Thesis (Ph. D.)--Michigan State University, 2007. / Includes bibliographical references (leaves 143-154). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

OBJECTIVE: To compare skeletal maturation of female and male subjects from historic samples to present day subjects by assessing Fishman’s Skeletal Maturity Index (SMI). Present day eating habits and lifestyle have been suggested as factors in accelerating pubertal maturation seen within the last century. Consequently, Body Mass Index (BMI) as well as BMI percentile were evaluated to determine whether it is associated with significant differences in skeletal maturation patterns. METHODS: This pilot study included hand-wrist films from 92 subjects from the Burlington and Forsyth longitudinal growth studies (1959-1970) and 146 patients currently enrolled in the Orthodontic department of the Boston University Henry M. Goldman School of Dental Medicine (BUGSDM). The age of the subjects ranged between 7 and 16 years. SMI stage was determined and BMI and BMI percentile were calculated for each subject. RESULTS: The mean chronologic ages of all the SMI stages were not different in males or females when comparing the historic sample to the present sample except for the mean ages at SMI stage 7 and 11 for females and SMI stage 5 for males. Females in the present sample reached SMI stages 7 and 11 significantly earlier: 11.6 versus 13.3 years for SMI 7 (p<0.001) and 15.6 vs. 16.0 for SMI 11 (p<0.05). Males in the present sample also reached SMI 5 significantly earlier: 12.5 vs 13.8 years (p<0.05). It was also seen that present day females at SMI stage 11 not only matured earlier, but also had significantly higher mean BMI and mean BMI percentile than the females at the same stage in the historic sample. This suggests that BMI may be associated with acceleration of maturation among females at SMI stage 11 (p<0.05). CONCLUSIONS: In both male and female subjects, there are differences between past and present populations at certain SMI stages. This evidence suggests that patterns of skeletal maturation may have changed and BMI may be associated with such changes. The differences in skeletal maturation between the two groups may also be a result of the different distribution of race in each group. In the current study, the historic sample consists of only Caucasian subjects whereas the present sample consists of subjects from many different backgrounds. As a result, effects of racial variations could have additionally played a role in the changes seen in skeletal maturation patterns. Increasing our sample size and controlling for race may help further elucidate these changes and determine if this transition towards earlier maturation is in fact due to increasing BMIs.

Thesis (Ph.D.)--McMaster University, 2006. / Supervisor: Shelley R. Saunders. Includes bibliographical references (leaves 285-322).

Thesis (M.S.)--Brock University, 2007. / Includes bibliographical references (leaves 123-135). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (M.S.)--University of Michigan, 1967.

Thesis (M.S.)--University of Michigan, 1967.

Bone age assessment is a method of assigning a level of biological maturity to a child. It is usually performed either by comparing an x-ray of a child's left hand and wrist with an atlas of known bones, or by analysing specific features of bones such as ratios of width to height, or the degree of overlap with other bones. Both methods of assessment are labour intensive and prone to both inter- and intra-observer variability. This is motivation for developing a computerised method of bone age assessment. The majority of research and development on computerised bone age assessment has focussed on analysing the bones of the hand. The wrist bones, especially the carpal bones, have received far less attention and have only been analysed in young children in which there is clear separation of the bones. An argument is presented that the evidence for excluding the carpal bones from computerised bone age assessment is weak and that research is required to identify the role of carpal bones in the computerised assessment of bone age for children over eight years of age. Computerised analysis of the carpal bones in older children is a difficult computer vision problem plagued by radiographic noise, poor image contrast, and especially poor definition of bone contours. Traditional image processing methods such as region growing fail and even the very successful Canny linear edge detector can only find the simplest of bone edges in these images. The field of partial differential equation-based image processing provides some possible solutions to this problem, such as the use of active contour models to impose constraints upon the contour continuity. However, many of these methods require regularisation to achieve unique and stable solutions. An important part of this regularisation is image denoising. Image denoising was approached through development of a noise model for the Kodak computed radiography system, estimation of noise parameters using a robust estimator of noise per pixel intensity bin, and incorporation of the noise model into a denoising method based on oriented Laplacians. The results for this approach only showed a marginal improvement when using the signal-dependent noise model, although this likely reflects how the noise characteristics were incorporated into the anisotropic diffusion method, rather than the principle of this approach. Even without the signal-dependent noise term the oriented Laplacians denoising of the hand-wrist radiographs was very effective at removing noise and preserving edges.

This study examines whether obesity affects the accuracy of estimating age-at-death as measured by the age-related changes of the pubic symphysis and auricular surfaces. I scored the hip bones of 119 adults of normal body mass and 126 obese adults (total n = 254) using the SucheyBrooks (1990) method for the pubic symphysis and the Buckberry and Chamberlain (2002) method for the auricular surface. Compared to normal weight individuals, obese individuals exhibited greater inaccuracy in age-at-death estimates when aged from the auricular surface, but not the pubic symphysis. However, age was estimated with less precision in obese individuals using both methods. Obese males are more likely to be aged inaccurately than obese females. The pubic symphysis method may be the preferred method when estimating age in obese individuals, especially males, but forensic anthropologists should use caution when assessing age-at-death in obese adults using either method. / by Jessica L. Drew. / Thesis (M.A.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Thesis--Copenhagen. / Summary in Danish. Bibliography: p. [129]-131.

Thesis--Copenhagen. / Summary in Danish. Bibliography: p. [129]-131.