Relación entre el Síndrome de clase II división 2 y la disfunción temporomandibular. Artículo de revisión / Relation between the Syndrome type II division 2 malocclusions and the temporomandibular joint dysfunction. Review article

Introducción: Los pacientes con el Síndrome de clase II división 2, además de presentar clínicamente una relación de molares y caninos en disto-oclusión, muestran una retroinclinación de los incisivos centrales superiores con proinclinación de los laterales y sobremordida profunda, lo cual puede llegar a convertirse en un factor de riesgo que provoca disfunción temporomandibular. Objetivo: Identificar la relación entre el Síndrome de clase II división 2 y la disfunción temporomandibular. Material y Métodos: Se realizó una revisión bibliográfica automatizada en las bases de datos de los sistemas MEDLINE, PubMed, Hinari y Google; se utilizó un total de 17 artículos. Desarrollo: Por las características clínicas de la oclusión en los pacientes con este síndrome, el rango de movimiento mandibular está limitado, y produce un efecto traumático que se relaciona con una posición de los cóndilos desplazados hacia atrás e intruidos en la fosa glenoidea. Este desplazamiento más distal produce la presión del espacio retrodiscal ricamente inervado y sería causa de inflamación de los tejidos circundantes y afectación de la función de la articulación por elongación de los ligamentos discales o adelgazamiento del disco que afecta el complejo cóndilo-disco. Conclusiones: Los estudios consultados muestran la relación entre el Síndrome de clase II división 2 y la disfunción temporomandibular, dada las características clínicas presentes en este síndrome, que afectan el funcionamiento de la articulación temporomandibular y que al sobrepasar las capacidades adaptativas del paciente producen la disfunción en la misma(AU)

Introduction: Patients with Syndrome type II division 2 malocclusions, besides presenting a clinically established relationship between molars and canines in a distal occlusion, show a retro-inclination of the upper front teeth with pro-inclination of the lateral incisors and a deep overbite, which can result in a risk factor of temporomandibular dysfunction. Objective: To identify the relationship between Syndrome type II division 2 malocclusions and the temporomandibular dysfunction. Material and Methods: A bibliographic review was carried out through a search of databases such as MEDLINE, PubMed, Hinari, and Scholar Google. A total of 17 articles were used. Development: Because of the clinical characteristics of the occlusion in the patients with this syndrome, the range of jaw movement is limited, producing a traumatic effect that is related with a position of the condyles displaced backward and with glenoid fossa intrusion. This more distal displacement produces the pressure of the richly innervated retrodiscal tissue, which could be the cause of inflammation of the surrounding tissues and the affectation of the joint function due to an elongation of the discal ligaments or a thinning of the disc affecting the disc-condyle complex. Conclusions: The studies conducted demonstrate the relationship between the Syndrome type II division 2 and the temporomandibular joint dysfunction, given the clinical characteristics that are present in this syndrome, which affect the functioning of the temporomandibular joint, and produce its dysfunction when exceeding the adaptive capacities of the patient(AU)

Side effects of intraoral devices for OSAS treatment / Side effects of intraoral devices for OSAS treatment

Abstract Introduction: Intraoral devices have increasingly assumed a key role in the treatment of obstructive sleep apnea syndrome, but there are limitations to their indication and side effects that result from their continuous use, as well as the use of the continuous positive airway pressure device. Objectives: To evaluate the changes in dental positioning caused by the continuous use of mandibular advancement devices. Methods: A prospective longitudinal study with a sample of 15 patients, with evaluation of complete documentation after a mean time of 6.47 months, assessed changes in dental positioning due to the use of the Twin Block oral device for the treatment of patients with apnea. The following variables were evaluated: overjet, overbite, upper and lower intermolar distances, upper and lower intercanine distances, Little's irregularity index and the incisor mandibular plane angle. An intraclass correlation test was performed and a correlation index > 0.08 was accepted. After verifying the normal sample distribution (Shapiro-Wilks), a parametric test was used (t test), with a significance level set at 5%. Results: There was a decrease in the values of overjet, overbite and Little's irregularity index, whereas there was an increase in the lower intercanine distance and IMPA values. All these variables are influenced, at different levels, by the forward inclination of the lower incisors, an action that can be expected due to the force applied by the device on the dentition. The other variables did not show statistically significant differences. Conclusion: After a mean time of 6.47 months of use of the mandibular advancement device, there were statistically significant changes in the dental positioning, but they were not clinically relevant. However, it is relevant that this device is commonly in use over long periods of time, making the monitoring of these patients of the utmost importance for the duration of their therapy.

