Bruxism an issue between the myths and fact / Bruxismo, un problema entre los mitos y los hechos

Abstract Is our goal in this paper to discuss the current concepts about bruxism, a topic that has been a matter of discussion on the dental field for many years. Recent International efforts have been made to challenge bruxism old definitions; this has derivate to a consensus and an actual new concept that defines bruxism as a behavior instead of a disorder. As a behavior, it is explained in this review how it can have negative health consequences, can be innocuous and how new research support that bruxism can even be a protective factor. Different etiological factors are reviewed in this paper as well the influence of external and internal mechanism related to medications, emotional stress, systemic factors, and potential pharmacological pathways. Moreover, it is briefly summarized the role of oral appliances on sleep bruxism. Finally, clinical considerations and recommendation for the dental professional regarding sings that should be notice during the exam are part of this overview.

Resumen Es nuestro objetivo en este artículo discutir los conceptos actuales sobre el bruxismo, un tema que ha sido motivo de discusión en el campo odontológico durante muchos años. Se han hecho esfuerzos internacionales recientes para desafiar las viejas definiciones de bruxismo; esto ha derivado en un consenso y en la actualidad un nuevo concepto que define al bruxismo como un comportamiento en lugar de un trastorno. Como conducta, se explica en esta revisión cómo puede tener consecuencias negativas para la salud, puede ser inocuo y cómo nuevas investigaciones avalan que el bruxismo puede incluso ser un factor protector. En este artículo se exponen diferentes factores etiológicos, así como la influencia de mecanismos externos e internos relacionados como: medicamentos, estrés emocional, factores sistémicos y posibles vías farmacológicas. Además, se resume brevemente el papel de los aparatos orales en el bruxismo del sueño. Finalmente, se presentan consideraciones clínicas y la recomendación para el profesional en odontología con respecto a los signos que deben ser observados durante el examen clínico son parte de esta revisión.

Logistic regression analysis of the relationship between abnormal dental occlusion and temporomandibular disorders in lower grade college students / 口腔疾病防治

Objective @#To investigate the influence of abnormal occlusion factors on the incidence of temporomandibular disorders (TMDs) in junior college students and to provide an etiological basis for the prevention and treatment of TMDs.@*Methods @# We examined the temporomandibular joint (TMJ) and dental occlusion in 754 lower grade college students (male 354, female 400) at Zunyi Medical University (Zhuhai campus). A questionnaire was also administered. We analyzed the correlation between TMD and the other three factors (static abnormal occlusion, dynamical abnormal occlusion and oral parafunctional activity) from the perspective of multivariate unconditioned logistic regression and univariate unconditioned logistic regression with dummy variables.@*Results @#The prevalence of TMD was 31.7%. The incidence of TMD was significantly (P<0.05) associated with sleep bruxism (OR=2.070), clenching (OR=2.553), diurnal (OR=2.642) and anterior teeth overbite (OR=1.228). Univariate unconditioned logistics regression analysis by dummy variables was used to analyze the incidence of TMD at different deep overbites (mild, OR=1.558; moderate, OR=2.189; severe, OR=3.236; P<0.05). @*Conclusion@#The risk factors for TMD in lower grade college students included anterior teeth occlusion, sleep bruxism, clenching, and diurnal treatment. Worse deep overbite might increase the risk of TMD.

Conocimientos actuales para el entendimiento del bruxismo: revisión de la literatura / Current knowledge for the understanding of bruxism: review of the literature

El bruxismo es considerado una actividad parafuncional músculomandibular repetitiva, caracterizada principalmente por apretamiento y/o rechinamiento dental. El bruxismo tiene dos diferentes manifestaciones circadianas: puede ocurrir durante la vigilia (bruxismo en vigilia) o durante el sueño (bruxismo del sueño); en ambos casos puede poner en riesgo la integridad del sistema estomatognático, siempre y cuando la fuerza de las actividades músculo-mandibulares que se ejerzan logre superar la capacidad adaptativa de los componentes fi siológicos. El diagnóstico de bruxismo ha sido prevalentemente anatómico/lesional, esto es, la observancia clínica de atriciones o abfracciones sin entender sus causas y mecanismos de inducción, desarrollo y persistencia, restringiendo subsecuentemente el accionar odontológico al manejo de los efectos nocivos. Este artículo es una revisión de la literatura científi ca con el objetivo de otorgar los conocimientos básicos actuales para el entendimiento del bruxismo, una actividad muscular disfuncional con orígenes neurobiológicos que lo explican más allá de su efecto periférico evidente (AU)

