Cemento-osseous dysplasia : a diagnostic challenge

Cemento-osseous dysplasia is the most common fibroosseous lesion affecting the jaw bones. Due to the potential risk of introducing an infection, biopsy of an asymptomatic lesion is contra-indicated and it is therefore mandatory to establish an accurate diagnosis only on clinical and radiological information. In order to achieve this, a thorough knowledge of the clinical manifestations of cemento-osseous dysplasia together with the pertinent radiological features is required. This paper is aimed at providing oral health practitioners with the diagnostic features and clinical differential diagnosis of the spectrum of lesions categorised as cemento-osseous dysplasia.http://www.sada.co.zaam2019Oral Pathology and Oral Biolog

White rhinoceros Ceratotherium simum horn development and structure : a deceptive optical illusion

The alleged traditional medicinal properties of rhinoceros horn resulted in a dramatic escalation in rhinoceros poaching in South Africa. Despite the listing of all species of rhinoceros in the International Union for Conservation of Nature Red List of threatened animals, their numbers are still declining rapidly. Based on the assumption that rhinoceros' horn consists of a collection of hollow tubules and intertubular hollow spaces, which allow internal fluid distribution, a horn devaluation procedure through infusion of chemicals and dyes was recently introduced. This procedure is costly and has a mortality risk. This study provides the first detailed description of the development and resultant structure of the rhinoceros horn. The unique solid structure which consists of a large number of tightly packed filaments is the result of the cellular orientation of squamous epithelium corneocytes. What was previously thought to be microtubules is an optical illusion created by the orientation of the corneocytes in the solid filaments. We contest the scientific basis for infusing chemicals into the rhinoceros horn as a deterrent for human use.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1469-79982016-07-31hb201

Clinical and pathological differences between the pyogenic granuloma and lobular capillary hemangioma in the oral cavity : a scoping review

Since initially described, the terms “pyogenic granuloma” (PG) and “lobular capillary hemangioma” (LCH) have undergone a significant change in meaning, which leads to a confusion in the literature. In this study, we attempted to investigate if there are any clinical and pathological differences between the pyogenic granuloma and lobular capillary hemangioma through a scoping review of the available literature. A Medline search has identified 342 articles from 2001 to 2018, from which English papers, case series, retrospective studies, and cross-sectional studies were selected. Data from the articles was charted using appropriate subheadings for the clinical question (e.g., number of patients, clinical features, histology, pathogenesis, differential diagnosis, treatment). Compared to LCH, PG seems to occur more in the middle-aged range, has a clearer predilection for (pregnant) females, and has more frequently a known triggering factor in the history. Histologically, PGs appear as radially organized capillaries (while LCHs have a lobular pattern), have a mixed inflammatory infiltrate (compared to the occasional lymphocytic infiltrate in LCHs), and can undergo fibrosing transformation when chronic, which is not seen in LCHs. Finally, besides basic excision, several other treatment options have been described for both lesions. Since the pyogenic granuloma and lobular capillary hemangioma show clinical and pathological differences, we propose them to be considered as distinct lesions, which makes interpreting the literature much easier.https://www.termedia.pl/Journal/Journal_of_Stomatology-137am2021Oral Pathology and Oral Biolog

Human papillomavirus infection of the oral cavity : what the dentist should know

The incidence of human papilloma virus-induced oropharyngeal carcinoma is steadily rising globally and the observation has become widely publicised in recent times. Human papilloma virus (HPV) is therefore an important infectious oncogenic agent. The aim of this article is to highlight the modes of transmission in HPV-related oral and oropharyngeal lesions whilst explaining the morphological spectra of benign and malignant disease which are attributed to low-risk and high-risk subtypes respectively. These issues as well as the topic of vaccination against HPV are likely to be the concern of many dental patients. The oral health care worker is therefore expected to provide appropriate counselling and education when informing patients of the potential health risks posed by HPV.https://www.sada.co.za/the-sadjam2018Oral Pathology and Oral Biolog

