Ghost cell odontogenic carcinoma arising in dentinogenic ghost cell tumor, peripheral: A case report.

Ghost cell odontogenic carcinoma (GCOC) is an extremely rare intraosseous malignant odontogenic tumor with prominent ghost cell keratinization and dentinoid formation. Here, we present the first case of GCOC arising in dentinogenic ghost cell tumor (DGCT), peripheral. The patient was a man in his 60s with an exophytic mass in the anterior part of lower gingiva. The resected tumor measured 4.5 cm in maximum diameter. Histologically, the nonencapsulated tumor proliferated in the gingiva without bone invasion. It was predominantly composed of ameloblastoma-like nests and islands of basaloid cells with ghost cells and dentinoid in the mature connective tissue, suggesting DGCT, peripheral. As minor components, sheets of atypical basaloid cells and ameloblastic carcinoma-like nests with pleomorphism and high proliferative activity (Ki-67 labeling index up to 40%) consistent with malignancy were identified. CTNNB1 mutation and ß-catenin nuclear translocation were observed in both benign and malignant components. Final diagnosis was GCOC arising in DGCT, peripheral. GCOC shows similar histological features to DGCT. In this unique case without invasion, the cytological atypia and high proliferative activity supports the diagnosis of malignant transformation from DGCT.

Comparison of the bone regeneration ability between stem cells from human exfoliated deciduous teeth, human dental pulp stem cells and human bone marrow mesenchymal stem cells.

Cleft lip and palate is the most common congenital anomaly in the orofacial region. Autogenous iliac bone graft, in general, has been employed for closing the bone defect at the alveolar cleft. However, such iliac bone graft provides patients with substantial surgical and psychological invasions. Consequently, development of a less invasive method has been highly anticipated. Stem cells from human exfoliated deciduous teeth (SHED) are a major candidate for playing a significant role in tissue engineering and regenerative medicine. The aim of this study was to elucidate the nature of bone regeneration by SHED as compared to that of human dental pulp stem cells (hDPSCs) and bone marrow mesenchymal stem cells (hBMSCs). The stems cells derived from pulp tissues and bone marrow were transplanted with a polylactic-coglycolic acid barrier membrane as a scaffold, for use in bone regeneration in an artificial bone defect of 4 mm in diameter in the calvaria of immunodeficient mice. Three-dimensional analysis using micro CT and histological evaluation were performed. Degree of bone regeneration with SHED relative to the bone defect was almost equivalent to that with hDPSCs and hBMSCs 12 weeks after transplantation. The ratio of new bone formation relative to the pre-created bone defect was not significantly different among groups with SHED, hDPSCs and hBMSCs. In addition, as a result of histological evaluation, SHED produced the largest osteoid and widely distributed collagen fibers compared to hDPSCs and hBMSCs groups. Thus, SHED transplantation exerted bone regeneration ability sufficient for the repair of bone defect. The present study has demonstrated that SHED is one of the best candidate as a cell source for the reconstruction of alveolar cleft due to the bone regeneration ability with less surgical invasion.

Central mucoepidermoid carcinoma arising from glandular odontogenic cyst confirmed by analysis of MAML2 rearrangement: A case report.

Central mucoepidermoid carcinoma (MEC) poses a diagnostic challenge because of its rarity and histological overlap with glandular odontogenic cyst (GOC). In MEC of both salivary glands and jaws, MAML2 arrangement has been well known as the specific gene alteration. We report a case of central MEC arising from GOC diagnosed by MAML2 fusion gene. A 57-year-old male presented a multilocular cystic lesion in left molar region of the mandible. Histopathologically, multiple cysts lined by thin cuboidal or non-keratinized squamous epithelium with small duct-like structures, mucous cells and ciliated cells were present. It was diagnosed as GOC. The recurrent lesion after nine years showed the proliferation of many cystic and solid nests composed of epidermoid, mucous and intermediated cells. Nested PCR revealed CRTC3-MAML2 fusion gene in the recurrent lesion, but not in the primary one. Similarly, MAML-2 rearrangement by FISH analysis was positive in the recurrent lesion, while negative for the primary one, thus confirming the diagnosis of central MEC arising from GOC. Analysis of MAML2 rearrangement can be used as a supportive evidence to distinguish central MEC from GOC.

