Odontogenic tumours in a Chilean population: a retrospective study of 544 cases based on 2022 WHO classification

Background: Odontogenic tumours are infrequent lesions. Studies on the frequency of odontogenic tumours from Latin America are scarce. This work aimed to determine the relative frequency of odontogenic tumours in a Chilean population using the 2022 World Health Organization classification. Material and Methods: This is a case series retrospective study. We reviewed 35,530 samples from 1975 to 2022 from the Oral Pathology Referral Institute and the Pathological Anatomy Service, Faculty of Dentistry, University of Chile. We utilized the 2022 World Health Organization classification for histological typification. Results: According to 2022 World Health Organization classification, 544 odontogenic tumours were confirmed. The most frequent odontogenic tumours were: odontoma (n=241; 44.3%), ameloblastoma (n=109; 20.0%) and cemento-ossifying fibroma (n=71; 13.1%). Benign odontogenic tumours corresponded to 538 cases (98.9%) and malignant tumours were only six cases (1.1%). Conclusions: In our population, odontoma was the most frequent odontogenic tumour followed by ameloblastoma and cemento-ossifying fibroma. Malignant odontogenic tumours were very rare. The results of this study are similar to reports from America, but there are some differences concerning the data from Africa and Asia. (AU)

Immunohistochemical expression of COX-2, Ki-67, Bcl-2, Bax, VEGF and CD105 according to histological grading in oral squamous cell carcinoma / Expresión inmunohistoquímica de COX-2, Ki-67, Bcl-2, Bax, VEGF y CD105 según el grado histológico en el carcinoma oral de células escamosas

Introduction: Oral squamous cell carcinoma (OSCC) is the most prevalent head and neck cancer. Few studies have analyzed the expression of proteins related to inflammation (COX-2) and tumor progression according to the histological grade of OSCC. Objective: Analyze the immunohistochemical expression of COX-2, Ki-67 (cell proliferation), Bcl-2/Bax (apoptosis), VEGF, and CD105 (angiogenesis) according to histological grades of OSCC.Material and methodsThe immunohistochemical expression of COX-2, Ki-67, Bcl-2, Bax, VEGF, and CD105 of 58 cases of OSCC was analyzed. 13 cases of oral mucosa (OM) were analyzed as controls. Results: COX-2, VEGF, CD105, and Ki-67 were higher in OSCC than in OM, particularly in poorly differentiated OSCC (p<0.05). Bax expression was lower in poorly differentiated OSCC (p<0.001). The Bcl-2/Bax ratio was higher in OSCC compared to MO (p<0.05). Conclusion: There are immunohistochemical differences according to histological grades of OSCC, which could influence clinical behavior.(AU)

Introducción: El carcinoma oral de células escamosas (COCE) es el cáncer de cabeza y cuello más prevalente. Escasos estudios analizan la expresión de proteínas relacionadas a inflamación (COX-2) y progresión tumoral según el grado histológico de COCE. Objetivo: Analizar la expresión inmunohistoquímica de COX-2, Ki-67 (proliferación celular), Bcl-2/Bax (apoptosis), VEGF y CD105 (angiogénesis) según grados histológicos de COCE.Material y métodos. Se analizó la expresión inmunohistoquímica de COX-2, Ki-67, Bcl-2, Bax, VEGF y CD105 de 58 casos de COCE. Trece casos de mucosa oral (MO) fueron analizados como control. Resultados: Las expresiones de COX-2, VEGF, CD105 y Ki-67 fueron mayores en el COCE comparadas con la MO, particularmente en el COCE pobremente diferenciado (p < 0,05). La expresión de Bax fue menor en el COCE pobremente diferenciado (p < 0,001). La razón Bcl-2/Bax fue mayor en COCE comparado con MO (p < 0,05). Conclusión: Existen diferencias inmunohistoquímicas según grados histológicos de COCE, lo que podría determinar una evolución clínica diferenciada.(AU)

Immunohistochemical expression of COX-2, Ki-67, Bcl-2, Bax, VEGF and CD105 according to histological grading in oral squamous cell carcinoma.

