Philosophiae Doctor - PhD (Community Oral Health)
http://hdl.handle.net/11394/38
2024-03-28T14:12:35ZCommercial baby food: Consumption, sugar content and labelling practices in Uganda
http://hdl.handle.net/11394/9945
Commercial baby food: Consumption, sugar content and labelling practices in Uganda
Mwesigwa, Catherine Lutalo
There has been a worldwide increase in the consumption of processed foods in low- and middle-income countries. Processed foods are now easily available and accessible with the increased presence of transnational corporations, urbanisation and improving economies—all essential drivers of the nutritional transition. Ultra-processed foods and beverages (UPFB) have been identified as a significant contributor to total dietary energy and, in specific settings, the biggest source of sugar for infants and young children. High consumption of free sugars in early childhood is associated with poor health outcomes, including early childhood caries, overweight/obesity and an increased risk of developing other non-communicable diseases (NCDs).
Philosophiae Doctor - PhD
2022-01-01T00:00:00ZDie ontwikkeling van die epiteel en keratien in die menslike mondholte: In histologiese, elektronmikroskopiese en histochemiese studie
http://hdl.handle.net/11394/9113
Die ontwikkeling van die epiteel en keratien in die menslike mondholte: In histologiese, elektronmikroskopiese en histochemiese studie
van Wyk, Christian Werner
Histological observations revealed that oral epithelium originated from a single ectodermal layer. As the ectoderm grew so it differentiated into squamous epithelium. The first features of squamous differentiation were noticed at 8 weeks in utero in areas where keratinized mucosae were developing, and these were the changing of cuboidal to cylindrical basal cells and the subsequent growth of prickle cells from these cylindrical basal cells. The prickle cells merged with the existing primitive cells and at no stage could a separate squamous epithelial layer I such as the stratum tritermedium of the epidermis I be observed inside the mouth. At 12 weeks in utero squamous differentiation had reached a stage where acidophilic layers appeared in certain regions on the epithelial layer. The time of appearance of these layers varied from case to case. At this stage most of the primitive characteristics had disappeared from the keratinizing epithelium. Unlike the periderm of the skin which was shed into the amniotic fluid, shedding of primitive epithelial cells from the keratinizing squamous epithelium was not noticeable. Thence, the growth of keratinizing epithelium was followed by an increase of acidophilic layers, the appearance of
keratohyaline granules in cells and, in some instances, full keratinization. The latter I however I was almost exclusively confined to the vermilion border of the lip. The squamous epithelium of the lining mucosa, which is unkeratinized I developed at a much slower tempo. It retained its cuboidal-shaped basal cells and the primitive features of the overlying cells were lost only at about 4- 5 months in utero I when squamous differentiation set in. At no stage was the squamous differentiation a prominent feature. At junctions between keratinized and unkeratinized epithelia and epidermis the epithelium exhibited features of both types of epithelia that were being joined. This was especially noticeable at the junction between vermilion epithelium and epidermis, where part of the vermilion epithelium displayed a prominent intermediate type of layer. Similarly, acidophilic layers of keratinizing epithelium merged imperceptibly with the walls of cells of
unkeratinizing epithelium, creating a small region of an unkeratinizing type of epithelium with keratinized cells. Thus the development of the oral epithelium is through differentiation and renewal of epithelial cells: the ectodermal layer developes into an epithelial layer which is recognised by its squamous appearance. The subsequent growth is by constant renewal of this differentiated epithelium. The pattern
of epithelial development I the appearance of the junctional epithelia and the manner in which acidophilic layers merge with unkeratinized epithelial cells I indicate a unity between these epithelia. According to these developmental features, the epithelium of the mouth and epidermis can be classified into less differentiated and better differentiated, but with a commonbackground for these epithelia. When the formation and the established appearance of keratin in the mouth and on the skin was compared histologically I ultrastructurally and
histochemically I a unity between these features became apparent. Ultrastructurally it appeared that keratin consisted basically of 2 cytoplasmic constituents: tonofilaments and a fine granular substance. The tonofilaments were gathered at first into bundles and then broken up into finer tonofibrils. These finer fibrils mixed with a granular ground substance to form a homogenous granular filamentous material. This product can be regarded as a pre-keratin. With the addition of a keratohyaline layer to the process I keratin was formed,
Apart from the keratohyaline granules several additional changes took place in cells concerned in this process I whether keratin was formed or not. These changes were flattening of cells, extensive interdigitation between cell walls, disappearance of micro-villi I loss of structure in desmosomes I thickening of cell walls and the disappearance of glycogen from cells. Some of these features were displayed in each of the types of epithelium examined here.
