,20,25 Two documents did not report the level of competition attached to their
samples.15,23 Relating the level of competition to each sport, we have: handball (2 studies with professional athletes and 1 with amateurs), basketball (the 3 studies with a very varied mix of amateurs to professionals), soccer (amateur only) and rugby (majority with amateur athletes).
With regard to the average age of each sport, was found the studies with basketball athletes with the highest mean 22.73 years (standard deviation = 4.51). The other sports had the following results: rugby 21.47 years (standard deviation = 5.43); handball 20.05 years (standard deviation = 6.24); and soccer 14.73 years (standard deviation = 0.56).
Some studies have noted the issue of knowledge of the importance of using mouthguards. Galic et al, 2018, identified that 97.3 of the sample of handball players had this knowledge. Despite this high percentage, only 14.5% of handball players in the study use
mouthguards. Uzel et al., 2014, with soccer athletes, had prevalence of oral protection 0.29% and only 38.2% of the sample had knowledge of the importance of the use.
Most of the studies (9)10,12,14,15,16,17,18,20,21 had samples with male athletes. While the female was reported in only 1 (one) study.23 Six 9,11,13,15,19,22 other studies, both sexes and only one, did not report.24 This shows that sports with men still have more visibility and therefore, more studies carried out.
It is important to know the reasons for not wearing mouth guards. Some articles have reported these reasons. The most cited was discomfort during use. Other reasons cited were: difficulty in breathing, communication and aesthetics. They were also reported by some athletes who did not find use of the mouthguard needed.
A high percentage (66.17%) of rugby players who used mouth guards in sports practice; however, these percentages varied among the studies, registering a variation of 9.21% and 100%.12,14,15,18,21,23,24 In contrast, the average percentage found for soccer was the lowest, with 3.35%. Among them, handball has 16.06% and basketball, 12.76%. This result can be explained through the level of contact. Rugby is the sport with the most contact between players, while soccer is the lightest. In this way, rugby players usually look for more protective devices.
Strengths and limitations
This systematic review presents as important points: unrestricted research in the literature, selection of the best evidence available, study search process included in the study, data extraction and risk analysis bias.
Some limitations may be related to this review: the studies do not present calculations to determine the sample size, the studies do not present as primary objective to find the prevalence of the use of mouthguards and sports dentistry is not very widespread within the area.
Recommendations for further research
With the increase of competitiveness in sports, the protection of the teeth and adjacent structures are of paramount importance for health maintenance. Studies with an emphasis on oral protection should be more carried out to increase the knowledge of coaches, athletes and dentists about the importance of using this protective device. Another important issue would be to address the reasons for the non-use of mouthguards routinely by athletes. Knowing these reasons, dentists and industry will be able to perfect the materials and, consequently, increase their prevalence of use.
CONCLUSION
Based on the available data, it was evidenced that the prevalence of mouthguards use in rugby practitioners is very reasonable. The results showed that the average use in rugby was 66.17%. Compared with the other sports of this review, it presented the highest average. The other sports (handball, basketball and soccer), presented average low percentage of use.
It is suggested for Sports Dentistry that new studies should seek reasons for not using mouthguards in a way that would be suitable for use by athletes. In addition, to spread to all the importance of these devices for the health of orofacial structures.
REFERENCES
1- Queiróz, A. F. V. R., de Brito Jr, R. B., Ramacciato, J. C., Motta, R. H. L., & Flório, F. M. (2013). Influence of mouthguards on the physical performance of soccer players. Dental
Traumatology, 29(6), 450-454.
2- Dursun, E., Ilarslan, Y. D., Ozgul, O., & Donmez, G. (2015). Prevalence of dental trauma and mouthguard awareness among weekend warrior soccer players. Journal of oral
3- Andreasen, J. O., & Andreasen, F. M. (2001). Texto e atlas colorido de traumatismo dental. Artmed.
4- Yamada, T., Sawaki, Y., & Ueda, M. (1997). Mouth guard for athletes during orthodontic treatment. Dental Traumatology, 13(1), 40-41.
5- Wells GA, Shea B, O’connell D, et al. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses. The Ottawa Hospital Research Institute, University of Ottawa, Canada.
6- Canto, G. de L. et al. Protetores bucais: uma necessidade dos novos tempos. Rev Dent ortoped facial, v.4, n.6, p.20-6, nov./dez. 1999.
