Aim This study determined whether COVID-19 fear is correlated with sociodemographic characteristics, general health, mental health, and sleep quality in an elderly Brazilians. Methods Elderly people aged ≥ 60 years replied to an online survey containing questions about their sociodemographic characteristics; general health; levels of stress, anxiety, and depression; sleep quality; and COVID fear. Results Data were statistically analyzed using descriptive statistics (α = 5%). In total, 705 elderly people with mean age of 66 ± 5 years, and most (82.7%) respondents were women, graduated and from southeastern Brazil. COVID-19 fear correlated positively and moderately with sleep quality and symptoms of depression, anxiety, and stress (all p < 0.001). It was associated with females. Elderly people from northern and northeastern Brazil and diabetics had increased COVID-19 fear (all p < 0.05). Conclusion The fear of COVID-19 exists among Brazilian female old people, diabetics, increases anxiety and stress symptoms, and worsen sleep quality in elderly people.

Aim This study aimed to evaluate the effect of frozen storage on the physical properties of a silicone-based test food material, highly used to evaluate the masticatory performance in research settings. Methods A total of 1,666 silicone cubes of Optosil Comfort® with 5.6-mm edges were shaped and stored at -18°C. The cubes were subsequently tested for flexural strength (maximum force, displacement, stress, and strain) before breaking (n = 136), changes in weight and size (n = 170), and masticatory performance (n = 1360) at eight timepoints: immediately after cube preparation (baseline, no freezing), and 1, 2, 3 and 4 weeks, and 2, 4 and 6 months after frozen storage. The cubes were thawed 8 h before each assessment. Results The maximum force, stress, maximum displacement, and deformation values for the cubes were not affected by freezing (P > 0.05). At all of the time points, the cubes exhibited similar weight (P = 0.366) and size (identical values). The masticatory performance for the cubes also showed no differences from baseline through 6 months (P = 0.061). Conclusion Freezing Optosil Comfort® silicone cubes did not alter the physical and mechanical properties of the material, being suitable to optimize the assessment of masticatory parameters for research purposes.

Aim This cross-sectional observational study aimed to evaluate the influence of the Universities lockdown measures on academic perspectives and psychosocial aspects of Brazilian final-year dental students. Methods 268 undergraduate students regularly enrolled in a Dentistry course at public universities were asked about anxiety, depression, stress sensitivity, and their academic perspectives by using an online survey. The Hospital Anxiety and Depression Scale (HADS) was used to measure anxiety and depression, while the Perceived Stress Scale (PSS) evaluated stress levels. The academic perspective was evaluated by five affirmatives regarding possible difficulties that will be faced when school reopens and after graduation. The possible association between fear of having COVID-19 with psychosocial outcomes and COVID-19 association with academic perspectives were analyzed by ANOVA and chi-square tests, respectively, considering a significance level of 5%. Results Considering possible associations between the fear of having COVID-19 and psychosocial aspects, significant values were found for anxiety (P = 0.018) and stress sensitivity (P = 0.002). Regarding students’ academic perspectives, COVID-19 had significant impact on less opportunity to perform procedures (P = 0.023), additional expenses with personal protective equipment (P = 0.007), and concerns of consulting elderly people (P = 0.012). Conclusion The COVID-19 pandemic led to increased psychological impairments and enlarged concerns with learning and biosecurity, which might impact academic perspectives. Thus, being aware of these apprehensions, university professors and staff can improve the clinical training of final-year dental students in an empathetic way.