Resumo: Introdução: Os aparelhos intraorais têm assumido cada vez mais um papel importante no tratamento da síndrome da apneia obstrutiva do sono, mas existem limitações a sua indicação e efeitos colaterais com o seu uso contínuo, assim como com o uso do aparelho de pressão aérea positiva contínua. Objetivos: Avaliar as alterações no posicionamento dentário produzido pelo uso contínuo do aparelho de projeção mandibular. Método: Através de estudo longitudinal prospectivo com amostra de 15 pacientes, com avaliação de documentações completas após um tempo médio de 6,47 meses do uso do aparelho oral de Twin Block para tratamento de pacientes com apneia, foram avaliadas as alterações do posicionamento dos dentes decorrentes do seu uso. As seguintes variáveis foram avaliadas: overjet, overbite, distâncias intermolares superior e inferior, distâncias intercaninos superior e inferior, índice de irregularidade de Little e ângulo do plano incisivo mandibular. Foi feito teste de correlação intraclasse e foram aceitos índices de correlação acima de 0,08. Após atestada a distribuição normal da amostra (Shapiro-Wilks), foi usado um teste paramétrico (teste t), com nível de significância de 5%. Resultados: Houve diminuição nos valores de overjet, overbite e irregularidade de Little e aumento nos valores da distância intercanino inferior e do ângulo do plano incisivo mandibular. Todas essas variáveis sofrem influência, com diferentes expressividades, da inclinação para frente dos incisivos inferiores, uma ação que pode ser esperada devido à força aplicada pelo aparelho sobre a dentição. As demais variáveis não demostraram diferenças estatisticamente significativas. Conclusão: Houve mudanças estatisticamente significativas no posicionamento dos dentes, porém clinicamente sem relevância, com um tempo médio de uso de 6,47 meses do aparelho de avanço mandibular. Contudo, deve-se considerar que o uso dessa aparelhagem é comum durante longos períodos, fazendo com que seja de suma importância o acompanhamento desses pacientes a longo prazo.

Frequência, razão de prevalência e associação do transpasse vertical dentário anterior em diferentes padrões faciais / Frequency, prevalence ratio and association of anterior overbite in different facial patterns

Determinados padrões faciais são citados na literatura como responsáveis diretos pelo acometimento de más oclusões de transpasse vertical anterior. Apesar disso, ainda não está elucidado de que forma as diferenças dos padrões faciais estão associadas aos problemas dentários. Os objetivos deste estudo são: verificar a correlação do grau de transpasse vertical com os padrões faciais e com fatores esqueléticos e dentários; investigar a frequência dos hábitos deletérios de acordo com os tipos de overbite; e investigar a frequência e as razões de prevalência dos tipos de transpasse vertical dentário anterior de pacientes com diferentes padrões faciais. A amostra consistiu de telerradiografias de perfil de adultos, com registro de ausência ou presença de hábitos deletérios e a coleta foi realizada em diferentes centros de ensino de ortodontia do território brasileiro. Os filmes radiográficos foram digitalizados e analisados através do software Dolphin Imaging 11.0 e os resultados foram obtidos através de uma análise estatística descritiva, utilizando o software SPSS 17.0. Quanto às correlações, o overbite apresentou fraca correlação com fatores esqueléticos e dentários, inclusive com a variável AFPI/AFAI, determinante do padrão facial. A presença ou a ausência de hábitos deletérios não apresentou diferença estatística quando comparadas aos tipos de problemas verticais. Todos os padrões faciais apresentaram todos os tipos de transpasse vertical anterior, porém pacientes hiperdivergentes apresentaram uma frequência estatisticamente significativa de casos com mordida aberta anterior, assim como uma razão de prevalência indicativa de situação de risco, quando comparados aos pacientes normodivergentes e hipodivergentes. Presume-se que exista a predisposição de outros fatores associados aos problemas verticais, seja a presença de hábitos deletérios, sejam os desequilíbrios de forças musculares em pacientes hiperdivergentes para que a presença da mordida aberta anterior seja mais frequente neste padrão facial.

