Lencwadzi ibhalelwe bantfwana belibanga lesitsatfu Grade Ill lasebakwati kufundza nekubhala

Magister Artium - MATsine bantfwana bemaSwati siyahlonipha. Kuhlonipha sikufundziswa emakhaya. Asidzingi kufundziswa kuhlonipba esikolweni. Umntfwana makangahloniphi uyashaywa. Nasihlangana nemuntfu lomdzala endleleni siyaphambuka. Sicolela kuhamba esikhotseni. Siyabese 'siyema. Kuba ngitsi lesibingelelako. Sibingelela ngenhlonipho. Siyayekela futsi. nekudlala. Tsi~e bantfwana asihlali n~bantfu labadzala. Nabakulendlu siyaphuma siye kulenye. Sentela kutsi bacoce kahle _tindzaba tabo. Umntfwana akatilaleli tindzaba tebantfu labadzala. Kunjalo nje bantfwana· abambuki emohlweui.umuntfu lomdzala. Nasikhuluma sibuka phansi. Bantfu labadzala nabahleti phansi asibameli. ·sihlala , . . phansi natsi. Kumbe singaguca ngemadvolo. Noma sikhuluma nalabadzala siyaguca. Umuntfu lomdala nakakhaspane make nobe babe. Siya dvutane naye nasifuna khuluma. Sikhulumela phantsi •ngaso sonkhe sikhatsi Nebuso betfu bufanele buhlale bumamatseka. Tsine siyakutsandza kuhloniph

The handling of undated pig embryos and foetuses as a prelude to histological studies of morphogenesis in the oral region

Magister Chirurgiae Dentium (MChD)The author is interested in the morphogenesis of the oral region including the nasopalatine complex. With the intention of undertaking a study of the· embryological development in this area, perusal of available literature failed to reveal a single compreh.ensive description of the reception and handling of embryonic and foetal material, mensuration and preparation for miscroscopy. Human material for embryological study is relatively scarce in· the Republic of South Africa. According to the literature there is, however, a distinct similarity between human and domestic pig development in certain regions, notably the palate. Furthermore, pig embryos and foetuses are available in comparative abundance from sows slaughtered at abattoirs. As a consequence of the above-mentioned factors it was,decided to undertake a -preparatory study in order to firstly evaluate existing methods of handling of embryonic and foetal material and secondly, to statistically evaluate data relating to mass and measurements.'· The aim was to draw a comparison with existing information and to select a sample for investigation. Embryos and foetuses were removed from slaughtered sows in a fresh state and removed to the laboratory immersed in 10 per cent neutral buffered formol saline. In the laboratory foetal membranes were removed, umbilical cords cut and the specimens weighed. They were then placed in Bouin's solution for final fixation and decalcification. Instruments were designed to measure crown-tailroot length, crown-rump length and dorsal profile length. After one day in Bouin's solution all specimens were measured. In order to determine the accuracy of the weighing and measuring procedures ten fixed specimens were weighed and measured on seven consecutive days. Statistical analysis of this data indicated that crown-rump length was the most accurately determinable linear measurement, judged by both the coefficient of variation and the standard deviation. On this basis crown-rump length was chosen as the criterion for selecting the sample to be studied. Correlation between linear measurements and between linear measurements and mass for the entire series showed a very strong positive relationship between all the parameters indicating that a dimensional relationship was maintained during growth. After measuring, the small specimens were embedded whole while larger embryos and foetuses were decapitated. A method was described for trimming and embedding these heads in such a way that subsequent sectioning would take place in a standardised transverse plane. In larger specimens this procedure had to be delayed until demineralization had taken place. Conclusions based on a consideration of data for the entire population included the following: 1. The mean number of specimens per litter was 6,475. 2. The number of pigs per litter stayed relatively constant throughout the period of gestation. 3. Mass showed a greater intra-litter variation than any of the three linear measurements recorded. 4. Relatively, lengths appeared to vary less in older than in younger Ldtt.ers-, irrespective of litter siz

Mandibulo-facial dysostosis - An investigation of the cranio-facial and oral manifestations in South African bantu.