7- Moher D, Liberati A, Tetzlaff J, Altman DG, Group P. Preferred reporting items for systematic reviews and meta -analyses: The PRISMA statement. PLoS Med. 2009;6: e1000097. 8- Modesti, Pietro Amedeo, et al. "Panethnic differences in blood pressure in Europe: a systematic review and meta-analysis." PLoS One 11.1 (2016): e0147601.
9- Galic, Tea, et al. "Knowledge and attitudes about sports‐related dental injuries and mouthguard use in young athletes in four different contact sports—water polo, karate, taekwondo and handball." Dental traumatology (2018).
10- Bergman, Lana, et al. "Prevalence of dental trauma and use of mouthguards in professional handball players." Dental traumatology 33.3 (2017): 199-204.
11- Tiryaki, Murat, et al. "Prevalence of dental injuries and awareness regarding mouthguards among basketball players and coaches." The Journal of sports medicine and physical
fitness 57.11 (2017): 1541-1547.
12- Kroon, Jeroen, et al. "Mouthguard use and awareness of junior rugby league players in the Gold Coast, Australia: a need for more education." Clinical journal of sport medicine 26.2 (2016): 128-132.
13- Petrović, Mateja, et al. "Dental and General Trauma in Team Handball." Swiss dental
14- Ilia, E., K. Metcalfe, and M. Heffernan. "Prevalence of dental trauma and use of mouthguards in rugby union players." Australian dental journal 59.4 (2014): 473-481.
15- Liew, Amy Kia Cheen, et al. "Factors associated with mouthguard use and discontinuation among rugby players in M alaysia." Dental Traumatology 30.6 (2014): 461-467.
16- Uzel, Ilhan, et al. "Dental trauma and mouthguard usage among soccer players in Izmir, Turkey." Dentistry Journal 2.3 (2014): 78-84.
17- Vieira, Rafaela Amarante de Andrade. "Prevalência das injúrias orofaciais e uso de protetores bucais em uma população de atletas que praticam futebol e jiu-jitsu." (2013). 18- Boffano, Paolo, et al. "Rugby athletes’ awareness and compliance in the use of mouthguards in the North West of Italy." Dental Traumatology 28.3 (2012): 210-213.
19- Khodaee, Morteza, Michael D. Fetters, and Daniel W. Gorenflo. "Football (soccer) safety equipment use and parental attitudes toward safety equipment in a community youth sports program." Research in sports medicine 19.2 (2011): 129-143.
20- Frontera, Renata Reis, et al. "Orofacial trauma in Brazilian basketball players and level of information concerning trauma and mouthguards." Dental traumatology 27.3 (2011): 208-216. 21- Jagger, Robert G., et al. "The prevalence of dental, facial and head injuries sustained by schoolboy rugby players. A pilot study." Primary dental care 17.3 (2010): 143-146.
22- Delaney, J. Scott, et al. "The effect of protective headgear on head injuries and concussions in adolescent football (soccer) players." British journal of sports medicine 42.2 (2008): 110-115.
23- Comstock, R. Dawn, Sarah K. Fields, and Christy L. Knox. "Protective equipment use among female rugby players." Clinical Journal of Sport Medicine 15.4 (2005): 241-245. 24- Muller‐Bolla, Michèle, et al. "Orofacial trauma and rugby in France: epidemiological survey." Dental Traumatology 19.4 (2003): 183-192.
25- Cornwell, Helen, Louise Brearley Messer, and Harriet Speed. "Use of mouthguards by basketball players in Victoria, Australia." Dental Traumatology 19.4 (2003): 193-203.
5– CONCLUSÃO
Com base nos dados disponíveis, evidenciou-se que a prevalência do uso de protetor bucal em praticantes de rúgbi é bastante razoável. Os resultados demonstraram que a média de uso no rúgbi foi de 66,17%. Comparando com os outros esportes dessa revisão, apresentou a maior média. Os demais esportes (handball, basquete e futebol), apresentaram médias percentuais baixas de uso.
Sugere-se para a Odontologia esportiva, que novos estudos busquem os motivos para a não utilização dos protetores bucais de maneira a adequá-los para serem mais utilizados pelos atletas. Além disso, difundir a todos a importância desses dispositivos para a saúde das estruturas bucofaciais.
