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Journal of Oral and Maxillofacial... 2024Ameloblastoma is one of the major odontogenic neoplasms with an invasive and recurrence potential. Its tumourigenesis and proliferative capacity can be attributed to the...
Immunohistochemical evaluation of yes-associated protein molecule in the odontogenic epithelium of different histopathological variants of ameloblastoma and unicystic ameloblastoma.
BACKGROUND
Ameloblastoma is one of the major odontogenic neoplasms with an invasive and recurrence potential. Its tumourigenesis and proliferative capacity can be attributed to the activation or inactivation of certain molecular signalling pathways. Hippo signalling pathway is known to regulate diverse physiological processes related to mitosis and organ growth and is an emerging tumour suppressor pathway, the dysfunction of which is implicated in various diseases including cancers. Yes-associated protein1 (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are the downstream effectors in the Hippo cascade, which on nuclear activation leads to cellular proliferation in various tumours.
AIM
The current study was undertaken to evaluate the expression of YAP in various histopathological variants of ameloblastoma and unicystic ameloblastoma.
MATERIALS AND METHODS
Fifty formalin-fixed paraffin-embedded tissue samples of histopathologically diagnosed cases of ameloblastoma, and 10 histopathologically diagnosed cases of unicystic ameloblastoma were obtained from the departmental archives to evaluate the immunohistochemical expression of YAP both manually and by software analysis.
RESULTS
More than 90% of cases of conventional ameloblastoma and unicystic ameloblastoma elicited positive expression of YAP. No statistical difference was found among different histopathological variants of conventional ameloblastoma. Significant difference between the means of all four quantitative score groups was observed.
CONCLUSION
In view of the modulating effect of YAP in tumourigenesis and its higher expression in ameloblastoma, further exploration of this molecule appears to be a promising area of research.
PubMed: 38800449
DOI: 10.4103/jomfp.jomfp_215_23 -
Journal of Oral and Maxillofacial... 2024Glucose uptake may be considered the rate-limiting step for the growth and metabolism of the cancer cell. Studies on GLUT1 have shown that GLUT1 is involved in cell...
CONTEXT
Glucose uptake may be considered the rate-limiting step for the growth and metabolism of the cancer cell. Studies on GLUT1 have shown that GLUT1 is involved in cell survival and proliferation in both healthy and pathological circumstances. GLUT1 expression is regarded as one of the crucial elements in the development of local aggressiveness, tumour invasiveness, and metastasis, particularly in malignant tumours. The role of glut1 in odontogenic cysts and tumours has remained uncertain.
AIM
The aim of the study is to assess the expression of Glut1 in dentigerous cysts, odontogenic keratocysts, and ameloblastoma.
SETTINGS AND DESIGN
The study was conducted in GSL Dental College. The study design was a resprospective immunohistochemical study.
METHODS AND MATERIAL
Formalin-fixed, paraffin-embedded blocks of histologically confirmed cases (n = 50), 10 cases of odontogenic keratocysts, dentigerous cysts, ameloblastomas solid, ameloblastomas unicystic, and dental follicles each. Brown colour staining was considered as positive staining for GLUT1. Quantitative analysis was performed by counting the number of labelled cells, and semi-quantitative analysis was conducted by assigning immunostaining intensity scores.
STATISTICAL ANALYSIS
Chi-square test was used to compare differences between the groups. A value of ≤0.05 was considered as statistically significant.
RESULTS
Odontogenic keratocysts and unicystic ameloblastoma showed ≥50% of label cells with strong intensity of staining. Odontogenic keratocysts and solid ameloblastoma showed sub-cellular localisation of staining in the cytoplasm and membrane. Dentigerous cysts exhibited combined nucleus, cytoplasm, and membrane sub-cellular localisation of staining.
CONCLUSIONS
The development of ameloblastomas, odontogenic keratocysts, and dentigerous cysts appears to be influenced by GLUT-1. Variation in its expression may aid in explanation of some of the differences in biological activity of these lesions.
PubMed: 38800443
DOI: 10.4103/jomfp.jomfp_455_23 -
Journal of Oral and Maxillofacial... 2024[This corrects the article on p. 727 in vol. 27, PMID: 38304525.].
[This corrects the article on p. 727 in vol. 27, PMID: 38304525.].
