Conservative Management of Odontogenic Fibromyxoma of the Maxilla: A Case Report.

Odontogenic fibromyxoma typically presents as painless swelling in the jaw, and clinically, it grows slowly, becoming benign and asymptomatic. It causes the cortical plates to expand gradually, which leads to mobility and drifting of the teeth. Root resorption is also common. The tumor is locally aggressive in nature. It is also known to have a high recurrence rate. We present the case of a 30-year-old female patient who was diagnosed and treated for odontogenic fibromyxoma of the maxilla conservatively with enucleation. The radiograph showed a multilocular lesion, which can be confused with ameloblastoma, aneurysmal bone cyst, or odontogenic keratocyst. Hence, with proper clinical, radiographic, and histopathological examination, a correct diagnosis can be made and adequate treatment can be planned.

The evolving molecular characterisation, histological criteria and nomenclature of adenoid ameloblastoma as a World Health Organisation tumour type.

Adenoid ameloblastoma (AA) was recently recognised as a separate tumour type in the most recent World Health Organisation (WHO) classification of head and neck tumours. This decision has been considered controversial by several groups, who have described AA as a subtype of ameloblastoma, a hybrid odontogenic tumour or to fall within the spectrum of other recognised odontogenic tumours, including dentinogenic ghost cell tumour and adenomatoid odontogenic tumour. Here we review the reasons for the WHO decision to classify AA as a separate tumour type. We also critique molecular and histological findings from recent reports published since the WHO classification. While acknowledging that the classification of tumours is constantly evolving, the balance of current evidence suggests that AA should remain a distinct tumour type, and not a subtype of ameloblastoma, pending further molecular characterisation.

Clinical Spectrum and Treatment of Odontogenic Myxoma: Analysis of 37 Cases.

Background: Odontogenic myxoma is one of the benign mesenchymal odontogenic tumours with aggressive behaviour and showed slow and asymptomatic expansion, the second until the third decade of life is the most targeted age group. With high female preponderance, about the management, surgical management is the only option concerning this odontogenic pathology with a variety of treatment options. This study aims to analyse a series of 37 patients with odontogenic myxoma treated in a single institution. Materials and method: In total, 37 patients with odontogenic myxoma were treated at KTDH in Sudan and were retrospectively reviewed. With the analysis of medical records of all patients diagnosed with odontogenic myxoma and the related variables, data were analysed using the SPSS statistical program (version 23). Results: Most of the cases were females (26 patients 70.27%), and males were about (11 patients 29.73%). In most of the cases maxilla was affected more than the mandible (25 cases, 67.57%) mostly in its posterior segment (32 cases, 86.49). The most age group affected was the group of cases (0-20) which were about 18 cases (48.65%). In total, 35 of the cases noticed swelling (94.59%), while 14 noticed tooth mobility (37.84%) and paraesthesia was a positive finding in just one case (2.70%). In total, 12 patients (32.43%) had a positive history of tooth extraction related to the lesion, and recurrence was positive in (64, 86%). Conclusion: Odontogenic myxoma is locally aggressive. There is no gold standard protocol for surgical treatment so choosing the most suitable and reliable treatment option relay on the operator taking into consideration the characteristic of each case and the recurrence rate with the associated postoperative impairments.

Collision Tumour Comprising Desmoplastic Ameloblastoma and Squamous Odontogenic Tumour in the Anterior Maxilla: A Case Report.

Collision tumours, characterized by the simultaneous occurrence of two distinct neoplasms within the same anatomical site, are exceedingly rare in oral pathology. This case report presents an uncommon collision tumour involving desmoplastic ameloblastoma and squamous odontogenic tumour in the anterior maxilla of a 52-year-old male from the Indian population. Desmoplastic ameloblastoma is a variant of ameloblastoma known for its unique histopathological features, while squamous odontogenic tumour is a benign epithelial odontogenic tumour with distinctive clinical behaviour. The rarity of this occurrence emphasizes the need for accurate diagnosis and effective treatment strategies. This report discusses the clinical presentation, radiographic findings, and histopathological characteristics of this collision tumour. Through the presentation of this case, we aim to contribute to the understanding of these rare entities and their management considerations.

