Insight into the molecular pathogenesis of odontogenic lesions

A Comparison of Immunohistochemical Expression of Epidermal Growth Factor Receptor and Human Epidermal Growth Factor Receptor 2 in Dental Follicles with Different Radiographic Sizes

Background

Odontogenic cysts and tumors develop from the dental follicle of asymptomatic impacted teeth. Odontogenic tissues express the epidermal growth factor receptor family (EGFR), which mediates cell proliferation, survival, and neoplastic differentiation. The present study aimed to compare the immunohistochemical expression of EGFR and human epidermal growth factor receptor 2 (HER2) in the dental follicle of impacted wisdom teeth with normal and abnormal radiographic size.

Methods

In this analytical study, immunohistochemical staining of EGFR and HER2 was performed on 30 normal and 30 abnormal follicles of impacted third molars. Follicles with a width of <2.5 mm were considered normal, whereas those with a width of ≥2.5 mm were regarded as abnormal. The immunoreactive score (IRS) was used to report the expression levels of EGFR and HER2. The obtained data were analyzed using SPSS software. Age and sex were compared in normal and abnormal groups with independent t test and Chi square test, respectively. P<0.05 was considered statistically significant.

Results

The EGFR and HER2 overall expression was high in all normal and abnormal follicles. The comparison of the percentage of stained cells and intensity of EGFR and HER2 staining in normal and abnormal follicles were not significantly different (P=0.73, P=0.63, P=0.95, respectively).

Conclusion

Due to the high expression of EGFR and HER2 in normal and abnormal follicles, as well as the lack of significant differences in these two groups, the radiographic size of dental follicles might not indicate the potential capabilities of their cells, and more research in this field is recommended.

A systematic review on odontogenic cysts and tumours

Background

There are still certain gaps in the research that need to be filled despite the fact that numerous studies have looked into the transformation of odontogenic cysts into neoplastic lesions. To identify pertinent research that had been published and to synthesise the available data and provide an overview of the current body of knowledge, this review also sought to do so.

Materials and Methods

Adopting the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a search strategy was implemented across several online databases to search for relevant articles as per the defined selection criterion.

Results

After the search strategy was complete, 31 studies were chosen. Men tended to have more cancer than women. Swelling and discomfort were the primary pathology-related complaints. Although two cases were not detailed, radiologically, well-defined and poorly defined borders were reported in 18 and 11 participants, respectively. Squamous cell carcinoma with good differentiation (n = 12) was the most common cancer kind. More than 74% of patients were still living 6 months to 10 years following follow-up, four (12.90%) experienced recurrences and/or metastases and two (6.45%) experienced a disease-related mortality between 2 months and a year.

Conclusion

Prompt surgical follow-ups and cautious excision of odontogenic cysts are essential to avoiding neoplastic change and recurrence. Future research is required to look at possible reasons why odontogenic cysts can convert neoplastically.

Differential expression of PEA3 in odontogenic cysts and tumors

BACKGROUND

PEA3 transcription factor has been identified as a downstream target of the MAPK and PI3K pathways, and PEA3 overexpression has been observed in a variety of tumor types. We aimed to evaluate PEA3 expression in odontogenic cysts and tumors and compare the expression among odontogenic lesions. In addition, the correlations between PEA3 expression and clinicopathological characteristics of conventional ameloblastoma and unicystic ameloblastoma were investigated.

METHODS

This study was performed on 165 samples of odontogenic cysts and tumors including 20 dentigerous cysts, 20 odontogenic keratocysts, 16 adenomatoid odontogenic tumors, 5 ameloblastic fibromas, 45 unicystic ameloblastomas, and 59 conventional ameloblastomas. The sections were immunohistochemically stained with mouse monoclonal anti-PEA3 antibody and PEA3 expression was evaluated as the immunoreactive score.

RESULTS

PEA3 expression was absent in all dentigerous cysts (DCs) and odontogenic keratocysts, while all adenomatoid odontogenic tumors showed either no (75%) or low (25%) expression of PEA3. Most of the ameloblastic fibromas (60%) displayed no PEA3 expression. A high expression of PEA3 was observed in a substantial number of unicystic ameloblastomas (48.9%) and conventional ameloblastomas (49.2%) in our study. PEA3 expression in DCs, odontogenic keratocysts and adenomatoid odontogenic tumors were significantly different from that in conventional ameloblastomas and that in unicystic ameloblastomas (p < 0.05). The expression of PEA3 was significantly different in the age groups of unicystic ameloblastomas and histological subtypes of conventional ameloblastomas (p < 0.05).

CONCLUSION

PEA3 overexpression is predominant in unicystic ameloblastomas and conventional ameloblastomas compared to other odontogenic lesions, indicating a pivotal role of PEA3 as a downstream effector of MAPK pathway in these two odontogenic lesions.

Transformation of Odontogenic Cysts to Neoplasms - A Systematic Review

Background

Odontogenic cysts have the potential to transform into neoplasms. However, the characteristics of those which transformed to neoplastic tissues have not been well described and the exact causes of that phenomenon are not yet clear.

Objectives

This study aims to describe characteristics of odontogenic cysts that transformed into neoplasms and to look for their potential etiologies.

Data Sources

English-written studies indexed in PubMed, Science Direct, and Proquest were assessed using keywords verified by Medical Subject Headings: 'Odontogenic Cyst' and 'Neoplastic Cell Transformation'.

Study Eligibility Criteria

Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines were used as guidance.

Participants

Following steps in PRISMA guidelines, 19 articles were fully reviewed (three case series and 16 case reports) with 27 subjects of 16 males (59%) and 11 females (41%) from 15 to 86 years old.

Results

Cystic origins were eight dentigerous cysts, four odontogenic keratocysts, two residual cysts, one radicular cyst, one calcifying odontogenic cyst, one follicular cyst, one glandular odontogenic cyst, and nine unspecified odontogenic cysts that transformed to ameloblastoma (3 cases) and carcinoma (24 cases).

Limitations

Neoplastic transformations of odontogenic cysts arose from epithelial remnants of inadequate odontogenic cyst removal and chronic inflammation due to infection. However, the exact causes of their transformations remain unclear.

Conclusions

Therefore, careful removal of odontogenic cysts and regular postoperative follow-ups are key to prevent recurrence and neoplastic transformation. Future studies are needed to investigate potential causes of neoplastic transformation of odontogenic cysts.

Oral biosciences: The annual review 2021

BACKGROUND

The Journal of Oral Biosciences is devoted to advancing and disseminating fundamental knowledge concerning every aspect of oral biosciences.

HIGHLIGHT

This review features review articles in the fields of "Extracellular Vesicles," "Propolis," "Odontogenic Tumors," "Periodontitis," "Periodontium," "Flavonoids," "Lactoferrin," "Dental Plaque," "Anatomy," "Induced Pluripotent Stem Cells," "Bone Cell Biology," "Dysgeusia," "Dental Caries," and "Dental Pulp Cavity," in addition to the review article by the winners of the "Lion Award" ("Sox9 function in salivary gland development") presented by the Japanese Association for Oral Biology.

CONCLUSION

These reviews in the Journal of Oral Biosciences have inspired its readers to broaden their knowledge regarding various aspects of oral biosciences. The current editorial review introduces these exciting review articles.