Magister Chirurgiae Dentium (MChD)The subject, an adult bantu male with most of the features of the classical syndrome, is subjected to a physical investigation with the - emphasis on the cranio-facial and oral manifestations. The clinical appearance of the facies and head is discussed and the findings correlated with those of the accepted syndrome. Special attention is paid to the oral and dental manifestations and measurements are recorded and compared. A rontgenographic examination is .performed on the cranium, facial bones and the jaws. Utilising the lateral skull radiograph ·(cephalogram), a cephalometric analysis is done of the skull and jaws to determine the development that has occurred

A study of some cultural characteristics and blood serum antibodies: titers 0f enterococci isolated from the mouth and faeces

Magister Scientiae Dentium - MSc(Dent)Crevicular epithelium presents no effective barrier to the biologicaJly active constituents of plaque. Moreover, it seems that the production of circulating antibodies, the development of a state of delayed hypersensitivity and the development of immunologicai tolerance all play a part in the pathogenesis of periodontal disease. An investigation was undertaken to study the cultural characteristics of enterococci isolated from the mouth and gut of a group of students, and to determinethe serum antibody titres to these organisms. Enterococci were isolated from faeces and the gingival crevice of 9 male dental students. Blood was obtained from each subject and allowed to clot. The serum was removed and stored at -20 0 C• unt'i l requi• red. Blood serum antibody titres to the bacteria were obtained by the indirect fluorescent antibody technique. In order to investigate for the presence· of antibodies to homologous and heterologous enterococcal strains, each subject's serum was tested against all the strains of enterococci isolated. Higher antibody titres were obtained to oral enterococci than to faecal microorganisms. This investigation suggests that there are either differences in the immunogenic iii potential of oral and faecal streptococci or micro-environmental conditions in the host which favour antibody production to oral streptococci as opposed to streptococci in the gut. There are also differences in the cultural characteristics and bio= chemical reactions of the gut and mouth organisms

Maturation of the permanent teeth in a Western Cape sample

Doctor EducationisThe need for in-depth knowledge of dental emergence and calcification in orthodontic diagnosis and treatment planning cannot be disputed. Serial extractions, treatment timing, bite opening and closing, expansion and various other orthodontic procedures cannot be successfully executed without an in depth knowledge of the calcification and eruption of teeth. Besides its orthodontic implications, dental calcification and eruption plays a significant role in physical anthropology, forensic odontology, endocrinology and nutrition (Demirjian, 1978). Forensic scientists are agreed that teeth constitute the most important and reliable means for determining age from approximately 10 week in utero to old age (Altini, 1983). It is a generally accepted fact that there is no correlation between biological age and chronological age (Prahl-Andersen and Van der Linden, 1972; Demirjian, 1978), an aspect, which will be discussed in further detail later in the review of the literature. Biological age is seen to be a more accurate indicator of an individuals maturity than chronological age (Moorees et al, 1963; Prahl-Andersen and Van der Linden, 1973; Oemirjian et al, 1973). However, allocating a biological age to an individual is not an easy exercise as no definite consensus has, to date, been reached regarding the best method of determining biological age (Moorees et al, 1963; Garn et al, 1967; Demirjian, 1978). Today, many different methods are being used to establish this, for example bone age, height, menarche, circumpubertal growth and dental age

Die ontwikkeling van die epiteel en keratien in die menslike mondholte: In histologiese, elektronmikroskopiese en histochemiese studie

Philosophiae Doctor - PhDHistological 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

