Recent debate concerning the suitability of mortality profile analysis for identifying secondary product utilisation within archaeozoological assemblages has prompted the search for alternative methodologies. This research explores the potential of using weaning age to provide insight into herding strategies in ovicaprines, determined through the prevalence of developmental enamel defects. A histological methodology was developed, adapted to the specific nature of sheep molars through an understanding of formation processes and enamel structures. This established a relationship between weaning and developmental defects in modern sheep, revealed as distinct patterns in defect distribution within the enamel. Based on historical/archaeological data a weaning age model was developed for the North Atlantic region by which herding strategies could be recognised, specifically: mixed milk/meat subsistence, with an emphasis on milk (0-2 months) or on meat (2-4 months), and the optimisation of meat and/or wool (4-6 months). This methodology was then tested on archaeological material to interpret husbandry at Iron Age and Norse/Viking period sites. The results of this analysis showed that interpretations were in general agreement with those of mortality profile and correspondence analysis conducted as a methodological comparative. Some disparity, however, highlighted the ability of this new technique to provide more sensitivity in cases of mixed subsistence systems, possibly identifying the economic focus of husbandry, or where mortality profiles are confused. It was concluded that the study of weaning age has potential to provide valuable insight into ovicaprine husbandry in archaeological contexts, adding to the understanding of faunal assemblages, especially when supported with other evidence.

Abstract: Recent debate concerning the suitability of mortality profile analysis for identifying secondary product utilisation within archaeozoological assemblages has prompted the search for alternative methodologies. This research explores the potential of using weaning age to provide insight into herding strategies in ovicaprines, determined through the prevalence of developmental enamel defects. A histological methodology was developed, adapted to the specific nature of sheep molars through an understanding of formation processes and enamel structures. This established a relationship between weaning and developmental defects in modern sheep, revealed as distinct patterns in defect distribution within the enamel. Based on historical/archaeological data a weaning age model was developed for the North Atlantic region by which herding strategies could be recognised, specifically: mixed milk/meat subsistence, with an emphasis on milk (0-2 months) or on meat (2-4 months), and the optimisation of meat and/or wool (4-6 months). This methodology was then tested on archaeological material to interpret husbandry at Iron Age and Norse/Viking period sites. The results of this analysis showed that interpretations were in general agreement with those of mortality profile and correspondence analysis conducted as a methodological comparative. Some disparity, however, highlighted the ability of this new technique to provide more sensitivity in cases of mixed subsistence systems, possibly identifying the economic focus of husbandry, or where mortality profiles are confused. It was concluded that the study of weaning age has potential to provide valuable insight into ovicaprine husbandry in archaeological contexts, adding to the understanding of faunal assemblages, especially when supported with other evidence. / Recent debate concerning the suitability of mortality profile analysis for identifying secondary product utilisation within archaeozoological assemblages has prompted the search for alternative methodologies. This research explores the potential of using weaning age to provide insight into herding strategies in ovicaprines, determined through the prevalence of developmental enamel defects. A histological methodology was developed, adapted to the specific nature of sheep molars through an understanding of formation processes and enamel structures. This established a relationship between weaning and developmental defects in modern sheep, revealed as distinct patterns in defect distribution within the enamel. Based on historical/archaeological data a weaning age model was developed for the North Atlantic region by which herding strategies could be recognised, specifically: mixed milk/meat subsistence, with an emphasis on milk (0-2 months) or on meat (2-4 months), and the optimisation of meat and/or wool (4-6 months). This methodology was then tested on archaeological material to interpret husbandry at Iron Age and Norse/Viking period sites. The results of this analysis showed that interpretations were in general agreement with those of mortality profile and correspondence analysis conducted as a methodological comparative. Some disparity, however, highlighted the ability of this new technique to provide more sensitivity in cases of mixed subsistence systems, possibly identifying the economic focus of husbandry, or where mortality profiles are confused. It was concluded that the study of weaning age has potential to provide valuable insight into ovicaprine husbandry in archaeological contexts, adding to the understanding of faunal assemblages, especially when supported with other evidence.