Certain facial patterns are described in the literature as directly responsible for the involvement in vertical anterior malocclusions. However, how differences in facial patterns are associated with dental problems it is not yet elucidated. The aims of this study were to verify the correlation between the degree of overbite with the facial pattern, and with skeletal and dental factors; to investigate the frequency of deleterious habits according to the overbite; and to investigate the frequency and odds ratio of the types of overbite of patients with different facial patterns. The sample consisted of cephalometric radiographs of adults, with records on the presence or absence of deleterious habits. The sample was collected in different centers of orthodontic education in Brazil. The radiographic films were scanned and analyzed using the Dolphin Imaging 11.0 software and the results were obtained through a descriptive statistical analysis using SPSS 17.0 software. The overbite showed a weak correlation with the skeletal and dental factors, including the variable LPFH/LAFH, which determines facial pattern. The presence or absence of habits showed no statistical difference when compared to the overbite types. All facial patterns presented all sorts of overbite, but hyperdivergent patients showed a statistically significant higher frequency of cases with anterior open bite, compared to normodivergents and hypodivergent patients, as well as the odds ratio indicated a risk situation. It is assumed that there is a predisposition of other factors associated to anterior vertical problems, such as the presence of deleterious habits or imbalanced muscle forces in hyperdivergent patients, for a greater frequency of anterior open bite to be found in this facial pattern.

Bottle feeding, increased overjet and Class 2 primary canine relationship: is there any association?

The aim of this study was to investigate the association between bottle feeding and prevalence rates of increased overjet and Class 2 primary canine relationship. The sample consisted of 911 children (461 boys, 450 girls) aged 3 (13.9 percent), 4 (40.8 percent), 5 (34 percent) and 6 (11.3 percent) years, with complete primary dentition. Information about nutritive and nonnutritive (pacifier and/or digit) sucking habits was collected through questionnaires. Three calibrated dentists (κ: 0.9-1.0 and Rs > 0.90) performed the clinical assessments. The children were divided into four groups: G1 - not bottle-fed; G2 - exclusively bottle-fed; G3 - breast- and bottle-fed, bottle feeding ceased before 3 years of age; and G4 - breast- and bottle-fed, bottle feeding ceased between 3 and 4 years of age. Associations between nutritive and nonnutritive sucking behaviors and the malocclusions studied were analyzed by multiple binary logistic regression (α= 0.05). The frequencies of increased overjet were: 25.3 percent (G1), 38.8 percent (G2), 39.2 percent (G3) and 47.8 percent (G4). The percentages of Class 2 canine relationship were: 27.9 percent (G1), 48.8 percent (G2), 43.4 percent (G3) and 43 percent (G4). No significant effect of bottle feeding was found. The chances of diagnosing increased overjet (O.R. = 4.42, p < 0.001) and Class 2 canine relationship (O.R. = 4.02, p < 0.001) were greater for children with pacifier and/or digit-sucking habits, compared to those without a history of nonnutritive sucking behavior. It may be suggested that bottle feeding alone is not directly associated with higher prevalence rates of increased overjet and Class 2 canine relationship in the primary dentition.

Correlations between dentoskeletal variables and deep bite in Class II Division 1 individuals

This study aimed to evaluate the cephalometric pattern of Class II Division 1 individuals with deep bite, and to determine possible correlations between dentoskeletal variables and deep bite. Comparisons were also made between genders and cases that were to be treated both with and without premolar extraction. A total of 70 lateral cephalograms were used, from both male (n = 35) and female (n = 35) individuals with an average age of 11.6 years, who simultaneously presented with ANB > 5º and overbite > 4 mm. Statistical analysis involved parametric (t-test) and non-parametric (Mann-Whitney) tests for independent samples, as well as the Spearman correlation test (p < 0.05). The values of Go-Me, Ar-Pog, PM-1 and PM-CMI were higher in males (p < 0.05). However, no significant differences were found among the averages of the cephalometric measurements when the sample was divided by treatment with and without extraction. Deep bite was positively correlated to the PM-1 and SNA measurements, and negatively correlated to the Go-Me, Ar-Pog, SNB and SNGoMe measurements. The main factors associated with the determination of deep bite in Angle's Class II Division 1 cases were: greater lower anterior dentoalveolar growth and/or lower incisor extrusion, horizontal growth pattern, maxillary protrusion and mandibular retrusion.