Bruxism is a repetitive jaw-muscle activity characterized by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible. Bruxism has two distinct circadian manifestations: it can occur during sleep (indicated as sleep bruxism) or during wakefulness (indicated as awake bruxism), in both situations, the integrity of the stomatognathic system components can be at risk as long as the strength of the jaw-muscle activities are able to overcome the adaptive capacity of the physiological components. The diagnosis of bruxism has been predominantly anatomical/lesional that is, the clinical observance of attritions or abfractions without understanding their causes and mechanisms of induction, development, and persistence, subsequently restricting the dental action to the management of harmful eff ects. This article is a review of the scientifi c literature with the aim of granting the current basic knowledge for the understanding of bruxism, a dysfunctional muscular activity with neurobiological origins that explain it beyond its evident peripheral eff ect (AU)

Hábito parafuncional e disfunção temporomandibular, uma questão de gênero? / Oral parafunction and temporomandibular disorders, a matter of gender?

Introdução: as disfunções temporomandibulares (DTM) são caracterizadas por dor na região da articulação temporomandibular e região pré auricular, nos músculos mastigatórios, limitação da mobilidade articular e ruídos articulares. Fatores biomecânicos, neuromuscular, biopiscossocial e neurobiológico podem contribuir para esta disfunção. Objetivo: o propósito deste trabalho foi demonstrar a associação de hábitos parafuncionais entre os gêneros portadores da DTM. Método: realizou-se um estudo transversal com 150 sujeitos com questões estruturadas sobre hábitos parafuncionais e o Índice Anamnésico de Fonseca para classificação da DTM. Resultado e discussão: dos sujeitos tinham como pratica o habito parafuncional, 70% apresentavam algum grau de DTM sendo 82% destes do sexo feminino (p< 0,05); os hábitos orais mais prevalentes foram roer unha (34%) e mascar chicletes (30%). Considerações finais: as diferenças fisiológicas e de os papéis ocupados na sociedade deveexplicar associação do hábito parafuncional com o gênero feminino.

Introduction: Temporomandibular disorders (TMD) are characterized by pain in the region of the temporomandibular joint and pre-auricular region, in the masticatory muscles, limitation of joint mobility and articular noises. Biomechanical, neuromuscular, biopisco-social and neurobiological factors may contribute to this dysfunction. Objective: the purpose of this study was to demonstrate the association of oral parafunction among patients genres of Temporomandibular Disorders (TMD). Method: we conducted a cross-sectional study with 150 subjects with structured questions about parafunctional habits and the Fonseca Anamnesic Index for TMD classification. Results and Discussion: the subjects had to practice the parafunctional habit, 70% had some degree of TMD and 82% of females (p <0.05). The most prevalent oral habits were nailbiting (34%) and chewing gum (30%). Final remarks: physiologicaldifferences and the roles occupied in society should explain the association parafunctional habit with females.

Sleep Bruxism, Awake Bruxism and Sleep Quality among Brazilian Dental Students: A Cross-Sectional Study

The aim of the study was to evaluate the association of sleep bruxism, awake bruxism and sleep quality among dental students of the Federal University of Minas Gerais, Belo Horizonte, Brazil. A cross-sectional study was performed including 183 Brazilian dental students aged from 17 to 46 years old. The complete course curriculum consists of 9 semesters. Students enrolled in the first semester, the middle semester and the final semester of the course participated in the survey. The PSQI-BR (the Brazilian version of the Pittsburgh Sleep Questionnaire Index) was used for data collection. The PSQI-BR was distributed during lecture classes. Sleep bruxism and awake bruxism diagnosis was based on self-reported data. Descriptive analysis, Kruskal-Wallis, Mann-Whitney and Poisson regression with robust estimator were the statistical tests used. Sleep bruxism prevalence was 21.5% and awake bruxism prevalence was 36.5%. Sleep duration components were associated with sleep bruxism (PR=1.540; 95% CI: 1.00-2.37) and awake bruxism (PR=1.344; 95% CI: 1,008-1,790). There was an association between awake bruxism and habitual sleep efficiency component (PR=1.323; 95% CI: 1.03-1.70). Sleep disturbance component and awake bruxism were associated (PR=1.533; 95% CI: 1.03-2.27). Poor sleep quality was an important factor among dental students, who reported sleep bruxism as well as among those who presented awake bruxism.

