Associations between real-life light exposure patterns and sleep behaviour in adolescents.

One of the most striking changes in the regulation of sleep-wake behaviour during adolescence is circadian phase delay. Light exposure synchronises circadian rhythms, impacting sleep regulation, however, the influence of real-life light exposure on sleep variations remains less clear. We aimed to describe the sleep and light exposure patterns of high school students with comparable schedules and socio-economic backgrounds, and to evaluate whether there was any association between them, considering chronotype. We analysed five school days and two free days of actigraphy records, from 35 adolescents (24 female, mean age: 16.23 ± 0.60). The sample was described using the Sleep Regularity Index (SRI), chronotype (actigraphy MSFsc), and self-reported diurnal preference (Morning/Evening Scale). Regression models were constructed to assess the impact of light exposure (daytime and nighttime) on subsequent sleep episodes; and to confirm whether the associations could be an indirect consequence of chronotype. Despite following similar routines, the SRI varied considerably (48.25 to 88.28). There was compatibility between the actigraphy proxy for chronotype and the self-reported diurnal preference, extracted using the circadian rhythm scale for adolescents. Less light exposure during the day was associated with later sleep onset and shorter sleep duration. An increase of 100 lux in average daytime light exposure advance of 8.08 minutes in sleep onset and 7.16 min in sleep offset. When the regressions were controlled for chronotype, these associations persisted. These findings facilitate discussions regarding the behavioural aspect of the impact of real-life light exposure on sleep and its potential as a target for interventions aiming to enhance adolescents' sleep quality.

Evaluation of the behavioral, histopathological, and immunohistochemical effects resulting from ventriculosubcutaneous shunt obstruction in kaolin-induced hydrocephalus in rats.

PURPOSE: Hydrocephalus is a brain disease prevalent in the pediatric population that presents complex pathophysiology and multiple etiologies. The best treatment is still ventricular shunting. Mechanical obstruction is the most frequent complication, but the resulting pathological effects are still unknown. OBJECTIVE: Evaluation and comparison of clinical, histopathological, and immunohistochemical aspects in the acute phase of experimental hydrocephalus induced by kaolin, after treatment with adapted shunt, and after shunt obstruction and posterior disobstruction. METHODS: Wistar rats aged 7 days were used and divided into 4 groups: control group without kaolin injection (n = 6), untreated hydrocephalic group (n = 5), hydrocephalic group treated with ventriculosubcutaneous shunt (DVSC) (n = 7), and hydrocephalic group treated with shunt, posteriorly obstructed and disobstructed (n = 5). The animals were submitted to memory and spatial learning evaluation through the Morris water maze test. The rats were sacrificed at 28 days of age and histological analysis of the brains was performed with luxol fast blue, in addition to immunohistochemical analysis in order to evaluate reactive astrocytosis, inflammation, neuronal labeling, and apoptotic activity. RESULTS: The group with shunt obstruction had worse performance in memory tests. Reactive astrocytosis was more evident in this group, as was the inflammatory response. CONCLUSIONS: Obstruction of the shunt results in impaired performance of behavioral tests and causes irreversible histopathological changes when compared to findings in the group with treated hydrocephalus, even after unblocking the system. The developed model is feasible and efficient in simulating the clinical context of shunt dysfunction.

The effect of brain-derived neurotrophic factor Val66Met polymorphism on adolescent activity and rest rhythms, circadian preferences and attentional performance.

BACKGROUND: Variations in circadian regulating mechanisms generate different individual preferences in respect of sleep and activity timing, which are known as chronotypes. In this sense, specifically during adolescence, there is a greater tendency for an eveningness chronotype. One factor that has been shown to have an impact on circadian rhythm patterns, as well as on some aspects of cognitive function, is the relatively common Val66Met (rs6265) polymorphism in the human brain-derived neurotrophic factor gene. OBJECTIVE: This study aimed to evaluate the effect of the BDNF Val66Met polymorphism on the performance of adolescents in attentional tests, circadian preferences and activity-rest rhythm. METHODS: 85 healthy high school students completed the Morningness-Eveningness Questionnaire to assess their circadian preferences; were evaluated using the Psychological Battery for Attention Assessment; and were categorized as carriers and non-carriers of the rs6265 polymorphism using the TaqMan rt-PCR technique. A subsample of 42 students had their activity/rest rhythm recorded by actigraphy for nine days from which sleep parameters were estimated. RESULTS: Circadian preference did not affect attentional performance (p > 0.1), but the time that the students attended school had an impact on all types of attention with morning shift students scoring higher, regardless of chronotype (p < 0.05). The presence of the BDNF Val66Met polymorphism was associated only with alternate attention performance (p < 0.05). Regarding actigraphy evaluation, the carriers of the polymorphism demonstrated significantly higher total time in bed, total sleep time, social jetlag, and earlier sleep onset. CONCLUSIONS: The results indicate some degree of adaptation in the students' attentional performance, according to their school schedules. The presence of BDNF polymorphism demonstrated a counterintuitive impact on attentional performance, comparing to previous findings. The findings reinforce the effect of genetic traits on sleep-wake rhythm parameters, when objectively evaluated.

