Clinicopathological characteristics and diagnostic accuracy of BRAF mutations in ameloblastoma: A Bayesian network analysis.

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.

Comparison of the histopathological characteristics of diffuse sclerosing osteomyelitis of the mandible, chronic suppurative osteomyelitis, and craniofacial fibrous dysplasia.

BACKGROUND: There are relatively few reports on the histopathological characteristics of diffuse sclerosing osteomyelitis of the mandible (DSOM), which is difficult to distinguish from chronic suppurative osteomyelitis (CSO) and craniofacial fibrous dysplasia (CFD). This study aimed to summarize and compare the histopathological characteristics of DSOM, CFD, and CSO. MATERIALS AND METHODS: In this study, hematoxylin and eosin-stained sections of patients with DSOM, CSO, and CFD at the Peking University Hospital of Stomatology from 2015 to 2020 were retrieved. The histopathological characteristics were summarized, including new bone formation, inflammatory cell infiltration, bone trabecular morphology, osteoclasts, sequestrum, bacterial mass, and calcified spherules, similar to cementicles. The histopathological characteristics of DSOM, CSO, and CFD were compared, and the results were statistically analyzed. RESULTS: In total, 50, 13, and 10 patients with DSOM, CSO, and CFD were included in this study, respectively. In terms of new bone formation, both DSOM and CSO showed reactive bone formation (p = 1), whereas CFD mainly showed fiber osteogenesis (p < 0.001). The inflammatory cells of DSOM were mainly lymphocytes and plasma cells, whereas those of CSO were mainly lymphocytes and neutrophils (p < 0.001), and there was usually no inflammatory cell infiltration in the CFD specimens (p < 0.001). DSOM, CSO, and CFD showed irregular bone trabeculae (p = 0.045, p = 0.703) and active osteoclasts (p1 = 0.189, p2 = 0.256). DSOM showed a small amount of bacterial mass but no sequestrum; neither of which was found in CFD (p = 1, p = 1), but it was common in CSO (p = 0.011 and p = 0.025). DSOM and CSO showed smooth and regular basophilic lines (p = 0.308), whereas CFD showed a rough and irregular basophilic line (p < 0.001). CONCLUSIONS: The histopathological characteristics of the three diseases were partly similar, but there were evident differences. The main differences are the type of new bone formation, types and distribution of inflammatory cells, and presence of sequestrum and bacterial masses. These differences will help clinicians diagnose DSOM.

PTCH/SMO gene mutations in odontogenic keratocysts and drug interventions.

BACKGROUND: Odontogenic keratocysts (OKCs) are odontogenic jaw lesions that cause destruction and dysfunction of the jawbone. OKCs can be sporadic or associated with nevoid basic cell carcinoma syndrome (NBCCS). However, the factors that initiate OKCs and the mechanism of cyst formation remain unclear. Here, we investigated the impact of PTCH1 and SMO mutations on disease progression, as well as the effects of sonic hedgehog (SHH) signaling pathway inhibitors GDC-0449 and GANT61 on OKC fibroblasts. METHODS: Eight sporadic OKC fibroblasts without gene mutations were used as the control, and six NBCCS-related fibroblasts were cultured in vitro. The effect of PTCH1 non-truncated mutation 3499G>A (p.G1167R) and SMO c.2081C>G (p.P694R) mutation on OKC fibroblast proliferation was examined by EdU assay. CCK8 and wound-healing assays detected the effects of OKC fibroblasts carrying PTCH1 c.3499G>A (p.G1167R) and SMO c.2081C>G (p.P694R) mutations on the proliferation and migration of HaCaT cells after co-culture. Quantitative real-time PCR detected the effects of GDC-0449 or GANT61 on the SHH signaling pathway in NBCCS-related OKCs with PTCH1 truncated mutations and PTCH1 c.3499G>A (p.G1167R) and/or SMO c.2081C>G (p.P694R) mutations. RESULTS: PTCH1 c.3499G>A (p.G1167R) and SMO c.2081C>G (p.P694R) promoted the proliferation of OKC fibroblasts. The proliferation and migration of HaCaT cells were affected by NBCCS-related OKC fibroblasts carrying PTCH1 c.3499G>A (p.G1167R) and SMO c.2081C>G (p.P694R) mutations. GDC-0449 significantly inhibited the SHH signaling pathway in NBCCS-related OKC fibroblasts with PTCH1 truncated mutations. An NBCCS-related OKC carrying PTCH1 c.3499G>A (p.G1167R) and SMO c.2081C>G (p.P694R) mutations were resistant to GDC-0449 but inhibited by GANT61. CONCLUSIONS: Genetic mutations in OKC fibroblasts may affect the biological behavior of epithelial and stromal cells and cause disease. GDC-0449 could be used to treat OKCs, especially NBCCS-related OKCs with PTCH1 truncated mutations. SMO c.2081C>G (p.P694R) may lead to resistance to GDC-0449; however, GANT61 may be used as an alternative inhibitor.

