Estudo dos efeitos da expansão rápida de maxila em pacientes com mordida cruzada posterior tratados com aparelhos de Haas e de Hyrax

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos da expansão rápida da maxila com aparelho expansor tipo Hyrax: avaliação cefalométrica póstero-anterior e em modelos de estudo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modificação de forma e dimensões dos arcos superior e inferior obtidas em modelos de estudo após expansão rápida da maxila com o aparelho hyrax

The aim of an orthodontic treatment is the achievement of a balanced, esthetic and, most of all, stable, intra and inter arches relationship. A common problem observed in occlusion is posterior crossbite and atresic maxilla. This problem may be treated by slow expansion, rapid expansion or surgically assisted expansion. For the present study cast models of 14 children between 7 and 11 years old were evaluated. There were 7 male and 7 female subjects that presented posterior crossbite and needed rapid maxillary expansion. The Hyrax appliance performed the therapy for correction of this transversal alteration, which is a common possibility in the treatment of this malocclusion. It was observed that the distance between the upper first molars and upper cuspids increased significantly; the length of the upper arch decreased and its perimeter increased significantly. At the lower arch there were no dimensional changes.

Vertical growth control during maxillary expansion using a bonded Hyrax appliance

INTRODUCTION: Rapid maxillary expansion (RME) for the treatment of maxillary deficiency and posterior crossbite may induce changes in the vertical dimension. Expanders with occlusal splints have been developed to minimize unwanted vertical effects. OBJECTIVE: This preliminary study used cephalometri radiographs to evaluate the vertical effects of RME using a Hyrax appliance in children with maxillary deficiency. METHOD: Twenty-six patients (11 boys; mean age = 8 years and 5 months) with maxillary deficiency and posterior crossbite were treated using a Hyrax appliance with an acrylic occlusal splint. Radiographs and cephalometric studies were performed before the beginning of the treatment (T1) and after RME active time (T2), at a mean interval of 7 months. Results were compared with normative values. RESULTS AND CONCLUSIONS: At the end of treatment, there were no statistically significant changes, and measurements were similar to the normative values. Data showed that there were no significant effects on vertical growth, which suggests that appliances with occlusal splints may be used to correct transverse deficiencies regardless of the patient's growth pattern.

Early and Middle Holocene Hunter-Gatherer Occupations in Western Amazonia: The Hidden Shell Middens

We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region’s past and offers a new context within which the late Holocene “Earthmovers” of the Llanos de Moxos could have emerged.

Zur Anatomie des Darmrohres und des Urogenitalsystemes von Hyrax.

Thesis (doctoral)--Konigl. Universitat Breslau.

'Nothing exists for one cause' : putting biology back into evolution

The opening phrase of the title is from Charles Darwin’s notebooks (Schweber 1977). It is a double reminder, firstly that mainstream evolutionary theory is not just about describing nature but is particularly looking for mechanisms or ‘causes’, and secondly, that there will usually be several causes affecting any particular outcome. The second part of the title is our concern at the almost universal rejection of the idea that biological mechanisms are sufficient for macroevolutionary changes, thus rejecting a cornerstone of Darwinian evolutionary theory. Our primary aim here is to consider ways of making it easier to develop and to test hypotheses about evolution. Formalizing hypotheses can help generate tests. In an absolute sense, some of the discussion by scientists about evolution is little better than the lack of reasoning used by those advocating intelligent design. Our discussion here is in a Popperian framework where science is defined by that area of study where it is possible, in principle, to find evidence against hypotheses – they are in principle falsifiable. However, with time, the boundaries of science keep expanding. In the past, some aspects of evolution were outside the current boundaries of falsifiable science, but increasingly new techniques and ideas are expanding the boundaries of science and it is appropriate to re-examine some topics. It often appears that over the last few decades there has been an increasingly strong assumption to look first (and only) for a physical cause. This decision is virtually never formally discussed, just an assumption is made that some physical factor ‘drives’ evolution. It is necessary to examine our assumptions much more carefully. What is meant by physical factors ‘driving’ evolution, or what is an ‘explosive radiation’. Our discussion focuses on two of the six mass extinctions, the fifth being events in the Late Cretaceous, and the sixth starting at least 50,000 years ago (and is ongoing). Cretaceous/Tertiary boundary; the rise of birds and mammals. We have had a long-term interest (Cooper and Penny 1997) in designing tests to help evaluate whether the processes of microevolution are sufficient to explain macroevolution. The real challenge is to formulate hypotheses in a testable way. For example the numbers of lineages of birds and mammals that survive from the Cretaceous to the present is one test. Our first estimate was 22 for birds, and current work is tending to increase this value. This still does not consider lineages that survived into the Tertiary, and then went extinct later. Our initial suggestion was probably too narrow in that it lumped four models from Penny and Phillips (2004) into one model. This reduction is too simplistic in that we need to know about survival and ecological and morphological divergences during the Late Cretaceous, and whether Crown groups of avian or mammalian orders may have existed back into the Cretaceous. More recently (Penny and Phillips 2004) we have formalized hypotheses about dinosaurs and pterosaurs, with the prediction that interactions between mammals (and groundfeeding birds) and dinosaurs would be most likely to affect the smallest dinosaurs, and similarly interactions between birds and pterosaurs would particularly affect the smaller pterosaurs. There is now evidence for both classes of interactions, with the smallest dinosaurs and pterosaurs declining first, as predicted. Thus, testable models are now possible. Mass extinction number six: human impacts. On a broad scale, there is a good correlation between time of human arrival, and increased extinctions (Hurles et al. 2003; Martin 2005; Figure 1). However, it is necessary to distinguish different time scales (Penny 2005) and on a finer scale there are still large numbers of possibilities. In Hurles et al. (2003) we mentioned habitat modification (including the use of Geogenes III July 2006 31 fire), introduced plants and animals (including kiore) in addition to direct predation (the ‘overkill’ hypothesis). We need also to consider prey switching that occurs in early human societies, as evidenced by the results of Wragg (1995) on the middens of different ages on Henderson Island in the Pitcairn group. In addition, the presence of human-wary or humanadapted animals will affect the distribution in the subfossil record. A better understanding of human impacts world-wide, in conjunction with pre-scientific knowledge will make it easier to discuss the issues by removing ‘blame’. While continued spontaneous generation was accepted universally, there was the expectation that animals continued to reappear. New Zealand is one of the very best locations in the world to study many of these issues. Apart from the marine fossil record, some human impact events are extremely recent and the remains less disrupted by time.