INTRODUCTION: Oral squamous cell carcinoma (OSCC) is the most prevalent head and neck cancer. Few studies have analyzed the expression of proteins related to inflammation (COX-2) and tumor progression according to the histological grade of OSCC. OBJECTIVE: Analyze the immunohistochemical expression of COX-2, Ki-67 (cell proliferation), Bcl-2/Bax (apoptosis), VEGF, and CD105 (angiogenesis) according to histological grades of OSCC. MATERIAL AND METHODS: The immunohistochemical expression of COX-2, Ki-67, Bcl-2, Bax, VEGF, and CD105 of 58 cases of OSCC was analyzed. 13 cases of oral mucosa (OM) were analyzed as controls. RESULTS: COX-2, VEGF, CD105, and Ki-67 were higher in OSCC than in OM, particularly in poorly differentiated OSCC (p<0.05). Bax expression was lower in poorly differentiated OSCC (p<0.001). The Bcl-2/Bax ratio was higher in OSCC compared to MO (p<0.05). CONCLUSION: There are immunohistochemical differences according to histological grades of OSCC, which could influence clinical behavior.

Aberrant immunoexpression of p53 tumour-suppressor and Bcl-2 family proteins (Bcl-2 and Bax) in ameloblastomas and odontogenic keratocysts.

Background: The growth of ameloblastomas (odontogenic tumours) and odontogenic keratocyst (OKC) (developmental cyst) is associated with the expression of proteins related to cell survival and apoptosis. Bcl-2-associated protein X (Bax) and the tumour suppressor protein p53 collectively promote p53-mediated apoptosis. This study aimed to assess the immunohistochemical expression of p53, Bcl-2 and Bax in conventional ameloblastoma (CA), unicystic ameloblastoma (UA) types, and OKC sporadic (OKC-NS/S) and syndromic (OKC-NBSCC). Material and Methods: Paraffinized blocks of CA (n=18), UA (n=15), OKC-NS/S (n=18) and OKC-NBSCC (n=15) fixed in 10% formalin were used. After diagnosis, tissue specimens were stained by immunohistochemistry for p53, Bcl-2 and Bax marker. Stained cells were randomly counted in five high power fields. The data analysis was performed via Shapiro-Wilk test, ANOVA with Tukey's multiple comparisons or Kruskal-Wallis with Dunn's multiple comparisons. Statistical significance was defined as p<0.05. Results: We did not observe differences between p53 expression in CA, mural UA (MUA), intraluminal/luminal UA (I/LUA), OKC-NS/S, and OKC-NBSCC (19.69%, 18.74%, 16.76%, 12.35% and 9.04%, respectively). Similar results were recognized for Bax expression in CA, MUA, I/LUA, OKC-NS/S, and OKC-NBSCC (33.72%, 34.95%, 22.94, 21.58% and 20.76%, respectively). However, we recognized significant differences between Bcl-2 expression in OKC-NS/S vs MUA, OKC-NS/S vs I/LUA, OKC-NS/S vs CA, OKC-NBSCC vs MUA, OKC-NBSCC vs I/LUA, and I/LUA vs CA. P53, Bcl-2 and Bax levels were higher in mural morphological areas versus intraluminal and luminal morphological areas in UA. Conclusions: There is a tendency for an increased expression of p53, Bcl-2, and Bax proteins in CA, and mural proliferation of UA, compared to lesions with a cystic morphology, which could be associated with a local aggressive behaviour. Key words:p53, Bcl-2, Bax protein, apoptosis, odontogenic tumour, odontogenic cyst.

Cyclooxygenase-2 protein expression modulates cell proliferation and apoptosis in solid ameloblastoma and odontogenic keratocyst. An immunohistochemical study.

