The age of three Middle Palaeolithic sites: Single-grain optically stimulated luminescence chronologies for Pech de l'Azé I, II and IV in France.

Optically stimulated luminescence (OSL) measurements were made on individual, sand-sized grains of quartz from Middle Palaeolithic deposits at three sites (Pech de l'Azé I, II and IV) located close to one another in the Dordogne region of southwest France. We were able to calculate OSL ages for 69 samples collected from these three sites. These ages reveal periods of occupation between about 180 and 50 thousand years ago. Our single-grain OSL chronologies largely support previous age estimates obtained by thermoluminescence dating of burnt flints at Pech IV, electron spin resonance dating of tooth enamel at Pech I, II and IV and radiocarbon dating of bone at Pech I and IV, but provide a more complete picture due to the ubiquitous presence of sand-sized quartz grains used in OSL dating. These complete chronologies for the three sites have allowed us to compare the single-grain ages for similar lithic assemblages among the three sites, to test the correlations among them previously proposed by Bordes in the 1970s, and to construct our own correlative chronological framework for the three sites. This shows that similar lithic assemblages occur at around the same time, and that where a lithic assemblage is unique to one or found at two of the Pech sites, there are no deposits of chronologically equivalent age at the other Pech site(s). We interpret this to mean that, at least for these Pech de l'Azé sites, the Mousterian variants show temporal ordering. Whether or not this conclusion applies to the wider region and beyond, the hypothesis that Mousterian industrial variation is temporally ordered cannot be refuted at this time.

Reconstructing Late Pleistocene paleoclimate at the scale of human behavior: an example from the Neandertal occupation of La Ferrassie (France).

Exploring the role of changing climates in human evolution is currently impeded by a scarcity of climatic information at the same temporal scale as the human behaviors documented in archaeological sites. This is mainly caused by high uncertainties in the chronometric dates used to correlate long-term climatic records with archaeological deposits. One solution is to generate climatic data directly from archaeological materials representing human behavior. Here we use oxygen isotope measurements of Bos/Bison tooth enamel to reconstruct summer and winter temperatures in the Late Pleistocene when Neandertals were using the site of La Ferrassie. Our results indicate that, despite the generally cold conditions of the broader period and despite direct evidence for cold features in certain sediments at the site, Neandertals used the site predominantly when climatic conditions were mild, similar to conditions in modern day France. We suggest that due to millennial scale climate variability, the periods of human activity and their climatic characteristics may not be representative of average conditions inferred from chronological correlations with long-term climatic records. These results highlight the importance of using direct routes, such as the high-resolution archives in tooth enamel from anthropogenically accumulated faunal assemblages, to establish climatic conditions at a human scale.

Desarrollo tardío de dientes supernumerarios en la región de premolares: reporte de un caso / Late development of supernumerary teeth in the premolar region: report of a case

Este reporte describe el desarrollo tardío de premolares suplementales supernumerarios en tres cuadrantes de la región premolar. El descubrimiento de estas piezas fue por medio de radiografías de aleta de mordida y posterior confirmación con radiografías periapicales

Bases científicas de la implantología / Scientific bases of implantology

Se presentan las bases científicas que todo cirujano dentista debe conocer acerca de la implantología. Se compara la estructura del implante con el diente natural, adentrándose en la cicatrización ósea y en la inmunidad

Conceptos actuales en articulación temporomandibular. Artrocentesis: presentación de dos casos clínicos / Current concepts in temporomandibular joint. Arthrocentesis: presentation of two clinical cases

La artrocentesis es un método de tratamiento que permite llevar a cabo un lavado mecánico del compartimento superior de la articulación temporomandibular, que se presenta como una alternativa primaria en el tratamiento de los desarreglos internos. Ayuda a la liberación del disco en casos agudos y a la eliminación de toxinas que provocan el dolor. Sin embargo, en caso de que fracase la artrocentesis, se tendría que realizar una artroscopía o en su defecto una cirugía abierta

Ameloblastoma uniquístico: reporte de un caso / Unicystic ameloblastoma: report of a case

Se presenta un caso de un paciente del sexo femenino de 15 años de edad con una lesión radiológica en la región del tercer molar inferior, sin dolor, sin parestesia y sin deformación facial. La paciente no tenía antecedentes patológicos de importancia, a excepción de una amigdalectomía. La pacientes presentaba una lesión uniquística proveniente del tercer molar derecho y en la tomografía mostraba corticales bucal y lingual adelgazadas, preservando el borde inferior de la mandíbula, con una lesión de 35 mm de diámetro mayor. Se realizó biopsia diagnóstica, encontrándose un ameloblastoma uniquístico. El tratamiento fue enucleación y curetaje con colocación de placa de fijación rígida