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Medicina Oral, Patologia Oral Y Cirugia... Nov 2023Odontogenic tumours are infrequent lesions. Studies on the frequency of odontogenic tumours from Latin America are scarce. This work aimed to determine the relative... (Review)
Review
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.
Topics: Humans; Ameloblastoma; Odontoma; Retrospective Studies; Cementoma; Chile; Odontogenic Tumors; World Health Organization
PubMed: 37823289
DOI: 10.4317/medoral.26008 -
Oral Oncology Nov 2023Although complete excision is the standard of care for ameloblastoma, a subset of recurrent and/or metastasizing ameloblastomas are difficult to treat surgically. Over... (Review)
Review
Although complete excision is the standard of care for ameloblastoma, a subset of recurrent and/or metastasizing ameloblastomas are difficult to treat surgically. Over the past decade, several recurrent mutations in the mitogen-activated protein kinase pathway genes have been identified in ameloblastoma, based on which the efficacy of targeted therapy has been investigated. However, most of the literature has focused on BRAF V600E mutations, the most common oncogenic mutations in ameloblastoma. Hence, this study aims to review the current knowledge of targetable genetic alterations in ameloblastoma from a broader perspective. In addition, the therapeutic potential of immunotherapy for ameloblastoma will be briefly discussed in the context of tumoral PD-L1 expression and the tumor immune microenvironment.
Topics: Humans; Ameloblastoma; Precision Medicine; Jaw Neoplasms; Proto-Oncogene Proteins B-raf; Mutation; Tumor Microenvironment
PubMed: 37816291
DOI: 10.1016/j.oraloncology.2023.106585 -
Head and Neck Pathology Dec 2023Squamous odontogenic tumor (SOT) is a rare benign but locally infiltrative tumor often misdiagnosed as other entities, such as ameloblastoma and squamous cell carcinoma,...
Squamous odontogenic tumor (SOT) is a rare benign but locally infiltrative tumor often misdiagnosed as other entities, such as ameloblastoma and squamous cell carcinoma, due to overlapping morphological findings. We document here the clinicopathological and imaging findings of an aggressive intraosseous SOT in the posterior left region of the maxilla in a 25-year-old male patient. On intraoral examination, the tumor extended from the region of the left lateral incisor to the upper left premolar and was covered by reddish mucosa, with discrete areas of ulceration. Imaging exams revealed an osteolytic lesion causing thinning, erosion, and buccal and lingual cortical plate perforation associated with an impacted canine. Microscopically, the tumor showed a proliferation of islands of well-differentiated squamous epithelium in a variably collagenized background. The peripheral cells of the islands were flat or slightly cuboidal and did not exhibit nuclei with peripheral palisade and reverse polarization. The diagnosis of SOT was rendered. The patient underwent surgical resection and has been under clinical follow-up for approximately 12 months with no signs of recurrence. A careful morphological evaluation is essential to avoid misdiagnosis and ensure a satisfactory treatment approach.
Topics: Male; Humans; Adult; Odontogenic Tumor, Squamous; Maxilla; Odontogenic Tumors; Ameloblastoma; Epithelium
PubMed: 37768443
DOI: 10.1007/s12105-023-01585-3 -
BMC Oral Health Sep 2023The reconstruction of large mandibular defects is a challenge, and free vascularized bone flaps are most commonly used. However, the precision and symmetry of this...
BACKGROUND
The reconstruction of large mandibular defects is a challenge, and free vascularized bone flaps are most commonly used. However, the precision and symmetry of this repair are deficient, and patients have a risk of vascular embolism, flap necrosis, and donor site complications. Therefore, to explore an ideal alternative in mandibular reconstruction with high surgical accuracy and low complications is indispensable.
METHODS
Seven patients with recurrent or large-scope ameloblastoma were enrolled in this study. All patients were provided with a fully digital treatment plan, including the design of osteotomy lines, surgical guides, and three-dimensional printed titanium mesh for implantation. With the assistance of surgical guide, ameloblastomas were resected, and custom 3D printed titanium mesh combined with posterior iliac bone harvest was used in mandibular reconstruction. A comparison was made between the discrepant surgical outcomes and the intended surgical plan, as well as the average three-dimensional deviation of the mandible before and after the surgery. At the same time, the resorption rate of the implanted bone was evaluated.
RESULTS
All patients completed the fully digital treatment process successfully without severe complications. Image fusion showed that the postoperative contour of the mandible was basically consistent with surgical planning, except for a slight increase in the inferior border of the affected side. The mean three-dimensional deviation of the mandible between the preoperative and postoperative periods was 0.78 ± 0.41 mm. The mean error between the intraoperative bone volume and the digital planning bone volume was 2.44%±2.10%. Furthermore, the bone resorption rates of the harvested graft 6 months later were 32.15%±6.95%.
CONCLUSIONS
The use of digital surgical planning and 3D-printed templates can assist surgeons in performing surgery precisely, and the 3D-printed titanium mesh implant can improve the patient's facial symmetry. 3D printed titanium mesh combined with posterior iliac cancellous bone graft can be regarded as an ideal alternative in extensive mandibular reconstruction.