O objetivo deste estudo foi avaliar a associação entre o bruxismo do sono, bruxismo diurno e qualidade do sono entre estudantes de odontologia da Universidade Federal de Minas Gerais, Belo Horizonte, Brasil. Um estudo transversal foi desenvolvido com 183 estudantes de odontologia brasileiros com idade entre 17 e 46 anos. O curriculum completo do curso consiste de 9 semestres. Estudantes matriculados no primeiro semestre, no semestre do meio e no último semestre do curso participaram do estudo. O PSQI-BR (versão brasileira do Pittsburgh Sleep Questionnaire Index) foi utilizado para a coleta dos dados. O PSQI-BR foi distribuído em sala de aula. O diagnóstico de bruxismo do sono e bruxismo diurno foi baseado em auto-relato dos estudantes. Análise descritiva, Kruskal-Wallis, Mann-Whitney e regressão de Poisson com estimativa robusta foram os testes estatísticos utilizados. A prevalência do bruxismo do sono foi de 21,5% e a prevalência do bruxismo diurno foi de 36,5%. O componente duração do sono apresentou associação com bruxismo do sono (PR=1,540; 95%IC: 1,00-2,37) e com bruxismo diurno (PR=1,344; 95%CI: 1,008-1,790). Houve associação entre bruxismo diurno e o componente eficiência habitual do sono (PR=1,323; 95%IC: 1,03-1,70). O componente distúrbio do sono e o bruxismo diurno também apresentaram associação (PR=1,533; 95%IC: 1,03-2,27). A má qualidade do sono foi um fator importante tanto entre os universitários que relataram bruxismo do sono quanto entre os que apresentaram bruxismo diurno.

A relação do bruxismo com a dopamina / Relation between bruxism and dopamine

O bruxismo é uma parafunção muito comum na população e não há um consenso sobre uma etiologia específica, sendo considerado assim de natureza multifatorial. Entre os fatores etiológicos encontra-se a atuação dos neurotransmissores: noradrenalina, serotonina e, principalmente, a dopamina, devido a sua função, entre outras, de inibir movimentos musculares espontâneos. Com base na revisão da literatura confrontamos dados que pudessem ajudar a comprovar a influência dos neurotransmissores na gênese da parafunção e como drogas que atuam nos mesmos receptores desses neurotransmissores apresentam relevância para o desencadeamento ou atenuação dos episódios de bruxismo.

Bruxism is a common parafunction found in the population and there is no consensus about a specific etiology, being considered as multifactorial. Among the etiological factors it’s possible to find the performance of the following neurotransmitters: norepinephrine, serotonin and especially dopamine, due to its function, among others, is to inhibit spontaneous muscle movements. Based on the literature, we were able to confront data that could help proving the influence of neurotransmitters in the genesis of this parafunction and how drugs that act on the same receptors of these neurotransmitters are relevant for triggering or mitigating episodes of bruxism.

Parafunciones y caries dentales en preescolares de comunidades pehuenches / Parafunctions and decay in preschool children from pehuenches communities