GNAS mutation analysis assists in differentiating chronic diffuse sclerosing osteomyelitis from fibrous dysplasia in the jaw.

Chronic diffuse sclerosing osteomyelitis of the mandible (DSOM) and fibrous dysplasia (FD) are distinct lesions with overlapping clinicopathological features that complicate their diagnosis. This study aimed to evaluate the efficacy of GNAS mutation analysis in differentiating between these two conditions. DNA samples from patients with DSOM (n = 35) and FD (n = 29) were collected to analyze the presence of GNAS mutations in exons 8 and 9, the two previously reported hotspot regions, using polymerase chain reaction and direct sequencing. Twenty-four of 29 patients (83%) with FD showed missense mutations in codon 201 in exon 8, whereas no mutation was detected in exon 9. No mutations were found in any of the 35 cases with DSOM. We also identified one case with an uncertain diagnosis due to overlapping clinicopathological features of DSOM and FD. A Q227H mutation was detected in this case, that confirmed the diagnosis of FD. Taken together, the findings indicate that mutational analysis of the GNAS is a reliable approach to differentiate between DSOM and FD of the jaw.

Orthokeratinized odontogenic cysts: A clinicopathologic study of 159 cases and molecular evidence for the absence of PTCH1 mutations.

BACKGROUND: Orthokeratinized odontogenic cyst (OOC), a newly designated entity of odontogenic cysts, is an intraosseous jaw cyst that is entirely or predominantly lined by orthokeratinized squamous epithelium. The aim of this study was to report a large series of OOC to substantiate its clinicopathologic profiles and to investigate PTCH1 mutations in OOCs. METHOD: The clinicopathologic features of 167 OOCs from 159 patients were analyzed and the immunohistochemical expression of markers related to cell differentiation and proliferation was evaluated. Furthermore, PTCH1 mutations were analyzed in 14 fresh samples of OOC. RESULTS: OOCs occurred mostly in the third and fourth decades (60.4%) with a male predilection (66.7%). The lesions developed more often in the mandible than maxilla, primarily in the posterior mandible and ramus. Eight patients (5.0%) showed multiple locations of either bilateral posterior mandible (n = 6) or both the maxilla and mandible. Radiographically, the majority of OOCs (91.2%) showed a well-demarcated, unilocular radiolucency with 14 multilocular cases (8.8%). A follow-up of 131 patients (123 treated by enucleation with or without marsupialization and eight by peripheral ostectomy) revealed no recurrence during an average period of 4.56 years after surgery. Immunohistochemistry indicated lower proliferative activity and a varying epithelial differentiation pattern in OOC compared with odontogenic keratocysts (OKC). No PTCH1 mutation was detected, except for three known single nucleotide polymorphisms. CONCLUSION: The clinicopathological and molecular differences between OOC and OKC justified their separation, and unlike OKCs, OOCs did not harbor PTCH1 mutations, suggesting different pathogenesis underlying these two jaw cysts.

Salivary gland papillary adenocarcinoma with intestinal-like features: Clinicopathologic, immunohistochemical, and genetic study of six cases.