Philosophiae Doctor - PhD
1972-01-01T00:00:00ZThe history of dentistry in South Africa since 1900
http://hdl.handle.net/11394/9080
The history of dentistry in South Africa since 1900
Grob1er, Vilma
Nineteenth Century dentists in South Africa were brought under the provision of legislation in Natal and the Transvaal (1896) and the Cape Colony and the Orange Free State (1899). By the end of the Nineteenth Century a group identity had been established and the transition
from a craft to a profession completed. From 1900-1958 dental societies were formed. Key dates are 1922 when the South African Dental Society, which became the Dental Society of South Africa (D.A.S.A.) after Incorporation in 1935, was constituted. Collective action by
dentists, implemented through the societies, shaped the profession. From 1933-1948 the constitution of the D.A.S.A. was streamlined. The Magna Charta of Dentistry (Act 13, 1928) was enacted defining dentistry and the practice thereof. The Dental Mechanicians Act (1945) protected the mechanician, the dentist and the public against illicit practitioners. The D.A.S.A. initiated the Professional Provident Society
for dentists, now extended to include all the professions. In 1936 tbe first National Congress was held, in 1953 the first International Congress, setting a future pattern. The status of the dentist was further improved by obtaining the right to use the courtesy title Dr and by the abolition of the professional licence fee (1938). The earliest .societies set up voluntary clinics for children and the indigent. The Transvaal initiated a provincial scheme for childrens' followed by the other provinces. Dental Services, a fully fledged of Health. dentistry, This evolved into branch of the Department Witwatersrand University established a dental school in 1925, followed by .the Universities of Pretoria, Stellenbosch , Western Cape and Medunsa. Facilities for postgraduate 'study exist at all these institutions. The R.E.D. Fund Aids Research Education and Development in the field of dentistry. The first unofficial Dental Journal was published in 1927, followed by the Official Bulletin (1945-1946) and finally the Official Journal of the D.A.S.A. During the Anglo Boer War the importance of healthy dentitions'for soldiers was first realised. Four conntract dentists att~nded to the British soldiers. The South African dentists served in the Army Dental Corps during the two world wars. Dentistry in South Africa is now on a par with dentistry in any country of the Western world.
Philosophiae Doctor - PhD
1983-01-01T00:00:00ZDie ontwikkeling van 'n innoverende kurrikulum vir die opleiding van tandheelkundiges
http://hdl.handle.net/11394/9060
Die ontwikkeling van 'n innoverende kurrikulum vir die opleiding van tandheelkundiges
Snyman, Willem Diederik
SUMMARY
This study has shown that the environment in which a dentist receives his training, has, over
the past decades, changed drastically, and is still changing. Also, that the existing
curriculum model, in use in most dental faculties, is an anachronism and that the sands of
time for a paradigm shift in terms of the curriculum, are fast running out. It follows,
therefore, that the curriculum, training and evaluation programmes will, without delay, have
to undergo changes in order to fulfil the requirements of the community in general and the
clients of the Faculty in particular. In addition, adjustments in terms of the numbers and
types of dental manpower to be trained, will have to be made.
The purpose of this study was to investigate the management of dental education as a critical
performance area and to develop a curriculum at the macro-level for three cadres of dental
manpower, which will fulfil certain identified requirements.
The curriculum model used in this study, should ideally fit in with the organisational structure
of the Faculty. Therefore, this organisational structure was investigated and found to consist
of a mixture of a "machine" and a "professional bureaucracy". It was also demonstrated that
the disadvantages of this bureaucratic hybrid could be counteracted, whilst still retaining the
advantages of the existing system, by the implementation of an "adhocracy" in the form of
a matrix-functioning system.
A management manual, essential for the effective functioning of a matrix system, which had
already been developed for the management of teaching in the Faculty of Dentistry of the
University of Pretoria, was found to be suitable, not only for this purpose, but also as a basis
for future strategic planning in teaching.
The rationale for the necessity of altering the traditional dental curriculum is given in the
thesis and three strategies are recommended for solving the problem. Curriculum designs
were carefully scrutinized and the most important of these relating to dental education, as well
as the ideal positioning in terms of the SPICES curriculum strategy, have been indicated.
Basic premises, with their priorities and weighted values, developed for this study were
utilised in comparing the traditional model with the proposed diagonally-layered curriculum
design. This proposed curriculum design, and subject structure, is illustrated in detail with
the aid of diagrams.
An empirical comparison showed that the proposed diagonally-layered curriculum would be
an improvement on the traditional curriculum in terms of: professional and market orientation,
the promotion of meta-learning, the support of teaching and evaluation, the early exposure
of students to preventive clinical dentistry, the promotion of horizontal and vertical integration
of various subjects and courses, rationalisation of the curriculum, easier "through-flow"
possibilities for oral hygienists and dental therapists, as well as practical implementation and
cost effectiveness.
Philosophiae Doctor - PhD
1993-01-01T00:00:00Z