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BACKGROUND: Histological techniques are essential for the microscopic study and investigation of the human dental pulp. The aim of this study was to evaluate the impact of decalcification-free technique by examining dental pulp morphology by histological staining with haematoxylin and eosin and immunohistochemistry. MATERIALS AND METHODS: The sample consisted of 30 healthy third molars extracted for orthodontic indication, the pulp tissue was obtained by removing the mineralized tissues, separating the enamel and dentine and by marking with a flexible diamond disc on the coronal surface and longitudinal axis of the root. These guides made it possible to separate the fragments and obtain the pulp tissue for fixation and staining with H&E and subsequent immunohistochemistry with CD34 and S-100 antibodies. RESULTS: The technique showed preservation of pulp morphology with adequate preservation of microscopic structures. No alterations in tissue viability were observed. The staining allowed an accurate assessment of vascular and nervous components by means of CD34 and S-100 markers, respectively. CONCLUSIONS: This technique allows preservation of pulp tissue, maintaining viable tissue for histological analysis and immunohistochemistry tests, as well as reducing sample processing time.

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BACKGROUND: Dental fluorosis (DF) is caused by excessive exposure to fluoride during odontogenesis and leads to various changes in the development of tooth enamel. Some regions in Mexico are considered endemic fluorosis zones due to the high fluoride content in drinking water. The objective of this study was to perform a systematic review and meta-analysis to identify the association between the concentration of fluoride in drinking water and the severity of dental fluorosis in northern and western Mexico. METHODS: This protocol was registered in the PROSPERO database (ID: CRD42023401519). The search for information was carried out in the PubMed/Medline, Scopus, SpringerLink, and Google Scholar databases between January 2015 and October 2023. The overall relative risk was calculated using the inverse of variance approach with the random effects method. The RoB 2.0 tool was used to construct risk plots. RESULTS: Eleven articles were analyzed qualitatively, and most of the included studies presented at least one level of DF severity; six articles were analyzed quantitatively, dividing them into two regions. In North region it was observed a higher prevalence of severe TF cases, corresponding to ≥ TF 5 category (4.78) [3.55, 6.42]. In the West region, most of the included studies presented a higher prevalence of less severe cases, corresponding to ≤ TF 4, in comparison with the North region (0.01) [0.00, 0.52], interpreted as a protective effect. CONCLUSION: The concentrations of fluorides in drinking water are reportedly high in these regions and are directly related to the severity of dental fluorosis experienced by the inhabitants. In the Northern region exists a major concentration of fluoride in drinking water compared with the Western region as well as a prevalence of higher severity cases of dental fluorosis.

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Targeted therapy has the potential to be used in the neoadjuvant setting for odontogenic tumors, reducing the morbidities associated with major surgery. In this regard, the aim of this study was to summarize the current evidence on the different forms of targeted therapy, effectiveness, and drawbacks of this course of treatment. Four databases were searched electronically without regard to publication date or language. Grey literature searches and manual searches were also undertaken. Publications with sufficient clinical data on targeted therapy for odontogenic tumors were required to meet the criteria for eligibility. The analysis of the data was descriptive. A total of 15 papers comprising 17 cases (15 ameloblastomas and 2 ameloblastic carcinomas) were included. Numerous mutations were found, with BRAF V600E being most common. Dabrafenib was the most utilized drug in targeted therapy. Except for one case, the treatment reduced the size of the lesion (16/17 cases), showing promise. Most of the adverse events recorded were mild, such as skin issues, voice changes, abnormal hair texture, dry eyes, and systemic symptoms (e.g., fatigue, joint pain, and nausea). It is possible to reach the conclusion that targeted therapy for ameloblastoma and ameloblastic carcinoma may be a useful treatment strategy, based on the findings of the included studies.

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The International Agency for Research on Cancer (IARC) and World Health Organization (WHO) collaboratively produce the 'WHO Blue Books' essential tools standardizing the diagnostic process for human cancers. Regular updates in this classification accommodate emerging molecular discoveries, advances in immunohistochemical techniques, and evolving clinical insights. The 5th edition of the WHO/IARC classification of head and neck tumors refines the 'Oral Cavity and Mobile Tongue' chapter, including sections for non-neoplastic lesions, epithelial tumors, and tumors of uncertain histogenesis. Notably, the epithelial tumors section is rearranged by tumor behavior, starting with benign squamous papillomas and progressing through potentially malignant oral disorders to oral squamous cell carcinoma (OSCC). The section on OSCC reflects recent information on epidemiology, pathogenesis, and histological prognostic factors. Noteworthy is the specific categorization of verrucous carcinoma (VC) and carcinoma cuniculatum (CC), both associated with the oral cavity and distinct in clinical and histologic characteristics. This classification adjustment emphasizes the oral cavity as their predominant site in the head and neck. Designating specific sections for VC and CC aims to provide comprehensive insights into these unique subtypes, elucidating their clinical features, distinct histological characteristics, prevalence, significance, and clinical relevance. By categorizing these subtypes into specific sections, the 5th edition of the WHO classification aims to provide a more nuanced and detailed account, enhancing our understanding of these specific variants within the broader spectrum of head and neck tumors.