Recurrence Patterns of Odontogenic Keratocysts in Syndromic and Non-Syndromic Patients.

Purpose: Odontogenic keratocysts (OKCs) have high recurrence rates. We aimed to identify recurrence patterns in OKCs and the onset of second primary OKCs in non-syndromic and syndromic patients. Material and Methods: Patients with OKCs reporting to our department from 1998 to 2021 (23 years) were retrospectively evaluated using demographic, clinical (age, sex, location, and size), histopathological, radiographic, and treatment data. All patients were followed-up for > 3 years and evaluated for OKC recurrence. Patients with naevoid basal cell carcinoma syndrome (NBCCS) were evaluated separately. Results: We included 38 and 13 patients in the non-syndromic and syndromic OKC groups, respectively. The recurrence rates were 15.8 and 21.4% in the non-syndromic and syndromic groups, respectively; 8.9% of patients exhibited a second recurrence and 1.8% a third recurrence. No second primary OKCs were observed in the non-syndromic group; 76.9% of patients in the syndromic group developed at least one. Conclusion: We found a higher recurrence rate in patients with NBCCS compared with patients with non-syndromic OKCs (21.4 versus 15.8%). The probability of developing a second primary OKC in patients with NBCCS was higher compared with that in patients with non-syndromic OKCs (76.9 versus 0%). No statistically significant risk factors for OKC recurrence were identified.

Immunohistochemical expression of beta-catenin, BMP4 and TGF-beta in odontomas.

Changes in the expression of nuclear ß-catenin are responsible for tumorigenesis. Beta-catenin acts synergistically with the TGF-ß/BMPs pathway. This interaction leads to greater dentin deposition and may explain the differences between distinct tooth morphologies and hamartomas. The aim of this study was to investigate the role of ß-catenin, BMP4 and TGF-ß in the development of odontomas. This cross-sectional, retrospective, immunohistochemical study evaluated 30 compound odontomas, 30 complex odontomas and 17 tooth germs. The results showed that BMP4 and TGF-ß were more immunoexpressed in the ectomesenchyme of complex odontomas (median = 33.7, p < 0.001; median = 76.4, p = 0.002, respectively). Higher immunoexpression of BMP4 and TGF-ß was also observed in the epithelium of tooth germs (median = 2.0, p < 0.001; median = 120.3, p < 0.001, respectively). TGF-ß and BMP4 showed a positive and significant correlation (p < 0.001). Both TGF-ß and BMP4 were positively correlated with nuclear ß-catenin in ectomesenchyme (p = 0.047 and p = 0.023, respectively). Developing teeth exhibited higher concentrations of the proteins studied in odontogenic epithelium, especially during the bud and cap stages. Higher immunoexpression in odontomas occurred mainly in the ectomesenchyme. We therefore suggest that changes in the ectomesenchyme can lead to the development of odontomas.

The Colossal Mandibular Ameloblastoma: Surgical Challenges and Current Perspectives of Management.

Ameloblastoma is the most common aggressive benign odontogenic tumour of the jaws. Ameloblastoma is a benign epithelial odontogenic tumour that typically arises in the mandible or maxilla. A clinical, radiographic and histopathological report is presented of a case of giant acanthomatous ameloblastoma in the left hemi mandible of a 46-year-old healthy lady. The histopathological examination of the removed specimen revealed the histopathological pattern of an acanthomatous ameloblastoma. The radiographic appearance of the lesion showed the presence of multilocular radiolucencies, which were crossing the midline, which is rarely found in ameloblastoma. Due to its rarity and lack of data, we take this opportunity to present a case of advanced acanthomatous ameloblastoma and its surgical challenges.

A Rare Case of Central Odontogenic Fibroma of the Mandible.

The benign tumor central odontogenic fibroma (COF) accounts for less than 1% of all the existing odontogenic tumors. The mandibular or maxillary cortical plate is seen to show asymptotic diversification. It has been characterized as a benign jaw neoplasm. Radiographically, it primarily manifests as a multilocular radiolucency. Histologically, it comprises fibroblasts and mature collagen fibers. The popular choice for the management of COFs is enucleation, followed by the extraction of associated teeth. COFs have maintained a track record of showing rare chances of recurrence following surgery. COF was detected in a 38-year-old female who had edema in the lower right front tooth region. The lesion was surgically removed, and a histopathological examination was performed. Many case reports of COF have been stated in the literature. This indicates that cases of COF are not a rare appearance.