BACKGROUND: Salivary gland tumors with papillary architecture and intestinal-like mucinous cytologic features are rare. Their clinicopathologic and genetic features are not fully understood, and whether they represent one separate entity remains unclear. METHODS: Six salivary adenocarcinomas with papillary architecture and intestinal-like mucinous cytologic features were reported. Immunostaining was done for CK7, CK20, CDX2, SOX10, S100, MUC1, MUC2, and MUC5AC. Tumor DNA samples were extracted for Sanger sequencing. Previously reported morphology-analogous cases were reviewed. RESULTS: Six cases involved the palate (2), retromolar region (1), submandibular region (1), tongue (1), and mandible (1). Five cases were followed up, with one case of recurrence 1 year after surgery, one death from cerebral infarction 7 days after surgery, and three cases without signs of recurrence or metastasis over 5 years. All cases had abundant mucinous production and presented a typical immunophenotype common to salivary primaries, CK7 & MUC1 positive, CK20 & CDX2 negative. Sanger sequencing demonstrated recurrent AKT1 E17K mutations in four cases (4/6, 66.7%). A review of reported salivary intestinal-like tumors revealed 3 out of 13 cases presented with papillary morphology and CDX2 negative. Some salivary papillary neoplasms with mucinous cytologic features termed as intraductal papillary neoplasms or mucinous adenocarcinomas were also reported with AKT1 E17K mutations. CONCLUSION: We describe 6 cases of salivary gland papillary adenocarcinoma with intestinal-like mucinous cytologic features, which are different from conventional intestinal-type adenocarcinoma, presenting a consistent immunophenotype of CK7 & MUC1 positive, CK20 & CDX2 negative and exhibiting recurrent AKT1 E17K mutations.

Could the socket shield technique be better than conventional immediate implantation? A meta-analysis.

OBJECTIVES: The purpose of this study was to evaluate whether the clinical outcome of socket shield technique (SST) is superior to that of conventional immediate implantation (CII). MATERIALS AND METHOD: Five electronic databases (PubMed, Cochrane, Web of Science, CNKI, and Google Scholar) were searched to identify randomized controlled trials up to June 31, 2021. Five evaluation indexes were extracted, namely, buccal bone resorption at the horizontal and vertical levels (BBH and BBV), the soft tissue recession assessed by pink evaluation scores (PES), patient satisfaction (PS), ISQ, and the success rate of implantation (SRI), to compare the superiority between SST and CII operations. All data analyses were performed using Review Manager (version 5.4). RESULTS: Ten studies were included in this review. The sample included 388 implants, with 194 in the SST group and 194 in the CII group. Compared with the CII group, the SST group had a lower BBH and BBV (standardized mean difference (SMD), - 1.77; 95% CI, - 2.26 to - 1.28; P < 0.00001 and SMD, - 1.85; 95% CI, - 2.16 to 1.54; P < 0.00001), higher PES improvement (SMD, 2.27; 95% CI, 1.59 to 2.95; P < 0.00001), higher rate of PS (OR, 3.12; 95% CI, 1.08 to 9.04; P = 0.04), and slightly higher ISQ (SMD, 0.71; 95% CI, 0.28 to 1.15; P = 0.001). CONCLUSIONS: Compared with CII, SST could be a better option for esthetic area implantation, but evaluation of its long-term success is still needed. CLINICAL RELEVANCE: By comparing and analyzing the operations of immediate implant in esthetic zone, we could choose SST to effectively alleviate the absorption of bone tissue and improve the contouring of soft tissue after anterior teeth extraction, so as to achieve a more stable and superior clinical outcomes of implant in esthetic zone.

Biopsied non-dental plaque-induced gingival diseases in a Chinese population: a single-institute retrospective study.

BACKGROUND: While inflammatory diseases such as gingivitis and periodontitis induced by dental plaque biofilms constitute the majority of gingival lesions, gingiva can also be affected by a variety of diseases with aetiologies different from bacterial biofilms. The aim of this study was to retrospectively analyze the frequency and distribution of non-dental plaque-induced gingival diseases (NDPIGDs) in the Chinese population in a single institute. METHODS: A total of 6859 samples of biopsied gingival diseases during the period 2000-2019 were obtained from the Department of Pathology, Peking University Hospital of Stomatology. Lesions were categorized by histopathological diagnosis, pathological characteristics and the new classification of gingival health and gingival diseases/conditions. Demographic information, such as gender, location, and age, were also analyzed. RESULTS: Among 6859 biopsied NDPIGD samples, the five most frequent diagnoses included oral squamous cell carcinoma (OSCC, n = 2094), fibrous hyperplasia (n = 2026), pyogenic granuloma (n = 478), epithelial dysplasia (n = 477), and epithelial hyperplasia/hyperkeratosis (n = 436). All types could be grouped into nine categories according to their pathological characteristics. The most common biopsied NDPIGDs category was "hyperplastic lesions" (n = 2648, 38.61%), followed by "malignant neoplasms" (n = 2275, 33.17%). The most common diagnosis types in each category were fibrous hyperplasia and OSCC. Of all NDPIGDs, most lesions could be categorized into the new classification of gingival health and gingival diseases/conditions; only 7.07% did not fit the current classification system. CONCLUSIONS: The present study is the first report on the frequency and distribution of biopsied NDPIGDs in a Chinese population. Unlike previous studies, the most prevalent categories were "hyperplastic lesions" and "malignant neoplasms". The proportion of "malignant neoplasms" and "oral potentially malignant disorders" was remarkably higher than in previous researches. Nevertheless, the study provided epidemiological information on many NDPIGDs, which could be useful for future health policies as well as screening programs.