PubMed: 38800422
DOI: 10.4103/jomfp.jomfp_96_24 -
Journal of Stomatology, Oral and... May 2024Benign odontogenic lesions (BOLs) can cause severe jaw bone defects and compromise the quality of life of patients. Extracellular vesicles (EVs) are well-established and...
BACKGROUND
Benign odontogenic lesions (BOLs) can cause severe jaw bone defects and compromise the quality of life of patients. Extracellular vesicles (EVs) are well-established and versatile players in mediating pathophysiological events. EVs in the interstitial space (tissue-derived EVs or Ti-EVs) possess higher specificity and sensitivity in disease-related biomarker discovery. However, the role of Ti-EV-loaded proteins in mediating the development of BOLs has remained untapped. Herein, we aim to explore the contribution of Ti-EV-loaded proteins to the development of BOLs.
METHODS
Samples were obtained from 3 with dental follicle, 3 with dentigerous cyst (DC), 7 with odontogenic keratocyst (OKC), and 3 patients with ameloblastoma (AM). Tissue-derived EVs were then extracted, purified, and validated using ultracentrifugation, transmission electron microscopy, and western blotting. Proteins from Ti-EVs were analyzed using LC-ESI tandem mass spectroscopy and differentially expressed proteins were screened, which was then validated by immunohistochemistry and immunofluorescence assays.
RESULTS
The protein profile of Ti-EVs in each group was mapped by LC-MS analysis. The top 10 abundant proteins in BOL-derived Ti-EVs were COL6A3, COL6A1, ALB, HIST1H4A, HBB, ACTB, HIST1H2BD, ANXA2, COL6A2 and FBN1. Additionally, unique proteins in the Ti-EVs from various lesions were identified. Moreover, focal adhesion kinase (FAK) and myeloid differentiation primary response 88 (MyD88) showed higher expressions in Ti-EVs derived from OKC and AM, which were confirmed by immunohistochemistry and immunofluorescence staining.
CONCLUSIONS
Ti-EVs containing FAK and MyD88 might be related to the development of OKC and AM, which can be potential therapeutic targets.
PubMed: 38795909
DOI: 10.1016/j.jormas.2024.101921 -
Journal of Dental Education May 2024Interpretation of dental radiographs is a difficult process, particularly for inexperienced students. This study introduced concept mapping for dental students to help...
OBJECTIVES
Interpretation of dental radiographs is a difficult process, particularly for inexperienced students. This study introduced concept mapping for dental students to help in the radiographic interpretation of common jaw lesions. We aimed to analyze the efficacy of the concept map (CM) in radiographic interpretation, with a discussion of the diagnostic reasoning dilemma.
METHODS
This study included 39 dental students. After a 1-h class for CM guidance and based on three group discussions and one-on-one feedback, the students completed and submitted CMs for three jaw diseases (ameloblastoma, odontogenic keratocyst, and simple bone cyst). All participants underwent a pretest and posttest of knowledge and diagnosis; all students but one completed an open-ended questionnaire regarding the use of CMs.
RESULTS
Concept mapping effectively improved diagnostic accuracy. The participants' posttest scores were better than their pretest scores in both knowledge and diagnostic tests. Most of the students attempted radiographic interpretation through analytic reasoning. The time required for the students to draw a CM varied from student to student from 3-5 h to 1-3 days.
CONCLUSION
This study shows that CMs can improve the radiographic diagnostic ability of dental students by providing a framework for analytic reasoning. Continuous research is warranted to improve the effectiveness of CM in oral radiographic interpretation in the dental student's class.
PubMed: 38795325
DOI: 10.1002/jdd.13590 -
Journal of Oral Pathology & Medicine :... May 2024This Bayesian network meta-analysis was performed to analyze the associations between clinicopathological characteristics and BRAF mutations in ameloblastoma (AM)...
OBJECTIVE
This Bayesian network meta-analysis was performed to analyze the associations between clinicopathological characteristics and BRAF mutations in ameloblastoma (AM) patients and to evaluate the diagnostic accuracy.
MATERIALS AND METHODS
Four electronic databases were searched from 2010 to 2024. The search terms used were specific to BRAF and AM. Observational studies or randomized controlled trials were considered eligible. The incidence of BRAF mutation and corresponding clinicopathological features in AM patients were subjected to Bayesian network analyses and diagnostic accuracy evaluation.