Non-Calcifying/Langerhans Cell-Rich Calcifying Epithelial Odontogenic Tumour: A Critical Review of the Rare and Distinctive Entity.

BACKGROUND: The study aims to analyse the non-calcifying/Langerhans cell rich (NCLC) subtype of calcifying epithelial odontogenic tumour (CEOT).  METHOD: The features of cases of the NCLC subtype of CEOT noted in the English literature by PubMed as well as 3 new cases were reviewed. RESULTS: Overall, twenty-one cases were noted. Many were women in the fourth to sixth decades (male-to-female ratio =1 to 2). Radiologically, the lesion is often unilocular with resorption of the affected teeth. Nineteen of the 21 cases occurred in the maxilla, especially the anterior portion. On pathological examination, epithelial cells are noted in non-calcifying amyloid-rich fibrous stroma. The main differential diagnosis is the amyloid subtype of central odontogenic fibroma. Immunohistochemical studies revealed the tumour epithelial cells were positive for cytokeratins and p63 and contained CD1a, S-100, and langerin-positive Langerhans cells. On a median follow-up of 2 years, one patient had a recurrence one year after curettage. CONCLUSION: The NCLC subtype of CEOT is unique as it contains significant numbers of Langerhans cells and has clinicopathological features distinctive from classic CEOT.

Odontogenic tumours in a Chilean population: a retrospective study of 544 cases based on 2022 WHO classification

Background: Odontogenic tumours are infrequent lesions. Studies on the frequency of odontogenic tumours from Latin America are scarce. This work aimed to determine the relative frequency of odontogenic tumours in a Chilean population using the 2022 World Health Organization classification. Material and Methods: This is a case series retrospective study. We reviewed 35,530 samples from 1975 to 2022 from the Oral Pathology Referral Institute and the Pathological Anatomy Service, Faculty of Dentistry, University of Chile. We utilized the 2022 World Health Organization classification for histological typification. Results: According to 2022 World Health Organization classification, 544 odontogenic tumours were confirmed. The most frequent odontogenic tumours were: odontoma (n=241; 44.3%), ameloblastoma (n=109; 20.0%) and cemento-ossifying fibroma (n=71; 13.1%). Benign odontogenic tumours corresponded to 538 cases (98.9%) and malignant tumours were only six cases (1.1%). Conclusions: In our population, odontoma was the most frequent odontogenic tumour followed by ameloblastoma and cemento-ossifying fibroma. Malignant odontogenic tumours were very rare. The results of this study are similar to reports from America, but there are some differences concerning the data from Africa and Asia. (AU)

Rare Case of Peripheral Myxofibroma of Anterior Maxillary Gingiva: A Diagnostic Challenge.

The myxofibroma (MF) constitutes an uncommon, non-malignant, odontogenic neoplasm with potential mesenchymal derivation. The occurrence rate of this particular tumor is estimated to be around 0.05 new cases per million individuals annually. MFs exhibit a higher incidence rate within the age range of 10 to 30 years. The prevalence of these tumors is higher among the female population, with a predominant localization in the mandible, specifically in the posterior region. A female patient, 66 years old, was referred to the Department of Oral Surgery, Surgical Implantology and Radiology, Thessaloniki, Greece, complaining of a tumorous lesion in the anterior area of the maxilla and mild pain. Clinically, a solid in palpation lobulated tumor, covered by normal coloured mucosa was observed at the left upper incisor. After the excisional biopsy, the microscopic appearance of abundant fibromyxoid stroma, in particular, myxoid stroma intermingled with collagenous tissue, covered by stratified squamous epithelium, suggested the diagnosis of peripheral myxofibroma. During a 2-year follow-up, no recurrence was referred. This case illustrates the necessity of proper differential diagnosis of every tumorous lesion of the gingiva and of using the histopathological examination.

Localization of beta catenin across the domain of odontogenic lesions: A systematic review.