Introducción: las parafunciones bucales son consideradas uno de los factores causales de los trastornos temporomandibulares que han tomado mucha relevancia en las últimas décadas, especialmente en poblaciones infanto-juveniles, aunque la evidencia en preescolares es escasa y nula en grupos indígenas. El objetivo del presente estudio es determinar la prevalencia de parafunciones bucales y presencia de caries en preescolares de comunidades pehuenches, de la comuna de Alto Biobio, la más pobre de Chile, así como su posible relación con características etnodemográficas y socioeconómicas. Métodos: se tomó una muestra que estuvo conformada por 71 niños de 2 a 5 años los cuales asisten a jardín infantil. Se contó con la autorización de las autoridades locales y el consentimiento informado de los padres. Se evaluaron variables socio-etnodemográficas, presencia de caries en dientes temporales (índice ceod) de acuerdo con los criterios de la Organización Mundial de la Salud y la presencia de 8 parafunciones bucales: succión digital, de objetos, de mamadera, de chupete, labial, interposición lingual, onicofagia y respiración bucal mediante encuesta a las educadoras de los jardines. Resultados: el 9,86 por ciento de preescolares estaba libre de caries y el ceod fue 6,83 ± 4,65, lo que aumenta con la edad, 2,8 (a los 2 años) y 8,23 (a los 5 años). El promedio de parafunciones bucales por preescolar fue 1,73 ± 1,06, significativamente mayor en mujeres, pehuenches y preescolares de extrema pobreza. La prevalencia para alguna de las 8 parafunciones bucales fue de 90,86 por ciento y 77,46 por ciento para las asociadas a succión. Las más prevalentes son succión de mamadera y labial (26,76 por ciento), onicofagia (29,58 por ciento) y succión digital (47,89 por ciento). Conclusiones: la presencia de caries en estos preescolares es muy alta, mientras que la prevalencia de parafunciones bucales es similar a otras poblaciones, lo que afecta más a preescolares de extrema pobreza y pehuenches, posiblemente relacionado con las condiciones de vulnerabilidad social de la comuna. Estos resultados resaltan la urgencia de implementar medidas promocionales, preventivas y terapéuticas en esta población(AU)

Introduction: Oral parafunctions are considered one of the causal factors of temporomandibular disorders and have gained importance in recent decades, especially in child and young populations, although evidence is scarce in the preschool children and nonexistent in the indigenous groups. The objectives of this study were to determine the prevalence of oral parafunctions and the presence of caries in pehuenche preschool children, from Alto Biobio commune , the poorest one in Chile, as well as the possible association of the ethnodemographic and the socioeconomic characteristics. Methods: A sample comprised 71 children from 2 to 5 years attending kindergarten; the permission of local authorities and the informed consent of parents were granted. Socio-ethno-demographic variables, decay presence in primary teeth (dmft index) according to WHO criteria and the presence of 8 oral parafunctions: finger sucking, object sucking, sucking on bottle, pacifier and lip sucking, tongue thrust, onychophagia and mouth breathing, were all evaluated through a survey made to kindergarten educators. Results: Of the studied children, 9.86 percent were caries-free and the dmft index was 6.83 ±4.65, increasing with the age, hence, it was 2.8 at age 2 and 8.23 at age 5. Oral parafunctions average was 1.73 ±1.06 per child, significantly higher in women, pehuenches and extremely poor children. Prevalence for any of the 8 oral parafunctions was 90.86 percent and for those associated with non-nutritive sucking was 77.46 percent. The most prevalent were bottle and labial sucking (26.76 percent), onychophagia (29.58 percent) and finger sucking (47.89 percent). Conclusions: Decay presence in these preschool children is very high, whereas the prevalence of oral parafunctions is similar to that of other populations, affecting more children in extreme poverty setting and pehuenches. All this is possibly related to the social vulnerability of the commune. These results highlighted the urgent need of implementing preventive, promotional and therapeutic strategies in this population(AU)

Abfracciones: lesiones cervicales no cariosas en cuña, su relación con el estrés / Abfractions: non-carious cervical in wedge, its relationship with stress

La abfracción es una lesión por pérdida del tejido duro en la unión amelo cementaría del diente en vestibular o lingual, acompañada generalmente de sensibilidad. El estrés emocional, la acción de fuerzas excéntricas generadas por interferencias oclusales, el bruxismo, pueden ser considerados factores predisponentes; por ello se planteó un estudio observacional descriptivo con componente analítico, el objetivo fue determinar la prevalencia de abfracciones, para luego asociarlas con el estrés emocional en 110 pacientes de 15 a 59 años en edad en la Facultad de Odontología de la Universidad Nacional de Asunción y una clínica privada en el año 2008. Para determinar el nivel de estrés emocional se utilizó un cuestionario, Maslach Burnout Inventory, valorado en una escala de alto/moderado, leve y bajo, se utilizó la inspección clínica y el sondeo para diagnosticar la abfracción. Se encontró una prevalencia de abfracción de 44%, de los cuales el 49% correspondió al sexo masculino. El diente más afectado fue el primer premolar inferior izquierdo (9,9%). El 100% de los pacientes presentaban estrés y hubo asociación estadísticamente significativa entre la abfracción y el bruxismo 0,004 p<0,005(F), también con el estado civil de los pacientes 0,001 p<0,005(F) entre los que prevalecían los casados 59%. Un alto porcentaje de pacientes presentaban abfracciones y estrés, pero no hubo asociación estadísticamente significativa p=0,3(F).