published_or_final_version / Dentistry / Master / Master of Dental Surgery

O presente trabalho teve como objetivo avaliar a microdureza dentinária da região da furca de molares inferiores, assim como estudar, por meio da MEV, a morfologia da dentina nessa região. Utilizaram-se 10 espécimes, os quais tiveram a coroa seccionada transversalmente ao meio, sendo descartada a porção oclusal. As raízes mesial e distal foram cortadas próximas ao terço cervical, desprezando-se os terços médio e apical. O remanescente dental foi incluído em acrílico de rápida polimerização e cortado longitudinalmente ao meio, obtendo-se duas hemi-secções. Uma foi destinada ao estudo da morfologia, na qual observaram-se as características da dentina e o sentido dos canalículos dentinários. Na outra, realizou-se a análise da microdureza, por meio de aparelho de dureza Knoop, com carga de 10g por 15s. A área de furca foi estabelecida como sendo a região compreendida entre duas retas ortogonais traçadas a partir do ponto de máxima concavidade da superfície externa da bifurcação. A microdureza foi avaliada nas camadas de dentina superficial (próxima ao assoalho), média e interna (mais próxima à concavidade externa da furca), assim como nos três eixos, mesial (paralelo à reta traçada junto à mesial da furca), central (paralela à bissetriz entre as retas) e distal (paralela à reta traçada junto à distal). Realizaram-se cinco medidas para cada eixo, obtendo-se uma média por eixo. As mensurações foram submetidas à análise estatística (oneway ANOVA) ( &alpha;= 0,05). Os resultados mostraram não haver diferença significante (p>0,05) entre a dureza das porções mesial (46,5±6,4), central (47,3±8,1) e distal (49,7±6,5). Em relação às camadas, o teste de Tukey evidenciou diferença significante apenas entre as camadas interna (51,7±2,5) e externa (41,4±2,4) (p<0,05). As imagens da MEV mostraram que os canalículos dentinários assumem trajetória centrípeta em direção à porção interna. Os canalículos dentinários na camada externa apresentam-se amplos e com a luz bastante evidente. Na camada média os canalículos são mais atresiados, ao passo que na interna, a dentina assemelha-se à dentina esclerótica. Conclui-se que a microdureza dentinária na área de furca é uniforme nos 3 eixos. A camada interna é mais dura que a externa. A dentina da região de furca parece ser um tecido bastante mineralizado, tendendo a uma maior calcificação dos canalículos à medida que se aproxima da camada interna. / The aim of this study was to evaluate the dentin microhardness in furcation areas of mandibular molars and to study the dentin morphology in these regions by scanning electron microscopy (SEM). The crows of ten specimens were transversely sectioned and the occlusal portions were discarded. The mesial and distal roots were cut near to the cervical third ignoring the middle and apical thirds. The remaining teeth were included in rapid polymerization acrylic stubs and cut longitudinally resulting in two hemi-sections. One was designed to study the morphology in which was possible to observe characteristics of the dentin and dentinal tubules direction. The other one was used to perform analysis of the microhardness using a Knopp device with load of 10g/15s. The furcation areas were established as the regions between two orthogonal lines drawn from the point of maximum concavity of the outer surface of the bifurcation. Microhardness was measured in the superficial layers of dentin (next to the floor), middle and inner (closest to the concavity of the external furcation), as well as in the three axes: mesial (parallel to the straight line along the mesial furcation), central (parallel to the bisectrix between the lines) and distal (parallel to the line drawn along the distal). Five measurements were performed for each axis yielding an average in each one. The measurements were subjected to statistical analysis (one way - ANOVA) (&alpha; = 0.05). The results showed no significant difference (p> 0,05) between the microhardness of the mesial (46.5±6.4), central (47.3±8.1) and distal portions (49.7±6.5). In relation to the layers, the Tukey test showed significant differences only between the inner (51.7±2.5) and outer (41.4±2.4) layers (p <0.05). The SEM images showed that the dentinal tubules assumes centripetal trajectory toward the inner portion. These ones, in the outer layer, presents larger and more evident. In the middle layer are thinner and in the inner layer the dentin is similar to sclerotic dentin. In this study was possible to observe that the microhardness of dentin in the furcation areas is uniform across to the three axes. The inner layer is harder than the outer. The dentin of the furcation areas appears to be a very mineralized tissue having a bigger calcification as it approaches to the inner layer.