BACKGROUND: CTNNB1 gene encodes beta catenin, a transcriptional activator of Wnt pathway involved in the pathogenesis of odontogenic lesions. Though located intramembranously, its translocation into cytoplasm and nucleus could trigger cell proliferation, inhibition of apoptosis, invasion and migration of the tumour cell. MATERIALS AND METHODS: Five electronic databases including MEDLINE by PubMed, Google scholar, Scopus, Trip, Cochrane library and EMBASE until 1 January 2023 without period restriction were thoroughly searched. Those articles that identified CTNNB1 mutation and beta catenin in odontogenic lesions were included for review. Risk of bias was analysed for each study using QUADAS 2 tool and Review Manager 5.3 was used to output its result. RESULTS: Thirty four published articles were included for data synthesis. A total of 1092 cases of odontogenic lesions were assessed for both CTNNB1 mutation and beta catenin expression. CTNNB1 mutation was observed in ameloblastoma, calcifying odontogenic cyst, calcifying cystic odontogenic tumour and all malignant odontogenic tumours. The beta catenin expression (nuclear and cytoplasmic) was maximum in odontogenic keratocyst and calcifying odontogenic cyst. The expression was variable in ameloblastomas, membranous in odontomas, calcifying cystic odontogenic tumour and nuclear in all malignant tumours. DISCUSSION AND CONCLUSION: High recurrence of odontogenic keratocyst and aggressiveness of solid ameloblastoma and malignant odontogenic tumours could be associated with the nuclear translocation of beta catenin. Disparity between CTNNB1 mutation and beta catenin expression within odontogenic lesions suggests alternate routes of beta catenin activation. The review results support the unique localisation of beta catenin as a helpful diagnostic factor in the pathogenesis of odontogenic lesions.

A rare incidence and management of complex odontoma and surgical dehiscence in maxillary anterior region: A case report.

Odontoma is a benign odontogenic tumour, which is rather considered hamartoma. Hamartoma is not a true neoplasm, rather a growth of abnormal mixture of cells found in the body area they normally grows. Fully developed odontomas generally consist of enamel, dentin and pulpal tissues, in an unorganised manner. Some of them may contain cementum too. These are further grouped into compound and complex, depending on their clinical, radiographic and histologic features. Odontomas are generally asymptomatic and slow growing, but may cause bone expansion and hinderance in tooth eruption. These lesions are generally diagnosed by coincidence in radiograph. We are presenting a case and surgical management of complex odontoma and post-operative dehiscence in the anterior right maxillary region of a 38-year-old male.

Primordial odontogenic tumour: Report of a novel entity - The third case from India.

Primordial odontogenic tumour (POT) is a newly described benign mixed odontogenic neoplasm that has been included in the World Health Organization classification 2017. Only 19 cases that conform to the clinico-pathologic criteria for diagnosis have been reported worldwide. We present the 20th case of POT reported worldwide and is only the third case to be reported from India. The need for considering POT as a possible diagnosis in lesions affecting posterior mandible in patients below 10 years, the need for clinicians and pathologists to be aware of this entity and the need to draw more specific conclusions on the diagnostic criteria of POT make it necessary to report every single case of this entity from different parts of the world. Along with the case report in a 3-year-old child patient, we also present here a summary of the cases reported till date and the review of literature.

A proteomics study to explore differential proteins associated with the pathogenesis of ameloblastoma.

BACKGROUND: Reports on the proteomic studies of ameloblastoma and other common odontogenic lesions are limited. We thus explored the differential proteins among ameloblastoma, odontogenic keratocyst, dentigerous cyst, and normal gingival tissue using proteomics and identified hub proteins involved in the local aggressiveness and recurrence of ameloblastoma. METHODS: Samples were obtained from 14 patients with ameloblastoma, 6 with odontogenic keratocyst, 9 with a dentigerous cyst, and 5 with normal gingival tissue. Proteins were then extracted, purified, quantified, and analysed using Easy-nLC chromatography and mass spectrometry. Further functional annotation and enrichment analyses were performed using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes on the target protein collection. Protein clustering and protein-protein interaction network analyses were used to screen the hub proteins. Proteins with significant interactions were screened according to their degree index. These results were verified by immunohistochemical staining. Proteins meeting the screening criteria of expression difference ploidy >1.2-fold (upregulation and downregulation) and p < 0.05 were considered differential proteins. RESULTS: In ameloblastoma, 808 differential proteins were upregulated and 505 were downregulated compared with those in odontogenic keratocyst; 309 were upregulated and 453 were downregulated compared with those in dentigerous cyst; and 2210 were upregulated and 829 were downregulated compared with those in normal gingival tissue. The three groups of differential proteins were associated with cellular exosomes, antigen binding, complement activation, human papillomavirus infection, focal adhesion, cell adhesion molecules, and metabolic pathways. CONCLUSION: CDH3 is associated with the local aggressiveness and recurrence of ameloblastoma and is a potential therapeutic target.