Resumo A utilização de overdentures suportadas por dois implantes melhora a mastigação de pacientes idosos edêntulos que apresentam rebordos residuais reabsorvidos. No entanto, pouco se sabe sobre os efeitos de overdentures suportadas por único implante central mandibular (SIO) em relação à percepção oral e função mastigatória em tais idosos. O atual estudo comparou os efeitos de próteses totais convencionais (CD) e SIO na capacidade de sensorimotora oral (OSA), função mastigatória e ingestão nutricional de idosos com altura de rebordos mandibulares tipo III e IV de acordo com a Colégio Americano de Prótese. Doze idosos receberam primeiramente novas CD convencionais, as quais, posteriormente, foram transformadas em SIO. Variáveis foram avaliadas após o uso de cada prótese durante 2 meses. Para avaliar OSA, os idosos fecharam os olhos e testaram oralmente a identificação de formatos geométricos confeccionados de cenouras cruas. Um dispositivo cinesiográfico foi utilizado para medir os movimentos durante a mastigação de material de teste (Optocal). A performance mastigatória (MP) foi determinada com o método de fracionamento de peneiras e um diário de alimentação aplicado por 3 dias consecutivos verificou a ingestão de nutrientes com base em uma Tabela Brasileira Padrão de Composição de Alimentos. Os dados foram analisados utilizando os testes Wilcoxon signed rank test e Student’s paired t test (p<0,05). OSA resultados não diferiram de acordo com o tipo de prótese. No entanto, as velocidades de abertura e fechamento durante a mastigação e MP aumentaram após a inserção de SIO (p<0,05). Embora não tenha sido observada diferença na ingestão da maioria dos nutrientes, a ingestão de sódio diminuiu após a inserção de SIO (p<0,05). O uso de SIO não teve efeito sobre OSA, mas melhorou significativamente a mastigação e a ingestão de sódio de idosos com altura de rebordos residuais reduzidas (Registro Brasileiro de Ensaios Clínicos # RBR-3kgttj).

Abstract The use of two-implant overdentures improves mastication of edentulous elderly patients. However, little is known about the effects of single-implant overdentures (SIO) on oral perception and masticatory function in such elders. This study compared the effects of conventional complete dentures (CD) and SIO on the oral sensorimotor ability (OSA), masticatory function, and nutritional intake of elderly people with residual alveolar mandibular height classified as Class III or IV according to the American College of Prosthodontics. Twelve elders first received new conventional CD, which were later converted to SIO. All variables were evaluated after use of each prosthesis for 2 months. To evaluate OSA, elders closed their eyes and orally identified test pieces prepared from raw carrots. A kinesiographic device was used to measure chewing movements during mastication of a test material (Optocal). Masticatory performance (MP) was determined with the sieving method, and a 3-day food diary verified nutrient intake based on a standard Brazilian Food Composition Table. Data were analyzed using the Wilcoxon signed rank test and Student’s paired t test (P < 0.05). OSA results did not differ according to prosthesis type. However, opening and closing velocities during chewing and MP increased after SIO insertion (P < 0.05). Although no difference was observed in the intake of most nutrients, sodium ingestion decreased after SIO insertion (P < 0.05). SIO use had no effect on OSA, but significantly improved mastication and sodium intake of elders with decreased residual ridges height (Brazilian Registry of Clinical Trials #RBR-3kgttj).

Resumo A morfologia craniofacial afeta a performance mastigatória em individuos dentados saudáveis, mas pouco é conhecido sobre seus efeitos em pacientes com desordens temporomandibulares (DTMs) com sintomatologia dolorosa. Quarenta e oito pacientes do gênero feminino (idade média de 28±5,8 anos) com DTM e sintomatologia dolorosa foram submetidas à radiografia cefalométrica lateral. Por meio da análise cefalométrica de Ricketts e método Vert, as voluntárias foram divididas segundo a morfologia crabiofacial em: braquifaciais (n=22), mesofaciais (n=13) ou dolicofaciais (n=13). O Research Diagnostic Criteria for TMD (RDC/TMD) foi utilizado para diagnosticar a presença de DTM em cada paciente. A intensidade de dor foi reportada por cada paciente usando a escala visual analógica (EVA). A força máxima de mordida (FMM) foi medida com sensores de pressão colocados na região de primeiros molares. A performance mastigatória (PM) foi avaliada por meio da mastigação de material artificial confeccionado à base de silicone e determinada pelo tamanho da partícula, usando o método de fracionamento em peneiras. A habilidade mastigatória (HM) foi avaliada por meio de sete tipos de alimento e analisada por meio de EVA. Os dados foram analisados por ANOVA, seguido por teste de Tukey-Kramer (p<0,05). A FMM foi diferente entre cada grupo, sendo que as pacientes braquifaciais apresentaram os maiores valores. Não houve diferença na PM entre os grupos. Os grupos somente diferiram quanto à HM para mastigar apenas um dos sete tipos de alimentos avaliados. Em resumo, a morfologia craniofacial afeta a FMM sem prejudicar a PM ou HM em pacientes com DTM e sintomatologia dolorosa.