6– REFERÊNCIAS
1- Queiróz, A. F. V. R., de Brito Jr, R. B., Ramacciato, J. C., Motta, R. H. L., & Flório, F. M. (2013). Influence of mouthguards on the physical performance of soccer players. Dental Traumatology, 29(6), 450-454.
2- Dursun, E., Ilarslan, Y. D., Ozgul, O., & Donmez, G. (2015). Prevalence of dental trauma and mouthguard awareness among weekend warrior soccer players. Journal
of oral science, 57(3), 191-194.
3- Andreasen, J. O., & Andreasen, F. M. (2001). Texto e atlas colorido de traumatismo
dental. Artmed.
4- Çetinbaş, T., & Sönmez, H. (2006). Mouthguard utilization rates during sport activities in Ankara, Turkey. Dental traumatology, 22(3), 127-132.
5- Yamada, T., Sawaki, Y., Tomida, S., Tohnai, I., & Ueda, M. (1998). Oral injury and mouthguard usage by athletes in Japan. Dental Traumatology, 14(2), 84-87.
6- Andrade, R. A., Evans, P. L. S., Almeida, A. L. S., Silva, J. D. J. R. D., Guedes, A. M. L., Guedes, F. R., ... & Tinoco, E. M. B. (2010). Prevalence of dental trauma in Pan American games athletes. Dental traumatology, 26(3), 248-253.
7- Ferrari, C. H., & De Medeiros, J. M. F. (2002). Dental trauma and level of information: mouthguard use in different contact sports. Dental Traumatology, 18(3), 144-147. 8- Crow, R. W. (1991). Diagnosis and management of sports-related injuries to the face. Dental Clinics of North America, 35(4), 719-732.
9- Yamada, T., Sawaki, Y., & Ueda, M. (1997). Mouth guard for athletes during orthodontic treatment. Dental Traumatology, 13(1), 40-41.
10- Barberini, A. F., Aun, C. E., & Caldeira, C. L. (2002). Incidência de injúrias orofaciais e utilização de protetores bucais em diversos esportes de contato Incidence of orofacial injuries and utilization of mouthguards in various contact sports. Rev.
11- Emery, C. A., Black, A. M., Kolstad, A., Martinez, G., Nettel-Aguirre, A., Engebretsen, L., ... & Aubry, M. (2017). What strategies can be used to effectively reduce the risk of concussion in sport?. Br J Sports Med, bjsports-2016.
12- Josell, S. D., & Abrams, R. G. (1982). Traumatic injuries to the dentition and its supporting structures. Pediatric Clinics of North America, 29(3), 717-741.
13- Council on Dental Materials, Instruments, and Equipment. (1984). Mouth protectors and sports team dentists. The Journal of the American Dental
Association, 109(1), 84-87.
14- Guerard, S., Barou, J. L., Petit, J., & Poisson, P. (2017). Characterization of mouthguards: Impact performance. Dental Traumatology.
15- Heintz, WD. Maximum mouth protector for contact sports. J. Prosth. Dent. v. 9, n. 11, p. 874-880, 1959.
16- Canto, G. de L. et al. Protetores bucais: uma necessidade dos novos tempos. Rev Dent ortoped facial, v.4, n.6, p.20-6, nov./dez. 1999.
17- Alderson, P., Green, S., & Higgins, J. P. T. (2004). Cochrane Reviewers’ Handbook 4.2. 2. The Cochrane Library, 1.
18- Moher, D., Liberati, A., Tetzlaff, J., Altman, D. G., & Prisma Group. (2009). Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS medicine, 6(7), e1000097.
19- Modesti, Pietro Amedeo, et al. "Panethnic differences in blood pressure in Europe: a systematic review and meta-analysis." PLoS One 11.1 (2016): e0147601.
20- Galic, Tea, et al. "Knowledge and attitudes about sports‐related dental injuries and mouthguard use in young athletes in four different contact sports—water polo, karate, taekwondo and handball." Dental traumatology (2018).
21- Bergman, Lana, et al. "Prevalence of dental trauma and use of mouthguards in professional handball players." Dental traumatology 33.3 (2017): 199-204.
22- Tiryaki, Murat, et al. "Prevalence of dental injuries and awareness regarding mouthguards among basketball players and coaches." The Journal of sports medicine
and physical fitness 57.11 (2017): 1541-1547.
23- Kroon, Jeroen, et al. "Mouthguard use and awareness of junior rugby league players in the Gold Coast, Australia: a need for more education." Clinical journal of
sport medicine 26.2 (2016): 128-132.