A conservative approach to rehabilitate a molar-incisor hypomineralization case / Uma abordagem conservadora para reabilitar um caso de hipomineralização molar-incisivo

ABSTRACT Molar incisor hypomineralization is an increasingly common condition in our population. This condition can have great impact on the esthetics, function, and well-being of the child. This paper reports a case of a young patient diagnosed with this condition affecting all the first permanent molars and lower incisors, particularly teeth 31 and 41. The molars were treated with direct resin restorations with cusp coating and the incisors aesthetic was restored with different techniques such as bleaching with sodium hypochlorite, micro-abrasion and resin restorations. This treatment plan aimed to restore the proper teeth function, treat the already existing hypersensitivity and algic complains and to improve the aesthetic of the anterior sector. The presented case shows a conservative approach to deal with the molar incisor hypomineralization condition with satisfactory results after 1-year follow-up.

RESUMO A hipomineralização incisivo-molar (HIM) é uma condição cada vez mais comum na nossa população. Esta condição pode ter um grande impacto na estética, função e bem-estar da criança. Este artigo relata um caso de um paciente jovem diagnosticado com esta condição afetando todos os primeiros molares permanentes e incisivos inferiores, principalmente os dentes 31 e 41. Os molares foram tratados com restaurações diretas em resina composta com recobrimento de cúspides e a estética dos incisivos foi restabelecida com diferentes técnicas, como branqueamento com hipoclorito de sódio, micro-abrasão e restaurações de resina composta. Este plano de tratamento teve como objetivo restaurar a função dos dentes, tratar a hipersensibilidade e as queixas álgicas já existentes e melhorar a estética do sector anterior. O caso apresentado mostra uma abordagem conservadora para lidar com casos de hipomineralização incisivo-molar com resultados satisfatórios após 1 ano de acompanhamento.

Dental trauma in contact sports / Traumatismos dentários em esportes de contato

ABSTRACT Objective Investigate the prevalence of dental traumas in participants of two contact sports (Judo and Taekwondo) and characterise some related factors. Methods Cross-sectional pilot study of observational nature, conducted by observing and collecting data and information. The sample consisted of 60 individuals of both genders aged between 5 and 15 years old, participants of Judo or Taekwondo. The statistical analysis involved descriptive and inferential statistical measures. Results The prevalence of dental trauma in the studied sample was of 38,3%, with the majority occurring outside the practice of sport (82,6%). Only 4 children suffered trauma whilst playing their sport, corresponding to a prevalence of 6,67%. In addition, all 4 cases pertained to the practice of Judo. The most affected teeth were the primary maxillary central incisors followed by the permanent maxillary central incisors, with only one injured tooth in most cases. The lips were the soft tissue with greatest number of registered traumatic lesions. A statistically significant relationship was observed between risk factors and the occurrence of trauma. Conclusion A high prevalence of dental trauma in the studied population was found. Despite no record of traumatic lesions in Taekwondo, this prevalence was particularly noticeable in Judo.