Abstract Craniofacial morphology affects masticatory performance in healthy dentate subjects, but little is known about its effects in patients with painful temporomandibular disorders (TMDs). Forty-eight female patients (mean age of 28±5.8 years) with painful TMDs underwent lateral cephalometric radiography. Using Ricketts' cephalometric analysis and the Vert method, subjects were assigned to three groups according to their craniofacial morphology: brachyfacial (n=22), mesofacial (n=13), and dolichofacial (n=13). Research diagnostic criteria for TMD were used to confirm the TMD diagnosis for each patient. Pain intensity was reported by each patient based on a visual analog scale (VAS). Maximum bite force (MBF) was measured with pressure sensors placed on the first molar site. Masticatory performance (MP) was assessed by chewing a silicone-based artificial material and determining the resulting particle size by the sieve method. Chewing ability (CA) was evaluated for seven food types and analyzed by a VAS questionnaire. Data were analyzed by one-way ANOVA followed by a Tukey-Kramer test (p<0.05). MBF differed in each group, with brachyfacial patients having the highest MBF values. There was no difference in MP among the groups. The groups differed only in their ability to chew one of the seven evaluated food types. In summary, craniofacial morphology affects the MBF without impairing MP or CA in patients with painful TMDs.

Resumo Este estudo teve como objetivo avaliar objetiva e subjetivamente a saúde bucal em idosos com doença de Parkinson (DP), usando avaliações clínicas bucais e do General Oral Health Assessment Index (GOHAI). Os participantes foram 37 indivíduos usuários de prótese removível, 17 com DP (idade média 69,59±5,09 anos) e 20 sem DP (idade média 72,00±5,69 anos). A avaliação objetiva incluiu avaliação de características bucais,incluindo número de dentes remanescentes; dentes cariados, perdidos e obturados (CPOD); índice de placa visível (IPV), a taxa de fluxo salivar e as condições das próteses removíveis. A avaliação subjetiva incluiu autopercepção da saúde bucal, coletada usando o índice GOHAI. O número de dentes remanescentes, CPOD, IPV, fluxo salivar e os dados GOHAI foram comparadas entre os grupos utilizando o teste t . As condições das próteses removíveis foram analisadas utilizando o teste χ2 (p<0,05). Não houve diferenças entre os grupos no número de dentes remanescentes, CPOD, IPV ou fluxo salivar (p>0,05). Maiores defeitos na prótese superior foi observada no grupo controle (p=0,037). As pontuações do GOHAI foram baixa para o grupo DP e moderada para os controles, com diferença entre os grupos (p=0,04). Como conclusão, os idosos com doença de Parkinson tem saúde bucal semelhante aos controles. Embora todos os idosos tenham poucos dentes remanescentes, alto CPOD e alto IPV, os idosos com DP apresentaram autopercepção mais negativa da sua saúde bucal em relação aos controles.

Abstract This study aimed to evaluate objectively and subjectively the oral health of elders with Parkinson's disease (PD), using clinical oral assessments and the General Oral Health Assessment Index (GOHAI). Subjects included 37 removable prosthesis wearers, 17 with PD (mean age 69.59±5.09 years) and 20 without PD (mean age 72.00±5.69 years). The objective assessment included an evaluation of oral characteristics, including the number of remaining teeth, decayed, missing and filled teeth (DMFT), visible plaque index (VPI), salivary flow rate and removable prosthesis conditions. The subjective assessment included self-perception of oral health collected using the GOHAI index. The number of remaining teeth, DMFT, VPI, salivary flow rate and GOHAI data were compared between the groups using t-tests. Removable prosthesis conditions were analyzed using χ2 tests (p<0.05). There were no group differences in the number of remaining teeth, DMFT, VPI or salivary flow rate (p>0.05). Greater maxillary prosthesis defects were observed in the control group (p=0.037). GOHAI scores were low for the PD group and moderate for controls, yielding a group difference (p=0.04). In conclusion, elders with PD have similar oral health to controls. Although all elders had few remaining teeth, high DMFT and high VPI, PD elders had more negative self-perceptions of their oral health than did the controls.