A case of primordial odontogenic tumor: A new entity in the latest WHO classification (2017).

Primordial odontogenic tumor (POT) is a rare lesion in the jaw which has been included as a new entity of benign mixed epithelial and mesenchymal odontogenic tumour in the latest World Health Organization (WHO) classification (2017). Only seven cases have been reported. It typically occurs in the posterior mandible. We report an additional case of POT in the maxilla of an 8-year-old girl presenting with an asymptomatic buccal enlargement. A well-defined, unilocular, radiolucent lesion was observed radiographically. Histologically, the tumor was mostly composed of loose fibrous connective tissue resembling dental papilla and a single layer of columnar epithelium covering the periphery of the tumor. In part, cords or nests of epithelium were present in the mesenchyme close to the periphery. Nestin, a marker of odontogenic ectomesenchyme, was positive in the mesenchymal tumor cells. We finally diagnosed the lesion as POT considering the possibility of other odontogenic tumors like ameloblastic fibroma or developing odontoma as a differential diagnosis. The patient shows no recurrence after 16 months. This case is the first report from Japan using this novel diagnosis POT after it was recognized and defined in the latest WHO classification.

Transformation of an odontogenic keratocyst into a solid variant of odontogenic keratocyst/keratoameloblastoma during long­term follow­up: A case report.

Keratoameloblastoma (KA) and solid variant of odontogenic keratocyst (SOKC) are rare odontogenic lesions, and their relationship and differences are unclear. The present study described a case that started as an odontogenic keratocyst (OKC) and transformed to SOKC/KA upon recurrence. Briefly, a 26­year­old man presented with swelling in the right cheek and was referred to the Department of Oral and Maxillofacial surgery, Hiroshima University Hospital (Hiroshima, Japan). At the initial visit, unicystic bone permeation was observed extending from the right canine to the molar, maxillary sinus and nasal cavity. After the biopsy, the patient underwent excisional surgery and was diagnosed with OKC. Thereafter, the lesion recurred six times over a period of 13 years and showed different histopathological features from those of the primary lesion, all consisting of numerous cysts with keratinization, which were diagnosed as SOKC/KA. The Ki­67 positivity rate was ~10%, which was higher than that of the primary lesion, but there was no atypia. Genetic analysis of the recurrent lesion revealed mutations in adenomatous polyposis coli and Kirsten rat sarcoma viral oncogene homolog. This case originated from OKC, and the morphological features of OKC and KA were mixed upon recurrence, supporting the commonality and association between the two. However, multiple mutations different from those of OKC and ameloblastoma were detected, suggesting an association of SOKC/KA with increased proliferative activity and a high recurrence rate.

Relationship of oral bacterial number with medical hospitalization costs in analysis of Diagnosis Procedure Combination database from single institution in Japan.

Oral bacteria are known to be associated with perioperative complications during hospitalization. However, no presented reports have clarified the relationship of oral bacterial number with medical costs for inpatients. The Diagnosis Procedure Combination (DPC) database system used in Japan provides clinical information regarding acute hospital patients. The present study was conducted to determine the association of oral bacterial numbers in individual patients treated at a single institution with length of hospital stay and medical costs using DPC data. A total of 2369 patients referred by the medical department to the dental department at Hiroshima University Hospital were divided into the low (n = 2060) and high (n = 309) oral bacterial number groups. Length of hospital stay and medical costs were compared between the groups, as well as the associations of number of oral bacteria with Charlson comorbidity index (CCI)-related diseases in regard to mortality and disease severity. There was no significant difference in hospital stay length between the low (24.3 ± 24.2 days) and high (22.8 ± 20.1 days) oral bacterial number groups. On the other hand, the daily hospital medical cost in the high group was significantly greater (US$1456.2 ± 1505.7 vs. US$1185.7 ± 1128.6, P < 0.001). Additionally, there was no significant difference in CCI score between the groups, whereas the daily hospital medical costs for patients in the high group treated for cardiovascular disease or malignant tumors were greater than in the low number group (P < 0.05). Multivariate regression analysis was also performed, which showed that oral bacterial number, age, gender, BMI, cardiovascular disease, diabetes, malignant tumor, and hospital stay length were independently associated with daily hospitalization costs. Monitoring and oral care treatment to lower the number of oral bacteria in patients affected by cardiovascular disease or cancer may contribute to reduce hospitalization costs.

