published_or_final_version / Anatomy / Master / Master of Philosophy

Thesis (M. Phil.)--University of Hong Kong, 1995. / Includes bibliographical references (leave 177-200).

In 2005 the World Health Organisation classified the odontogenic keratocyst (OKC) as a benign cystic neoplasm, using the term keratocystic odontogenic tumour. Significantly higher expression of proto-oncogenes and loss of expression of tumour suppressor genes have been demonstrated in the OKC when compared to more indolent jaw counterparts. This together with the higher mitotic activity in the epithelial lining of OKC could explain the aggressive behaviour of the OKC consistent with that of benign neoplasms. The BCL-6 proto-oncogene was identified in 1993 as a transcription factor whose deregulated expression is associated with B-cell non-Hodgkin lymphomas. In epithelial neoplasms, the BCL-6 transcription factor is associated with continuous growth and its absence triggers apoptosis. It has been suggested that BCL-6 may also participate prominently in the process of differentiation of epithelial cells. The aim of the study was to evaluate BCL-6 protein expression in the dentigerous cyst (n=10), radicular cyst (n=10) and OKC (n=20) by immunohistochemistry. Expression of BCL-6 was significantly higher in the OKC than in the dentigerous cyst and radicular cyst. In the OKC BCL-6 further showed a distinct predilection for the suprabasal compartment while in the dentigerous and radicular cysts the staining tended to be uniform throughout all the cell layers of the cyst lining. The study findings suggest that BCL-6 may play a role in the regulation of the suprabasal proliferative compartment of the OKC and in the keratinising epithelial cell differentiation of the OKC.

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 (doctoral)--University of Turku, 1980. / Bibliography: p. [48]-51.

Faculty of Health Sciences School of Oral Health Sciences 9401428a vcvibha / There is considerable confusion regarding the origin and classification of the AOT with the most recent WHO classification including the AOT as a non-inductive tumour or hamartoma showing metaplastic mineralisation. This study reviewed the clinical and epidemiological features of 51 AOTs retrieved from the archives of the Division of Oral Pathology, University of the Witwatersrand. In addition a detailed histological analysis, including histochemical and immunohistochemical investigations, was undertaken with a view to provide evidence for induction in AOTs. 4μ haematoxylin and eosin sections were examined. Selected cases were stained with PAS, alcian blue at pH 2.5, Congo red, reticulin, mucicarmine, von Gieson, Masson’s trichrome and Prussian blue. Melanin bleach was performed on certain sections. Immunohistochemistry was performed in the presence of adequate preparations and controls with MNF 116 and Vimentin antisera. Analysis of the clinical and epidemiologic data revealed that the AOT in our series had the same clinicopathological features as those reported from other parts of the world. This data will be included in a review article being prepared to commemorate the 100th anniversary of the description of this lesion. AOTs occur in both follicular (64%) and extrafollicular forms (21%) most commonly in the anterior maxilla (62.7%) in females (63.6%) in the second decade (66.6%) where they are frequently associated with unerupted canines (42%). There is some evidence ii suggesting that extrafollicular AOTs may originate in other odontogenic cysts and that this might explain why some AOTs grow to a large size and behave aggressively causing root resorption and expansion. Histologically the unique and important presence of tall columnar cells resembling ameloblasts or odontoblasts were identified in 5 cases of AOT. These cells were arranged in a circular configuration and were actively secreting PAS positive material, which we have interpreted as dental matrix material. We have called these ‘circular secretory units’. The tall columnar cells did not always surround the entire secretory unit suggesting either that there was a variable rate of differentiation or that having completed their function these cells change shape and become unrecognisable. We regard these circular secretory units as providing definite evidence of induction. Further evidence of induction is provided by the presence of clusters or strands of odontogenic epithelium intimately associated with a lace-like pattern of dental matrix material. No evidence of residual ectomesenchyme was found, but this does not rule out the possibility that induction has indeed occurred. We can also find no evidence linking the circular secretory units with the pseudo-ductular spaces, which characterise the AOT. In conclusion, based on our observations, we recommend that the AOT be classified as a benign tumour with inductive capacity.