BACKGROUND: Cyclooxygenase-2 protein is a critically important mediator in inflammation that influences proliferation, apoptosis, angiogenesis and metastasis. Previous works showed a relationship between cyclooxygenase-2 and tumourigenesis in humans and animal models. In epithelial odontogenic tumours and cysts, increased cell proliferation and survival have been linked to its pathogenesis and tumour development. The aim of the present study was to analyse the immunohistochemical expression of cyclooxygenase-2 in solid ameloblastoma and odontogenic keratocyst and its association with proteins related to cell proliferation and apoptosis. METHODS: This study was conducted on 40 cases from the Pathological Anatomy Service, University of Chile. The cases were diagnosed as solid ameloblastoma (n = 21) and odontogenic keratocyst (n = 19) according to WHO 2017. Slides prepared from paraffin-embedded sections were immunohistochemically stained for cyclooxygenase-2, cyclin D1, Ki-67, p63 and Bcl-2. Statistical evaluation was performed by the Shapiro-Wilk test, ANOVA Mann-Whitney test and Spearman's correlation coefficient (p < 0.05). RESULTS: There were significant differences in the immunoexpression of cyclin D1, Ki-67 and Bcl-2 between solid ameloblastoma and odontogenic keratocyst. Likewise, there was a significant difference in the immunoexpression of p63 between follicular and plexiform histological types/subtypes of solid ameloblastoma. Lastly, there were statistical associations between cyclooxygenase-2 and Ki-67 for solid ameloblastoma and between cyclooxygenase-2 and p63 for odontogenic keratocyst. CONCLUSION: A high level of cyclooxygenase-2 is related to increased cell survival and proliferative activity in solid ameloblastoma and odontogenic keratocyst. This event might contribute to tumoural progression and local invasiveness in these lesions.

The Inflammatory Profile of the Tumor Microenvironment, Orchestrated by Cyclooxygenase-2, Promotes Epithelial-Mesenchymal Transition.

The tumor microenvironment (TME) corresponds to a complex and dynamic interconnection between the extracellular matrix and malignant cells and their surrounding stroma composed of immune and mesenchymal cells. The TME has constant cellular communication through cytokines that sustain an inflammatory profile, which favors tumor progression, angiogenesis, cell invasion, and metastasis. Although the epithelial-mesenchymal transition (EMT) represents a relevant metastasis-initiating event that promotes an invasive phenotype in malignant epithelial cells, its relationship with the inflammatory profile of the TME is poorly understood. Previous evidence strongly suggests that cyclooxygenase-2 (COX-2) overexpression, a pro-inflammatory enzyme related to chronic unresolved inflammation, is associated with common EMT-signaling pathways. This review article summarizes how COX-2 overexpression, within the context of the TME, orchestrates the EMT process and promotes initial metastatic-related events.

Patrones Epidemiológicos del Trauma Dentoalveolar (PatologíaGES) en Pacientes Adultos Atendidos en un Centro de Trauma de Chile Durante 2 Períodos / Epidemiological Patterns of Traumatic Dental Injuries (GES Disease) in Adult Patients Treated at a Chilean National Trauma Center during 2 Periods

El trauma dentoalveolar (TDA) constituye un conjunto de lesiones que comprometen los dientes o a sus estructuras periodontales. En Chile, desde el año 2007, la primera consulta/tratamiento de urgencia del TDA está cubierta por la Ley N 19.966, para todas las personas afiliadas al Fondo Nacional de Salud (FONASA) y a las Instituciones de Salud Previsional Privadas (ISAPRE) a través del Programa de Garantías Explícitas en Salud (GES). Escasos estudios nacionales se han realizado en TDA de adultos y ninguno en relación al impacto del GES en estas lesiones. Se realizó un estudio retrospectivo, descriptivo y transversal de TDA con los Datos de Urgencia de todos los pacientes adultos atendidos en el Hospital de Urgencia Asistencia Pública. Se compararon las variables clínicas, etiológicas, demográficas y sociales entre 2 períodos: pre-GES (1 de Julio de 2005 al 30 de Junio de 2006) y post-GES (1 de julio de 2012 al 31 junio de 2013). En los 2 períodos se observó una mayor frecuencia de TDA en el sexo masculino del grupo de 20­29 años, producidos en la mayoría de los casos por violencia interpersonal. Sin embargo se observó en el período post-GES una mayor consulta de TDA por Accidente vehículo-motorizado, presentándose lesiones de mayor gravedad. A pesar de la implementación del GES, se observó una alta frecuencia de TDA no tratados, esto podría deberse a la gravedad del estado sistémico del paciente (postergando el tratamiento de TDA), a la falta de insumos o a la inequidad en la entrega de recursos a los servicios de salud. Es necesario realizar más estudios y vigilancia de parte de la autoridad sanitaria para mejorar las garantías del GES en el tratamiento de los TDA.

