Annual tree-ring width of Southwestern conifers growing on dry sites exhibits sensitivity to variation in climatically created moisture stress. Douglas-fir, ponderosa pine, and pinyon in the eastern San Juan Basin in northwestern New Mexico and southwestern Colorado were sampled at four sites to investigate covariation of climate with intra-annual anatomy. The sites possessed characteristics that created different amounts of physiological stress in trees. Increment borer samples were glued into wooden mounts and machined to approximately 1.0 mm thickness by a special router-planer. All samples were crossdated by comparing climatically controlled synchronous patterns of ring widths. Moving slit X-ray densitometry (at Forintek Canada Corporation Western Forest Products Laboratory, Vancouver, British Columbia) objectively defined the earlywood zone (large, low density cells) and latewood zone (smaller, denser cells formed late in the growing season) in each ring. The densitometer measured eight parameters for each ring: ring, earlywood, and latewood width, minimum and maximum density, and mean ring, earlywood, and latewood density. Individual radial series were standardized (i.e, transformed to indices with 1.0 mean and homogeneous variance) by fitting curves and dividing annual values by the corresponding curve values. Density series proved more difficult to standardize than widths and usually correlated more poorly among individual radii of the same data data type. Statistical characteristics of site summary density chronologies differed from width chronologies. Response functions using monthly mean temperature and total precipitation showed climate influenced all data types. Low moisture stress increased ring, earlywood, and latewood width and ring, maximum, and latewood density. High moisture stress increased minimum and early— wood density. No width or density type consistently covaried more than any other with climate. Linkage of climatic variation with density parameters differed considerably from that reported in the literature for conifers growing in wetter, cooler climates. Southwestern conifers posed unique densitometric technical difficulties. Selection of sites that caused moderate physiological stress and samples with few missing rings proved critical. Acquisition of density data required much more time and effort than optical measurement of ring width, but yielded valuable intra—annual data. Intra—annual densitometric data hold great promise for reconstruction of seasonal paleoclimate.

This study was conducted to determine if either calcium intake or physical activity is related to bone mineral status in children and youth aged 10 to 15 years. Subjects (n = 30) with high, medium, and low bone mineral status were selected based on radius bone mineral index measurements from a sample of 108 subjects measured 9 to 12 months previously. Calcium intake was estimated from two 24-hour recalls and a food frequency questionnaire. Assessment of activity level was conducted by questionnaire. Single photon absorptiometry was used to obtain bone mineral content (g/cm) and bone mineral index (g/cm²) measurements for the radius and ulna at the midshaft and distal sites. Calcium intake and activity level were found to be similar among the bone mineral index groups. Using regression analysis, however, calcium intake was shown to be significantly related to midshaft ulna bone mineral index and activity level (sports participation) was found to be significantly related to distal ulna bone mineral index.