A case report of allergic reaction with acute facial swelling: a rare complication of dental acrylic resin.

Resin components, such as methyl methacrylate (MMA) can cause allergic contact dermatitis (ACD). Allergic reactions to resin are usually delayed. Only a few studies have reported dental resin allergy with acute symptoms. Here, a case of ACD with acute facial swelling after dental treatment using resin material is reported. A 55-year-old woman with a history of periungual inflammation when using gel nail polish had repeated episodes of facial swelling after dental treatment with resin material. The resin temporary crown was removed, and symptoms were alleviated with antihistamines and corticosteroids. With the suspicion of resin allergy, skin tests were performed. Patch testing revealed positive reactions to self-adhesive resin cement (primer and polymerized), self-curing acrylic resin (liquid and polymerized), 2-hydroxyethyl methacrylate (2-HEMA), and ethylene glycol dimethacrylate (EGDMA), whereas the prick test was negative for all allergens. Complement C4 and C1 inhibitor activity were reference values in the tests for hereditary angioedema. Based on these findings, the patient was diagnosed with ACD to 2-HEMA and EGDMA. Since diagnosis, no similar symptoms have been observed in subsequent dental treatment with non-resin materials. The use of dental resin materials may cause ACD with an acute reaction. This report alerts dentists who routinely use resin materials.

Resting saliva volume as a risk factor for hypogeusia: A retrospective study.

OBJECTIVES: The causes of hypogeusia include zinc deficiency, systemic illness, and consumption of drugs. Notably, patients with oral cavity diseases such as oral candidiasis and salivary gland hypofunction may present with risk factors that remain unreported. Hence, this study aimed to investigate the relationship between age, sex, smoking status, serum zinc concentration, oral candidiasis, saliva volume, and taste function in patients with hypogeusia. SUBJECTS AND METHODS: Overall, 335 participants who complained of taste abnormalities underwent a taste test. Based on the recognition threshold value, the participants were classified as normal individuals (recognition threshold of 1 and 2) and patients with hypogeusia (recognition threshold of ≥3). The clinical characteristics, including resting saliva volume (RSV) and stimulated saliva volume (SSV), were compared, and a multivariate logistic regression analysis focusing on RSV was performed. RESULTS: Patients with hypogeusia had a lower RSV than normal individuals for all tastes, but not for SSV. Based on the results of regression analysis, RSV was identified as an independent predictor of hypogeusia for salty and bitter tastes. Moreover, the proportion of patients with decreased RSV increased as the number of taste qualities exceeding the reference recognition threshold increased. Furthermore, a decrease in RSV was associated with an increase in the recognition threshold for salty and bitter tastes. CONCLUSIONS: Based on the results of the present study, moisturizing the oral cavity may be useful against hypogeusia.

A Third Supernumerary Tooth Occurring in the Same Region: A Case Report.