24- Petrović, Mateja, et al. "Dental and General Trauma in Team Handball." Swiss
dental journal 126.7-8 (2016): 682-686.
25- Ilia, E., K. Metcalfe, and M. Heffernan. "Prevalence of dental trauma and use of mouthguards in rugby union players." Australian dental journal 59.4 (2014): 473-481. 26- Liew, Amy Kia Cheen, et al. "Factors associated with mouthguard use and discontinuation among rugby players in M alaysia." Dental Traumatology 30.6 (2014): 461-467.
27- Uzel, Ilhan, et al. "Dental trauma and mouthguard usage among soccer players in Izmir, Turkey." Dentistry Journal 2.3 (2014): 78-84.
28- Vieira, Rafaela Amarante de Andrade. "Prevalência das injúrias orofaciais e uso de protetores bucais em uma população de atletas que praticam futebol e jiu-jitsu." (2013).
29- Boffano, Paolo, et al. "Rugby athletes’ awareness and compliance in the use of mouthguards in the North West of Italy." Dental Traumatology 28.3 (2012): 210-213. 30- Khodaee, Morteza, Michael D. Fetters, and Daniel W. Gorenflo. "Football (soccer) safety equipment use and parental attitudes toward safety equipment in a community youth sports program." Research in sports medicine 19.2 (2011): 129-143.
31- Frontera, Renata Reis, et al. "Orofacial trauma in Brazilian basketball players and level of information concerning trauma and mouthguards." Dental traumatology 27.3 (2011): 208-216.
32- Jagger, Robert G., et al. "The prevalence of dental, facial and head injuries sustained by schoolboy rugby players. A pilot study." Primary dental care 17.3 (2010): 143-146.
33- Delaney, J. Scott, et al. "The effect of protective headgear on head injuries and concussions in adolescent football (soccer) players." British journal of sports
medicine 42.2 (2008): 110-115.
34- Comstock, R. Dawn, Sarah K. Fields, and Christy L. Knox. "Protective equipment use among female rugby players." Clinical Journal of Sport Medicine 15.4 (2005): 241-245.
35- Muller‐Bolla, Michèle, et al. "Orofacial trauma and rugby in France: epidemiological survey." Dental Traumatology 19.4 (2003): 183-192.
36- Cornwell, Helen, Louise Brearley Messer, and Harriet Speed. "Use of mouthguards by basketball players in Victoria, Australia." Dental Traumatology 19.4 (2003): 193-203.
Figure 1: Study identification PRISMA flow diagram
Graphic 1 – Average prevalence of use of a mouth guard by sport
0,00% 10,00% 20,00% 30,00% 40,00% 50,00% 60,00% 70,00%
Basketball Soccer Handball Rugby
Author/Year Sport Measurement method Sport sample
Local Gender Level of competition
Age range Prevalence
Galic et al, 2018 Handball Questionnaire 55 Croatia Both Amateur 5 to 19 y 8 / 14,5%
Bergman et al, 2017 Handball Questionnaire 100 Croatia Male Professional 17 to 36 y 28 / 28%
Tyriaki et al, 2017 Basketball Questionnaire 351 Turkey Both Junior and
Professional
12 to 38 y 22 / 6,3%
Kroon et al, 2016 Rugby Questionnaire 494 Australia Male Junior 11,2
average
337 / 68,2%
Petrovic et al, 2016 Handball Interview/Questionnaire 507 Switzerland Both Professional 15 to 42 y 29 / 5,7%
Ilia et al, 2014 Rugby Questionnaire 225 Australia Male Amateur 18 to 51 y 173 / 76,9%
Liew et al, 2014 Rugby Questionnaire 456 Malaysia Male None 22,73
average
42 / 9,21%