Topics: Humans; Ameloblastoma; Titanium; Cancellous Bone; Surgical Mesh; Dental Implants; Mandible
PubMed: 37730602
DOI: 10.1186/s12903-023-03386-0 -
Journal of Cancer Research and Clinical... Dec 2023We used proteomic sequencing and experimental verification to identify the potential ferroptosis-related proteins in ameloblastoma.
PURPOSE
We used proteomic sequencing and experimental verification to identify the potential ferroptosis-related proteins in ameloblastoma.
METHODS
Samples of ameloblastoma (n = 14) and normal gingival tissues (n = 5) were collected for proteomic sequencing to identify differentially expressed proteins (DEPs) in ameloblastoma. Ferroptosis-related genes were downloaded from FerrDb V2, which were then compared with DEPs to obtain ferroptosis-related DEPs (FR-DEPs). A functional enrichment analysis was performed, and a protein-protein interaction network was built. The hub proteins were screened using the Cytoscape software, and potential drugs targeting them were retrieved from the DrugBank database. A hub protein was selected for immunohistochemical validation, and its expression was assessed in ameloblastomas, odontogenic keratocysts, dentigerous cysts, and normal gingival tissues. The primary ameloblastoma cells were cultured to explore the effect of the protein on the migratory properties of the tumour cells.
RESULTS
A total of 58 FR-DEPs were screened, and six hub proteins were identified: mTOR, NFE2L2, PRKCA, STAT3, EGFR, and CDH1. Immunohistochemical analysis showed that mTOR expression was upregulated in ameloblastomas compared with that in odontogenic keratocysts, dentigerous cysts, and normal gingival tissues. p-mTOR was highly expressed in ameloblastomas, with a positivity rate of 83.3%. In addition, rapamycin, an inhibitor of mTOR, can inhibit the migratory capacity of primary cultured ameloblastoma cells.
CONCLUSION
Our results revealed the ferroptosis-related proteins in ameloblastomas and their underlying biological processes. Additionally, mTOR was overexpressed and was found to be associated with the aggressiveness of ameloblastomas, which may be a potential target for future treatments.
Topics: Humans; Dentigerous Cyst; Ameloblastoma; Ferroptosis; Proteomics; Immunohistochemistry; Odontogenic Cysts; TOR Serine-Threonine Kinases
PubMed: 37725241
DOI: 10.1007/s00432-023-05412-8 -
International Journal of Surgical... Jun 2024
Topics: Humans; Ameloblastoma; Artifacts; Neoplasm Invasiveness; Mandibular Neoplasms; Jaw Neoplasms
PubMed: 37723941
DOI: 10.1177/10668969231195067 -
Journal of Oral Pathology & Medicine :... Nov 2023Odontogenic tumors (OT) are composed of heterogeneous lesions, which can be benign or malignant, with different behavior and histology. Within this classification,...
BACKGROUND
Odontogenic tumors (OT) are composed of heterogeneous lesions, which can be benign or malignant, with different behavior and histology. Within this classification, ameloblastoma and ameloblastic carcinoma (AC) represent a diagnostic challenge in daily histopathological practice due to their similar characteristics and the limitations that incisional biopsies represent. From these premises, we wanted to test the usefulness of models based on artificial intelligence (AI) in the field of oral and maxillofacial pathology for differential diagnosis. The main advantages of integrating Machine Learning (ML) with microscopic and radiographic imaging is the ability to significantly reduce intra-and inter observer variability and improve diagnostic objectivity and reproducibility.
METHODS
Thirty Digitized slides were collected from different diagnostic centers of oral pathology in Brazil. After performing manual annotation in the region of interest, the images were segmented and fragmented into small patches. In the supervised learning methodology for image classification, three models (ResNet50, DenseNet, and VGG16) were focus of investigation to provide the probability of an image being classified as class0 (i.e., ameloblastoma) or class1 (i.e., Ameloblastic carcinoma).
RESULTS
The training and validation metrics did not show convergence, characterizing overfitting. However, the test results were satisfactory, with an average for ResNet50 of 0.75, 0.71, 0.84, 0.65, and 0.77 for accuracy, precision, sensitivity, specificity, and F1-score, respectively.
CONCLUSIONS
The models demonstrated a strong potential of learning, but lack of generalization ability. The models learn fast, reaching a training accuracy of 98%. The evaluation process showed instability in validation; however, acceptable performance in the testing process, which may be due to the small data set. This first investigation opens an opportunity for expanding collaboration to incorporate more complementary data; as well as, developing and evaluating new alternative models.
Topics: Humans; Ameloblastoma; Artificial Intelligence; Deep Learning; Reproducibility of Results; Odontogenic Tumors; Carcinoma
PubMed: 37712132
DOI: 10.1111/jop.13481 -
Annals of Maxillofacial Surgery 2023Odontogenic cysts have the potential to transform into neoplasms. However, the characteristics of those which transformed to neoplastic tissues have not been well... (Review)
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.