Abfraction is a lesion due to hard tissue loss at the cementoenamel junction either on buccal or lingual surface of a tooth, generally accompanied by sensitivity. Emotional estrés, eccentric forces generated by occlusal interferences, bruxism can be considered as predisposing factors, therefore an observational descriptive study with an analytic component was set out in order to determine the prevalence of abfractions and to relate them to emotional estrés in 110 patients ages 15 - 59 at the Facultad de Odontología de la Universidad Nacional de Asunción as well as at a private clinic in 2008. In order to determine emotional estrés, a questionnaire by Maslach Burnout Inventory was used, ranging from high, moderate, mild and low. Clinical checkup and probing were the means to diagnose abfraction. A prevalence of 44% was found, 49% of which were males. The most affected tooth was lower left first premolar (9.9%). 100% presented estrés and there was statistically significant relationship between abfraction and bruxism 0,004 p<0,005(F), also regarding marital status, there was more prevalence among married patients (59%). A high percentage of patients presented both abfraction and estrés, but there was no statistically significant association p=0,3(F).

Signs, symptoms, parafunctions and associated factors of parent-reported sleep bruxism in children: a case-control study

Bruxism is the non-functional clenching or grinding of the teeth that may occur during sleep or less commonly in daytime. The aim of this study was to investigate the association between clinical signs and symptoms, parafunctions and associated factors of sleep bruxism in children. A population-based case-control study was carried out involving 120 children, 8 years of age, with sleep bruxism and 240 children without sleep bruxism. The sample was randomly selected from public and private schools in the city of Belo Horizonte, MG, Brazil. Groups were matched by gender and social class. The Social Vulnerability Index (SVI) drawn up by the city of Belo Horizonte was employed for social classification. Data collection instruments included clinical forms and pre-tested questionnaires. The diagnosis of sleep bruxism was supported by the American Association of Sleep Medicine (AASM) criteria. The McNemar test, binary and multivariate logistic regression models were used for statistical analysis. The risk factors associated with sleep bruxism included: primary canine wear (OR=2.3 IC 95% 1.2-4.3), biting of objects like pencils or pens (OR=2.0 IC 95% 1.2-3.3) and wake-time bruxism (tooth clenching) (OR=2.3 IC 95% 1.2-4.3). Children that present the parafunctions of object biting and wake-time bruxism were more susceptible to sleep bruxism.

Bruxismo é o ato não funcional de ranger os dentes enquanto se dorme ou apertar os dentes em vigília. O objetivo deste estudo foi investigar a associação entre sinais e sintomas clínicos associados ao bruxismo noturno em crianças. Foi desenvolvido um estudo de base populacional com desenho caso-controle, envolvendo 120 crianças, de 8 anos de idade, com bruxismo e 240 crianças sem bruxismo. A amostra foi selecionada de forma randomizada em escolas públicas e particulares da cidade de Belo Horizonte, Brasil. Os grupos caso e controle foram pareados por gênero e classe social. O Índice de Vulnerabilidade Social (IVS) desenvolvido pela prefeitura da cidade de Belo Horizonte foi utilizado para a classificação social. Como instrumentos de coleta foram utilizados: uma ficha clínica e um questionário pré-testados. O diagnóstico de bruxismo noturno foi baseado nos critérios da American Association of Sleep Medicine (AASM). Os testes estatísticos de McNemar, regressão logística binária e multivariada com modelo de regressão foram utilizados para análise dos dados. Foram considerados fatores de risco para o bruxismo noturno: desgaste em caninos decíduos (OR=2,3 IC 95% 1,2-4,3), morder objetos como lápis e canetas (OR=2,0 IC 95% 1,2-3,3) e apertar os dentes em vigília (OR=2,3 IC 95% 1,2-4,3). Crianças que apresentam outras parafunções tais como: morder objetos e apertar os dentes em vigília são mais susceptíveis ao bruxismo noturno.