Clinicopathologic study on a rare variant of ameloblastoma with basal cell features.

OBJECTIVES: To investigate the clinical features, pathologic manifestations, and biologic behaviors of a variant of ameloblastoma with basal cell features (AM-BC). MATERIALS AND METHODS: Following retrospective review of the clinical and pathological data of six cases of AM-BC, we described their histological and immunohistochemical (IHC) features and discussed the biologic behaviors, prognoses, pathogenesis, and clinical relevance of AM-BC. Direct sequencing of polymerase chain reaction products was also performed in all cases. RESULTS: The six cases of AM-BC involved four women and two men, aged 22-82 years. Four lesions occurred in the maxilla and two in the mandible. Histologically, the basal cells tended to be arranged as unequally sized follicles, strands, or cords of odontogenic epithelium in the connective tissue stroma. Little or no stellate reticulum was present in the central portion of the nest. Expression of CKs was consistent with other histological variants of ameloblastoma (AM), but AM-BC had significantly higher p53 and Ki-67 (p < 0.05) labeling indices than other histological variants of AM. Two patients had BRAF gene mutations. CONCLUSION: Ameloblastoma with basal cell features is a very rare variant of AM. Our study showed the differences and relationships that exist between AM-BC and other variants of AM, which could enhance understanding of AM-BC.

PTCH1 alterations are frequent but other genetic alterations are rare in sporadic odontogenic keratocysts.

OBJECTIVE: Odontogenic keratocysts (OKCs) are benign jaw lesions with high growth potential and propensity for recurrence. Our previous study revealed that PTCH1 mutations, which were frequently detected in sporadic OKCs, might be underestimated due to the masking effect of the stromal components within the tested tissues. We aimed to confirm these results in larger scale and further present the unbiased view of the genomic basis of sporadic OKCs except PTCH1. MATERIALS AND METHODS: We analyzed PTCH1 mutations in additional 19 samples. Using whole-exome sequencing (WES), we further characterized the mutational landscape of five sporadic OKC samples lacking PTCH1 mutation and loss of heterozygosity (LOH). RESULTS: Combined with our previously reported 19 cases, thirty of 38 (79%) cases harbored PTCH1 mutations. Through whole-exome sequencing and integrative analysis, 22 novel mutations were confirmed among five PTCH1-negative samples. No recurrent mutations were identified in the WES samples and validation cohort of 10 OKCs. CONCLUSIONS: Our data further confirmed the frequent PTCH1 mutation and other rare genetic alterations in sporadic OKCs, highlighting the central role of SHH signaling pathway. In PTCH1-negative cases, other rare mutations scattered in a subset of OKCs were independent of the SHH pathway. These results suggested that an SHH inhibitor may be effective to treat the majority of OKCs.

Disruption of Smad4 in odontoblasts and dental epithelial cells influences the phenotype of multiple keratocystic odontogenic tumors.

Keratocystic odontogenic tumors (KCOTs) are cystic epithelial neoplasms with a high recurrence rate. The molecular mechanisms underlying the initiation and progression of KCOTs are still largely unknown. Previous research showed that specific ablation of Smad4 in odontoblasts and dental epithelia resulted in spontaneous KCOTs in mice, and that constitutively activated Hedgehog (Hh) signaling was detected in the cyst epithelia of both Smad4(Co/Co) OC-Cre and Smad4(Co/Co) K5-Cre mice. Here, we ablated Smad4 in mouse odontoblasts and dental epithelia and compared the sizes and numbers of KCOTs. Both the number and size of KCOTs in Smad4(Co/Co) OC-Cre mice were larger than those in Smad4(Co/Co) K5-Cre mice, suggesting that paracrine signals from root odontoblasts play a more important role than those from Hertwig's epithelial root sheath (HERS) cells.