PubMed: 37711539
DOI: 10.4103/ams.ams_226_22 -
BMC Oral Health Sep 2023Enucleation, a surgical procedure, is commonly used to treat large jaw cysts, unicystic ameloblastomas and keratocysts. However, it remains unclear to what extent the...
BACKGROUND
Enucleation, a surgical procedure, is commonly used to treat large jaw cysts, unicystic ameloblastomas and keratocysts. However, it remains unclear to what extent the jaw bone regenerates after enucleation. We aimed to evaluate the percentage and the survival analysis of jaw bone regeneration, in terms of cavity volume residual (CVR), in patients who underwent enucleation of large jaw cysts, unicystic ameloblastomas and keratocysts.
METHODS
We collected data longitudinally from 75 patients who underwent jaw cystic lesions enucleation at the Stomatological Hospital of Xi'an Jiaotong University, between January 2015 and June 2021. All patients had both preoperative and postoperative cone-beam computed tomography (CBCT) imaging data. CBCT images were analyzed using Image J. Changes in the CVR were assessed at various follow-up time points, and the Kaplan-Meier method was utilized to evaluate the CVR over time.
RESULTS
The patients had a mean age of 31.7 years (range: 5.5-72 years) with 58.66% of them being male. The postoperative CVR was 32.20% at three months, 21.10% at six months, 15.90% at 12 months, and 5.60% at 24 months. The percentage of CVR during follow-up periods for the initial size Quartile (Q)1 (212.54-1569.60 mm) was substantially lower than those of Q2 and Q3 at and after seven months of follow-up and became statistically significant at the 12-month mark.
CONCLUSION
This study demonstrates that spontaneous bone regeneration can occur after enucleation of large jaw cysts, unicystic ameloblastomas and keratocysts, even without the use of filler materials. The initial size of the lesion had a significant impact on the outcome of cystic lesion enucleation over time. To minimize the risks associated with radiation exposure and expenses, we recommend reducing the frequency of CT imaging follow-ups for patients with small initial cavity sizes (ranging from 212.54 to 1569.60 mm).
Topics: Adult; Female; Humans; Male; Ameloblastoma; Bone Regeneration; Cone-Beam Computed Tomography; Dental Caries; Jaw Cysts; Odontogenic Cysts; Child; Adolescent; Young Adult; Middle Aged; Aged
PubMed: 37704975
DOI: 10.1186/s12903-023-03307-1 -
Biochemical and Biophysical Research... Oct 2023Murine tooth germ development proceeds in continuous sequential steps with reciprocal interactions between the odontogenic epithelium and the adjacent mesenchyme, and...
Murine tooth germ development proceeds in continuous sequential steps with reciprocal interactions between the odontogenic epithelium and the adjacent mesenchyme, and several growth factor signaling pathways and their activation are required for tooth germ development. The expression of ADP-ribosylation factor (Arf)-like 4c (Arl4c) has been shown to induce cell proliferation, and is thereby involved in epithelial morphogenesis and tumorigenesis. In contrast, the other functions of Arl4c (in addition to cellular growth) are largely unknown. Although we recently demonstrated the involvement of the upregulated expression of Arl4c in the proliferation of ameloblastomas, which have the same origin as odontogenic epithelium, its effect on tooth germ development remains unclear. In the present study, single-cell RNA sequencing (scRNA-seq) analysis revealed that the expression of Arl4c, among 17 members of the Arf-family, was specifically detected in odontogenic epithelial cells, such as those of the stratum intermedium, stellate reticulum and outer enamel epithelium, of postnatal day 1 (P1) mouse molars. scRNA-seq analysis also demonstrated the higher expression of Arl4c in non-ameloblast and inner enamel epithelium, which include immature cells, of P7 mouse incisors. In the mouse tooth germ rudiment culture, treatment with SecinH3 (an inhibitor of the ARNO/Arf6 pathway) reduced the size, width and cusp height of the tooth germ and the thickness of the eosinophilic layer, which would involve the synthesis of dentin and enamel matrix organization. In addition, loss-of-function experiments using siRNAs and shRNA revealed that the expression of Arl4c was involved in cell proliferation and osteoblastic cytodifferentiation in odontogenic epithelial cells. Finally, RNA-seq analysis with a gene set enrichment analysis (GSEA) and Gene Ontology (GO) analysis showed that osteoblastic differentiation-related gene sets and/or GO terms were downregulated in shArl4c-expressing odontogenic epithelial cells. These results suggest that the Arl4c-ARNO/Arf6 pathway axis contributes to tooth germ development through osteoblastic/ameloblastic differentiation.
Topics: Mice; Animals; Tooth Germ; Epithelial Cells; Epithelium; Ameloblastoma; Cell Differentiation; Tooth
PubMed: 37703759
DOI: 10.1016/j.bbrc.2023.09.014