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.

Application value of a hybrid tracer during sentinel lymph node biopsy for head and neck malignancies: A systematic review and meta-analysis.

To address the limitations of conventional sentinel lymph node biopsy (SLNB), a novel hybrid tracer (indocyanine green [ICG]-99mTc-nanocolloid) has been developed. This meta-analysis aimed to compare the differences between the novel hybrid tracer and conventional methods using ICG or radioisotope (RI) for SLNB in head and neck malignancies. This study was registered in the International Prospective Register of Systematic Reviews (CRD42023409127). PubMed, Embase, Web of Science, and the Cochrane Library were systematically searched. This study included raw data on the number of sentinel lymph nodes (SLNs) identified using different modalities during surgery for head and neck malignancies. The identification rate of SLNs was the main outcome of interest. Prognostic data and complication rate cannot be deduced from this article. The heterogeneity test (I2) determined the use of a fixed- or random-effects model for the pooled risk ratio (RR). Overall, 1275 studies were screened, of which 11 met the inclusion criteria for the meta-analysis. In SLN identification of head and neck malignancies, ICG-99mTc-nanocolloid was superior to ICG or RI. In the subgroup analyses, the detection rates of ICG and RI tracers in SLNB were comparable, regardless of the device, tumor type, or tumor stage. In conclusion, in SLN identification of head and neck malignancies, the use of ICG-99mTc-nanocolloid is superior to the single technique of ICG or RI. This study suggests that Hospitals using ICG or RI may find it beneficial to change their practice to ICG-99mTc-nanocolloid, especially in the head and neck area, owing to its superior effectiveness.

Vital staining with iodine solution in oral cancer: iodine infiltration, cell proliferation, and glucose transporter 1.

BACKGROUND: Vital staining with iodine solution has been used to distinguish dysplastic/malignant oral epithelium from normal mucosa. However, little is known about its critical mechanism. The purpose of this study was to visualize how iodine infiltrates the oral epithelium and reacts with glycogen. In addition, we tested the hypothesis that higher cell proliferation requires increased energy consumption, and consequently exhausted glycogen may lead to a failure to be stained by iodine solution. METHODS: Fifteen frozen tissue samples of iodine-stained and -unstained mucosa were obtained from 15 cases of oral squamous cell carcinoma (OSCC). Serial frozen sections were cut and examined with hematoxylin and eosin and periodic acid-Schiff methods and immunohistochemical staining for p53, Ki67 and glucose transporter 1 (GLUT 1). RESULTS: Iodine solution was able to penetrate normal epithelium to a maximum depth neighboring the parabasal layer, but iodine-stained areas were completely consistent with glycogen distribution only in the upper superficial layer. Iodine-negative epithelium presented significantly higher immunoreactions for P53 and GLUT 1 in basal, parabasal, and superficial layers, respectively, whereas the reaction for Ki67 in the superficial layer was higher than that in iodine-positive epithelium (Wilcoxon signed-rank test, P < 0.05). CONCLUSIONS: Iodine infiltrated and reacted with glycogen mainly in the upper superficial layer of the nonkeratinized epithelium. Both histological and molecular margins can be confirmed by iodine vital staining in OSCC. It is also suggested that high cell proliferation induced elevated glycolysis, resulting in an intraepithelial glycogen degradation and consequent failure to be stained by iodine solution.

Application of a vascularized bone free flap and survival rate of dental implants after transplantation: A systematic review and meta-analysis.

PURPOSE: As maxillofacial surgical techniques have advanced, vascularized bone free flap transplantation has become the standard treatment for repairing maxillofacial defects. In this meta-analysis, we summarize the survival rates of implants after VBFF surgery for maxillary and mandibular reconstructions and investigate the factors affecting patient outcomes. METHODS: The PubMed, Embase, and Wanfang databases were searched up to May 31, 2022. The results of the treatment effect are presented as the risk ratio or odds ratio, using 95% confidence intervals. Statistical significance was calculated at α = 0.05 (two-tailed z tests). RESULTS: 35 studies were included in our analysis. The results revealed a 3-year and 5-year implant survival rate of 95.2% and 85.4% in VBFFs, respectively. The location of jaw defects (maxilla or mandible) or timing of implantation was not found to have a statistically significant influence on the survival rate. However, statistically significant differences were observed in the failure of implants placed in irradiated bone tissue. CONCLUSIONS: Statistically significant differences were not found in the implant survival rate between simultaneous and delayed implantation, or between maxillary and mandibular defects. However, dental implants placed in irradiated flaps tended to have a lower survival rate than those surgically placed in non-irradiated flaps.