Inleiding tot die eksperimentele Sielkunde

Philosophiae Doctor - PhDElke skolier wat rue tevrede is om dit op skool slegs met lepels in te kry nie, het seker al gewonder hoe kennis oorspronklik verkry word. In daardie stadium is ons gewoonlik nog tevrede om die feite wat die onderwyser aan ons voorlê, of wat ons in die boeke gelees het, op gesag aan te neem. Maar selfs dan toets ons dikwels daardie gesag deur gewone en terloopse waarnemings. Byvoorbeeld: in die fisika leer ons dat as ons 'n groot en 'n klein klippie gelyktydig van enige hoogte laat val, hulle ook gelyktydig op die aarde sal beland as daar nie met die een klip intussen iets gebeur het wat nie met die ander klip gebeur het nie: met ander woorde as aIle faktore gelyk gebly het. Toe ons van hierdie gelyk-vallende klippies gehoor het, het party van ons op 'n dubbelverdieping gebou, of selfs op die dak van die buitegebou, opgeklim en die twee klippies self laat val om na te gaan of dit werklik so was. En hiermee het ons 'n eenvoudige eksperiment uitgevoer om te toefs of die hennis wat ons geleer het wel reg was. Dit was 'n eenvoudige eksperiment omdat die invloed van die lugdruk, en van die wind wat waai en 'n groter uitwerking op die groot klip het as op die klein klippie, buite rekening gehou is by die waarneming. Ons het ook net van ons oë gebruik gemaak om te kyk of die twee klippe gelyktydig op die aarde beland. Maar as ons middels kon aangewend het om die invloed van die genoemde twee faktore te bepaal, sou dit 'n meer presiese eksperiment gewees het en nie 'n terloopse waarneming nie. Sulke presiese eksperimente word in die laboratorium uitgevoer met die doelom betroubare kennis te kry. Die soort wetenskaplike kennis wat ons op skool leer, is reeds in die verlede deur navorsers vasgestel, en hulle bevindings is nou beskikbaar vir ons in teksboeke. Hulle eksperimente was bedoel om op nuwe kennis uit te kom. Maar die student wat sy verstand gebruik is nie noodwendig tevrede met gesag nie; hy wil self graag eksperimente maak om te sien of wat die gesag beweer werklik so is. Sy eksperimente is bedoel om eerstens te toets of die ander navorsers se resultate reg is, en tweedens 0111 hom oefening te gee met die uitvoering van eksperimente. Navorsers werk op wetenskaplike manier om nuwe kennis te verkry. Dit word vertel dat Newton S)' idee van die aantrekkingskrag van die aarde gekry het toe hy 'n appel sien val het, en dat Archimedes die idee van sy wet: dat voorwerpe in water van hulle gewig verloor, en dat die gewig wat daardie voorwerpe verloor gelykstaan aan die gewig van die volume water wat deur die voorwerpe verplaas word, gekry het terwyl hy besig was om te bad. Waarheid is dat albei allank besig was om oor hulle probleme na te dink en na te soek, en dat toe Newton die appel sien val het en Archimedes die gedagte in die. bad gekry het, dit feite was wat by vorige kennis aangesluit het. Hulle was egter nie daarmee alleen tevrede nie; daarna het albei die gedagte gaan toets .met wetenskaplike proefnemings om op kennis uit te kom. Die proefnemings en wetenskaplike navorsing kan jare en jare se harde werk vereis het. Om die eerste atoombom te laat ontplof het tientalle wetenskaplikes en duisende geskoolde assistente en werksmense jare se werk gekos. So het dit ook baie jare geverg om vas te stel dat mense wat siek word nie getoor is nie maar dat, byvoorbeeld, kieme 'n groot rol kan speel byeen of ander siekteverskynsel; en dit weer het ons aan die wetenskaplike navorsingsmetodes van 'n Pasteur te danke. Die verslag valt wetenshaplilu: navorsers se werk is nou ons wetenskaplike literatuur. Hierdie mense wat 'n eksperiment vir die eerste keer gemaak het, het dit nie gedoen om te toets of ander mense se feite korrek is nie, maar om uit te kom op oorspronklike feite van hul eie. In die Sielkunde is die basis vir die metodes van ondersoek dieselfde as vir ander wetenskappe. Daar is die noodsaaklikheid om deur middel van wetenskaplike proefneming op nuwe kennis uit te kom. Om dit te kan doen moet 'n mens eers leer hoe om 'n proefneming in te rig en moet jy voldoende oefening kry met proefnemings. As studente is dit vir ons 'n vereiste om die verskillende verskynsels self te kan ondersoek en later miskien self op nuwe kennis uit te kom en, wie weet, self een of ander oorspronklike bydrae te maak. Maar dan moet ons weet hoe om 'n eksperiment of ondersoek uit te voer. Om dit geleerd te stel: Ons moet die objektiewe metodes van 'n wetenskaplike eksperiment beheer; ons moet weet hoe om 'n proefneming in te rig

Dental caries clinical and experimental investigations

Magister Scientiae Dentium - MSc(Dent)pental caries is the most prevalent of all diseases among civilized peo_ple. ~_n_ol middl~~-~o=~ay with ~full c§rfectly healthy tee!h. From various statistics obtained ffo·m- practically every country in the world, the incidence is estimated to be over 95 per cent. By this is meant that more than 95 ont of every 100 persons suffer or have suffered at some time from one or more carious teeth. Statistics are based mostly on dental examinations of school children, because of the obvious difficulty of examining large groups of adults for dental defects. There is a lamentable lack of reliable and accurate statistics concerning the incidence of dental caries in most civilized countries. Klein and Palmer (1938) reported that the incidence of dental caries (as defined above) among elementary school children in the United States is 95 per cent. Day and Sedwick (1935) found the incidence among Rochester (N.Y.) schoolchildren to be 99 per cent. The final report of the Mixed Committee of the League of Nations of 1937 shows that in Norway, of 25,000 school children examined, only 160 possessed perfect sets of teeth, or 99 per cent. affected by dental caries. Day and Sedwick (1935) state that, in the county of Shropshire in England, 97 per cent. of the children at the age of 12 had dental caries. The Director-General of Health of New Zealand, in .his annual report of 1941, states that of 52,500 children examined, 95 per cent. were affected by caries: In India, Day and Tandan (1940) reported that the incidence of dental caries among urban children in Labore was 94 per cent. In South Africa, Friel and Shaw (1931) found 93 per cent. of urban children suffering from dental caries. Staz (1938) reported that of 300 European adults examined in Johannesburg none showed caries-free mouths