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BACKGROUND: Myofibromas are rare benign neoplasms composed of myoid cells and myofibroblasts. This study aimed to systematically review case reports and a series of myofibromas (MF) and myofibromatosis (MFT) occurring in the oral and maxillofacial regions in order to describe their main clinicopathological features. METHODS: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic searches were conducted in 2023 in four databases: MEDLINE/PubMed, Web of Science, Scopus, and EMBASE. A manual search and a search in the grey literature were also conducted. The lesions were classified as MF or MFT according to their original report. RESULTS: A total of 169 cases were included in this systematic review. Men were slightly more affected, with a painless nodule. When occurring in soft tissue, MF usually developed in the gingiva (mean age:29.23 ± 21.93 years) and when it was intra-osseous, it occurred more frequently in the posterior mandible (mean age:14.33 ± 15.62 years). MFT occurred mainly in the mandible and was predominantly described as well-circumscribed masses of spindle cells organized in fascicles with a prominent vascular activity in a hemangiopericytoma-like pattern. The lesions were mainly positive for smooth muscle actin and vimentin immunomarkers. Surgical excision was the treatment of choice in the majority of cases and recurrence was observed in only three cases. CONCLUSION: MF and MFT affect more men, with an indolent clinical course. Intra-osseous tumors and MFT seem to occur more frequently in younger individuals. These lesions seem to have a good prognosis and low recurrence.

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Hypoxia is characterized by a disparity between supply and demand of oxygen. The association between hypoxia and head and neck tumors is a topic of significant interest. Tumors frequently encounter areas with inadequate oxygen supply, resulting in a hypoxic microenvironment. Ameloblastoma is one of the most common benign odontogenic tumors of the maxillofacial region. It is a slow-growing but locally invasive tumor with a high recurrence rate. The literature has demonstrated the correlation between hypoxia and ameloblastoma, revealing a discernible link between the heightened expression of hypoxic markers in low oxygen conditions. This association is intricately tied to the tumoral potential for invasion, progression, and malignant transformation. Hypoxia profoundly influences the molecular and cellular landscape within ameloblastic lesions. The present review sheds light on the mechanisms, implications, and emerging perspectives in understanding this intriguing association to clarify the dynamic relationship between hypoxia and ameloblastoma.

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OBJECTIVE: This study aimed to explore perceived barriers to early diagnosis and management of oral cancer, as well as potential pathways for improvement in Latin America and the Caribbean (LAC). METHODS: This cross-sectional study used a self-administered online questionnaire created via the Research Electronic Data Capture platform. The survey was distributed to health professionals trained in Oral Medicine, Oral Pathology, Oral and Maxillofacial Surgery, and Dentists with clinical and academic expertise in oral potentially malignant disorder (OPMD) and oral cancer. Data obtained were systematically organized and analyzed descriptively using Microsoft Excel. RESULTS: Twenty-three professionals from 21 LAC countries participated. Major barriers included the limited implementation of OPMD and oral cancer control plans (17.4%), low compulsory reporting for OPMD (8.7%) and oral cancer (34.8%), unclear referral pathways for OPMD (34.8%) and oral cancer (43.5%), and a shortage of trained professionals (8.7%). Participants endorsed the utility of online education (100%) and telemedicine (91.3%). CONCLUSION: The survey highlights major perceived barriers to early diagnosis and management of OPMD and oral cancer in LAC, as well as potential avenues for improvement.

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Infection with high-risk human papillomaviruses like HPV-16 and HPV-18 is highly associated with the development of cervical and other cancers. Malignant transformation requires viral oncoproteins E5, E6 and E7, which promote cell proliferation and increase DNA damage. Oxidative stress and hypoxia are also key factors in cervical malignant transformation. Increased levels of reactive species of oxygen (ROS) and nitrogen (RNS) are found in the hypoxic tumor microenvironment, promoting genetic instability and invasiveness. In this work, we studied the combined effect of E5, E6 and E7 and hypoxia in increasing oxidative stress and promoting DNA damage and nuclear architecture alterations. HaCaT cells containing HPV-18 viral oncogenes (HaCaT E5/E6/E7-18) showed higher ROS levels in normoxia and higher levels of RNS in hypoxia compared to HaCaT parental cells, as well as higher genetic damage in hypoxia as measured by γH2AX and comet assays. In hypoxia, HaCaT E5/E6/E7-18 increased its nuclear dry mass and both cell types displayed marked heterogeneity in nuclear dry mass distribution and increased nuclear foci. Our results show contributions of both viral oncogenes and hypoxia to oxidative stress, DNA damage and altered nuclear architecture, exemplifying how an altered microenvironment combines with oncogenic transformation to promote tumor progression.

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OBJECTIVE: To determine the frequency of oral squamous cell carcinoma (OSCC) associated or not with oral potentially malignant disorders (OPMD), and the epidemiological profile and traditional risk factors in Latin America. METHODS: A retrospective observational study was conducted in 17 Latin American centres. There were included cases of OSCC, analysing age, gender, OSCC and their association with previous OPMD. Clinicopathological variables were retrieved. The condition of sequential-OSCC versus OSCC-de novo (OSCC-dn) was analysed concerning the aforementioned variables. Quantitative variables were analysed using Student's t-test, and qualitative variables with chi-square. RESULTS: In total, 2705 OSCC were included with a mean age of 62.8 years old. 55.8% were men. 53.75% of the patients were smokers and 38% were common drinkers. The lateral tongue border was the most affected site (24.65%). There were regional variations in OPMD, being leukoplakia the most frequent. Of the overall 2705 OSCC cases, 81.4% corresponded to OSCC-dn, while s-OSCC were 18.6%. Regarding lip vermillion SCC, 35.7% corresponded to de novo lip SCC and 64.3% were associated with previous OPMD. CONCLUSIONS: In Latin America, OSCC-dn seems to be more frequent with regional variations of some clinical and histopathological features. Further prospective studies are needed to analyse this phenomenon.