Digital pathology-based artificial intelligence models for differential diagnosis and prognosis of sporadic odontogenic keratocysts.

Odontogenic keratocyst (OKC) is a common jaw cyst with a high recurrence rate. OKC combined with basal cell carcinoma as well as skeletal and other developmental abnormalities is thought to be associated with Gorlin syndrome. Moreover, OKC needs to be differentiated from orthokeratinized odontogenic cyst and other jaw cysts. Because of the different prognosis, differential diagnosis of several cysts can contribute to clinical management. We collected 519 cases, comprising a total of 2 157 hematoxylin and eosin-stained images, to develop digital pathology-based artificial intelligence (AI) models for the diagnosis and prognosis of OKC. The Inception_v3 neural network was utilized to train and test models developed from patch-level images. Finally, whole slide image-level AI models were developed by integrating deep learning-generated pathology features with several machine learning algorithms. The AI models showed great performance in the diagnosis (AUC = 0.935, 95% CI: 0.898-0.973) and prognosis (AUC = 0.840, 95%CI: 0.751-0.930) of OKC. The advantages of multiple slides model for integrating of histopathological information are demonstrated through a comparison with the single slide model. Furthermore, the study investigates the correlation between AI features generated by deep learning and pathological findings, highlighting the interpretative potential of AI models in the pathology. Here, we have developed the robust diagnostic and prognostic models for OKC. The AI model that is based on digital pathology shows promise potential for applications in odontogenic diseases of the jaw.

GNAS mutational analysis in differentiating fibrous dysplasia and ossifying fibroma of the jaw.

Differential diagnosis of fibrous dysplasia and ossifying fibroma may often pose problems for pathologists. The purpose of this study was to evaluate the value of mutational analysis of the GNAS gene in differentiating these two conditions. DNA samples from patients with fibrous dysplasia (n=30) and ossifying fibroma (n=21) were collected to analyze the presence of GNAS mutations at exons 8 and 9, the two previously reported hotspot regions, using polymerase chain reaction and direct sequencing. In all, 90% (27/30) of cases with fibrous dysplasia showed missense mutations of codon 201 at exon 8, with a predilection of arginine-to-histidine substitution (p.R201H, 70%) as opposed to arginine-to-cysteine substitution (p.R201C, 30%), whereas no mutation was detected at exon 9. No mutation was found in all 21 cases with ossifying fibroma. In addition, a meta-analysis of previously published reports on GNAS mutations in fibrous dysplasia and ossifying fibroma was performed to substantiate our findings. A total of 24 reports including 307 cases of fibrous dysplasia and 23 cases of ossifying fibroma were reviewed. The overall incidence of GNAS mutations in fibrous dysplasia was 86% (264/307), and the major types of mutations were also R201H (53%) and R201C (45%). No GNAS mutation was detected in all patients with ossifying fibroma. We also reported one case with uncertain diagnosis due to overlapping clinicopathological features of fibrous dysplasia and ossifying fibroma. An R201H mutation was detected in this case, thus confirming a diagnosis of fibrous dysplasia. Taken together, our findings indicate that mutational analysis of GNAS gene is a reliable adjunct to differentiate ossifying fibroma and fibrous dysplasia of the jaws.

Biological effects on the migration and transformation of microplastics in the marine environment.

Microplastics(MPs) are ubiquitous, difficult to degrade, and potentially threatening to organisms in marine environment, so it is important to clarify the factors that affect their biogeochemical processes. The impact of biological activities on the MPs in marine environment is ubiquitous and complex, and there is currently a lack of systematic summaries. This paper reviews the effects of biological actions on the migration, distribution and degradation of MPs in marine environment from four aspects: biological ingestion and digestion, biological movement, biological colonization and biological adhesion. MPs in seawater and sediments can be closely combined with organisms through three pathways: biological ingestion, biofilm formation or adhesion to organisms, and are passed between species at different trophic levels through the food chain. The generation and degradation of faecal pellets and biofilms can alter the density of "environmental MPs", thereby affecting their vertical migration and deposition in water bodies. The movement of swimming organisms and the disturbance by benthic organisms can promote the migration of MPs in water and vertical migration and resuspension in sediments, thereby changing the distribution of MPs in local sea areas. The grinding effect of the digestive tract and the secretion of chemicals from the biofilm (such as enzymes and acids) can reduce the particle size and increase surface roughness of MPs, or even degrade them completely. Besides, biological adhesion may be an important mechanism affecting the distribution, migration and preservation of MPs. There may be complex interactions and linkages among marine dynamical processes, photochemical degradation and biological processes that collectively affect the biogeochemical processes of MPs, but their relative contributions remain to be more studied.