Broughton Archipelago Clam Terrace Survey : final report

During a 1995 aerial video survey of the coastline of Johnstone Strait, an unusual shoreline feature was noted and termed “clam terraces” (inset) because of the terrace-type morphology and the apparent association with high clam productivity on the sandflats. Typical alongshore lengths of the terrace ridges are 20-50m, and across-shore widths are typically 20-40m. An area with an especially high density of clam terraces was noted in the Broughton Archipelago, between Broughton and Gilford Islands of southeastern Queen Charlotte Strait. Clam terraces in this area were inventoried from the aerial video imagery to quantify their distribution. The terraces accounted for over 14 km of shoreline and 365 clam terraces were documented. A three-day field survey by a coastal geomorphologist, archeologist and marine biologist was conducted to document the features and determine their origin. Nine clam terraces were surveyed. The field observations confirmed that: the ridges are comprised of boulder/cobblesized material, ridge crests are typically in the range of 1-1.5m above chart datum, sandflats are comprised almost entirely of shell fragments (barnacles and clams) and sandflats have very high shellfish production. There are an abundance of shell middens in the area (over 175) suggesting that the shellfish associated with the terraces were an important food source of aboriginal peoples. The origin of the ridges is unknown; they appear to be a relict feature in that they are not actively being modified by present-day processes. The ridges may be a relict sea-ice feature, although the mechanics of ridge formation is uncertain. Sand accumulates behind the ridge because the supply rate of the shell fragments exceeds the dispersal rate in these low energy environments. The high density areas of clam terraces correspond to high density areas of shell middens, and it is probable that the clam terraces were subjected to some degree of modification by aboriginal shellfish gatherers over the thousands of years of occupation in the region. (Document contains 39 pages)