Introdução. O cirurgião-dentista é na maioria das vezes, o responsável pelo diagnóstico e tratamento das lesões ósseas dos maxilares. O diagnóstico é decisivo na conduta terapêutica a ser seguida. Na literatura, análises retrospectivas são vistas com maior frequência, onde foram coletados resultados de exames histopatológicos. Contudo, para algumas lesões, o diagnóstico é clínico e radiográfico, não sendo indicada a realização de biópsia. Objetivo. O objetivo deste estudo foi descrever a prevalência das lesões ósseas dos maxilares, assim como avaliar suas características clínicas e radiográficas. Correlacionar a principal hipótese diagnóstica com o diagnóstico final. Pacientes e Métodos. Estudo com 130 pacientes com lesões ósseas dos maxilares diagnosticadas no Centro de Diagnóstico Oral da Disciplina de Estomatologia Clínica da Faculdade de Odontologia da Universidade de São Paulo (CDO-FOUSP), entre Agosto de 2013 e Outubro de 2014. Os pacientes foram divididos em 4 grupos: 1: Tumores benignos odontogênicos e não odontogênicos. 2: Cistos odontogênicos e não odontogênicos. 3: Tumores malignos. 4: Outras lesões. Análise estatística foi realizada buscando estabelecer informações relevantes quanto aos dados epidemiológicos, clínicos e radiográficos destas lesões. Resultados. A idade média foi de 35,2 anos ±17,86, (variou entre 8 e 77 anos). Dos 130 pacientes, 71 eram mulheres (54,62%) e 87 leucodermas (66,92%). A mandíbula foi mais acometida (71,43%), do que a maxila (28,57%). As características clínicas mais observadas foram: aumento de volume em 60 casos (42,85%), dor em 38 (27,14%) e 16 casos (11,43%) apresentaram drenagem de secreção purulenta. O exame complementar de imagem mais utilizado foi a radiografia panorâmica, 124 exames (88,57%). Em 47 lesões (33,57%), o diagnóstico foi realizado através do exame clínico, radiográfico e conduta cirúrgica (displasias ósseas, cistos ósseos simples, escleroses ósseas, dentre outras). Lesões com imagens radiolúcidas representaram 89 casos (63,57%), a forma unilocular esteve presente em 114 casos (81,43%) e 101 lesões (72,14%) apresentaram relação com o ápice dental. Dos casos que houve análise histopatológica (93 casos), o cisto periapical foi a lesão mais frequente totalizando 38 casos, 12 cistos dentígeros, 9 odontomas (7 compostos e 2 complexos), 8 TOQ, 6 cistos residuais, 5 ameloblastomas, e outras lesões. Houve 3 casos de tumores malignos, sendo 1 osteossarcoma, 1 carcinoma mucoepidermóide e 1 mieloma múltiplo. O percentual de acerto entre a principal hipótese diagnóstica com o diagnóstico final foi de 76,82%. Conclusões. Lesões ósseas foram frequentes e representaram aproximadamente 30% das primeiras consultas. Lesões com características radiográficas radiolúcidas e uniloculares foram as mais frequentes. Em um terço dos casos, não foi indicado (necessário) o exame histopatológico para a conclusão do diagnóstico. Sendo utilizadas as informações clínicas, radiográficas e abordagem cirúrgica (casos de cisto ósseo simples). / Introduction. The dentist is the main professional responsible for the diagnosis and treatment of bone lesions of the jaws. The diagnosis is crucial to therapeutic decision. In the literature, retrospective analyzes are more frequents, and the data are collected from histopathological exams. However, for some lesions, the diagnosis is clinical and radiographic, and the biopsy is not indicated. Objective. The aim of this study was to describe the prevalence of bone lesions of the jaws, and evaluate its clinical and radiographic features. In addition, the correlation between the main diagnosis and the final diagnosis was performed. Patients and Methods. A study which evaluated a total of 130 patients with bone lesions of the jaws. All cases were diagnosed in Oral Diagnosis Center of the Stomatology Discipline, School of Dentistry, University of São Paulo (CDO-FOUSP), between August 2013 and October 2014. Patients were divided into 4 groups: 1: Benign odontogenic and non odontogenic tumors. 