Recentemente, a osteoporose tem sido apontada como fator associado a manifestações bucais representadas pela perda óssea, especialmente na mandíbula. Entretanto, as técnicas de avaliação direta da densidade mineral óssea mandibular ainda não demonstraram boa precisão e acurácia. O presente trabalho teve como objetivo avaliar, por meio de um estudo descritivo-analítico, a possibilidade da utilização das radiografias panorâmicas, como um método capaz de expressar as alterações morfológicas da mandíbula decorrentes da idade e estabelecer um único índice quantitativo e qualitativo, para identificar os casos de osteopenia e osteoporose. A pesquisa ocorreu em mulheres em período de menopausa e pós-menopausa em tratamento odontológico nas clínicas odontológicas da faculdade de Odontologia da Universidade de São Paulo, no município de São Paulo SP. A confirmação do diagnóstico da osteoporose foi estabelecida mediante verificação dos relatórios da densitometria de antebraço obtidos, e comparados aos diagnósticos obtidos nas radiografias panorâmicas para o estabelecimento de um único índice quantitativo e qualitativo que considere a reabsorção e a baixa espessura da cortical na avaliação. O novo Índice Panorâmico Quantitativo e Quantitativo (IPQQ) foi determinado. A concordância entre as duas avaliações, calculada como razoável, reflete sensibilidade (moderada) de 56%, especificidade (satisfatória) de 82% e VPN (Valor Preditivo Negativo) de 68%. O IPQQ apresentou associação e concordância significativa com a densitometria (padrão ouro) podendo ser utilizado como teste para o rastreamento, porém cuidados ou algumas restrições deverão ser tomados em sua utilização, pois a intensidade de concordância razoável foi devida a uma moderada sensibilidade deste teste em relação ao padrão ouro. / Recently, osteoporosis has been implicated as being associated with oral manifestations represented by bone loss, especially in the jaw. However, the techniques of direct assessment of mandibular bone mineral density has not demonstrated good accuracy and precision. This study aimed to evaluate, through a descriptive and analytical study, the possibility of the use of panoramic radiographs as a method to express the morphological changes of the jaw due to age and to establish a single index quantitatively and qualitatively, to identify cases of osteopenia and osteoporosis. The research period occurred in women in menopause and postmenopause in dental treatment in dental clinics of the Faculty of Dentistry, University of São Paulo, in São Paulo - SP. Confirmation of the diagnosis of osteoporosis was established by scanning densitometry reports obtained from the forearm, and compared the diagnoses obtained from panoramic radiographs for the establishment of a single index that considers both quantitative and qualitative resorption and lower cortical thickness in the assessment. The new Quantitative and Quantitative Panoramic Index (QQPI) was determined. The agreement between the two assessments, calculated as reasonable, reflects sensitivity (moderate) 56%, specificity (satisfactory) to 82% and NPV (Negative Predictive Value) of 68%. The QQPI showed significant association and agreement with densitometry (gold standard) can be used as a test for the screening, but some restrictions or care should be taken into use, because the intensity of reasonable agreement was due to a moderate sensitivity of this test in compared to the gold standard.

Introduction: Unicompartmental knee replacements (UKRs) are an alternative to total knee replacements (TKRs) for treating isolated medial compartment knee osteoarthritis. However, revision rates are consistently higher than for TKR and UKRs are commonly revised for “unexplained” pain, a possible cause of which is elevated proximal tibial bone strain. The influence of implant design on this strain has not been previously investigated. Aims: The aims of this thesis are to determine the effect of medial UKR tibial component design on proximal tibial strain and ongoing pain. Methods: A retrospective clinical cohort study was performed comparing patient reported outcome and implant survival of a metal backed mobile bearing UKR implant (n=289) and an all-polyethylene (AP) fixed bearing UKR implant (n=111) with minimum 5 year follow up. A method of digital radiological densitometry, the greyscale ratio b (GSRb), was developed, validated and applied to plain radiographs to measure changes in bone density over 5 years in both the metal backed (n=173) and all-polyethylene (n=72) UKR patients. A finite element model (FEM) was validated against previous mechanical testing data and was used to analyse the effect of metal backing and implant thickness on proximal tibial cancellous bone strain in fixed bearing UKR implants. Results: There were no significant differences in patient reported outcomes between implants throughout follow up. Ten year all cause survival was 90.2 (95%CI 86-94) for the metal backed implant and 79.9 (60.7 to 99) for the all-polyethylene. Revision for unexplained pain was significantly greater in the AP implant where revisions were performed significantly earlier. Overall, the mean GSRb reduced following medial UKR with no difference between implants. In those patients where GSRb increased, patient reported outcomes were worse with an association with ongoing pain. A finite element model was successfully validated using acoustic emission and digital image correlation data. This model confirmed that the volume of cancellous bone exposed to compressive and tensile strains in excess of 3000 (pathological overloading) and 7000 (fracture) microstrain were higher in the AP implants, as were peak tensile and compressive strains. Varying polyethylene insert thickness did not affect these strain parameters in the metal backed implant, but varying polyethylene thickness in the AP implants had significant effects at all loads with elevated strains in thinner implants. Increasing the AP thickness to 10mm did not reduce strains to the levels found under metal backed implants, and imminent cancellous bone failure was implied when AP thickness was reduced to 6mm. Conclusion: UKRs with all-polyethylene tibial components are associated with greater proximal tibial strains than metal backed implants and this is exacerbated in thinner implants. The clinical consequences of this are uncertain. Medial UKR implantation does alter proximal tibial GSRb, though this is not uniform and is independent of implant type. When GSRb increases it is associated with ongoing pain.