Clinical application of platelet-rich fibrin to enhance dental implant stability: A systematic review and meta-analysis.

Objective: To investigate the effect of platelet-rich fibrin application on implant stability. Study design: Five databases, namely, PubMed, Embase, Web of Science, Wiley, and China National Knowledge Infrastructure, were searched for reports published up to November 20, 2022. Randomized controlled trials (RCT), including parallel RCTs and split-mouth RCTs, with at least 10 patients/sites were considered for inclusion. Results: After screening based on the inclusion criteria, ten RCTs were included. Low heterogeneity was observed in study characteristics, outcome variables, and estimation scales (I2 = 27.2%, P = 0.19). The qualitative and meta-analysis results showed that PRF increased the effect of implant stabilizers after implant surgery. Conclusions: The results of the present systematic review and meta-analysis suggest that PRF can increase implant stability after implant surgery. PRF may also have a role in accelerating bone healing and tends to promote new bone formation at the implant site.

Surgical resection after orthodontic eruption: A case report of compound odontoma-induced impacted maxillary right central incisor.

Herein, we described the multidisciplinary treatment of a mixed dentition patient with impacted maxillary right central incisor and adjacent compound odontoma. In contrast to conventional treatment procedures, orthodontic traction was first performed for the affected tooth in this case, followed by resection of the odontoma. The odontoma did not shift after eruption of the incisor and was safely removed after alignment of the impacted tooth. No root resorption, gingival recession or bone defect occurred in this case. These results demonstrated that the orthodontic force can break the connection between the impacted tooth and the odontoma. The increased distance between the impacted tooth and odontoma may facilitate removal of the odontoma. Adhesion between the soft tissue capsule of odontoma and the dental follicle, rather than blocking the tooth, may play a role in tooth impaction.

Potential involvement of chondroitin sulfate A in the pathogenesis of ameloblastoma.

Ameloblastoma is classified as a benign odontogenic tumor characterized by locally invasive behavior and high risk of recurrence. Here, we evaluate a potential role for glycosaminoglycan, a structural component of cell membranes and extracellular matrix, in ameloblstoma pathogenesis. We subjected formalin-fixed, paraffin-embedded tissue sections of 34 cases of ameloblastoma, 10 of odontogenic keratocyst, and 17 of dentigerous cyst to immunohistochemistry using monoclonal antibodies recognizing chondroitin sulfate A (CS-A), heparan sulfate (HS), and keratan sulfate (KS). Expression levels of CS-A in epithelial component and stroma of ameloblastoma were significantly higher than those in odontogenic keratocyst and dentigerous cyst. Moreover, CS-A in ameloblastoma was more strongly expressed in stellate reticulum-like cells than in amelobast-like cells with statistical significance. On the other hand, expression levels of HS and KS in epithelial component and stroma of ameloblastoma were lower compared with CS-A. These results overall reveal that among these odontogenic lesions, CS-A is preferentially expessed in ameloblastoma, suggesting potential pathogenetic role probably in cytodifferention of tumor cells to stellate reticulum-like cells.

Difference in glycogen metabolism (glycogen synthesis and glycolysis) between normal and dysplastic/malignant oral epithelium.

BACKGROUND: The purpose of this study was to investigate a difference in glycogen metabolism (glycogen synthesis and glycolysis) between the iodine stained (normal non-keartinized) and the unstained (dysplasctic/malignant) oral epithelium. METHODS: Twenty-one frozen tissue samples of iodine-stained and unstained mucosal tissue were obtained from 21 OSCC patients. Serial frozen sections were cut and examined with the hematoxylin-eosin and periodic acid-Schiff methods and immunohistochemical (IHC) staining for Ki67, P53, molecules associated with glycogenesis (i.e., glycogen synthase (GS) and phospho-glycogen synthase (PGS)), and molecules associated with glycogenolysis (i.e., glycogen phosphorylase isoenzyme BB (GPBB) examine the glycogen metabolism in OSCC. Additionally, in vitro study, the expression levels of GS and GPBB in the cultured cells were analyzed by immunofluorescent staining, Western blot analysis, and the real-time quantitative polymerase chain reaction (PCR). RESULTS: There was no significant difference in GS and PGS immunoactivity between iodine stained and unstained area. On the other hand, significantly greater GPBB immunoreactivity was observed in the basal and parabasal layers of iodine-unstained epithelium, where higher positivity for p53 and Ki67 was also showed. Additionally, western blot analysis, immunofluorescent staining, and real-time quantitative PCR revealed that the oral squamous cancer cells exhibited greater expression of GPBB than normal epithelial cells. CONCLUSIONS: The results of this study showed that GPBB expression, which resulted in up-regulation of glycogenolysis, is enhanced in oral dysplastic/malignant epithelium compared with non-keartinized normal epithelium, in spite of the fact that glycogenesis continues in both of them. Premalignant and malignant epithelial cells consume greater quantities of energy due to their increased proliferation, and hence, exhaust their glycogen stores, which resulting in negative stain reaction with iodine solution.