Homeobox Genes in Odontogenic Lesions: A Scoping Review.

BACKGROUND: Homeobox genes play crucial roles in tooth morphogenesis and development and thus mutations in homeobox genes cause developmental disorders such as odontogenic lesions. The aim of this scoping review is to identify and compile available data from the literatures on the topic of homeobox gene expression in odontogenic lesions. METHOD: An electronic search to collate all the information on studies on homeobox gene expression in odontogenic lesions was carried out in four databases (PubMed, EBSCO host, Web of Science and Cochrane Library) with selected keywords. All papers which reported expression of homeobox genes in odontogenic lesions were considered. RESULTS: A total of eleven (11) papers describing expression of homeobox genes in odontogenic lesions were identified. Methods of studies included next generation sequencing, microarray analysis, RT-PCR, Western blotting, in situ hybridization, and immunohistochemistry. The homeobox reported in odontogenic lesions includes LHX8 and DLX3 in odontoma; PITX2, MSX1, MSX2, DLX, DLX2, DLX3, DLX4, DLX5, DLX6, ISL1, OCT4 and HOX C in ameloblastoma; OCT4 in adenomatoid odontogenic tumour; PITX2 and MSX2 in primordial odontogenic tumour; PAX9 and BARX1 in odontogenic keratocyst; PITX2, ZEB1 and MEIS2 in ameloblastic carcinoma while there is absence of DLX2, DLX3 and MSX2 in clear cell odontogenic carcinoma. CONCLUSIONS: This paper summarized and reviews the possible link between homeobox gene expression in odontogenic lesions. Based on the current available data, there are insufficient evidence to support any definite role of homeobox gene in odontogenic lesions.

Spatial distribution of CD34 protein in primordial odontogenic tumour, ameloblastic fibroma and the tooth germ.

BACKGROUND: Primordial odontogenic tumour is a benign mixed neoplasm of recent description, which has histological similarities with other odontogenic tumours such as the ameloblastic fibroma. In this article, we investigate the architecture of the sub-epithelial layer of mesenchymal cells expressing the marker CD34 in primordial odontogenic tumour. OBJECTIVE: Analyse the spatial patterns of CD34 expression in primordial odontogenic tumour and compare them with those in ameloblastic fibroma and the normal tooth germ by means of objective imaging approaches, to better characterise these lesions. METHODS: Two cases of primordial odontogenic tumour, four cases of ameloblastic fibroma and two cases of tooth germ in cap and bell stages were used for morphological, structural and immunohistochemical analyses. RESULTS: CD34 expression was found in vascular endothelium of primordial odontogenic tumour, ameloblastic fibroma and tooth germ. In addition, a characteristic sub-epithelial expression was observed only in primordial odontogenic tumour, corresponding to 84%-86% of the sample boundaries. Moreover, the zone expressing CD34 corresponded with a higher cellularity, which was absent in ameloblastic fibroma and tooth germ. CONCLUSION: Image analysis of the primordial odontogenic tumour architecture revealed characteristics absent in other odontogenic tumours and tooth germs. This study provides additional information to support the idea that this neoplasm is a distinct entity from early stage AF or developing odontoma.

BRAF V600E Mutation in Ameloblastoma: A Systematic Review and Meta-Analysis.