Traumatic dental injury (TDI) is a group of injuries that affect hard dental tissues and/or periodontal structures. Since 2007 the first emergency treatment/consult of TDI, for both the National Health Fund (FONASA) and profit private insurer (ISAPRE) affiliates, is guaranteed in the Regulation of Explicit Health Guarantees (GES) established by Chilean Law 19.966. Few national TDI studies in adults have been carried out, and none in relation to the impact of GES in this type of lesion. A retrospective cross sectional study of emergency charts of all adult patients attended at the Hospital de Urgencia Asistencia Pública. Etiological, clinical, demographic and social variables were compared between 2 time periods, Pre-GES period (July, 1 2005 to June, 30 June 2006) versus Post-GES period (July, 1 2012 to June, 31 2013). A high incidence of TDI caused by interpersonal violence in males between 20 and 29 years old was observed in both periods. However, an increased TDI with more severe injuries caused by automobile accident was observed during the post-GES period. In spite of GES implementation, high frequency of non-treated TDI was seen in the present study, this could be due to the severity of the patient´s systemic condition (delaying the TDI treatment), a lack of resources and/or inequity in the delivery of these healthcare resources. More studies and surveillance programs by the Government are needed to improve TDI treatment guarantees, and as well as regular assessment of GES compliance.

Quiste odontogénico: análisis de 2.944 casos en Chile / Odontogenic Cysts: analysis of 2.944 cases in Chile

Introducción. Los quistes odontogénicos constituyen un grupo de frecuentes lesiones intraóseas propias de los maxilares y una de las principales causas de destrucción de estos huesos. En Chile no existen estudios retrospectivos del conjunto de estas lesiones.Objetivos. El propósito de este trabajo es determinar la frecuencia de estas lesiones diagnosticadas y registradas en el Instituto de Referencia de Patología Oral (IREPO) de la Universidad de Chile en dos grupos etáreos, así como analizar y comparar los datos obtenidos con aquellos publicados en otros estudios previos.Material y Método. Se revisaron los archivos del IREPO de la Facultad de Odontología de la Universidad de Chile correspondientesal período transcurrido entre 1976 y septiembre de 2004 y se determinó la frecuencia según edad, género y localización de cada una de estas entidades. Se hizo la comparación entre dos grupos etáreos (menor o igual a 15 años y mayores a 15 años). Los casos en que la información era insuficiente para ser analizada no fueron considerados. Todas las placas histológicas fueron reevaluadas de acuerdo a los criterios diagnósticos incluidos en la Tipificación Histológica de Tumores Odontogénicos de la OMS.Resultados. Se encontraron 2.944 quistes odontogénicos (QO), de los cuales 1.935 (65,7%) fueron quistes inflamatorios y 1.009 (34,3%) quistes del desarrollo. Con respecto al total de los quistes, hubieron 1.554 (52,8%) en hombres y 1.390 (47,2%) en mujeres. De las variedades reconocidas por la OMS, se encontraron la totalidad de ellas. Los quistes más frecuentes fueron: quistes radiculares 1.494 (50,7%); quistes dentígeros 546 (18,5%); queratoquistes 421 (14,3%) y quistes residuales 328 (11,1%). Estas cuatro variedades representan el 94,7% del total de los QO, con 2.789 casos. En población menor o igual a 15 años predominan los quistes del desarrollo (354) por sobre los quistes Inflamatorios (155), siendo los más frecuentes los quistes dentígeros con 240 casos

