Comparison of histological delineations of medial temporal lobe cortices by four independent neuroanatomy laboratories.

The medial temporal lobe (MTL) cortex, located adjacent to the hippocampus, is crucial for memory and prone to the accumulation of certain neuropathologies such as Alzheimer's disease neurofibrillary tau tangles. The MTL cortex is composed of several subregions which differ in their functional and cytoarchitectonic features. As neuroanatomical schools rely on different cytoarchitectonic definitions of these subregions, it is unclear to what extent their delineations of MTL cortex subregions overlap. Here, we provide an overview of cytoarchitectonic definitions of the entorhinal and parahippocampal cortices as well as Brodmann areas (BA) 35 and 36, as provided by four neuroanatomists from different laboratories, aiming to identify the rationale for overlapping and diverging delineations. Nissl-stained series were acquired from the temporal lobes of three human specimens (two right and one left hemisphere). Slices (50 µm thick) were prepared perpendicular to the long axis of the hippocampus spanning the entire longitudinal extent of the MTL cortex. Four neuroanatomists annotated MTL cortex subregions on digitized slices spaced 5 mm apart (pixel size 0.4 µm at 20× magnification). Parcellations, terminology, and border placement were compared among neuroanatomists. Cytoarchitectonic features of each subregion are described in detail. Qualitative analysis of the annotations showed higher agreement in the definitions of the entorhinal cortex and BA35, while the definitions of BA36 and the parahippocampal cortex exhibited less overlap among neuroanatomists. The degree of overlap of cytoarchitectonic definitions was partially reflected in the neuroanatomists' agreement on the respective delineations. Lower agreement in annotations was observed in transitional zones between structures where seminal cytoarchitectonic features are expressed less saliently. The results highlight that definitions and parcellations of the MTL cortex differ among neuroanatomical schools and thereby increase understanding of why these differences may arise. This work sets a crucial foundation to further advance anatomically-informed neuroimaging research on the human MTL cortex.

Comparison of histological delineations of medial temporal lobe cortices by four independent neuroanatomy laboratories.

The medial temporal lobe (MTL) cortex, located adjacent to the hippocampus, is crucial for memory and prone to the accumulation of certain neuropathologies such as Alzheimer's disease neurofibrillary tau tangles. The MTL cortex is composed of several subregions which differ in their functional and cytoarchitectonic features. As neuroanatomical schools rely on different cytoarchitectonic definitions of these subregions, it is unclear to what extent their delineations of MTL cortex subregions overlap. Here, we provide an overview of cytoarchitectonic definitions of the cortices that make up the parahippocampal gyrus (entorhinal and parahippocampal cortices) and the adjacent Brodmann areas (BA) 35 and 36, as provided by four neuroanatomists from different laboratories, aiming to identify the rationale for overlapping and diverging delineations. Nissl-stained series were acquired from the temporal lobes of three human specimens (two right and one left hemisphere). Slices (50 µm thick) were prepared perpendicular to the long axis of the hippocampus spanning the entire longitudinal extent of the MTL cortex. Four neuroanatomists annotated MTL cortex subregions on digitized (20X resolution) slices with 5 mm spacing. Parcellations, terminology, and border placement were compared among neuroanatomists. Cytoarchitectonic features of each subregion are described in detail. Qualitative analysis of the annotations showed higher agreement in the definitions of the entorhinal cortex and BA35, while definitions of BA36 and the parahippocampal cortex exhibited less overlap among neuroanatomists. The degree of overlap of cytoarchitectonic definitions was partially reflected in the neuroanatomists' agreement on the respective delineations. Lower agreement in annotations was observed in transitional zones between structures where seminal cytoarchitectonic features are expressed more gradually. The results highlight that definitions and parcellations of the MTL cortex differ among neuroanatomical schools and thereby increase understanding of why these differences may arise. This work sets a crucial foundation to further advance anatomically-informed human neuroimaging research on the MTL cortex.

Factores predisponentes para la inflamación gingival asociada con coronas de acero en dientes temporales en la población pediátrica. Revisión sistemática de la literatura / Predisposing factors for gingival inflammation associated with steel crowns on temporary teeth in the pediatric population. A systematic literature review

Introducción: el objetivo de esta revisión sistemática fue determinar los factores predisponentes para la inflamación gingival producidos por las coronas de acero, en comparación con dientes temporales no restaurados en la población pediátrica. Métodos: revisión sistemática de la literatura mediante la búsqueda de artículos científicos en las bases de datos: Pubmed, Elsevier, Embase, Cochrane y Lilacs, basados en los siguientes términos: stainless steel crowns, pediatric crowns, gingivitis, pediatric dentistry, clinical parameters y child, reduciendo la búsqueda con los criterios de elegibilidad sin discriminación de idioma. Resultados: en el periodo de búsqueda desde el año 1970 hasta el 2012, posterior al proceso de lectura y análisis de la información, se identificaron 1450 artículos, de los cuales se seleccionaron 10 artículos que cumplieron los criterios de inclusión. Se descartaron los duplicados, y aquellos que no cumplían con la especificidad requerida para responder la pregunta de investigación. Finalmente quedaron 2 artículos que cumplieron los requisitos predeterminados. Conclusiones: fue insuficiente la evidencia científica para soportar que la adaptación de las coronas de acero sea uno de los factores predisponentes de la enfermedad gingival en el paciente pediátrico, ni que demuestre la alteración del tejido periodontal por la invasión del espesor biológico debido a la sobre-extensión de las coronas de acero. La variable relacionada con los excesos de material cementante no ha sido ampliamente documentada. A pesar de que un estudio clínico mostró que la salud gingival es afectada por las coronas de acero en presencia de biopelícula dental, la literatura no es contundente en relación con el comportamiento del tejido gingival de la población pediátrica. Palabras clave: coronas, acero inoxidable, gingivitis, odontología pediátrica, niño.

Introduction: the objective of this systematic review was to determine the predisposing factors for gingival inflammation produced by steel crowns, compared to unrestored temporary teeth in the pediatric population. Methods: a systematic literature review by searching scientific articles in these databases: Pubmed, Elsevier, Embase, Cochrane, and Lilacs using the following terms: stainless steel crowns, pediatric crowns, gingivitis, pediatric dentistry, clinical parameters, and child, and reducing the search with eligibility criteria with no language distinction. Results: once the process of reading and information analysis was completed, 1450 articles were identified in the period of study (1970-2012) and 10 were selected as they met the inclusion criteria. Duplicates were discarded as well as those that did not meet the specifications required to answer the research question. Finally, 2 articles were chosen as they met the previously set requirements. Conclusions: the scientific evidence was not enough to support the fact of steel crowns adaptation being one of the predisposing factors for gingival disease in the pediatric patients, nor does it prove the alteration of periodontal tissue by invading biological thickness due to the over-extension of steel crowns. The variable related to excessive cement material has not been widely documented. While a clinical study showed that gingival health is affected by steel crowns in the presence of dental biofilm, the literature is not conclusive regarding the behavior of gingival tissue in the pediatric population.