The discovery that ameloblastoma has a high mutation incidence of BRAF V600E may enable a better investigation of pathophysiology. However, there is inconsistent evidence regarding this mutation occurrence and its association with clinical information. This systematic review and meta-analysis aim to pool the overall mutation prevalence of BRAF V600E in reported ameloblastoma cases and to determine its association with patient demographic and clinicopathological features. Following the PRISMA guidelines, a comprehensive article search was conducted through four databases (Scopus, Google Scholar, PubMed, and Web of Science). Seventeen articles between 2014 and 2022 met the inclusion criteria with 833 ameloblastoma cases. For each included study, the significance of BRAF V600E on the outcome parameters was determined using odd ratios and 95% confidence intervals. Meta-analysis prevalence of BRAF V600E in ameloblastoma was 70.49%, and a significant meta-analysis association was reported for those younger than 54 years old and in the mandible. On the contrary, other factors, such as sex, histological variants, and recurrence, were insignificant. As a result of the significant outcome of BRAF V600E mutation in ameloblastoma pathogenesis, targeted therapy formulation can be developed with this handful of evidence.

Efficacy of Gas Combination Cryotherapy in the Management of Odontogenic Keratocyst of the Maxilla and Mandible: A Pilot Study.

Aim: The aim of this study was to evaluate outcome of management of odontogenic keratocyst (OKC) using gas combination cryotherapy (GCC). GCC is a treatment modality where cyst enucleation is followed by applying an adjuvant agent, a spray containing propane, butane and isobutene gas onto the bony bed. Materials and Methods: This was a prospective interventional study which included patients with radiographic and histopathologic evidence of OKC. All patients underwent enucleation of the cysts followed by spraying of the bony cavity with "ENDOFROST ™"(commercially available agent for GCC). Patients were periodically reviewed and the presence of wound dehiscence, infection and neurosensory deficit was noted. After 15 months, a CBCT was taken to assess the amount of bone formation, the presence of any pathologic fracture or recurrence. Comparison of the preoperative and the postoperative size of the defect was also assessed. Results: A total of 10 patients were included in the study of which only 2 presented with neurosensory deficit in the post-op period. One patient of the two patients recovered completely within 12 months, while the other recovered within 15 months. There was no evidence of any patient developing infection, wound dehiscence, recurrence or pathologic fracture. Conclusion: The results of the study show that enucleation followed by GCC is a safe, effective and low-cost therapy for the management of OKC.

Keratoameloblastoma: A Report of Seven New Cases and Review of Literature.

BACKGROUND: Keratoameloblastoma (KA) is an uncommon and controversial variant of ameloblastoma exhibiting central keratinisation. Due to their rarity, there is limited information in the literature on their clinical, radiologic and histologic features. This study adds seven additional cases of KA to the literature, and reviews the current published literature on this rare entity. METHODS: KAs were retrospectively reviewed over a 20-year period from three Oral and Maxillofacial Pathology Laboratories. Included cases were examined and the diagnosis confirmed under conventional microscopy. Immunohistochemistry with the use of a monoclonal antibody against calretinin was performed on included cases. The clinical, radiologic and histologic features of the seven new cases of KA were analysed and compared to existing cases in the literature. RESULTS: KAs presented at a mean age of 40 years with a nearly equal gender distribution and a mandibular predilection (65%). The majority (92%) of cases presented with localised swelling with associated pain in 32% of cases. Mixed density or internal calcifications were noted in 40% of cases. All tumours presented with bony expansion, with cortical destruction noted in 62% of cases. Histologically, all tumours consisted of solid and cystic follicles with surface parakeratinisation and lamellated accumulations of central keratin. In areas the cystic follicles had an epithelial lining suggestive of an OKC. There were focal luminal areas of loosely arranged polygonal cells reminiscent of the stellate reticulum. The basal cells consisted of columnar cells with evidence of palisading and prominent subnuclear vacuolisation. Of the cases treated via tumour resection, 27% presented with tumour recurrence. CONCLUSION: This case series reports seven additional cases of KA, taking the total to 26 reported cases. The identification of subtle histologic features, including focal stellate reticulum-like central areas, subnuclear vacuolisation and lamellated-type central keratinisation, are key in diagnosing KA. The radiologic features will often indicate signs of aggressiveness such as cortical destruction, differentiating KA from OKC. All cases were completely negative for calretinin IHC, limiting its use in distinguishing KA from OKC. Further large series are needed to expand the current understanding of this rare variant of ameloblastoma.