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Osteoblastoma is a benign bone tumor with predominance in those < 20 years of age and rarely occurs in the maxillofacial region. The identification of FOS gene rearrangements in osteoblastomas has been reported, however, a small subset of osteoblastomas do not show FOS gene rearrangements. There are no reports discussing the relationship between age and FOS gene rearrangement in osteoblastomas. We report the case of a 66-year-old female patient with histological features of osteoblastoma in the mandible without FOS gene rearrangement. According to a review of previously reported cases of osteoblastoma, FOS gene rearrangement is significantly less common in patients > 40 years of age (P = 0.041). Osteoblastomas occurring in older adult patients may exhibit pathogeneses different from those of young patients. Further data, including the relationship between age and FOS gene rearrangement, is necessary to clarify the pathogenesis of osteoblastoma. [ABSTRACT FROM AUTHOR]

The clinical differences between odontogenic myxoma (OM) and odontogenic myxofibroma (OMF), and the clinical significance of their classifications, remain unclear. This study reviewed the clinicopathological characteristics of patients with OM or OMF and evaluated the fibrous component of the specimens. Medical records of 21 patients with OM or OMF who underwent tumour resection were reviewed. The percentage of fibrous tissue on the representative sections was evaluated using haematoxylin and eosin- and Masson's trichrome-stained specimens. Histopathological diagnoses included 11 OMs and 10 OMFs with no tumour recurrence except for two cases in which the dredging method was applied. More cortical bone perforation was observed in OM than in OMF cases, without significant differences. Location-locularity and apparent diffusion coefficient value (ADC)-cortical bone perforation were significantly correlated in all OM and OMF cases. The percentage of fibrous tissue in specimens showed bimodal distribution bordered by 45%. There was a significant association between diagnosis based on 45% fibrous tissue criterion and the final pathological diagnosis. Our study showed a tendency for cortical bone perforation in OM compared to OMF and correlation between ADC and cortical bone perforation. According to the histopathological analyses, the fibrous component of each case was bimodal with 45%, which may be a criterion to distinguish between OM and OMF. Accumulating knowledge, such as significant differences in prognosis, may allow for minimal surgical treatment options based on the diagnosis according to this novel histopathological criterion. [ABSTRACT FROM AUTHOR]

The goal of this study was to evaluate the performance of automatic machine learning (ML)-based classification of the impacted status of the mandibular third molar. The dataset consisted of 1864 mandibular third molar images, and the impaction pattern for each mandibular third molar was annotated based on the Pell and Gregory classification and the Winter classification. To improve performance, data augmentation techniques were applied, including rotation, flip, and pseudo-images that mimic prostheses, and ML was performed using the VGG16 convolutional neural network. In the Pell and Gregory Class classification, the performance of the model trained on the augmented dataset exhibited good classification performance in three metrics, obtaining accuracy of 0.8609, macro-average F1-score of 0.7624, and an area under the receiver operating characteristic curve (AUC) of macro-average receiver operating characteristic (ROC) of 0.9334. For Pell and Gregory Position classification, the model obtained an accuracy value of 0.8432, a macro-average F1-score of 0.8156, and an AUC of macro-average ROC value of 0.9395. For Winter classification, the model obtained an accuracy value of 0.7959, a macro-average F1-score of 0.6423, and an AUC of macro-average ROC value of 0.9549. The constructed ML classification model for mandibular third molar impaction status demonstrated good performance when data augmentation was applied. [ABSTRACT FROM AUTHOR]

Marsupialization is a dependable choice for mandibular unicystic ameloblastoma (UA) management. However, investigations regarding its speed of shrinkage (SS) and reduction rate (RR) are lacking. This case report highlights the treatment of a huge mandibular UA with high SS and RR using marsupialization before secondary surgery. A 45-year-old male patient presented with severe swelling of the right side of the mandible, resulting in prominent facial asymmetry. Panoramic radiograph revealed a unilocular, radiolucent lesion extending from the mandibular midline to the right ramus. Computed tomography (CT) revealed a large radiolucent lesion that expanded in the buccolingual direction. Incisional biopsy showed that the lesion was UA. After 1.5 years of marsupialization, an SS of 0.183 % per day was reached, leading to an impressive RR of 98.7 %. Treatment was followed by enucleation and peripheral osteotomy. No recurrence was observed at 1 year post-surgery. The treatment of mandibular UA remains controversial, ranging from conservative approaches to aggressive interventions. In the current case, marsupialization was highly effective in reducing the volume of the lesion, thereby facilitating a minimally invasive secondary surgery to preserve function. The intact periosteum, which has the potential to differentiate into various cell types, may be associated with the regeneration of new bone after marsupialization. Marsupialization remains a successful strategy for managing mandibular UA. Even the huge lesions causing facial deformity can be treated with marsupialization combined with secondary surgery, avoiding the aesthetic and functional disruptions associated with radical treatment. • Marsupialization aids in managing mandibular unicystic ameloblastoma (UA). • A 45-year-old man presented with right mandibular swelling, causing facial asymmetry. • Marsupialization achieved no recurrence post-enucleation and peripheral osteotomy. • Marsupialization is a successful strategy for mandibular UA. [ABSTRACT FROM AUTHOR]