We analyze data on bone mineral density (BMD) and age for white females age 20+ in the third National Health and Nutrition Examination Survey. For the sample the age of each individual is known, but some individuals did not have their BMD measured, mainly because they did not show up in the mobile examination centers. We have data from 35 counties, the small areas. We use two types of models to analyze the data. In the ignorable nonresponse model, BMD does not depend on whether an individual responds or not. In the nonignorable nonresponse model, BMD is related to whether he/she responds. We incorporate this relationship in our model by using a Bayesian approach. We further divide these two types of models into continuous and categorical data models. Our nonignorable nonresponse models have one important feature: They are ``close' to the ignorable nonresponse model thereby reducing the effects of the untestable assumptions so common in nonresponse models. In the continuous data models, because the age of all nonrespondents are known and there is a relation between BMD and age, age is used as a covariate. In the categorical data models BMD has three levels (normal, osteopenia, osteoporosis) and age has two levels (younger than 50 years, at least 50 years). Thus, age is a supplemental margin for the $2 imes 3$ categorical table. Our research on the categorical models is much deeper than on the continuous models. Our models are hierarchical, a feature that allows a ``borrowing of strength' across the counties. Individual inference for most of the counties is unreliable because there is large variation. This ``borrowing of strength' is therefore necessary because it permits a substantial reduction in variation. The joint posterior density of the parameters for each model is complex. Thus, we fit each model using Markov chain Monte Carlo methods to obtain samples from the posterior density. These samples are used to make inference about BMD and age, and the relation between BMD and age. For the continuous data models, we show that there is an important relation between BMD and age by using a deviance measure, and we show that the nonignorable nonresponse models are to be preferred. For the categorical data models, we are able to estimate the proportion of individuals in each BMD and age cell of the categorical table, and we can assess the relation between BMD and age using the Bayes factor. A sensitivity analysis shows that there are differences, typically small, in inference that permits different levels of association between BMD and age. A simulation study shows that there is not much difference in inference between the ignorable nonresponse models and the nonignorable nonresponse models. As expected, BMD depends on age and this inference can be obtained for some small counties. For the data we use, there are virtually no young individuals with osteoporosis. The nonignorable nonresponse models generalize the ignorable nonresponse models, and therefore, allow broader inference.

