Analysis of Prevalence and Clinical Features of Ameloblastoma and its Histopathological Subtypes in Southeast Myanmar and Lower Northern Thailand Populations: A 13-Year Retrospective Study

Prevalence and Epidemiological Profile of Ameloblastoma in India: A Systematic Review and Meta-Analyses

INTRODUCTION

Ameloblastoma is regarded as the second most prevalent odontogenic tumor in the light of its prevalence, clinical characteristics, greater incidence of tumor recurrence, and therapeutic challenges. The aim of this systematic review was to establish the prevalence of ameloblastoma in the Indian subcontinent and to establish a national epidemiologic profile for these lesions.

MATERIAL AND METHODS

A systematic review was undertaken based on the PRISMA guidelines in search of epidemiologic studies concerning odontogenic tumors and ameloblastoma that are listed by PubMed, EBSCO, and Google Scholar embracing the period from January 2010 to December 2021, to evaluate the prevalence rate in India. A total of 277 publications were retrieved, of which 27 articles were selected, based on the World Health Organization classification of odontogenic tumors.

RESULTS

The affected individuals were on average in the third decade of life, with a higher male predominance. The majority of the tumors were multilocular radiolucencies in the posterior mandible, with follicular and plexiform histopathological features. The most common type of malignant lesion is ameloblastic carcinoma. Over 60% of follicular ameloblastoma recurred more frequently than the other types of ameloblastoma.The random effect model shows overall point estimate of 4.83 with 95% confidence interval (4.44 -5.26).

CONCLUSION

The systematic study indicates a slight male predisposition to ameloblastoma, with a peak incidence in the third decade of life and the mandible as the preferred anatomical site. The solid/multicystic ameloblastoma is the most prevalent histopathologic pattern. More epidemiological research on the prevalence rate of ameloblastoma is required, particularly in India, in an effort to accurately determine the national epidemiological profile of ameloblastoma.

Training the Trainers in Microsurgery: A Success Story from Vietnam's Hanoi National Hospital of Odonto-stomatology

Background:

Microsurgery is a highly specialized skill that requires advanced training. This is a recount of the 12-year development of Hanoi National Hospital of Odonto-Stomatology (NHOS) from a basic plastic surgery unit to a high-volume, subspecialized reconstructive center.

Methods:

We present a 12-year retrospective account of the development of NHOS with a brief summary of microsurgical reconstructive outcomes.

Results:

From 2008 to 2020, NHOS has performed 665 microsurgical flaps for reconstruction of various maxillomandibular defects. In the pioneering stage (2008-2011), without surgical microscopes, all five free flaps failed. After acquiring a microscope and mentoring from Hanoi's 108 Military Hospital, mandibular bone defect reconstruction with free fibula flaps had 85% success rate. In the growth stage (2012-2015), reconstruction advanced toward more complex defects requiring soft tissue, with a 98.7% success rate. The maturation stage (2016-2020) focused on refinement of reconstructive service to provide subspecialized care for malignant head and neck cancer patients with help from Taiwan's E-Da Hospital and Operation Smile's charity program. The charity mission trips were structured to facilitate good quality teaching rather than hit a quantitative goal of the number of surgeries done. And with a success rate of 99.4%, we have begun further education of the plastic surgery community in Vietnam.

Conclusions:

Our rapid 12-year maturation into a high-volume, subspecialized microsurgical center is the embodiment of the generous efforts of many international friends who invested their time and expertise. And we highly recommend charity mission trips to adopt the “training the trainers” concept to maximize lasting, local impact.

Atypical periosteal reaction and unusual bone involvement of ameloblastoma: A case report with 8-year follow-up

Unusual radiographic findings of intraosseous ameloblastoma have been reported and discussed. In the case discussed herein, cone-beam computed tomography (CBCT) clearly showed many radiographic features that were ambiguous on conventional radiographs, including an ill-defined periphery, extensive superficial buccal extension with minimal lingual extension, obvious bucco-crestal expansion, and multiple triangular (Codman's triangle-like) areas of periosteal reaction. Based on the above-mentioned findings, the differential diagnosis was a long-term infected benign or low-grade malignant lesion. An incisional biopsy was performed, and the histopathologic diagnosis was acanthomatous ameloblastoma. Recurrence of the lesion was clearly detected on CBCT images at 4 and 8 years after surgery. These unusual radiographic findings have never been reported to be associated with ameloblastoma, and thus may contribute to novel concepts in radiographic interpretation in the future. This report also underscores the important role played by CBCT as a comprehensive diagnostic tool and for definite confirmation of recurrence.

Ameloblastoma cell lines derived from different subtypes demonstrate distinct developmental patterns in a novel animal experimental model

Objective

Ameloblastoma is a representative odontogenic tumor comprising several characteristic invasive forms, and its pathophysiology has not been sufficiently elucidated. A stable animal experimental model using immortalized cell lines is crucial to explain the factors causing differences among the subtypes of ameloblastoma, but this model has not yet been disclosed. In this study, a novel animal experimental model has been established, using immortalized human ameloblastoma-derived cell lines.

Methodology

Ameloblastoma cells suspended in Matrigel were subcutaneously transplanted into the heads of immunodeficient mice. Two immortalized human ameloblastoma cell lines were used: AM-1 cells derived from the plexiform type and AM-3 cells derived from the follicular type. The tissues were evaluated histologically 30, 60, and 90 days after transplantation.

Results

Tumor masses formed in all transplanted mice. In addition, the tumors formed in each group transplanted with different ameloblastoma cells were histologically distinct: the tumors in the group transplanted with AM-1 cells were similar to the plexiform type, and those in the group transplanted with AM-3-cells were similar to the follicular type.

Conclusions

A novel, stable animal experimental model of ameloblastoma was established using two cell lines derived from different subtypes of the tumor. This model can help clarify its pathophysiology and hasten the development of new ameloblastoma treatment strategies.