A research report submitted to the Faculty of Health Sciences, University of Witwatersrand, Johannesburg, in partial fulfillment of the degree of Master of Science in the branch of Dentistry / Orthokeratinised jaw cyst (OJC) is an entity distinct from odontogenic keratocyst (OKC) but that has not been fully characterised at the molecular level. The aim of this study was to compare the proliferative activity between the epithelial linings of OKC and OJC by immunohistochemical staining for Ki-67 and cyclin D1. The total numbers of Ki-67 and cyclin D1 positively (+) stained cells/10 consecutive lengths of a light microscope calibration ruler were counted for each case (OKC, n=15; OJC, n=15) and statistically compared in the basal compartment, suprabasal compartment and full thickness of the cyst lining between the 2 cyst types. OJC showed significantly fewer Ki-67+ cells and cyclin D1+ cells than OKC, consistent with the clinically more indolent behaviour of the OJC. Ki-67 expression was mainly detected in the suprabasal compartment in OKC. Expression of Ki-67 was more uniform in OJC and notably without a significant predilection for the suprabasal compartment. The accumulation of Ki-67 positive cells suprabasally in OKC raises the possibility that a process of asymmetrical cell division may be operational in OKC. Expression between Ki-67 and cyclin D1 differed significantly both quantitatively and by distribution pattern in OKC and OJC, which suggests that the presence of the cyclin D1 protein may not necessarily reflect production of this molecule by cycling cells in OKC and OJC.

Thesis (M Dent (Orthodontics)) -- University of Limpopo, 2011 / Introduction: Flexion of the cranial base plays a very crucial role in the study of the craniofacial complex, particularly with the development of skeletal jaw relationships. An understanding of growth of the cranial base has come to assume great importance in orthodontics, and successful treatment of skeletal jaw malrelationships depends largely on the growth and flexion of the patients' cranial base. The aim of this study was to determine the relationship between cranial base flexion and skeletal jaw relationships in a sample of Black South Africans. Materials and method: The sample comprised of 300 pre-treatment lateral cephalograms of Black South Africans which was equally divided into Class I, Class . II and Class III skeletal jaw relationships according to the cephalometric tracing and analysis, and each class of skeletal jaw relationship had an equal number of male and female subjects. A digital cephalometric analysis software program (Orthview<ID, Netherlands) was used to trace and analyse the selected lateral cephalograms. The sample was first analysed to determine if gender differences existed for the mean cranial base flexion value in all three classes of skeletal jaw relationships. , , Comparisons among Class I, II and III mean cranial base flexton values using an independent t-test were made. The averag~ cranial base 'flexion value of the Black South Africans in this study was also compared with the average cranial base flexion value of Black and Caucasian South Africans from the previous studies for significance using an independent t-test. Results: Age distribution showed no statistically significant differences in all the three classes of skeletal jaw relationship (p > 0.05). There were no statistically significant differences between the mean cranial base flexion values of the male and female subjects in all the three classes of skeletal jaw relationships (p > 0.05). The results of this study demonstrated a significantly larger mean cranial base flexion value in the Class II skeletal jaw relationship sample when it was compared with the mean cranial base flexion values of Class I and Class III skeletal jaw relationship samples respectively (p < 0.05). There was no statistically significant difference between Class I and Class III skeletal jaw relationship samples with regards to the cranial base flexion (p> 0.05). The results of this study also showed no statistically . significant difference between the average cranial base flexion values of Black South Africans of the present study as well as Black and Caucasian South Africans of the previous study (p > 0.05). Conclusion: It was concluded that, in this sample, a larger cranial base flexion value is a feature of Class II skeletal jaw relationship and a smaller cranial base flexion value is a feature of both Class I and Class 11\ skeletal jaw relationships. Keywords: cranial base flexion, skeletal classification, skeletal jaw malrelationship

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Thesis (M.S)--University of Michigan, Ann Arbor, 1973. / Typescript (photocopy). X-ray films in pocket. Includes bibliographical references (leaves 41-42). Also issued in print.

Thesis (M.S.)--University of Michigan, 1975.

Thesis (doctoral)--Münster, 1933. / Includes bibliographical references (p. 23-24).

Thesis (doctoral)--Münster, 1933. / Includes bibliographical references (p. 23-24).

Thesis (D.D.)--Universität Düsseldorf, 1978. / Includes bibliographical references (p. 89-107).

Thesis (M.S)--University of Michigan, Ann Arbor, 1973. / Typescript (photocopy). X-ray films in pocket. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 41-42).

Thesis (M.S.)--University of Michigan, 1975.