The presence of a supernumerary tooth is one of the most common dental anomalies, and surgical treatment is often required to address this anomaly. Moreover, it may lead to malocclusion, and long-term follow-up is important to monitor its status. A 4-year-and-11-month-old boy was referred to our hospital for dental caries treatment. At 5 years and 5 months of age, a radiographic examination showed a supernumerary tooth (first supernumerary tooth) near the permanent maxillary left central incisor, and it was extracted 6 months later. Eighteen months after the extraction of the first supernumerary tooth, a new supernumerary tooth (second supernumerary tooth) was detected in the same region, which was extracted when the patient was aged seven years and seven months. Seven months later, another supernumerary tooth (third supernumerary tooth) was detected and extracted immediately. However, the permanent maxillary left central incisor did not erupt spontaneously even after 6 months. Therefore, surgical exposure was performed, and the central incisor erupted into the oral cavity. This report describes our experience with this patient with three metachronous supernumerary teeth and their management until the eruption of the permanent tooth. This report highlights the importance of long-term follow-up after supernumerary tooth extraction until the permanent teeth in that region have erupted completely.

Galectin-3 Plays an Important Role in Preterm Birth Caused by Dental Infection of Porphyromonas gingivalis.

Dental infection is risk for preterm birth (PTB) through unclear mechanisms. We established a dental infection-induced PTB mouse model, in which Porphyromonas gingivalis (P.g.) induced PTB by 2 days. We analysed pathogenic factors contributing to PTB and their effects on trophoblasts in vitro. TNF-α, IL-8, and COX-2 were upregulated in P.g.-infected placenta. Galectin-3 (Gal-3), an immune regulator, was significantly upregulated in placenta, amniotic fluid, and serum. In vitro, P.g.-lipopolysaccharide (P.g.-LPS) increased TNF-α and Gal-3 in trophoblasts via NF-κB/MAPK signalling. Gal-3 inhibition significantly downregulated P.g.-LPS-induced TNF-α production. TNF-α upregulated Gal-3. Gal-3 also increased cytokines and Gal-3 through NF-κB/MAPK signalling. Moreover, Gal-3 suppressed CD-66a expression at the maternal-foetal interface. Co-stimulation with Gal-3 and P.g.-LPS upregulated cytokine levels, while Gal-3 plus Aggregatibacter actinomycetemcomitans (A.a.)- or Escherichia coli (E. coli)-LPS treatment downregulated them, indicating the critical role of Gal-3 especially in P.g. dental infection-induced PTB. P.g.-dental infection induced PTB, which was associated with Gal-3-dependent cytokine production. New therapies and/or diagnostic systems targeting Gal-3 may reduce PTB.

Infection with Porphyromonas gingivalis exacerbates endothelial injury in obese mice.

BACKGROUND: A number of studies have revealed a link between chronic periodontitis and cardiovascular disease in obese patients. However, there is little information about the influence of periodontitis-associated bacteria, Porphyromonas gingivalis (Pg), on pathogenesis of atherosclerosis in obesity. METHODS: In vivo experiment: C57BL/6J mice were fed with a high-fat diet (HFD) or normal chow diet (CD), as a control. Pg was infected from the pulp chamber. At 6 weeks post-infection, histological and immunohistochemical analysis of aortal tissues was performed. In vitro experiment: hTERT-immortalized human umbilical vein endothelial cells (HuhT1) were used to assess the effect of Pg/Pg-LPS on free fatty acid (FFA) induced endothelial cells apoptosis and regulation of cytokine gene expression. RESULTS: Weaker staining of CD31 and increased numbers of TUNEL positive cells in aortal tissue of HFD mice indicated endothelial injury. Pg infection exacerbated the endothelial injury. Immunohistochemically, Pg was detected deep in the smooth muscle of the aorta, and the number of Pg cells in the aortal wall was higher in HFD mice than in CD mice. Moreover, in vitro, FFA treatment induced apoptosis in HuhT1 cells and exposure to Pg-LPS increased this effect. In addition, Pg and Pg-LPS both attenuated cytokine production in HuhT1 cells stimulated by palmitate. CONCLUSIONS: Dental infection of Pg may contribute to pathogenesis of atherosclerosis by accelerating FFA-induced endothelial injury.