2: Odontogenic and non odontogenic cysts. 3: Malignant tumors. 4: Other lesions. Statistical analysis was performed to establish relevant information on the epidemiological, clinical and radiographic data of these lesions. Results. The mean age of the patients was 35,2 years ± 17.86 (range, 8 to 77 years). Among 130 patients, 71 were women (54.62%) and 87 were Caucasians (66.92%). The mandible was more affected (71.43%) than the maxilla (28.57%). The most frequent clinical signs were swelling in 60 cases (42.85%), pain in 38 (27.14%) and 16 cases (11.43%) showed purulent drainage. The panoramic radiograph was the most used imaging exam, 124 exams (88.57%). In 47 lesions (33.57%), the diagnosis was done by clinical examination, radiographic and surgical management (bone dysplasia, simple bone cysts, bone sclerosis, and others). Radiolucent lesions accounted for 89 cases (63.57%), the unilocular form was present in 114 cases (81.43%) and 101 lesions (72.14%) were related to the dental apex. A total of 93 cases had histopathological analyses; periapical cyst was the most frequent lesion, representing 38 cases, 12 dentigerous cysts, 9 odontomas (7 compounds and 2 complexes), 8 OKT, 6 residual cysts, 5 ameloblastomas and other lesions. There were 3 malignant tumors, 1 osteosarcoma, 1 mucoepidermoid carcinoma and 1 multiple myeloma. The correlation between the main diagnosis hypotheses with a final diagnosis showed a success rate of 76.82%. Conclusions. Bone lesions were frequent and represented approximately 30% of the first visit patients. Lesions that presented radiolucent and unilocular radiograph pattern were the most frequent. In one third of cases, it was not indicated (necessary) the histopathological examination to conclude the diagnosis. Being used data of clinical, radiographic and surgical approach (cases of simple bone cyst).

Introdução. O cirurgião-dentista é na maioria das vezes, o responsável pelo diagnóstico e tratamento das lesões ósseas dos maxilares. O diagnóstico é decisivo na conduta terapêutica a ser seguida. Na literatura, análises retrospectivas são vistas com maior frequência, onde foram coletados resultados de exames histopatológicos. Contudo, para algumas lesões, o diagnóstico é clínico e radiográfico, não sendo indicada a realização de biópsia. Objetivo. O objetivo deste estudo foi descrever a prevalência das lesões ósseas dos maxilares, assim como avaliar suas características clínicas e radiográficas. Correlacionar a principal hipótese diagnóstica com o diagnóstico final. Pacientes e Métodos. Estudo com 130 pacientes com lesões ósseas dos maxilares diagnosticadas no Centro de Diagnóstico Oral da Disciplina de Estomatologia Clínica da Faculdade de Odontologia da Universidade de São Paulo (CDO-FOUSP), entre Agosto de 2013 e Outubro de 2014. Os pacientes foram divididos em 4 grupos: 1: Tumores benignos odontogênicos e não odontogênicos. 2: Cistos odontogênicos e não odontogênicos. 3: Tumores malignos. 4: Outras lesões. Análise estatística foi realizada buscando estabelecer informações relevantes quanto aos dados epidemiológicos, clínicos e radiográficos destas lesões. Resultados. A idade média foi de 35,2 anos ±17,86, (variou entre 8 e 77 anos). Dos 130 pacientes, 71 eram mulheres (54,62%) e 87 leucodermas (66,92%). A mandíbula foi mais acometida (71,43%), do que a maxila (28,57%). As características clínicas mais observadas foram: aumento de volume em 60 casos (42,85%), dor em 38 (27,14%) e 16 casos (11,43%) apresentaram drenagem de secreção purulenta. O exame complementar de imagem mais utilizado foi a radiografia panorâmica, 124 exames (88,57%). Em 47 lesões (33,57%), o diagnóstico foi realizado através do exame clínico, radiográfico e conduta cirúrgica (displasias ósseas, cistos ósseos simples, escleroses ósseas, dentre outras). Lesões