Prevalence of impacted teeth among a sample of yemeni population and their association with sex and age / Prevalencia de dientes impactados entre una muestra de población yemení y su asociación con el sexo y la edad

Aim: the aim of the study was to assess the prevalence of impacted teeth and its association with sex and age among a sample of the Yemeni population. Materials and Methods: A cross sectional study design was employed. The study included 999 radiographical records of patients who had panoramic X- rays previously done. All radiographs were assessed for the number and type of impacted teeth, pathology-associated impaction, sex, age and location (mandible and/or maxilla). The collected data was analyzed using SPSS®version21 software. Results: The study sample comprised digital panoramic radiographs of Yemeni patients aged 17 to 54 years (mean 26.6 years). The present study found 542 patients (54.3%) presented with at least one impacted tooth. The 17 to 25 years age group of the study sample had the highest prevalence of tooth impaction (28.6%). Only 10 (1.0%) case presented pathologies associated with the impacted teeth. There was a significant difference in the number of male 203 (20.3%) and female 339 (33.9%) patients with impacted teeth (p=0.031). Impacted teeth occurred slightly more often in the mandible (42.8%) compared to the maxilla (42.4%). Conclusion: The prevalence of impacted teeth among a sample of Yemeni population was high. Third molars and canines were the most common impacted teeth. The prevalence of impacted teeth in females was higher than in males and it was higher in the mandible than in the maxilla, with the younger patients with a higher prevalence of impaction.

Objetivo: el objetivo del estudio fue evaluar la prevalencia de dientes impactados y su asociación con el sexo y la edad en una muestra de la población yemení. Material y Métodos: se empleó un diseño de estudio transversal. El estudio incluyó 999 registros radiográficos de pacientes con radiografías panorámicas realizadas previamente. Todas las radiografías fueron evaluadas en relación al número y tipo de dientes impactados, patología asociada a la impactación, sexo, edad y ubicación (mandíbula y/o maxilar). Los datos recopilados se analizaron utilizando el software SPSS® version 21. Resultados: La muestra del estudio comprendió radiografías panorámicas digitales de pacientes yemeníes entre 17 a 54 años (media 26,6 años). El presente estudio encontró que 542 pacientes (54,3%) presentaron al menos un diente impactado. El grupo de edad de 17 a 25 años de la muestra de estudio tuvo la mayor prevalencia de impactación dental (28,6%). Solo 10 casos (1,0%) presentaron patologías asociadas a los dientes impactados. Hubo una diferencia significativa en el número de pacientes masculinos 203 (20.3%) y femeninos 339 (33.9%) con dientes impactados (p=0.031). Los dientes impactados ocurrieron con un poco más de frecuencia en la mandíbula (42.8%) en comparación con el maxilar (42.4%). Conclusión: La prevalencia de dientes impactados entre una muestra de población yemení fue alta. Los terceros molares y caninos fueron los dientes más comúnmente impactados. La prevalencia de dientes impactados en las mujeres fue mayor que en los hombres y fue mayor en la mandíbula que en el maxilar, y los pacientes más jóvenes mostraron una mayor prevalencia de impactación.

Date palm micropropagation: Advances and applications / Micropropagação de tamareira: Avanços e aplicações

ABSTRACT Date palm (Phoenix dactylifera L.) is a fruit tree resilient to adverse climatic conditions predominating in hot arid regions of the Middle East and North Africa. The date fruit contains numerous chemical components that possess high nutritional and medicinal values. Traditional propagation by offshoots is inefficient to satisfy current demands for date palm trees. Alternatively, micropropagation provides an efficient means for large-scale propagation of date palm cultivars. Both somatic embryogenesis and organogenesis, either directly or indirectly though the callus phase, have been demonstrated in date palm in vitro regeneration. Culture initiation commonly utilizes shoot-tip explants isolated from young offshoots. Recently, the immature inflorescences of adult trees were utilized as an alternative nondestructive source of explants. In addition to the nature of the explant used, successful plant regeneration depends on the cultivar, composition of the culture medium and physical status. Challenges of date palm micropropagation include long in vitro cycle, latent contamination, browning, somaclonal variation as well as ex vitro acclimatization and transplanting. A remarkable amount of research investigating these factors has led to optimized protocols for the micropropagation of numerous commercially important cultivars. This has encouraged the development of several international commercial tissue culture laboratories. Molecular characterization provides an assurance of genetic conformity of regenerated plantlets, a key feature for commercial production. This article describes date palm micropropagation protocols and also discusses recent achievements with respect to somaclonal variation, molecular markers, cryopreservation and future prospects.

RESUMO A tamareira (Phoenix dactylifera L.) é uma arvore frutífera adaptada à condições climáticas adversas predominantemente em regiões áridas do Oriente Médio e Norte Africano. As tâmaras possuem vários componentes químicos com alto valor medicinal e nutricional. A propagação tradicional por estacas não é suficiente para satisfazer a demanda por mudas e assim, a micropropagação apresenta-se como uma alternativa eficiente para a produção de mudas em larga escala. Embriogênese somática e organogênese, tanto direta quanto indireta via calos, tem sido usada para obter a regeneração in vitro de tamareira. O inicio do cultivo in vitro normalmente utiliza meristemas excisados de brotações jovens. Recentemente, inflorescências imaturas de árvores adultas são usadas como fonte alternativa de explantes não destrutiva. Além da origem do explante, o sucesso da regenerção depende do cultivar, da composição do meio de cultura e de condições físicas. Desafios na micropropagação de tamareira incluem um longo ciclo in vitro, contaminação, escurecimento do tecido, variação somaclonal além do enraizamento e aclimatização ex vitro. Diversos estudos investigando esses fatores tem conduzido à otimização de protocolos de micropropagação de inúmeros cultivares comerciais proporcionando o estabelecimento de vários laboratórios de cultura de tecidos de plantas. A caracterização molecular permite uma segura conformidade genética do material regenerado, considerado uma característica chave na produção comercial. Essa revisão descreve protocolos de micropropagação de tamareira e aborda as mais recentes conquistas relacionadas à variação somaclonal, marcadores moleculatres, criopreservação e perspectivas futuras.