Iodine penetration and glycogen distribution in vital staining of oral mucosa with iodine solution.

OBJECTIVE: To assess and compare iodine penetration and glycogen distribution in a vital staining of oral mucosa with iodine solution. STUDY DESIGN: Twenty samples were obtained including both iodine-stained and -unstained mucosa. Intraepithelial iodine was examined using frozen sections. Glycogen distribution was assessed by periodic acid-Schiff staining and transmission electron microscopy. RESULTS: Iodine accumulation was observed mainly superficially and in the upper and middle thirds of prickle cell layers, with glycogen in almost the whole epithelium except for the para- and basal cell layers. The pattern of iodine and glycogen distribution was classified into 3 types (full-, surround-, and scatter-type). The iodine color was mainly derived from the cells with full- and surround-type distributed glycogen in the upper half of the oral epithelium. CONCLUSIONS: The results of this study suggested that iodine penetrated into nonkeratinized oral epithelium and reacted mainly with intraepithelial glycogen homogeneously distributed in the cytoplasm.

Clinical significance of apoptosis-associated speck-like protein containing a caspase recruitment domain in oral squamous cell carcinoma.

OBJECTIVES: To assess apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) expression in oral squamous cell carcinoma (OSCC) and analyze its clinical and pathological significance. STUDY DESIGN: ASC expression was studied using immunohistochemistry in 119 OSCCs patients. The relationships between ASC expression and clinical and pathological parameters were statistically analyzed. In addition, the relationships between ASC expression and cell differentiation [IVL (involcrin) expression] and apoptosis (TUNEL [TdT-mediated dUTP nick end labeling] positive cell number) were investigated. RESULTS: ASC expression showed significant correlations with parameters including clinical tumor stage, mode of invasion, and histological differentiation, and had a significant impact on survival of OSCC. The distribution of ASC correlated well with that of IVL. ASC expression was significantly correlated with the TUNEL-positive cell number. CONCLUSIONS: Lower ASC expression correlates with clinical and pathological malignancy and, consequently, poor prognosis of OSCC. ASC has a close association with cell differentiation and apoptosis.

Impact of different surgical margin conditions on local recurrence of oral squamous cell carcinoma.

The purpose of this study was to analyze the impact of different surgical margin conditions on local recurrence of oral squamous cell carcinoma (SCC) in 148 consecutive patients who underwent planned radical resection of oral SCC. The patients were classified into four categories according to the status of the surgical margin: clear (no SCC within 5mm, n=103), close (SCC within 5mm, n=21), dysplasia (dysplastic epithelium at margin, n=13), and involved (SCC at margin, n=11). Cox's proportional hazard model showed that the status of the surgical margin had a significant impact on local recurrence (p<0.003); hazard ratio was 3.79 (95%CI: 1.17-12.28) with a close and 7.89 (2.38-26.17) with an involved margin. The presence of mucosal dysplasia at the surgical margin was also a significant predictor of local recurrence (hazard ratio: 5.29, 95%CI: 1.31-21.29). Local recurrence was observed only with severe dysplasia, while no recurrence with mild and moderate dysplasia. In the patients with a clear and closed surgical margin, local recurrence was related with T4 tumor and an advanced mode of tumor invasion. The results of this study suggested that the presence of tumor cells at or close to the surgical margin increased the risk of local recurrence. The presence of dysplastic epithelium (especially severe dysplasia) at the mucosal surgical margin has a significant impact on local control. It was also suggested that not simply the width of the free margin but also clinical and histological risk factors should be included in deciding the necessity for adjuvant radiotherapy.