RESULTS
A total of 937 AM patients from 20 studies were included. The pooled prevalence of BRAF mutations in AM patients was 72%. According to the Bayesian network analysis, BRAF mutations are more likely to occur in younger (odds ratio [OR], 2.3; credible interval [CrI]: 1.2-4.5), mandible site (OR, 3.6; 95% CrI: 2.7-5.2), and unicystic (OR, 1.6; 95% CrI: 1.1-2.4) AM patients. Similarly, higher diagnostic accuracy was found in the younger, mandible, and unicystic AM groups.
CONCLUSIONS
The incidence, risk, and diagnostic accuracy of BRAF mutation in AM were greater in younger patients, those with mandible involvement, and those with unicystic AM than in patients with other clinicopathological features. In addition, there was a strong concordance in the diagnostic accuracy between molecular tests and immunohistochemical analysis.
PubMed: 38777565
DOI: 10.1111/jop.13542 -
Prague Medical Report 2024Salivary gland neoplasms account for 3% of all head and neck tumours. Pleomorphic adenoma (PA) is the most common salivary gland tumour that mainly occurs in the parotid...
Salivary gland neoplasms account for 3% of all head and neck tumours. Pleomorphic adenoma (PA) is the most common salivary gland tumour that mainly occurs in the parotid gland, followed by minor salivary glands of the oral cavity, however, the occurrence of PA inside the jaw bones is exceedingly rare and very few cases have been reported in the literature. Inside jaw bones these lesions tend to imitate large osteolytic lesions encompass a diagnostic challenge. An exhaustive review of the literature revealed only 10 cases of central pleomorphic adenoma. We present a rare case of primary PA that occurred inside the mandible and was provisionally diagnosed as ameloblastoma.
Topics: Humans; Male; Adenoma, Pleomorphic; Ameloblastoma; Diagnosis, Differential; Mandibular Neoplasms; Adult
PubMed: 38761048
DOI: 10.14712/23362936.2024.14 -
Zhongguo Xiu Fu Chong Jian Wai Ke Za... May 2024To explore the feasibility and effectiveness of mixed reality technology for localizing perforator vessels in the repair of mandibular defects using free fibular flap.
OBJECTIVE
To explore the feasibility and effectiveness of mixed reality technology for localizing perforator vessels in the repair of mandibular defects using free fibular flap.
METHODS
Between June 2020 and June 2023, 12 patients with mandibular defects were repaired with free fibular flap. There were 8 males and 4 females, with an average age of 61 years (range, 35-78 years). There were 9 cases of ameloblastomas and 3 cases of squamous cell carcinomas involving the mandible. The disease duration ranged from 15 days to 2 years (median, 14.2 months). The length of mandibular defects ranged from 5 to 14 cm (mean, 8.5 cm). The area of soft tissue defects ranged from 5 cm×4 cm to 8 cm×6 cm. Preoperative enhanced CT scans of the maxillofacial region and CT angiography of the lower limbs were performed, and the data was used to create three-dimensional models of the mandible and lower limb perforator vessels. During operation, the mixed reality technology was used to overlay the three-dimensional model of perforator vessels onto the body surface for harvesting the free fibular flap. The length of the fibula harvested ranged from 6 to 15 cm, with a mean of 9.5 cm; the size of the flap ranged from 6 cm×5 cm to 10 cm×8 cm. The donor sites were sutured directly in 7 cases and repaired with free skin grafting in 5 cases.
RESULTS
Thirty perforator vessels were located by mixed reality technology before operation, with an average of 2.5 vessels per case; the distance between the exit point of the perforator vessels located before operation and the actual exit point ranged from 1 to 4 mm, with a mean of 2.8 mm. All fibular flaps survived; 1 case had necrosis at the distal end of flap, which healed after dressing changes. One donor site had infection, which healed after anti-inflammatory dressing changes; the remaining incisions healed by first intention, and the grafts survived smoothly. All patients were followed up 8-36 months (median, 21 months). The repaired facial appearance was satisfactory, with no flap swelling. Among the patients underwent postoperative radiotherapy, 2 patients had normal bone healing and 1 had delayed healing at 6 months.