Adenoid Ameloblastoma Shares Clinicopathologic, Immunohistochemical, and Molecular Features With Dentinogenic Ghost Cell Tumor: A Comparative Analysis.

The updated classification of odontogenic tumors by the World Health Organization (WHO) has included adenoid ameloblastoma (AA) as a distinct entity. However, distinguishing between AA and dentinogenic ghost cell tumor (DGCT) can still be challenging due to their significant morphologic similarities. In this study, we aimed to compare the clinicopathologic, immunohistochemical, and molecular characteristics of AA and DGCT to aid in their differentiation and to shed light on their pathologic mechanisms. Thirteen cases of AA and 14 cases of DGCT (15 samples) were analyzed, along with 11 cases of adenomatoid odontogenic tumor (AOT) and 18 cases of conventional ameloblastoma (AM) for comparative purposes. The study found that AA and DGCT shared a similar long-term prognosis. Immunohistochemically, all cytokeratins detected, except CK8/18, were not statistically significant in differentiating AA and DGCT, while there was a statistically significant difference in the immunophenotype of CK7 and CK10/13 between AA and AM. Nuclear ß-catenin accumulation were detected in all cases of AA and DGCT, while AOTs and AMs exhibited cytoplasmic ß-catenin. Molecularly, CTNNB1 hotspot mutations were found in only 1 case of AA (1/13), but not found in the other 3 types of tumors. BRAF p.V600E mutation was positive in 2/13 (15%) AA, 1/15 (7%) DGCT, and 2/11 (18%) AOT cases. In comparison, conventional AM was positive for BRAF p.V600E mutation in 94% (17/18) of cases, while KRAS mutations were detected in 63% (7/11) of AOT cases. The study suggests that the so-called AA is a rare benign tumor that exhibits clinical, immunohistochemical, and molecular features similar to DGCTs. Based on these findings, AA should not be categorized as a standalone entity solely based on the presence of whorls/morules and cribriform/duct-like structures. Further studies are needed to investigate the pathologic mechanisms of these tumors and to identify potential therapeutic targets.

Head and neck carcinoma in children: A clinicopathological study of 42 cases.

Background/purpose: Cancer is an important part of the global burden of childhood diseases. Head and neck carcinoma in children is rare and related research is limited. This study aimed to investigate the clinicopathological features of childhood head and neck carcinoma. Materials and methods: Forty-two cases of childhood head and neck carcinoma treated in our institution were reviewed and analyzed. Results: Median age overall was 11 years. Twenty-three patients (54.8%) were male and 19 (45.2%) were female. Parotid gland location was most common (54.8%). Mucoepidermoid carcinoma and squamous cell carcinoma were the most common histological types (57.1% and 11.9%, respectively). Two patients had a history of bone marrow transplantation and two had a history of odontogenic keratocyst. The recurrence rate after treatment was 8.6%. Conclusion: Early diagnosis and treatment and close follow-up of childhood head and neck carcinoma are warranted to prevent recurrence and improve clinical outcome.

Burnout and Its Association With Competence Among Dental Interns in China.

Intern physicians are generally more burdened by stress than the general population. This cross-sectional study aimed to evaluate the current situation regarding burnout and explore its association with the self-evaluation of competence among Chinese dental interns. A self-administered anonymous survey was conducted on 91 dental interns in the Peking University School of Stomatology, from August 2019 to June 2020. It consisted of a psychological stress questionnaire, including burnout and self-evaluation of clinical competence. The Wilcoxon signed rank test was used to determine the differences between self-evaluation scores of clinical competence. Results showed average scores for emotional exhaustion, depersonalization, and personal accomplishment of 22.22 ± 9.04, 8.16 ± 5.21, and 36.08 ± 7.76, respectively. Dental clinical technology was considered more useful than other clinical competencies, and there was a correlation between its importance and the stress caused by its deficiency (r = -0.201, p = 0.056). Significant associations were found between stress due to a lack of dental clinical technology and high emotional exhaustion (r = 0.273, p < 0.05). Burnout was common among the dental interns, which may be a valuable finding. Among the six different aspects of clinical competence, "dental clinical technology" represented the most stressful item. Strengthening pre-clinical training and promptly conducting targeted training in the early clinical process may be considered as decompression measures.