The History of Oyster Farming in Australia

Aboriginal Australians consumed oysters before settlement by Europeans as shown by the large number of kitchen middens along Australia's coast. Flat oysters, Ostrea angasi, were consumed in southeastern Australia, whereas both flat and Sydney rock oysters, Saccostrea glomerata, are found in kitchen middens in southern New South Wales (NSW), but only Sydney rock oysters are found in northern NSW and southern Queensland. Oyster fisheries began with the exploitation of dredge beds, for the use of oyster shell for lime production and oyster meat for consumption. These natural oyster beds were nealy all exhausted by the late 1800's, and they have not recovered. Oyster farming, one of the oldest aquaculture industries in Australia, began as the oyster fisheries declined in the late 1800's. Early attempts at farming flat oysters in Tasmania, Victoria, and South Australia, which started in the 1880's, were abandoned in the 1890's. However, a thriving Sydney rock oyster industry developed from primitive beginnings in NSW in the 1870's. Sydney rock oysters are farmed in NSW, southern Queensland, and at Albany, Western Australia (WA). Pacific oysters, Crassostrea gigas, are produced in Tasmania, South Australia, and Port Stephens, NSW. FLant oysters currently are farmed only in NSW, and there is also some small-scale harvesting of tropical species, the coarl rock or milky oyster, S. cucullata, and th black-lip oyster, Striostrea mytiloides, in northern Queensland. Despite intra- and interstate rivalries, oyster farmers are gradually realizing that they are all part of one industry, and this is reflected by the establishment of the national Australian Shellfish Quality Assuarance Program and the transfer of farming technology between states. Australia's oyster harvests have remained relatively stable since Sydney rock oyster production peaked in the mid 1970's at 13 million dozen. By the end of the 1990's this had stabilized at around 8 million dozen, and Pacific oyster production reached a total of 6.5 million dozen from Tasmania, South Australia, and Port Stephens, a total of 14.5 million dozen oysters for the whole country. This small increase in production during a time of substantial human population growth shows a smaller per capita consumption and a declining use of oysters as a "side-dish."

A tentative determination of upwelling influence on the paleo-surficial marine water reservoir effect in southeastern Brazil.

Previous work has suggested that seasonal and inter-annual upwelling of deep, cold, radiocarbon depleted waters from the South Atlantic has caused variations in the reservoir effect (R) through time along the southern coast of Brazil. This work aims to examine the possible upwelling influence on the paleo-reservoir age of Brazilian surficial coastal waters based on paired terrestrial/marine samples obtained from archaeological remains. On the Brazilian coast there are hundreds of shell-middens built up by an ancient culture that lived between 6500 to 1500 years ago, but there are few located on open coast with a known upwelling influence. Three archaeological sites located in a large headland in Arraial do Cabo and Ilha de Cabo Frio, southeastern coast of Brazil with open ocean conditions and a well-known strong and large upwelling of the Malvinas/Falkland current were chosen for this study. The 14C age differences between carbonized seed and marine samples varied from 281 ± 44 to 1083 ± 51 14C yr. There are also significant age differences between carbonized seed samples (977 14C yr) and marine samples (200 and 228 14C yr) from the same archaeological layer that cannot be explained by a reservoir effect or an old-wood effect for charcoal. Therefore the present data from the southeastern Brazilian coast are inconclusive for identifying an upwelling effect on R. To do so it would be necessary to more precisely define the present-pre-bomb R in upwelling regions and to analyze paired marine/terrestrial samples that are contemporaneous beyond doubt.

Doonloughan: a seasonal settlement site on the Connemara coast

A series of shell middens and miscellaneous habitation sites, located in a dune
system in west County Galway, have been exposed and are slowly disappearing
through wind, wave and surface erosion. In 1992 a project was initiated to
record, sample and date some of these sites and the radiocarbon results
demonstrated that activity in the area spanned the Early Bronze Age through to
the Iron Age and into the early and post medieval periods. This preliminary
fieldwork was succeeded by the excavation of three of the better-preserved sites; a Bronze Age midden in 1994 and two early medieval sites (the subject of this paper), in 1997. The medieval sites dated to the late-seventh to ninth century adand were represented by a sub-circular stone hut with a hearth and the charred remains of a more ephemeral wooden tent-like structure. The discovery of a bronze penannular brooch of ninth/tenth century date at the latter site wouldsuggest that the settlements are not the remains of transient, impoverishedpeoples of the lower classes of society, eking out a living along the coast. The calcareous sands ensured good preservation of organic remains*fish and mammal bones, charred cereal grains, seeds and seaweed, and marine molluscs. Analyses of these indicated exploitation of marine resources but, otherwise, were comparable with the diet and economy represented by assemblages from established contemporary site types of the period. Unlike raths, cranno´gs and monastic settlements, however, the volume of material represented at the Galway sites was slight, despite the excellent preservation conditions. A range of seasonal indicators also suggested temporary habitation: probable latespring/summer occupation of the stone hut site and autumnal occupancy of the second, less substantial site. It is suggested that the machair plain, beside which the dunes are located, was most probably the attraction for settlers to the area and was exploited as an alternative pasture for the seasonal grazing of livestock.
*