Resumo: Este estudo avaliou a qualidade de vida relacionada à saúde bucal (QVRSB) em indivíduos parcialmente dentados, apresentando perda extrema de dentes na região posterior com ausência de dentes pós-caninos, comparando a reabilitação por meio de próteses parciais removíveis convencionais (PPRs) e PPRs implanto-suportadas. A QVRSB foi mensurada utilizando a versão brasileira do Oral Health Impact Profile (OHIP-49). Doze indivíduos apresentando edentulismo total maxilar e Classe I de Kennedy mandibular (idade média 62,6±7,8 anos) receberam primeiramente próteses totais maxilares e PPRs mandibulares convencionais de extremidade livre. Após dois meses de uso destas próteses, a QVRSB dos voluntários foi avaliada. Implantes osseointegrados foram bilateralmente instalados na região de primeiros molares inferiores e, após quatro meses, pilares do tipo bola foram instalados para suportar a extremidade livre da PPR. Após dois meses a QVRSB dos voluntários foi reavaliada. O teste pareado de Wilcoxon foi utilizado para avaliar as diferenças de QVRSB (α=0,05). Os resultados mostraram melhora em todos os domínios do OHIP-49 (p<0,05) após a associação dos implantes à PPR. PPRs de extremidade livre mandibulares implanto-suportadas melhorou significativamente a QVRSB.

Abstract: This study aimed to evaluate oral health-related quality of life (OHRQoL) in partially dentate subjects, presenting extreme tooth loss in posterior region with missing post-canines, comparing the use of conventional removable partial dentures (RPDs) and implant-supported RPDs. OHRQoL was measured using the Brazilian version of the Oral Health Impact Profile. Twelve subjects presenting maxillary total and mandibular Kennedy Class I edentulism (mean age 62.6±7.8 years) first received complete maxillary dentures and conventional mandibular free-end RPDs. After two months, the subjects had their OHRQoL assessed. Osseointegrated implants were inserted bilaterally in the mandibular first molar regions, and after four months ball abutments were placed to support the free-end RPD. Two months later, the patients had their OHRQoL reassessed. Wilcoxon signed-rank test was used to evaluate differences in OHRQoL (α=0.05). Results showed improvement in all OHIP-49 domains (p<0.05) after associating implants to the RPD. The mandibular implant-supported free-end RPD significantly improved OHRQoL.

<p>A falta de critérios padronizados para a avaliação dos resultados faz com que seja difícil tirar conclusões sobre o desempenho clínico dos implantes curtos e, nestas circunstâncias, determinar as razões para o fracasso do implante. Este estudo avaliou, através de uma revisão sistemática da literatura, os parâmetros essenciais necessários para avaliar o desempenho clínico em longo prazo de implantes curtos e extra-curtos. Bases de dados eletrônicas (PubMed-MEDLINE, Base de dados da Biblioteca Cochrane, Embase e Lilacs) foram avaliadas por dois revisores independentes, sem limitação da linguagem, de modo a identificar artigos elegíveis. As referências dos artigos selecionados foram também analisadas. A revisão incluiu estudos clínicos, publicados entre janeiro de 2000 e março de 2014, envolvendo implantes dentais curtos, instalados em seres humanos, nos quais foram descritos os parâmetros utilizados para mensuração dos resultados e fornecidos dados sobre as taxas de sobrevivência. Treze estudos metodologicamente aceitáveis foram selecionados, sendo identificados 24 parâmetros. Os parâmetros avaliados com maior frequencia foram a perda óssea marginal e a taxa cumulativa de sobrevivência do implante, seguida pela taxa de falha dos implantes e complicações biológicas, tais como sangramento à sondagem e profundidade de sondagem. Apenas a taxa cumulativa de sobrevivência dos implantes permitiu a meta-análise revelando efeito positivo (variação de 0.052 (efeito fixo) até 0.042 (efeito aleatório)), demonstrando que os implantes curtos parecem ser uma opção de tratamento bem sucedida. Complicações mecânicas e a mensuração da proporção coroa-implante foram também referidas, entretanto, considerando-se as evidências disponíveis, não se pode chegar a fortes conclusões, pois diferentes métodos foram utilizados para avaliar cada parâmetro. Por meio desta revisão da literatura, um esquema padronizado de avaliação é proposto, sendo útil para arregimentar novas investigações e permitir a comparação de estudos futuros.</p>