Recentemente, a osteoporose tem sido apontada como fator associado a manifestações bucais representadas pela perda óssea, especialmente na mandíbula. Entretanto, as técnicas de avaliação direta da densidade mineral óssea mandibular ainda não demonstraram boa precisão e acurácia. O presente trabalho teve como objetivo avaliar, por meio de um estudo descritivo-analítico, a possibilidade da utilização das radiografias panorâmicas, como um método capaz de expressar as alterações morfológicas da mandíbula decorrentes da idade e estabelecer um único índice quantitativo e qualitativo, para identificar os casos de osteopenia e osteoporose. A pesquisa ocorreu em mulheres em período de menopausa e pós-menopausa em tratamento odontológico nas clínicas odontológicas da faculdade de Odontologia da Universidade de São Paulo, no município de São Paulo SP. A confirmação do diagnóstico da osteoporose foi estabelecida mediante verificação dos relatórios da densitometria de antebraço obtidos, e comparados aos diagnósticos obtidos nas radiografias panorâmicas para o estabelecimento de um único índice quantitativo e qualitativo que considere a reabsorção e a baixa espessura da cortical na avaliação. O novo Índice Panorâmico Quantitativo e Quantitativo (IPQQ) foi determinado. A concordância entre as duas avaliações, calculada como razoável, reflete sensibilidade (moderada) de 56%, especificidade (satisfatória) de 82% e VPN (Valor Preditivo Negativo) de 68%. O IPQQ apresentou associação e concordância significativa com a densitometria (padrão ouro) podendo ser utilizado como teste para o rastreamento, porém cuidados ou algumas restrições deverão ser tomados em sua utilização, pois a intensidade de concordância razoável foi devida a uma moderada sensibilidade deste teste em relação ao padrão ouro. / Recently, osteoporosis has been implicated as being associated with oral manifestations represented by bone loss, especially in the jaw. However, the techniques of direct assessment of mandibular bone mineral density has not demonstrated good accuracy and precision. This study aimed to evaluate, through a descriptive and analytical study, the possibility of the use of panoramic radiographs as a method to express the morphological changes of the jaw due to age and to establish a single index quantitatively and qualitatively, to identify cases of osteopenia and osteoporosis. The research period occurred in women in menopause and postmenopause in dental treatment in dental clinics of the Faculty of Dentistry, University of São Paulo, in São Paulo - SP. Confirmation of the diagnosis of osteoporosis was established by scanning densitometry reports obtained from the forearm, and compared the diagnoses obtained from panoramic radiographs for the establishment of a single index that considers both quantitative and qualitative resorption and lower cortical thickness in the assessment. The new Quantitative and Quantitative Panoramic Index (QQPI) was determined. The agreement between the two assessments, calculated as reasonable, reflects sensitivity (moderate) 56%, specificity (satisfactory) to 82% and NPV (Negative Predictive Value) of 68%. The QQPI showed significant association and agreement with densitometry (gold standard) can be used as a test for the screening, but some restrictions or care should be taken into use, because the intensity of reasonable agreement was due to a moderate sensitivity of this test in compared to the gold standard.

These PhD projects represent secondary analyses of data from the ongoing Iowa Fluoride Study (IFS)/Iowa Bone Development Study (IBDS). The aim of this dissertation was to explore the associations between period-specific and cumulative fluoride intakes from birth to age 17, and from birth to age 19 years and bone measures of participants. Also, this dissertation looked into the associations between the clinical presence of dental fluorosis and bone outcomes. Participants have been participating in the IBDS that grew out of the IFS, which is a longitudinal investigation of dietary and non-dietary fluoride exposures, dental fluorosis and dental caries. IFS participants were recruited during 1992-95 from 8 hospital postpartum wards in Iowa, and detailed questionnaires were sent every 1.5-6 months. Data on intakes from water, other beverages, selected foods, dietary fluoride supplements and dentifrice were collected from the questionnaires, and, in combination with water and beverage fluoride levels, combined fluoride was estimated. For the first dissertation project, the association between fluoride intake and peripheral quantitative computed tomography (pQCT)-derived bone outcomes at age 17 were assessed. Participants underwent pQCT of the radius and tibia (XCT-2000) at age 17 years. pQCT results of trabecular bone mineral density (BMD) and bone mineral content (BMC), cortical BMD and BMC, and compression and torsion strength were related to fluoride intake through bivariate and multivariable analyses, adjusting for height, weight, years since peak height velocity, average daily time spent in moderate-to-vigorous intensity physical activity, daily calcium intake, and daily protein intake. P-values < 0.01 were considered statistically significant rather than p< 0.05 due to multiple hypothesis tests. The mean daily fluoride intake estimated by area-under-the-curve (AUC) from birth to 17 years