CONCLUSION
In free fibular flap reconstruction of mandibular defects, the use of mixed reality technology for perforator vessel localization can achieve three-dimensional visualization, simplify surgical procedures, and reduce errors.
Topics: Humans; Male; Middle Aged; Female; Adult; Free Tissue Flaps; Aged; Fibula; Mandible; Plastic Surgery Procedures; Carcinoma, Squamous Cell; Mandibular Neoplasms; Mandibular Reconstruction; Perforator Flap; Ameloblastoma
PubMed: 38752246
DOI: 10.7507/1002-1892.202402027 -
Journal of Oral Biosciences Jun 2024Odontogenic tumors arise in the jawbone and originate from cells associated with tooth development. Therefore, understanding odontogenic tumors requires knowledge of all... (Review)
Review
BACKGROUND
Odontogenic tumors arise in the jawbone and originate from cells associated with tooth development. Therefore, understanding odontogenic tumors requires knowledge of all aspects of dental research, including tooth development and eruption. Ameloblastoma is the most common odontogenic tumor.
HIGHLIGHT
Although a benign tumor, ameloblastoma progresses with marked jawbone resorption. Because of its locally aggressive features, it can be treated surgically by resecting the surrounding bone. From a molecular pathology perspective, several genetic mutations and dysregulated signaling pathways involved in ameloblastoma tumorigenesis have been identified. Histopathologically, ameloblastomas consist of peripheral ameloblast-like cells and an inner stellate reticulum. The stromal region consists of fibrovascular connective tissue, showing a characteristic sparse myxoid histology. In general, the tumor microenvironment, including the surrounding non-tumor cells, contributes to tumorigenesis and progression. In this review, we focus on the tumor microenvironment of ameloblastomas. In addition, we present some of our recent studies on osteoclastogenesis, tubulin acetylation-induced cell migration, and hypoxia-induced epithelial-mesenchymal transition in ameloblastomas.
CONCLUSION
Further research on ameloblastomas can lead to the development of new treatments and improve patients' quality of life.
Topics: Ameloblastoma; Humans; Tumor Microenvironment; Cell Transformation, Neoplastic; Cell Movement; Jaw Neoplasms; Osteogenesis; Epithelial-Mesenchymal Transition; Osteoclasts
PubMed: 38734178
DOI: 10.1016/j.job.2024.05.002 -
Diagnostics (Basel, Switzerland) Apr 2024Odontogenic tumors (OTs) are distinct conditions that develop in the jawbones, exhibiting diverse histopathological features and variable clinical behaviors....
UNLABELLED
Odontogenic tumors (OTs) are distinct conditions that develop in the jawbones, exhibiting diverse histopathological features and variable clinical behaviors. Unfortunately, the literature on this subject in Saudi Arabia remains sparse, indicating a pressing need for more comprehensive data concerning the frequency, demographics, treatment modalities, and outcomes of OTs.
OBJECTIVES
The study aims to evaluate the frequency, demographic features, treatment, and outcomes of OTs across three tertiary medical centers.
METHODS AND MATERIAL
OT cases were identified in King Abdulaziz Medical City (KAMC), King Fahad Medical City (KFMC), and Prince Sultan Military Medical City (PSMMC) from January 2010 to December 2021.
RESULTS
Ninety-two OT cases were identified from the anatomical pathology laboratories of three tertiary hospitals. KFMC contributed the highest number of cases (43.5%), followed by KAMC (30.4%) and PSMMC (26.1%). The median age of OT patients was 29 years (range: 5-83), with males representing more than half of the patients (56.5%). The mandible was the most frequent site of OT occurrence (72.5%), with ameloblastoma being the predominant OT (63.0%), followed by odontoma (19.5%). Among the treatment modalities, bone resection was employed the most (51.0%), followed by enucleation (25.6%). Notably, 11.5% of OT cases with available follow-up data exhibited recurrence, with ameloblastoma accounting for eight recurrent cases.
CONCLUSIONS
Although OTs are relatively common in the jaws, they are rare in anatomical pathology laboratories and the general population. This study contributes valuable insights into the epidemiology characteristics, treatment trends, and recurrence rates of OTs in Saudi Arabia.
PubMed: 38732324
DOI: 10.3390/diagnostics14090910