Leukoplakia and erythroplakia in youngers versus older individuals: a clinicopathological retrospective study.

BACKGROUND: The incidence of oral cancer has exhibited a rise within the young population. Considering that oral potentially malignant disorders (OPMDs) can precede the development of oral cancer, it is imperative to conduct studies in this particular younger population. This study aimed to evaluate the frequency and conduct a comparative analysis of the clinical-demographic characteristics of OPMDs in two distinct age groups. MATERIAL AND METHODS: A retrospective analysis was conducted with patients diagnosed with leukoplakia, erythroplakia, and leukoerythroplakia between 1965 and 2020. The individuals were categorized into two groups: those aged up to 40 years (Group Younger) and those aged 41 years and above (Group Older). RESULTS: A total of 640 lesions were subjected to analysis. Among these, patients aged up to 40 years constituted 10.63% of the sample, however, this proportion decreased significantly to 6.9% between 2010 and 2020. A predominant male representation was observed in both groups, with white lesions being the most common in both as well. However, the frequency of red or mixed lesions was significantly higher (p=0.034) in the older group, along with a higher prevalence of dysplastic lesions (26.9% versus 11.8%, p=0.01). Moreover, the older group exhibited a relatively higher percentage of smokers/ex-smokers (78.6%), compared to the younger group (61.5%, p=0.085) and alcohol consumers/ex-consumers (54.9% versus 22.7%, p=0.028). Elderly individuals exhibited an unfavorable progression (p=0.028). However, a logistic regression analysis identified as significant variables associated with malignant transformation, the presence of epithelial dysplasia, and red lesions diagnosed as erythroplakia. CONCLUSIONS: A declining frequency of OPMDs in young adults was observed over the years, whereas in older adults, these disorders exhibited an unfavorable progression.

Development of an in vitro model to study tooth cystogenesis.

AIM: To describe an in vitro experimental model of cystic structure formation to conduct research on radicular cyst development. METHODOLOGY: To form spheroid structures, various numbers (1 × 104 , 5 × 104 or 1 × 105 ) of epithelial cells (HaCaT and Cal27) were seeded in 96-well plates previously coated with 1.5% low-melting agarose. After 24 h, the spheroids were collected, embedded in 3D collagen matrix and transferred to 24-well plates previously coated with polymerized collagen and kept for up to 21 days. Images of spheroids were captured at each time-point (1, 5, 9, 15 and 21 days), and samples underwent histological and confocal microscopy analyses. Spheroid area, perimeter and cell dispersion were measured. One-way Anova was used for statistical analysis. RESULTS: Both epithelial cell lines were able to generate regular and circular spheroids after 24 h of incubation regardless of cell density. Spheroid structures in the collagen matrix were uniform in most samples until day 15, when several spots that appeared to be new cultures were seen. Spheroids from HaCaT were significantly more stable than those from Cal27 (P < 0.05). Starting on the third day, the examination of histological sections revealed a cavity with epithelial lining morphology, similar to a pathological radicular cyst. CONCLUSIONS: This study describes an experimental model of cystogenesis in vitro that may be used to test theories and investigates the effects of different growth factors during cyst development and maintenance.

Epithelial oral mucosal cells: Do they behave differently when exposed to oral carcinogens?

OBJECTIVE: To assess the level of maturation and proliferation of epithelial cells and the correlation with immunocytochemical expression of adhesion (E-cadherin) and cell differentiation (involucrin) markers. METHODS: Cytopathological samples were obtained from four groups of patients: control (CG, n=30); alcohol/tobacco (ATG, n=31), leucoplakia (LG, n=31), and squamous cell carcinoma (SCCG, n=22). Cytopathological smears were collected from all groups for AgNOR, Papanicolaou and immunocytochemical staining. RESULTS: There was an increase in anucleated cells in ATG compared to CG and in LG compared to lesion-free groups (P<.05). In addition, there was a higher rate of intermediate cells in lesion-free groups than in LG (P=.001). When these findings were correlated with positive E-cadherin expression, there was a smaller number of anucleated and intermediate cells (P<.05). The proliferation rate was higher in the SCCG than in the CG (P<.05) and in the ATG compared to LG (P<.05). Moreover, cell proliferation increased in the presence of positive E-cadherin expression in the ATG and LG. No statistically significant results were obtained for involucrin analysis. CONCLUSION: Cytopathology combined with quantitative techniques such as Papanicolaou, AgNOR, and immunocytochemical expression of E-cadherin detects changes associated with oral carcinogenesis. The innovative approach used in this study allows assessing the expression of cell adhesion (E-cadherin) and differentiation (involucrin) markers by means of oral mucosal cytopathology. The E-cadherin imunocytochemical expression indicated changes associated with the oral carcinogenesis process. An increase in cell proliferation rate in oral squamous cell carcinoma group was associated with the lower immunoexpression of E-cadherin. Cytopathology combined with quantitative techniques and immunocytochemical expression of E-cadherin may detect early alterations associated with oral carcinogenesis.