was 0.79 mg (SD = 0.32) for males and 0.70 mg (SD = 0.25) for females. Spearman correlation coefficients between daily fluoride intake and pQCT bone measures were weak (for females r= -0.01 to 0.15 for radius bone outcomes and -0.001 to 0.23 for tibia bone outcomes; for males r= 0.03 to 0.24 for radius bone outcomes and -0.008 to 0.27 for tibia bone outcomes). In sex-specific linear regression analyses for females, partially-adjusted for height, weight, and years since peak height velocity, statistically significant negative associations were detected between all radial bone outcomes and period-specific fluoride intake from 0-8.5 years. Significant positive associations were detected for females between period-specific fluoride intakes from 14-17 years and all tibia bone outcomes, and between period-specific fluoride intakes from 14-17 years and all radius and tibia bone outcomes for males. In the fully-adjusted models, which also included physical activity, protein intake and calcium intake, statistically suggestive negative associations were detected for females during the early fluoride intake period from 0 to 8.5 years and radial cortical bone content and torsion bone strength. A statistically suggestive positive association was found between period-specific fluoride intake from 8.5 to 14 years and torsion bone strength (pSSI) (p< 0.05) for females. For males, statistically significant positive associations were detected between fluoride intake for the period from 14 to 17 years and cortical content and torsion strength (pSSI) at the 0.01 level. The second project examined the associations between period-specific and cumulative fluoride intakes from birth to age 19 years and MDCT-derived bone outcomes at age 19. Age 19 MDCT-derived trabecular and cortical bone micro-architecture scans were acquired at the University of Iowa Comprehensive Lung Imaging Center. MDCT results of the trabecular (volumetric bone mineral density (vBMD), transpose bone mineral density (tBMD), plate trabecula bone mineral density (pBMD), plate width (TS-PW), trabecular thickness (Tb.Th), trabecular spacing (Tb.Sp), trabecular network area (Tb.NA)) and cortical (cortical bone porosity (Cb.Poro), cortical thickness (Cb.Th)) bone were related to fluoride intake through bivariate and multivariable analyses, adjusting for height, weight, years since peak height velocity, average daily time spent in moderate-to-vigorous intensity physical activity, Healthy Eating Index (HEI) score, calcium intake and protein intake. P-values < 0.01 were considered statistically significant rather than p< 0.05 due to multiple hypothesis tests. The mean daily fluoride intake estimated by area-under-the-curve (AUC) from birth to 19 years was 0.81 mg (SD = 0.33) for males and 0.69 mg (SD = 0.27) for females. Spearman correlation coefficients between daily fluoride intake and MDCT bone measures were weak (for females r= -0.001 to 0.20 for trabecular bone outcomes and -0.01 to 0.02 for cortical bone outcomes; for males r= -0.003 to 0.16 for trabecular bone outcomes and -0.09 to -0.02 for cortical bone outcomes). In sex-specific partially-adjusted regression analysis adjusted for height, weight, and years since peak height velocity, no statistically significant associations were found for females or males. In the fully-adjusted models, which also included physical activity, HEI score, and protein and calcium intakes, no statistically significant associations were found for either females or males. The third project explored the associations between dental fluorosis score at age 8 and DXA-derived bone outcomes at age 5. DXA bone assessments of the whole body, proximal femur (hip), and lumbar spine were performed at The University of Iowa in the Clinical Research Center (Hologic QDR-2000 DXA unit). The dental fluorosis score was defined as the proportion of zones with definitive or severe fluorosis per person. In the unadjusted associations between bone outcomes and dental fluorosis score, no statistically significant associations were detected for females at the 0.05 level. For males, a statistically significant negative association was found between hip BMD and dental fluorosis score. Sex-specific partial correlation coefficients were estimated between DXA-derived bone outcomes and dental fluorosis score adjusted for height, weight, physical activity, calcium intake and fluoride intake. No statistically significant associations were found for females. For males, a statistically significant negative association was detected between dental fluorosis score and hip BMD. The findings of this dissertation show that life-long intakes from combined sources for adolescents and young adults living in fluoridated areas in the United States were weakly associated with bone measures at age 17 and 19. Furthermore, it was shown that bone outcomes can’t be predicted by the score of dental fluorosis. Fluoride is a mineral that plays an important role in the mineralization of bone and teeth, as well as in dental caries prevention. Numerous professional health organizations endorse the adjusted fluoridation of public water supplies for caries prevention. Results from this dissertation will also help in supporting additional efforts to promote water fluoridation and expand its use, as this dissertation’s outcomes did not demonstrate adverse outcomes related to bone.