Schwannomas are benign tumours that originate from the Schwann cells of the nerve. Despite the frequency of their occurrence in the head and neck, data relating to their clinicopathological features in the region are limited. This study reviews the clinicopathological characteristics and specific pathology of ancient (degenerative) change in 40 cases in the oral and maxillofacial region. Medical records were reviewed of the 40 cases treated at Tokyo Medical and Dental University Hospital Faculty of Dentistry between 2000 and 2020. The most frequently involved site was the tongue, and the average tumour size was 13.2 mm. Degenerative changes were observed in eight cases. All tumours were completely excised through biopsy or local excision, and no recurrence was observed on clinical follow up. Statistical analyses revealed significant associations (p < 0.05) between ancient change and tumour size, and between ancient change and the apparent diffusion coefficient (ADC) value derived from diffusion-weighted magnetic resonance imaging (MRI). Analysis suggests that schwannoma progresses over a long period and subsequently undergoes secondary ancient changes. Pathological events such as cystic formation and haemorrhage that are associated with ancient changes, cause hypocellularity and lead to high ADC values. These values may indicate ancient change and should be considered when distinguishing schwannoma from other lesions. [ABSTRACT FROM AUTHOR]

Objective: Adenoid cystic carcinoma (AdCC) is a rare, indolent salivary gland tumor that is reported to be driven by fusion genes. However, MYB/MYBL1-NFIB fusions have been detected in <60% of all AdCC cases and the oncogenic driver mutations in approximately 40% of AdCC remain unknown. Our aim was to identify novel gene fusions in AdCC.Study Design: We investigated 20 AdCC cases using a targeted RNA sequencing panel to identify gene fusions and performed quantitative real-time reverse transcription polymerase chain reaction to assess MYB, MYBL1, and NFIB expression levels.Results: A total of 36 fusion transcripts in 15 cases were detected and validated by Sanger sequencing. The MYB-NFIB and MYBL1-NFIB fusion genes were detected in 9 and 3 cases, respectively, in a mutually exclusive manner. Furthermore, novel gene fusions, namely, NFIB-EPB41L2, MAP7-NFIB, NFIB-MCMDC2, MYBL1-C8orf34, C8orf34-NFIB, and NFIB-CASC20, were identified. Among them, NFIB-EPB41L2 and NFIB-MCMDC2 are thought to activate MYB and MYBL1 expression, respectively, through the insertion of a genomic segment in proximity to MYB and MYBL1 genes, respectively.Conclusion: Six novel gene fusions other than MYB/MYBL1-NFIB were identified. The detection of novel fusion genes and investigation of the molecular mechanism will contribute to the development of novel molecular targeted therapies for this disease. [ABSTRACT FROM AUTHOR]

Osteosarcoma (OS) in the jaw is rare, accounting for 4–6% of all OS. Small cell osteosarcoma (SCO), which is the rarest of the several subtypes of OS, accounts for about 1.5% of all OS. To the best of our knowledge, only three cases of SCO in the jaw have been reported previously in the literature. We report here a case of SCO in the left mandible of a 26-year-old female, which was successfully treated with surgery and postoperative chemotherapy. This case suggested that differential and confirmed diagnoses of SCO were difficult. [ABSTRACT FROM AUTHOR]

Highlights • Modified citrus pectin size-fractionated has different structures. • Lower DM HG enrichment and branched chains depletions enhanced anti-cancer effects. • Increased amounts of AG and loss of RG enhanced anti-cancer effects. • Fractions differentially interact with ECM proteins and galectin-3. • Fractionation can be useful to the development of functional food supplements. Abstract While chemically and thermally modified citrus pectin (MCP) has already been studied for health benefits, it is unknown how size-fractionated oligo- and polysaccharides differentially affect cancer cell behavior. We produced thermally MCP and fractionated it by molecular size to evaluate the effect these polymers have on cancer cells. MCP30/10 (between 30 and 10 kDa) had more esterified homogalacturonans (HG) and fewer rhamnogalacturonans (RG-I) than MCP and MCP30 (higher than 30 kDa), while MCP10/3 (between 10 and 3 kDa) showed higher amounts of type I arabinogalactans (AGI) and lower amounts of RG-I. MCP3 (smaller than 3 kDa) presented less esterified HG and the lowest amount of AGI and RG-I. Our data indicate that the enrichment of de-esterified HG oligomers and the AGI and RG-I depletions in MCP3, or the increase of AGI and loss of RGI in MCP30/10, enhance the anticancer behaviors by inhibiting migration, aggregation, and proliferation of cancer cells. [ABSTRACT FROM AUTHOR]