<p>Lack of standard criteria in the outcome assessment makes it difficult to draw conclusions on the clinical performance of short implants and, under these circumstances, determine the reasons for implant failure. This study evaluated, through a systematic review of the literature and meta-analysis, the essential parameters required to assess the long-term clinical performance of short and extra-short implants. Electronic databases (Pubmed-MEDLINE, Cochrane Library Database, Embase, and Lilacs) were searched by two independent reviewers, without language limitation, to identify eligible papers. References from the selected articles were also reviewed. The review included clinical trials involving short dental implants placed in humans, published between January 2000 and March 2014, which described the parameters applied for outcome's measurements and provided data on survival rates. Thirteen methodologically acceptable studies were selected and 24 parameters were identified. The most frequent parameters assessed were the marginal bone loss and the cumulative implant survival rate, followed by implant failure rate and biological complications such as bleeding on probing and probing pocket depths. Only cumulative implant survival rate data allows meta-analysis revealing a positive effect size (from 0.052 (fixed) to 0.042 (random)), which means that short implant appears to be a successful treatment option. Mechanical complications and crown-to-implant (C/I) ratio measurement were also commonly described, however, considering the available evidence; no strong conclusions could be drawn since different methods were used to assess each parameter. By means of this literature review, a standard evaluation scheme is proposed, being helpful to regiment further investigations and comparisons on future studies.</p>

Resumo A oligodontia é uma doença rara, congênita, caracterizada pela ausência de seis ou mais dentes. Este relato de caso descreve uma abordagem terapêutica multidisciplinar de um adolescente de 12 anos de idade com ausência de 11 dentes permanentes. Antes de qualquer procedimento, todos os dentes decíduos foram extraídos devido à pobre relação coroa-raiz. O plano de tratamento foi constituído por duas fases: 1. terapia ortodôntica e fonoaudiológica com o objetivo de ajuste de sobre-mordida e mordida aberta anterior, bem como melhoria da posição da língua, e 2. tratamento reabilitador protético através da instalação de próteses parciais removíveis provisórias. A abordagem multidisciplinar envolvendo os tratamentos ortodônticos, fonoaudiológico e protético reestabeleceram a função mastigatória e a estética, melhorando a autoestima e aceitação social do paciente.

Oligodontia is a rare congenital disorder consisting in the absence of six or more teeth. This case report describes a multidisciplinary treatment approach for a 12-year-old male with absence of 11 permanent teeth. Prior to any procedure, all primary teeth were scheduled for extraction due to poor crown-to-root ratio. The treatment plan comprised two phases: 1. orthodontic and speech therapy aimed at overbite and anterior open bite adjustment, as well as tongue position improvement; and 2. prosthetic treatment by insertion of removable temporary partial dentures. The multidisciplinary treatment involving orthodontics, speech and prosthetic therapies have reestablished the masticatory function and aesthetics, allowing the patient to achieve greater self-esteem and better social acceptance.