The Klondike goldfields and Pleistocene environments of Beringia

The Klondike goldfields of Yukon, Canada, contain a key record of Pleistocene Beringia, the region of Alaska, Siberia, and Yukon that remained largely unglaciated during the late Cenozoic. A concentration of mining exposures, with relict permafrost that is locally more than 700,000 years old, provides exceptional preservation of paleoenvironmental archives and a new perspective on the nature of paleoenvironments during the Pleistocene. A critical feature is the stratigraphic association of distal tephra beds with these paleoenvironmental archives, which facilitates their regional correlation and, in many cases, provides independent ages for the paleoenvironmental assemblages. Paleoenvironmental analyses of fossil arctic ground-squirrel middens and buried vegetation indicate the presence of cryoxerophilous ("steppe-tundra") vegetation growing on well-drained substrates with deep active layers (seasonal thaw depths) during cold intervals of the Pleistocene. Studies of full-glacial paleosols and cryostratigraphic relations of associated ground ice indicate the importance of active loess deposition and surface vegetation cover in maintaining the functionally distinct mammoth-steppe biome, which supported grazing mega-fauna populations, including mammoth, horse, and bison.

Inland shell midden site-formation:Investigation into a late Pleistocene to early Holocene midden from Trang An, Northern Vietnam

Over the course of the past two decades there has been growing research interest in the site formation processes of shell middens. This stands along-side and is being used to inform cultural, dietary and palaeo-environmental reconstructions. Just as midden site formation processes have turned out to be many and varied, however, the kinds of shell-bearing sites that past human communities created are likely to have been no less diverse. Subsuming such sites under a single category - shell middens - normalises that variation and may lead to the misinterpretation of site function. The greater part of research in this field also continues to focus on coastal shell middens; comparatively little attention has been paid to middens containing freshwater and especially terrestrial molluscs from hinterland locations. As a result, much of the current understanding about shell-midden sites carries a spatial as well as a functional bias. This paper hopes to contribute towards discussion on both fronts. It presents a detailed examination of the formation processes that went into the creation of a land snail-dominated late- to post-glacial midden from northern Vietnam, and considers the role that it may have played in the early settlement of this area. The data presented comes from ongoing archaeological excavations at Hang Boi, a cave located in the sub-coastal karstic uplands of Trang An park, in the Vietnamese Province of Ninh Binh. (C) 2010 Elsevier Ltd and INQUA. All rights reserved.

Évaluation des effets de l’expansion palatine rapide assistée chirurgicalement (EPRAC) sur les voies aériennes supérieures à l’aide de la tomodensitométrie à faisceau conique

Introduction : L’expansion palatine rapide assistée chirurgicalement (EPRAC) est une option de traitement privilégiée chez les patients ayant atteint la maturité squelettique et présentant une déficience transverse du maxillaire. L’effet bénéfique de l’EPRAC sur la fonction respiratoire est régulièrement mentionné, toutefois, encore peu d’études ont évalué son impact sur les voies aériennes supérieures. L’objectif de cette étude clinique prospective comparative consistait à évaluer les effets tridimensionnels de l’EPRAC sur la cavité nasale, le nasopharynx et l’oropharynx à l’aide de la tomodensitométrie. Méthodologie : L’échantillon était constitué de 14 patients (5 hommes, 9 femmes) dont l’âge moyen était de 23,0 ± 1,9 ans (16 ans 4 mois à 39 ans 7 mois). Tous ont été traités avec un appareil d’expansion de type Hyrax collé et l’expansion moyenne a été de 9,82 mm (7,5 - 12,0 mm). Tous ont eu une période de contention d’une année avant le début de tout autre traitement orthodontique. Une évaluation par tomodensitométrie volumique à faisceau conique a été réalisée aux temps T0 (initial), T1 (6 mois post-expansion) et T2 (1an post-expansion) et le volume des fosses nasales, du nasopharynx et de l’oropharynx ainsi que les dimensions de la zone de constriction maximale de l’oropharynx ont été mesurés sur les volumes tridimensionnels obtenus. Résultats : Les résultats radiologiques ont démontré une augmentation significative du volume des fosses nasales et du nasopharynx ainsi qu’une augmentation de la zone de constriction maximale de l’oropharynx à 6 mois post-expansion. Par la suite, une portion du gain enregistré pour ces trois paramètres était perdue à un an post-EPRAC sans toutefois retourner aux valeurs initiales. Aucun effet significatif sur le volume de l’oropharynx n’a été observé. De plus, aucune corrélation significative entre la quantité d’expansion réalisée et l’ensemble des données radiologiques n’a été observée. L’analyse de la corrélation intra-classe a démontré une excellente fiabilité intra-examinateur. Conclusions : L’EPRAC entraîne un changement significatif du volume de la cavité nasale et du nasopharynx. L’EPRAC ne modifie pas le volume de l’oropharynx, par contre, un effet significatif sur la zone de constriction maximale de l’oropharynx est noté. Les effets observés n’ont pas de corrélation avec le montant d’activation de la vis d’expansion.