Caries of the pits and fissures of permanent teeth continues to be a problem for children. Newly erupted permanent molars are particularly at risk. Oral hygiene measures have been shown to be able to reduce the incidence of caries. The aim of this study was to compare the caries preventive effects of a professional tooth cleaning and oral health education programme (test) with a standard preventive programme (comparison), comprising selective fissure sealing and application of topical fluorides on newly erupted first permanent molars. School Dental Service clinics of the Health Department of Western Australia, in Perth, were assigned to test (4)or comparison (4) clinics. Schoolchildren, mean age 6.3 plus or minus 0.3 (s) yr with, sound, newly erupted first permanent molars were included in the study (n=404; 207 test; 197 control).Children were examined after twelve and twenty-four months by an examiner who was 'blind' to the test or control status of the children. After twelve months, 186 test and 163 control children were examined, and after twenty-four months, 179 test and 156 control children were examined. Three hundred and twenty children were examined in both years. After twenty-four months, 32 children in test and 31 children in control developed caries of the first permanent molars, the estimated risk ratio was 0.90 (95% CI 0.58, 1.41); and children in the test group had an average DFT score of 0.30 plus or minus 0.75 compared with 0.30 plus or minus 0.70 DFT in the control group (t-test, p=0.96). The results suggest that, after two years, there was no statistically significant difference between the caries preventive effects of a professional tooth cleaning and oral health education programme and a programme based on selective fissure sealing and application of topical fluorides.Baseline deciduous caries experience, presence of hypomineralised first ++ / permanent molars and frequency of toothbrushing were statistically significant factors in predicting molar caries. Using baseline deciduous caries experience as a screening criterion to predict permanent molar caries, sensitivity of 0.67 and specificity 0.61 were obtained at a cutpoint of 1 dmfs. Sensitivity and specificity values were maximised at 0.72 by using a combined baseline dmfs and hypomineralisation as screening criteria. Cost-effectiveness analysis indicated an incremental cost-effectiveness ratio of $40/child/year. The test programme was more costly and produced similar outcomes and does not warrant adoption on economic grounds.

Thesis (M.D.S.)--University of Hong Kong, 1992. / Also available in print.

Ill. mounted. Bibliography: 9.1-9.20.

Some mounted ill. Bibliography: leaves 191-226.

Purpose: This retrospective study was performed to assess the clinical and radiographic success rates of a non-vital formocresol and zinc oxide eugenol (ZOE) primary molar root canal therapy (RCT) technique. The effects of this treatment on the permanent successors and on exfoliation times were also investigated. Methods: The study included 161 patients with 211 primary molars treated by RCT by a single operator in a private pediatric dental office in the Toronto area. Results: A clinical success rate of 90.0% and a radiographic success rate of 77.3% were obtained. Enamel defects were found in 6.8% of permanent successors and in patients who were significantly younger at the time of root canal therapy treatment (p = .001). Treated molars exfoliated on average 5.8 months sooner than contralateral teeth (p<0.001). Conclusions: Formocresol and ZOE RCT is a viable treatment for necrotic primary molars and yielded very high clinical success rates with moderate radiographic success rates.

Purpose: This retrospective study was performed to assess the clinical and radiographic success rates of a non-vital formocresol and zinc oxide eugenol (ZOE) primary molar root canal therapy (RCT) technique. The effects of this treatment on the permanent successors and on exfoliation times were also investigated. Methods: The study included 161 patients with 211 primary molars treated by RCT by a single operator in a private pediatric dental office in the Toronto area. Results: A clinical success rate of 90.0% and a radiographic success rate of 77.3% were obtained. Enamel defects were found in 6.8% of permanent successors and in patients who were significantly younger at the time of root canal therapy treatment (p = .001). Treated molars exfoliated on average 5.8 months sooner than contralateral teeth (p<0.001). Conclusions: Formocresol and ZOE RCT is a viable treatment for necrotic primary molars and yielded very high clinical success rates with moderate radiographic success rates.