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Background: Ameloblastoma is an aggressively growing, highly recurrent odontogenic jaw tumor. Its association with BRAFV600E mutation is an indication for BRAFV00E‐inhibitor therapy The study objective was to identify a sensitive low‐cost test for BRAFV600E‐positive ameloblastoma. We hypothesized that immunohistochemical staining of formalin‐fixed paraffin‐embedded tissues for BRAFV600E mutation is a low‐cost surrogate for BRAFV600E gene sequencing when laboratory resources are inadequate for molecular testing. Methods: Tissues from 40 ameloblastoma samples were retrieved from either formalin‐fixed paraffin‐embedded blocks, RNAlater™ stabilization solution or samples inadvertently pre‐fixed in formalin before transfer to RNAlater™. BRAFV600E mutation was assessed by Direct Sanger sequencing, Amplification Refractory Mutation System‐PCR and immunohistochemistry (IHC). Results: BRAFV600E mutation was detected by IHC, Amplification Refractory Mutation System‐PCR and Direct Sanger sequencing in 93.33%, 52.5% and 30% of samples respectively. Considering Direct Sanger sequencing as standard BRAFV600E detection method, there was significant difference between the three detection methods (휒2 (2) = 31.34, p < 0.0001). Sensitivity and specificity of IHC were 0.8 (95% CI: 0.64–0.90) and 0.9 (95% CI: 0.75–0.99) respectively, while positive predictive value and negative predictive value (NPV) were 0.9 and 0.8 (Fischer's test, p < 0.0001) respectively. Sensitivity and specificity of Amplification Refractory Mutation System‐PCR detection method were 0.7 (95% CI: 0.53–0.80) and 0.9 (95% CI = 0.67–0.98) respectively, while PPV and NPV were 0.9 and 0.6 respectively (Fischer's test, p < 0.0001). Conclusion: Low‐cost and less vulnerability of IHC to tissue quality make it a viable surrogate test for BRAFV600E detection in ameloblastoma. Sequential dual IHC and molecular testing for BRAFV600E will reduce equivocal results that could exclude some patients from BRAFV600E‐inhibitor therapies. [ABSTRACT FROM AUTHOR]

Ameloblastoma is a locally aggressive odontogenic tumor. Etiopathogenesis and locally aggressive growth properties of ameloblastoma can be attributed to a hypoxic microenvironment conducive to tumor cell survival. Epithelial‐derived follicular ameloblastoma cells (EP‐AMCs) display enhanced basal autophagy, but the interplay of hypoxia and autophagy in EP‐AMCs survival and ameloblastoma recurrence is unclear. We evaluated differential expression of autophagic markers in primary and recurrent ameloblastomas and hypothesized that hypoxia‐induced autophagy supports EP‐AMC survival. Primary and recurrent ameloblastomas were comparatively assessed for expression levels of pan‐cytokeratin, Vimentin, and autophagic markers SQSTM1/p62, LC3, and pS6. EP‐AMCs compared with human odontoma‐derived cells (HODCs) were subjected to severe hypoxia to determine the interplay of hypoxia and autophagic process in posthypoxia survival. Pan‐cytokeratin and SQSTM1/p62 were expressed by both primary and recurrent ameloblastoma epithelial cells while the ameloblastoma connective tissues displayed weak reactivity to vimentin. Under hypoxia, EP‐AMC expression levels of hypoxia‐inducible factor (HIF)‐1α, p62, and LC3 were increased while pS6 was decreased posthypoxia. The combined decrease in pS6 and enhanced LC3 in EP‐AMCs under hypoxia indicate that EP‐AMCs re‐establish basal autophagy under hypoxia. Taken together, these suggest a possible role of LC3‐associated phagocytosis (LAP) in ameloblastoma cell survival. [ABSTRACT FROM AUTHOR]

Oral multifocal epithelial hyperplasia (MEH), or Heck's disease, is a rare benign proliferation of the oral mucosa associated with human papillomavirus (HPV). It clinically presents as multiple asymptomatic papules and nodules that mostly affect the lips, buccal mucosa, and tongue. MEH is predominantly found in children and young adults while relatively few cases have been reported in the elderly population. Here, we report a case of oral MEH in a 65‐year‐old man with history of lung transplantation. This case highlights the potential susceptibility of organ transplant recipients to the development of MEH. Since MEH that does not require treatment unless the lesion bothers the patient, clinicians should promptly establish a definitive diagnosis to rule out other HPV‐related precancerous lesions. [ABSTRACT FROM AUTHOR]

Objectives: Severe alveolar bone loss affects dental implant placement. Bone augmentation by grafting iliac crest bone rich in osteoprogenitor cells such as bone marrow stromal cells (BMSCs) requires a second surgical procedure in non-orofacial bone. Skeletal site-specific osteogenesis indicates maxilla and mandible BMSCs are highly proliferative and exhibit osteogenic properties superior to iliac crest BMSCs. Alveolar bone can be easily obtained during routine dental surgery, but it is unclear if titanium-attached alveolar BMSCs will retain their superior osteogenic properties. This study evaluated and compared in vitro osteogenic properties of titanium-attached maxilla and iliac crest BMSCs in same individuals. Material and methods: Primary culture of maxilla and iliac crest BMSCs from four normal healthy volunteers was expanded in culture. In 24-well plates, first passage BMSCs were seeded directly (1 × 104 cells/well) on oxidized titanium disks (1.27 cm diameter and 2 mm thickness) or tissue culture plate. Each cell type was assessed for affinity for titanium, post-attachment survival and osteogenic differentiation based on alkaline phosphatase and osteopontin expressions. Results: There was no difference in the affinity of maxilla and iliac crest BMSCs to titanium. However, titanium-attached maxilla BMSCs were apparently more osteogenically responsive than iliac crest cells based on calcium accumulation and gene expression of alkaline phosphatase and osteopontin. But these differences were not statistically significant in this small patient sample. Conclusion: Maxilla and iliac crest BMSCs have similar attachment affinity for titanium. This pilot study indicates that titanium-attached maxilla BMSCs are more osteogenically responsive and may be a viable and more readily available donor graft material in implant dentistry. [ABSTRACT FROM AUTHOR]

The article presents bone marrow stromal stem cells (BMSSCs) as possible alternative treatment for repair of skeletal defects of older people. BMSSCs are determined from postnatal tissues that are capable of renewal and generation of specific tissue types such as osteoblasts, adipocytes, neural cells and others.