RESUMO Objetivo Investigar a prevalência de traumatismos dentários na população praticante de dois esportes de contacto (Judo e Taekwondo) e caraterizar alguns fatores associados. Métodos Estudo piloto transversal com carácter observacional, realizado com recurso a observação e registo de dados e informações. A amostra foi de 60 indivíduos com idades compreendidas entre os 5 e os 15 anos, de ambos os sexos, praticantes de Judo ou Taekwondo no Parque de Jogos 1º de Maio - INATEL. A análise estatística envolveu medidas de estatística descritiva e estatística inferencial. Resultados A prevalência de traumatismos dentários na população em estudo foi de 38,3%, em que a maioria ocorreu fora da prática desportiva (82,6%). Apenas 4 crianças sofreram traumatismos durante a prática desportiva, correspondendo a uma prevalência de 6,67%. O único esporte predisponente para o trauma neste estudo foi o Judo. Os dentes mais atingidos foram os incisivos centrais superiores decíduos seguidos dos incisivos centrais superiores definitivos, e a maioria das situações afetou apenas um dente. O lábio foi o tecido mole com maior número de lesões traumáticas registadas. O hábito de utilização de protetor oral teve frequência nula. Verificou-se relação estatisticamente significativa entre a ocorrência de trauma e os fatores de risco estudados. Conclusão Foi encontrada uma alta prevalência de traumatismos dentários na população estudada. Esta mostrou-se alta no Judo, no entanto no Taekwondo não houve qualquer registo de lesões traumáticas.

Quantification of color variation of restorative materials used on pediatric dentistry after pigmentation / Quantificação da variação da cor de materiais restauradores utilizada em Odontopediatria após pigmentação

Objective: To quantify the color variation of two glass ionomer cements and a composite resin used in pediatric dentistry, after being immersed in different pigments agents. Methods: Using two glass ionomer cements (Ketac(tm) Molar and Photac(tm) Fil) and a microhybrid composite resin (Filtek(tm) z250), were produced 40 disks of each material (10 mm in diameter and 2 mm thick). The samples were soaked in artificial saliva (control group), coke, peach Ice Tea (r) and chocolate milk, for 72 hours in an oven at 37ºC. After this period, the samples were washed in 50 ml of distilled water. Finally, using the spectrophotometer, it was made the reading of results. The color change was measured according to the CIE L * a * b * system. Color changes were statistically analyzed using parametric one-way ANOVA and ANOVA with Welch correction, the nonparametric Kruskal-Wallis tests and post-hoc Tukey and Dunnet T3 with p≤ 0.05. Results: The immersion of restorative materials in different pigmentation agents caused a significant color variation on the samples. The agent who presented higher results was the Peach Ice Tea (r). The chocolate milk was the fluid with lowest pigmentation capacity of all restorative materials under study. The greater color variation was found on the Ketac(tm) Molar submerged in Coca-Cola (r) and the smallest on the Filtek(tm) z250 in chocolate milk. Conclusion: All restorative materials were shown to be susceptible to pigmentation by all agents. The Filtek(tm) z250 proved to have better color stability, followed by Photac(tm) Fil and finally by Ketac(tm) Molar.

Objetivo: Quantificar a variação da cor de materiais restauradores utilizados emodontopediatria, após serem imersos em agentes pigmentantes. Métodos: Recorrendo aos cimentos de ionómero de vidro Photac(tm) Fil e Ketac(tm) Molar, e à resina composta microhíbridaFiltek(tm) z250, foram efectuados 40 discos de cada material (10 milímetros de diâmetro e 2 milímetros de espessura). As amostras foram imersas em saliva artificial (grupo controlo), Coca-Cola(r), Ice Tea(r) de pêssego e Leite com chocolate, durante 72 horas, numa estufa a 37ºC. Decorrido este período, as amostras foram lavadas em 50 mililitros de água destilada. Por último, através da utilização do Espectrofotómetro, procedeu-se à leitura dos resultados. A variação da cor foi medida de acordo com o sistema CIE L* a* b* e analisada estatisticamente utilizando os testes paramétricos ANOVA one-way e ANOVA com correcção de Welch, o teste não paramétrico Kruskal-Wallis e os testes post-hoc Dunnet T3 e Tukey com p≤ 0,05. Resultados: A imersão das amostras nos fluidos, provocou uma variação de cor significativa das mesmas. O agente que apresentou resultados de pigmentação mais elevados foi o Ice Tea(r)de pêssego. O leite com chocolate foi o fluido que apresentou menor capacidade pigmentante em todos os materiais em estudo. A maior variação de cor verificou-se no Ketac(tm) Molar em Coca-Cola(r) e a menor no Filtek(tm) z250 em leite com chocolate. Conclusão: Todos os materiais restauradores demonstraram ser suscetíveis à pigmentação, por parte dos agentes. O Filtek(tm) z250 demonstrou ter uma melhor estabilidade de cor, seguido pelo Photac(tm) Fil e pelo Ketac(tm) Molar.