Introduction: Odontogenic cysts constitute a group of frequent intraosseous lesions characteristic in the maxillary bones and one of the main causes of the destruction of these bones. In Chile there are no retrospective studies of these lesions as a whole.Objective: The purpose of this study is to determine the frequency of these lesions in so far as they were diagnosed and registered in the Referral Institute for Oral Pathology (IREPO) of the University of Chile in two age groups as well as to analyze and to compare the data obtained with the data published in previous studies.Material and Method: We studied the records from IREPO of the University of Chile for the period between 1976 and September, 2004; and we determined the frequency according to age, gender and site of each of these lesions. We compare two age groups: younger than or equal to 15 years old and older than 15 years old. Those cases in which the information did not suffice for the purposes of analysis were not considered. All the histological slides were reclassiffed according to the diagnostic criteria included in the Histological Typification of the World Health Organization.Results: We found 2.944 odontogenic cysts (OC), of which 1.935 (65.7%) were inflammatory cysts and 1.009 were developmental cysts. Out of this total, there were 1.554 cysts (52.8%) in men and 1.390 (47.2%) in women. The most frequent cysts were 1.494 radicular cysts (50.7%), 546 dentigerous cysts (18.5%), 421 keratocysts (14.3%) and 328 residualcysts (11.1%).These four varieties represent 94.7% of the OC , that is, 2789 cases. In the population younger than or equal to 15 years of age the developmental cysts (354 cases) are more frequent than the inflammatory cysts (155 cases), the most frequent being dentigerous cysts (240 cases)

Odontogenic cysts: analysis of 2,944 cases in Chile.

INTRODUCTION: Odontogenic cysts constitute a group of frequent intraosseous lesions characteristic in the maxillary bones and one of the main causes of the destruction of these bones. In Chile there are no retrospective studies of these lesions as a whole. OBJECTIVE: The purpose of this study is to determine the frequency of these lesions in so far as they were diagnosed and registered in the Referral Institute for Oral Pathology (IREPO) of the University of Chile in two age groups as well as to analyze and to compare the data obtained with the data published in previous studies. MATERIAL AND METHOD: We studied the records from IREPO of the University of Chile for the period between 1976 and September, 2004; and we determined the frequency according to age, gender and site of each of these lesions. We compare two age groups: younger than or equal to 15 years old and older than 15 years old. Those cases in which the information did not suffice for the purposes of analysis were not considered. All the histological slides were reclassiffed according to the diagnostic criteria included in the Histological Typification of the World Health Organization. RESULTS: We found 2.944 odontogenic cysts (OC), of which 1.935 (65.7%) were inflammatory cysts and 1.009 were developmental cysts. Out of this total, there were 1.554 cysts (52.8%) in men and 1.390 (47.2%) in women. The most frequent cysts were 1.494 radicular cysts (50.7%), 546 dentigerous cysts (18.5%), 421 keratocysts (14.3%) and 328 residual cysts (11.1%). These four varieties represent 94.7% of the OC , that is, 2789 cases. In the population younger than or equal to 15 years of age the developmental cysts (354 cases) are more frequent than the inflammatory cysts (155 cases), the most frequent being dentigerous cysts (240 cases).

Odontogenic tumors in Chile: a study of 362 cases.

BACKGROUND: Odontogenic tumors are infrequent lesions. Thus, the review of a large number of cases becomes a necessity for both the pathologist and the clinician. Studies on odontogenic tumors have been published in many parts of the world, but there is little information available in the English language literature on the relative frequency of odontogenic tumors in Latin America. The aim of this study was to determine the relative frequency of this heterogeneous group of lesions in a Chilean population, and to compare these data with previous reports. METHODS: We reviewed the records of 28,041 specimens from 1975 to 2000 in the Oral Pathology Referral Institute (IREPO), and using the criteria for histological typification published by the World Health Organization in 1992, we reclassified the odontogenic tumors. RESULTS: We confirmed a total of 362 odontogenic tumors. The frequency of odontogenic tumors as a percentage of all pathological specimens in our institute was 1.29%. The most frequent histological type was odontomas (44.7%), followed by ameloblastomas (20.4%) and myxomas (8.8%). CONCLUSIONS: Odontogenic tumors are uncommon lesions in the Chilean population and malignant odontogenic tumors are very rare. The relative frequency of various types of odontogenic tumors, as well as the age and gender distribution are similar to those reported in the North American series and different from those found in recently published Asian and African series.