High impact loading activities such as jumping, performed during childhood is advocated as one preventive method for increasing peak bone mass. Thus, we conducted a randomized intervention to examine the effect of high impact loading on bone mass in 34 pre-pubescent boys and girl over a seven month period. Participants meeting all inclusion criteria were randomized into either a jumping (n=18) or stretching group (n=16), both of which exercised three times per week for 15 minutes. The jumping group completed 100 jumps off 24-inch boxes each session, while the stretching group performed low impact flexibility exercises. Attrition was 85% (6 drop outs), with an overall attendance rate of 95%. Bone area and bone mineral content (BMC) was assessed using dual energy x-ray absorptiometery (Ho logic QDR 1000/W) for the left hip (femoral neck, greater trochanter, total hip), and lumbar spine (L[subscript 2-4]). Other measures were body composition (Lang skinfold calipers); physical activity (self-report questionnaire); and calcium intake (food survey). All measurements were assessed at baseline and 7 months. Significance is denoted as p<.05. Analysis of variance (ANOVA) revealed no baseline difference between groups for age, height, weight, body fat, physical activity, or calcium intake (p>.05); however, gender differences were found for FN BMC at baseline (p<.05). Repeated measures ANOVA identified significant group differences for FN BMC (p=.015), with a trend for significance for FN area (p=.055). No significant differences in BMC or bone area were found at all other skeletal sites (p>.05). No group by gender interactions were found at baseline or at the completion of the seven month intervention. No significant differences between groups were identified for body composition, physical activity, or calcium intake in repeated measures ANOVA analyses (p>.05). In conclusion, 100 jumps performed 3 times per week at approximately 8x body weight were sufficient to stimulate an osteogenic response at the femoral neck in pre-pubescent boys and girls. Implementing jumping exercises into regular physical activity programs during pre-pubescent growing years may increase peak bone mass and potentially reduce the onset of osteoporosis. / Graduation date: 1999

Thesis (M.S.)--Oregon State University, 2004. / Includes bibliographical references.

The development of a cost-effective multiphase flow meter to determine the individual phase flow rates of oil, water and gas was investigated through the exploitation of a single clamp-on gamma densitometer and signal processing techniques. A fast-sampling (250 Hz) gamma densitometer was installed at the top of the 10.5 m high, 108.2 mm internal diameter, stainless steel catenary riser in the Cranfield University multiphase flow test facility. Gamma radiation attenuation data was collected for two photon energy ranges of the caesium-137 radioisotope based densitometer for a range of air, water and oil flow mixtures, spanning the facility’s delivery range. Signal analysis of the gamma densitometer data revealed the presence of quasi-periodic waveforms in the time-varying multiphase flow densities and discriminatory correlations between statistical features of the gamma count data and key multiphase flow parameters. The development of a mechanistic approach to infer the multiphase flow rates from the gamma attenuation information was investigated. A model for the determination of the individual phase flow rates was proposed based on the gamma attenuation levels; while quasi-periodic waveforms identified in the multiphase fluid density were observed to exhibit a strong correlation with the gas and liquid superficial phase velocity parameters at fixed water cuts. Analysis of the use of pattern recognition techniques to correlate the gamma densitometer data with the individual phase superficial velocities and the water cut was undertaken. Two neural network models were developed for comparison: a single multilayer-perceptron and a multilayer hierarchical flow regime dependent model. The pattern recognition systems were trained to map the temporal fluctuations in the multiphase mixture density with the individual phase flow rates using statistical features extracted from the gamma count signals as their inputs. Initial results yielded individual phase flow rate predictions to within ±10% based on flow regime specific correlations.