Uzel et al, 2014 Soccer Interview/Questionnaire 343 Turkey Male Amateur 11 to 21 y 1 / 0,29%
Vieira, 2013 Soccer Questionnaire 260 Brazil Male Pre-child to junior 10 to 20 y 4 / 1,54%
Boffano et al, 2012 Rugby Questionnaire 65 Italy Male Amateur 13 to 39 y 35 / 53,85%
Khodaee et al, 2011 Soccer Questionnaire 865 USA Both Amateur 5 to 14 y 8%
Frontera et al, 2011 Basketball Questionnaire 388 Brazil Male Adult, juvenil and
cadet
23,2 average
27 / 7%
Jagger et al, 2010 Rugby Questionnaire 178 England/ Australia Male Amateur 17 to 18 y 178 / 100%
Delaney et al, 2007 Soccer Interview/Questionnaire 278 Canada Both Amateur 12 to 17 y 10 / 3,6%
Comstock et al, 2005 Rugby Questionnaire 234 USA Female None 18 to 52 y 90,80%
Muller-Bolla et al, 2003
Rugby Questionnaire 1140 France None Professional 26,42
average
733 / 64,29%
Cornwell et al, 2003 Basketball Questionnaire 496 Australia Both Recreational,
non-elite and non-elite
Young (12 to 15)/ Adults (>18
Table 2. Assessment of quality and the risk of bias (modified NOS Scale) – included studies Author/Year Selection Results Total 8/8 Representativeness of the sample Sample Size Non-respondents Ascertainment of the exposure Assessment of the outcome Statistical test Galic et al, 2018 0 * * * * 5/8 Bergman et al, 2017 * 0 * * * * 5/8 Tyriaki et al, 2017 * 0 * * * * 5/8 Kroon et al, 2016 * 0 * ** * * 6/8 Petrovic et al, 2016 * 0 * * * * 5/8 Ilia et al, 2014 * 0 * ** * * 6/8 Liew et al, 2014 * 0 * ** * * 6/8 Uzel et al, 2014 * 0 0 ** * * 5/8 Vieira, 2013 * 0 * * * * 5/8 Boffano et al, 2012 * 0 * * * * 5/8 Khodaee et al, 2011 * 0 * ** * * 6/8 Frontera et al, 2011 * 0 * * * * 5/8 Jagger et al, 2010 * 0 * * * * 5/8 Delaney et al, 2007 * 0 * * * * 5/8 Comstock et al, 2005 * 0 * ** * * 6/8 Muller-Bolla et al, 2003 * 0 * * * * 5/8 Cornwell et al, 2003 * 0 * ** * * 6/8
Table 3. Assessment of quality and the risk of bias (modified NOS Scale) – excluded studies
Representativeness
of the sample Sample Size
Non-respondents Ascertainment of the exposure Assessment of the outcome Statistical test Semencio et al, 2017 * 0 0 * * * 4/8 Schulze et al, 2017 * 0 0 * * * 4/8 Dursun et al, 2015 * 0 0 * * 0 3/8 Costa Palau et al, 2014 * 0 0 * * 0 3/8 Gialain et al, 2014 * 0 0 * * 0 3/8 Ozbay et al, 2013 * 0 0 * * * 4/8 Schildknecht et al, 2012 * 0 0 * * * 4/8 Lesić et al, 2011 * 0 0 * * 0 3/8 Gay-Escoda, 2011 * 0 0 * * * 4/8 Nicol et al, 2010 * 0 * * * 0 4/8 Rayner et al, 2008 * 0 0 0 * 0 2/8 Lieger et al, 2006 * 0 0 * * 0 3/8 Perunski et al, 2005 * 0 0 * * * 4/8 Keçeci et al, 2005 * 0 0 * * * 4/8 Levin et al, 2005 * 0 * * * 0 4/8 Holtzhausen et al, 1999 * 0 * * * 0 4/8 Lang et al, 2002 * 0 0 * * * 4/8 Ferrari et al, 2002 * * 0 * * 0 4/8 Newsome et al, 1998 * 0 * * * 0 4/8 Chapman et al, 1996 * 0 0 * * 0 3/8 Flanders et al, 1995 * 0 0 * * 0 3/8 Chapman et al, 1993 * 0 0 * * 0 3/8 Jenning, 1990 * 0 0 * * 0 3/8 Chapman, 1990 * 0 0 * * 0 3/8 Kay, 1990 * 0 0 * * 0 3/8 Chapman, 1987 * 0 0 * * 0 3/8 Maestrello-deMoya, 1989 * 0 * * * 0 4/8 Chapman, 1988 * 0 0 * * 0 3/8 Chapman, 1985 * 0 0 0 * 0 2/8 Chapman, 1985 * 0 0 0 * 0 2/8 Chapman, 1985 * 0 0 0 * 0 2/8 Davies et al, 1977 * 0 0 0 * 0 3/8 Author/Year Selection Results Total 8/8