Craniofacial dimensions influence oral functions; however, it is not known whether they are associated with function asymmetry. The objective of this study was to evaluate chewing side preference and lateral asymmetry of occlusal contact area and bite force of individuals with different craniofacial patterns. Seventy-eight dentate subjects were divided into 3 groups according to the VERT index as follows: (1) mesofacial, (2) brachyfacial and (3) dolichofacial. Chewing side preference was evaluated using jaw tracking equipment, occlusal contact area was measured by silicon registration of posterior teeth, and bite force was measured unilaterally on molar regions using 2.25 mm-thick sensors. Statistical analysis was performed using ANOVA on Ranks, Student's t-test, and Mann-Whitney tests at a 5% significance level. Mesofacial, brachyfacial, and dolichofacial subjects presented more occlusal contact area on the left side. Only dolichofacial subjects showed lateral asymmetry for bite force, presenting higher force on the left side. No statistically significant differences were found for chewing side preference among all groups. Within the limitations of this study, it can be concluded that craniofacial dimensions play a role in asymmetry of bite force. ClinicalTrials.gov ID: NCT01286363.

The aim of this study was to evaluate whether patients with hyposalivation present damaged mastication or mandibular movements during speech. Forty subjects composed 2 groups: control and hyposalivation. Masticatory performance was assessed with a silicon-based artificial material and a 10-sieve method. Mandibular movements during speech were observed with a 3D jaw-tracking device. Data were analyzed with Student's t-test or the Mann-Whitney method (P < 0.05). The masticatory performance (mm) of control and hyposalivation were 4.40 ± 0.62 and 4.74 ± 1.34, respectively. Outcomes for speech movements (mm) were as follows: maximum vertical opening amplitude (10.8 ± 4.2; 9.9 ± 2.7) and displacements to the right (1.0 ± 0.8; 0.5 ± 0.6), left (1.8 ± 1.4; 2.3 ± 1.2), or anterior-posterior (2.8 ± 1.1; 2.9 ± 1.0) for control and hyposalivation, respectively. No statistical difference was found between groups for any variable. The results indicated that hyposalivation did not affect masticatory performance or mandibular movements during speech.

OBJECTIVE: The aim of this study was to evaluate whether vertical facial patterns influence maximal occlusal force (MOF), masticatory muscle electromyographic (EMG) activity, and medial mandibular flexure (MMF). MATERIAL AND METHODS: Seventy-eight dentate subjects were divided into 3 groups by Ricketts's analysis: brachyfacial, mesofacial and dolychofacial. Maximum occlusal force in the molar region was bilaterally measured with a force transducer. The electromyographic activities of the masseter and anterior temporal muscles were recorded during maximal voluntary clenching. Medial mandibular flexure was calculated by subtracting the intermolar distance of maximum opening or protrusion from the distance in the rest position. The data were analyzed using ANOVA followed by Tukey's HSD test. The significance level was set at 5%. RESULTS: Data on maximum occlusal force showed that shorter faces had higher occlusal forces (P<0.0001). Brachyfacial subjects presented higher levels of masseter electromyographic activity and medial mandibular flexure, followed by the mesofacial and dolychofacial groups. Additionally, dolychofacial subjects showed significantly lower electromyographic temporalis activities (P<0.05). CONCLUSION: Within the limitations of the study, it may be concluded that maximum occlusal force, masticatory muscle activity and medial mandibular flexure were influenced by the vertical facial pattern.

As flutuações hormonais durante o ciclo menstrual podem influenciar as tensões musculares e possivelmente alterar a força oclusal. O objetivo deste estudo foi avaliar se os níveis hormonais afetam a força máxima oclusal (FMO) de mulheres saudáveis durante as diferentes fases do ciclo menstrual. Sessenta pacientes completamente dentadas que não usavam contraceptivos orais foram selecionadas para participar neste estudo. FMO foi avaliada bilateralmente na região dos molares, durante 3 ciclos menstruais completos, utilizando sensores de 5,65 mm de espessura. As mensurações foram realizadas durante cada fase do ciclo menstrual: menstrual, folicular e lútea periovulatória, identificadas por teste ovulatório. Os dados foram analisados por ANOVA um critério seguido do teste de Tukey-Kramer (p<0,05). As comparações entre as fases do ciclo menstrual não apresentaram diferenças na FMO (p=0,27). Segundo as condições deste estudo, pode-se concluir que as flutuações hormonais durante o ciclo menstrual não afetaram a FMO de mulheres saudáveis.