com imagens radiolúcidas representaram 89 casos (63,57%), a forma unilocular esteve presente em 114 casos (81,43%) e 101 lesões (72,14%) apresentaram relação com o ápice dental. Dos casos que houve análise histopatológica (93 casos), o cisto periapical foi a lesão mais frequente totalizando 38 casos, 12 cistos dentígeros, 9 odontomas (7 compostos e 2 complexos), 8 TOQ, 6 cistos residuais, 5 ameloblastomas, e outras lesões. Houve 3 casos de tumores malignos, sendo 1 osteossarcoma, 1 carcinoma mucoepidermóide e 1 mieloma múltiplo. O percentual de acerto entre a principal hipótese diagnóstica com o diagnóstico final foi de 76,82%. Conclusões. Lesões ósseas foram frequentes e representaram aproximadamente 30% das primeiras consultas. Lesões com características radiográficas radiolúcidas e uniloculares foram as mais frequentes. Em um terço dos casos, não foi indicado (necessário) o exame histopatológico para a conclusão do diagnóstico. Sendo utilizadas as informações clínicas, radiográficas e abordagem cirúrgica (casos de cisto ósseo simples). / Introduction. The dentist is the main professional responsible for the diagnosis and treatment of bone lesions of the jaws. The diagnosis is crucial to therapeutic decision. In the literature, retrospective analyzes are more frequents, and the data are collected from histopathological exams. However, for some lesions, the diagnosis is clinical and radiographic, and the biopsy is not indicated. Objective. The aim of this study was to describe the prevalence of bone lesions of the jaws, and evaluate its clinical and radiographic features. In addition, the correlation between the main diagnosis and the final diagnosis was performed. Patients and Methods. A study which evaluated a total of 130 patients with bone lesions of the jaws. All cases were diagnosed in Oral Diagnosis Center of the Stomatology Discipline, School of Dentistry, University of São Paulo (CDO-FOUSP), between August 2013 and October 2014. Patients were divided into 4 groups: 1: Benign odontogenic and non odontogenic tumors. 2: Odontogenic and non odontogenic cysts. 3: Malignant tumors. 4: Other lesions. Statistical analysis was performed to establish relevant information on the epidemiological, clinical and radiographic data of these lesions. Results. The mean age of the patients was 35,2 years ± 17.86 (range, 8 to 77 years). Among 130 patients, 71 were women (54.62%) and 87 were Caucasians (66.92%). The mandible was more affected (71.43%) than the maxilla (28.57%). The most frequent clinical signs were swelling in 60 cases (42.85%), pain in 38 (27.14%) and 16 cases (11.43%) showed purulent drainage. The panoramic radiograph was the most used imaging exam, 124 exams (88.57%). In 47 lesions (33.57%), the diagnosis was done by clinical examination, radiographic and surgical management (bone dysplasia, simple bone cysts, bone sclerosis, and others). Radiolucent lesions accounted for 89 cases (63.57%), the unilocular form was present in 114 cases (81.43%) and 101 lesions (72.14%) were related to the dental apex. A total of 93 cases had histopathological analyses; periapical cyst was the most frequent lesion, representing 38 cases, 12 dentigerous cysts, 9 odontomas (7 compounds and 2 complexes), 8 OKT, 6 residual cysts, 5 ameloblastomas and other lesions. There were 3 malignant tumors, 1 osteosarcoma, 1 mucoepidermoid carcinoma and 1 multiple myeloma. The correlation between the main diagnosis hypotheses with a final diagnosis showed a success rate of 76.82%. Conclusions. Bone lesions were frequent and represented approximately 30% of the first visit patients. Lesions that presented radiolucent and unilocular radiograph pattern were the most frequent. In one third of cases, it was not indicated (necessary) the histopathological examination to conclude the diagnosis. Being used data of clinical, radiographic and surgical approach (cases of simple bone cyst).