Clinicopathological and genetic study of a rare occurrence: Malignant transformation of fibrous dysplasia of the jaws.

BACKGROUND: Malignant transformation of fibrous dysplasia (FD) is very rare and little is known about this occurrence. METHODS: We present the detailed clinical course of three cases of osteosarcoma arising from FD of the jaws and explore the genetic aberrations by Sanger sequencing, whole-exome sequencing (WES) and immunohistochemistry (IHC). A literature review of important topics related to this occurrence was also performed. RESULTS: It was observed that patients with secondary sarcoma from FD showed a wide range of ages, with most during the third decade. Female and males were equally affected. Craniofacial bones and femurs were the most affected sites. High-risk factors for this occurrence included polyostotic FD, McCune-Albright syndrome and excess growth hormone. Notably, a potential relationship between thyroid hormones and sarcoma development was suggested in one patient, who began to show malignant features after hypothyroidism correction. Sanger sequencing revealed GNAS mutations of FD retained in all malignant tissues. Additionally, abnormal TP53 was demonstrated in all three cases by WES and IHC. WES also revealed two other driver mutations, ROS1 and CHD8, and large amounts of somatic copy number alterations (CNAs) where various oncogenes and tumour suppressors are located. CONCLUSION: This study demonstrated and reviewed the clinical features and risk factors for a rare occurrence, secondary sarcoma from FD, and provided important new knowledge about its genetics.

Epidemiology of needlestick injury exposures among dental students during clinical training in a major teaching institution of China: A cross-sectional study.

BACKGROUND/PURPOSE: Dental students are particularly vulnerable for needlestick injuries (NSI). However, the epidemiology of NSI exposures among Chinese dental students was rarely reported. The objectives of this study were to determine the prevalence of NSI among dental students in a major teaching institution of China, and to identify associated factors. MATERIALS AND METHODS: A self-administrated online questionnaire was developed based on previously published studies, and distributed to dental students of Class 2011-2015 recruited from Peking University School and Hospital of Stomatology. RESULTS: Two hundred and sixty-eight dental students including 38.8% of males and 61.2% of females (response rate of 90.0%) completed the survey. Approximately 36.2% of the respondents had sustained at least one NSI. A total of 112 NSI cases were reported. The majority of NSIs were related to the procedures of local anesthesia administration (15.2%) and tooth cleaning or scaling (15.2%). Syringe needles, dental burs and ultrasonic chips were the most notorious devices. Statistical analysis showed significant distribution in NSI occurrence between July-September and October-December. The main cause was lapse in concentration (67.9%), followed by fatigue (22.3%). Up to 66.1% of the exposures occurred when the student was working alone, while only 10.7% with assisting. Unfortunately, 26.8% of the incidents were under-reported. CONCLUSION: Dental students are prone to needlestick injuries. The present study clearly reveals a need for increased awareness of NSI prevention among dental students. The quality of infection control education at dental teaching institutions is crucial and indispensable for reducing NSI exposures.

Comparing the sorption of pyrene and its derivatives onto polystyrene microplastics: Insights from experimental and computational studies.

In this study, the sorption behaviors and mechanisms between polystyrene microplastics (micro-PS) and 4-rings polycyclic aromatic hydrocarbons (PAHs) pyrene (Pyr) and its derivatives (S-Pyr), including 1-methylpyrene (P-CH3), 1-hydroxypyrene (P-OH), 1-aminopyrene (P-NH2), 1-pyrenecarboxylic acid (P-COOH) were investigated at neutrality. The results revealed that the sorption rates of micro-PS for S-Pyr were higher than those for parent Pyr. Meanwhile, -CH3 could slightly facilitate the sorption, whereas -OH, P-NH2, and P-COOH intensively inhibit the sorption of S-Pyr onto micro-PS. The sorption capacities of Pyr/S-Pyr increased with decreasing size of micro-PS. Besides, the effects of salinity and temperature on the sorption characteristics of micro-PS for Pyr/S-Pyr depended on their substituents. Combined with experimental and computational methods, it could be concluded that the main sorption mechanisms were possibly hydrophobic interaction, π-π interaction and pore-filling. The observations reported here could improve predictions of environmental behaviors and bioavailability of PAHs and micro-PS.