Hormonal fluctuations during the menstrual cycle may influence on muscular tensions and probably alter occlusal force. The aim of this study was to evaluate whether hormonal levels affect maximum occlusal force (MOF) of healthy women throughout the different phases of the menstrual cycle. Sixty complete dentate subjects who were not under use of oral contraceptives were selected to participate in this study. MOF was bilaterally evaluated on the molar region, during 3 complete menstrual cycles, using 5.65 mm-wide sensors. Measurements were carried out during each of the following menstrual cycle phases: menstrual, follicular, periovulatory and luteal, presumed by ovulation test. Data were analyzed by one-way ANOVA and Tukey-Kramer test (p<0.05). Comparisons among menstrual cycle phases showed no differences on MOF (p=0.27). Under the conditions of this study, it may be concluded that hormonal fluctuations during the menstrual cycle do not affect MOF of a sample of healthy women.

This study evaluated the relationship among malocclusion, number of occlusal pairs, masticatory performance, masticatory time and masticatory ability in completely dentate subjects. Eighty healthy subjects (mean age = 19.40 ± 4.14 years) were grouped according to malocclusion diagnosis (n = 16): Class I, Class Class II-2, Class III and Normocclusion (control). Number of occlusal pairs was determined clinically. Masticatory performance was evaluated by the sieving method, and the time used for the comminute test food was registered as the masticatory time. Masticatory ability was measured by a dichotomic self-perception questionnaire. Statistical analysis was done by one-way ANOVA, ANOVA on ranks, Chi-Square and Spearman tests. Class II-1 and III malocclusion groups presented a smaller number of occlusal pairs than Normocclusion (p < 0.0001), Class I (p < 0.001) and II-2 (p < 0.0001) malocclusion groups. Class I, and III malocclusion groups showed lower masticatory performance values compared to Normocclusion (p < 0.05) and Class II-2 (p < 0.05) malocclusion groups. There were no differences in masticatory time (p = 0.156) and ability (χ2 = 3.58/p= 0.465) among groups. Occlusal pairs were associated with malocclusion (rho = 0.444/p < 0.0001) and masticatory performance (rho = 0.393/p < 0.0001), but malocclusion was not correlated with masticatory performance (rho = 0.116/p= 0.306). In conclusion, masticatory performance and ability were not related to malocclusion, and subjects with Class I, II-1 and III malocclusions presented lower masticatory performance because of their smaller number of occlusal pairs.

This study evaluated accuracy of fit, impact strength, types and morphology of fractures of a microwave acrylic resin polymerized with a cycle alternative to that recommended by the manufacturer. Onda Cryl was polymerized according to the manufacturer's instructions (MC), 3 min at 360 W, 4-min pause, and 3 min at 810 W; and with an alternative cycle (AC) of 6 min at 630 W. Accuracy of fit was measured at 3 points at the right (A) and left (B) ridge crests and at the midline (C) on the posterior palatal seal for each denture base (n = 10/group). The measurements were taken immediately after finishing and after 30-day storage in water. The impact strength test (Charpy method) was performed with a 40 kJ/cm load (n = 20/group). Fractographic analysis was accomplished for all fragments and the fracture types were characterized by means of their morphology, crack propagation angles and microstructure. Accuracy of fit data were analyzed by ANOVA, impact strength and radius values were compared by the t test, and the fractographic analysis data, by the Wilcoxon Mann-Whitney test. The significance level was fixed at p < 0.05. No statistical differences were found between the two cycles of polymerization used. However, after the 30-day storage period in water, the denture bases showed better fit (P < .05). Most of the fractures were classified as brittle (MD: 70%, AC: 80%). Based on the results of this study, it could be concluded that both polymerization cycles are adequate to polymerize the denture resin studied.