Introduction Previous studies on the glandular odontogenic cyst (GOC) have largely focused on the application of immunohistochemistry for determining how the GOC lining epithelium compares with that of other odontogenic cysts. Studies on the histochemical composition of the mucous cells in the GOC are, however, lacking. This study therefore aimed to determine the mucin phenotype of the mucous cells in the GOC and compared these findings with the mucous cells in the epithelial linings of other odontogenic cysts and with normal salivary gland mucous acinar cells. Materials and Methods Twenty-seven cases made up of 10 GOCs, 9 dentigerous cysts (DC) with mucous cells and 8 radicular/residual radicular cysts (RC) with mucous cells were stained using the combined alcian blue pH 2.5-PAS (AB-PAS) histochemical technique. AB-PAS allows for differentiation between acidic- (type I mucous cells), neutral- (type II mucous cells) and mixed mucin-containing cells (type III mucous cells). Submandibular, sublingual and palatal salivary gland tissue was also subjected to AB-PAS staining. The odontogenic cysts and salivary glands were evaluated for the frequency of type I, II and III mucous cells in these tissues. Results There were significant differences between the level of type I, type II and type III mucous cells within each of the three cyst types; GOC (p=0.006), DC (p=0.0004), RC (p=0.0017). There were no significant differences in the cell counts for each mucous cell type between the 3 cyst types;type I mucous cells (p=0.54); type II mucous cells (p=0.73) and type III mucous cells (p=0.97).All 3 odontogenic cysts showed a predominance of type III mucous cells and this mirrored the mucin phenotype of the submandibular and sublingual salivary glands. Conclusion The mucin phenotype of the GOC is shared by DC and RC with mucous metaplasia. The overlapping mucin phenotypes of the different odontogenic cysts unfortunately does not support the use of the AB-PAS stain as a potential histochemical marker to distinguish between the GOC and other odontogenic cysts with mucous metaplasia. Similarities in the mucin phenotype between odontogenic cysts, submandibular and sublingual salivary glands may suggest a common ectodermal histogenetic origin for the mucous cells in odontogenic cysts and major salivary glands.

O ameloblastoma é uma das neoplasias odontogênicas mais freqüentes universalmente. Seu estudo se reveste de grande importância porque, não obstante benigna, é localmente agressiva, com alto índice de recorrências, sendo o tratamento cirúrgico radical, com margem de segurança, freqüentemente preconizado, e tido, por boa parcela de especialistas, como única alternativa efetiva para seu tratamento. Em decorrência, observam-se, muitas vezes, seqüelas importantes, do ponto de vista funcional e estético, para os pacientes acometidos por essa neoplasia. O objetivo do presente trabalho foi revisar a literatura, traçando um perfil comparativo, por continente, da biodemografia do ameloblastoma, com ênfase na discussão de suas possíveis diferenças e similitudes regionais. As informações coletadas na literatura disponível para consulta indicaram ter sido a segunda neoplasia de origem odontogênica mais prevalente universalmente, ressalvada a consideração sobre os odontomas serem ou não, classificados como neoplasias. Foi mais freqüente no gênero masculino. A localização mais comum do ameloblastoma foi no segmento posterior da mandíbula, sendo essa, uma unanimidade nos trabalhos consultados. Houve diferenças regionais quando se comparou aspecto relativo aos itens estudados (freqüência do ameloblastoma em relação às neoplasias odontogênicas; incidência do ameloblastoma em relação ao gênero). Foi encontrada, na revisão de literatura pesquisada, uma freqüência significativa de informações incompletas com relação aos itens estudados, sendo exceções, os trabalhos referentes aos continentes, europeu e africano / Ameloblastoma is one of the universally most prevalent odontogenic neoplasias. Its correct knowledge has great importance in view of its local aggressiveness potential, although being a benign neoplasia, with a high number of recurrences. The elective treatment for ameloblastoma is the surgical radical resection with safety margins, being in the opinion of many specialists, the only correct method for its management. Notwithstanding of this fact, functional and aesthetical damage has been frequently observed after treatment, among the patients suffering from this neoplasia. The purpose of the present study was to perform a literature review, building a comparative continental profile of ameloblastoma biodemographics, emphasizing the discussion of its possible regional differences and similarities. The information collected from the literature indicated ameloblastoma as the second most frequent odontogenic neoplasia, despite of the consideration on the odontoma classification as a true neoplasia or not. Ameloblastoma was more frequent among male gender and the most common location was in the posterior segment of the jaw, being this data unanimous among the literature. There were regional differences regarding some of the studied variables (freqüency of ameloblastoma related to odontogenic neoplasias and related to gender). Incomplete data was an important occurrence during the literature reviewing, with exception of the papers from European and African continents.