Human papillomavirus and carcinoma of the mucosal surfaces of the head and neck

Human papillomavirus induced cervical cancer is the fourth most prevalent malignancy affecting females globally. Over the past two decades scientific information unveiled an increasing role for the virus in the pathogenesis of malignancies developing from the mucosal surfaces of the oropharynx. It is feasible to postulate that we may be in the beginning of a global pandemic of oropharyngeal cancer if the mode of transmission of the virus is taken into account. The main goals of this manuscript are to present a brief summary of the mechanisms of human papillomavirus induced malignant transformation, provide guidelines for the microscopic diagnosis of high risk human papillomavirus involvement in mucosal biopsies and highlight the implications thereof in cancers of the mucosal surfaces of the head and neck.http://www.elsevier.com/locate/jomsmp2019-01-01hj2017Oral Pathology and Oral Biolog

Lung adenocarcinoma promotion by air pollutants

A complete understanding of how exposure to environmental substances promotes cancer formation is lacking. More than 70 years ago, tumorigenesis was proposed to occur in a two-step process: an initiating step that induces mutations in healthy cells, followed by a promoter step that triggers cancer development1. Here we propose that environmental particulate matter measuring ≤2.5 μm (PM2.5), known to be associated with lung cancer risk, promotes lung cancer by acting on cells that harbour pre-existing oncogenic mutations in healthy lung tissue. Focusing on EGFR-driven lung cancer, which is more common in never-smokers or light smokers, we found a significant association between PM2.5 levels and the incidence of lung cancer for 32,957 EGFR-driven lung cancer cases in four within-country cohorts. Functional mouse models revealed that air pollutants cause an influx of macrophages into the lung and release of interleukin-1β. This process results in a progenitor-like cell state within EGFR mutant lung alveolar type II epithelial cells that fuels tumorigenesis. Ultradeep mutational profiling of histologically normal lung tissue from 295 individuals across 3 clinical cohorts revealed oncogenic EGFR and KRAS driver mutations in 18% and 53% of healthy tissue samples, respectively. These findings collectively support a tumour-promoting role for PM2.5 air pollutants and provide impetus for public health policy initiatives to address air pollution to reduce disease burden

Development of the tush and tusk and tusklessness in African elephant (<i>Loxodonta africana</i>)

The embryologic development of the tush and tusk of the African elephant was studied by means of serial histologic sections prepared from elephant embryos with masses varying between Ig and 240 g. Statistics on tusklessness obtained during a four year population control programme in the Kruger National Park were analysed and compared with those reported in other elephant reserves in Southern Africa. Maxillae of eight elephant embryos, the maternal histories of which were available in six cases, were radiographed, dissected and examined microscopically. This study has shown that the tush and tusk develop from one tooth germ in a deciduous to permanent tooth relationship. Tusklessness was found to be unilateral or bilateral and associated with either the absence or presence of a tush. The possible causes of the differences in the frequency of bilateral tusklessness in different elephant populations are discussed

Correlation between p53 gene mutation, p53 protein labeling and PCNA expression in oral squamous cell carcinomas

Background: The prevalence of oral squamous cell carcinoma (OSCC) among the Black community in South Africa is unacceptably high. The association between p53 protein, and PCNA overexpression and the presence of p53 gene mutations was evaluated. Materials and Methods: One hundred and ten formalin-fixed, paraffin-embedded blocks of OSCC were selected for immunohistochemical studies for p53 protein and PCNA expression using the DO-7 and PC10 monoclonal antibodies, respectively. DNA was extracted from fifty-five blocks and exons 5 to 9 of the p53 gene were amplified with nested primers, thereafter sequencing was performed to confirm the presence of mutations detected by single stranded conformational polymorphism. Results: Fifty-six cases (51%) showed p53 expression, while fourteen mutations (25%) were detected. A significant difference was found between the PCNA index in p53 positive and p53 negative tumors while the mean PCNA index for the tumors with p53 mutations was not significantly different from the tumors without mutations. Conclusions: No association between p53 protein overexpression and p53 gene mutations could be demonstrated.Articl