Oral Mucosa Could Be an Infectious Target of SARS-CoV-2.

The World Health Organization reported that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission is caused by respiratory droplets and aerosols from the oral cavity of infected patients. The angiotensin-converting enzyme 2 (ACE2) is considered the host functional protein for SARS-CoV-2 infection. In this article, we first revealed that the positive proportion of ACE2 expression in gingival cells collected from the gingival sulcus was increased to the same level as the tongue.

[A Case of Malignant Transformation of Previously Diagnosed Oral Leukoplakia].

Oral leukoplakia is the most common premalignant and potentially malignant lesion of the oral mucosa. Several studies have reported that the prevalence of oral cancer in young people is increasingly rapidly. The patient in this report was a 47- year-old man who complained of left tongue discomfort.

[A Case of Maxillary Gingival Carcinoma Possibly Caused by Chronic Inflammation Related to Oral Candidiasis].

Oral candidiasis infection is generally treated with antifungal agents. However, it often requires long-term treatment, and epithelial dysplasia may persist even after the infection has been resolved depending on the case. Malignant transformation has been reported in long-term cases involving chronic inflammation, and surgical excision should be performed as the treatment of choice when the treatment period is prolonged.

Bone Regeneration Potential of Uncalcined and Unsintered Hydroxyapatite/Poly l-lactide Bioactive/Osteoconductive Sheet Used for Maxillofacial Reconstructive Surgery: An In Vivo Study.

Uncalcined and unsintered hydroxyapatite/poly l-lactide (u-HA/PLLA) material has osteoconductive characteristics and is available for use as a maxillofacial osteosynthetic reconstruction device. However, its bone regeneration ability in the maxillofacial region has not been fully investigated. This study is the first to assess the bone regenerative potential of osteoconductive u-HA/PLLA material when it is used for repairing maxillofacial bone defects.

Efficacy of Bacterial Cellulose as a Carrier of BMP-2 for Bone Regeneration in a Rabbit Frontal Sinus Model.

If the alveolar bone height of patients requiring dental implants in the maxillary molar region is inadequate, it is difficult to achieve satisfactory outcomes using existing bone graft materials. We previously reported the possible utility of bacterial cellulose (BC) as a new dental treatment material. BC has a high absorptive capacity, good mechanical strength, and good volume retention.

Application of a Bioactive/Bioresorbable Three-Dimensional Porous Uncalcined and Unsintered Hydroxyapatite/Poly-D/L-lactide Composite with Human Mesenchymal Stem Cells for Bone Regeneration in Maxillofacial Surgery: A Pilot Animal Study.

A novel three-dimensional (3D) porous uncalcined and unsintered hydroxyapatite/poly-d/l-lactide (3D-HA/PDLLA) composite demonstrated superior biocompatibility, osteoconductivity, biodegradability, and plasticity, thereby enabling complex maxillofacial defect reconstruction. Mesenchymal stem cells (MSCs)-a type of adult stem cell-have a multipotent ability to differentiate into chondrocytes, adipocytes, and osteocytes. In a previous study, we found that CD90 (Thy-1, cluster of differentiation 90) and CD271 (low-affinity nerve growth factor receptor) double-positive cell populations from human bone marrow had high proliferative ability and differentiation capacity in vitro.

[Clinicopathological Study of the Resected Oral Leukoplakia Cases].

Oral leukoplakia is the most common premalignant or potentially malignant lesion in the oral mucosa. This retrospective study examined 67 lesions from 62 patients with clinical diagnoses of oral leukoplakia who underwent surgical excision in our department from 2015 to 2017. The patients comprised 22 men and 40 women.

Feasibility of a Three-Dimensional Porous Uncalcined and Unsintered Hydroxyapatite/poly-d/l-lactide Composite as a Regenerative Biomaterial in Maxillofacial Surgery.

This study evaluated the feasibility of a novel three-dimensional (3D) porous composite of uncalcined and unsintered hydroxyapatite (u-HA) and poly-d/l-lactide (PDLLA) (3D-HA/PDLLA) for the bony regenerative biomaterial in maxillofacial surgery, focusing on cellular activities and osteoconductivity properties in vitro and in vivo. In the in vitro study, we assessed the proliferation and ingrowth of preosteoblastic cells (MC3T3-E1 cells) in 3D-HA/PDLLA biomaterials using 3D cell culture, and the results indicated enhanced bioactive proliferation. After osteogenic differentiation of those cells on 3D-HA/PDLLA, the osteogenesis marker genes runt-related transcription factor-2 (Runx2), and Sp7 (Osterix) were upregulated.

Expression of aquaporin 3 and 5 as a potential marker for distinguishing dry mouth from Sjögren's syndrome.

A study was performed to investigate whether expression of aquaporin (AQP) 3 and 5 has potential as a marker for distinguishing dry mouth from Sjögren's syndrome. Twenty-five patients underwent labial minor salivary gland biopsy (dry mouth, n = 9; Sjögren's syndrome, n = 16; control, n = 8). All patients were interviewed about their medical history and subjective oral symptoms, and intraoral examinations were conducted.

Diagnostic accuracy of oral cancer cytology in a pilot study.

Background: Recently, cytology has been applied to the diagnosis of oral lesions. We aimed to explore the diagnostic accuracy of oral cytology based on the histological diagnosis.

Methods: Histological diagnoses of 327 cases were classified as Negative, Borderline lesion -, Borderline lesion +, oral intraepithelial neoplasia/carcinoma in situ (OIN/CIS), or Positive.

Nucleus Accumbens-Associated Protein 1 Expression Has Potential as a Marker for Distinguishing Oral Epithelial Dysplasia and Squamous Cell Carcinoma.

Background: Oral epithelial dysplasia (OED) and carcinoma in situ (CIS) are defined by dysplastic cells in the epithelium. Over a third of oral squamous cell carcinoma (OSCC) patients present with associated OED. However, accurate histopathological diagnosis of such lesions is difficult.

Applicability of preoperative nuclear morphometry to evaluating risk for cervical lymph node metastasis in oral squamous cell carcinoma.

Background: We previously reported the utility of preoperative nuclear morphometry for evaluating risk for cervical lymph node metastases in tongue squamous cell carcinoma. The risk for lymph node metastasis in oral squamous cell carcinoma, however, is known to differ depending on the anatomical site of the primary tumor, such as the tongue, gingiva, mouth floor, and buccal mucosa. In this study, we evaluated the applicability of this morphometric technique to evaluating the risk for cervical lymph node metastasis in oral squamous cell carcinoma.

Applicability of bacterial cellulose as an alternative to paper points in endodontic treatment.

Dental root canal treatment is required when dental caries progress to infection of the dental pulp. A major goal of this treatment is to provide complete decontamination of the dental root canal system. However, the morphology of dental root canal systems is complex, and many human dental roots have inaccessible areas.

Maxillary verrucous carcinoma coincident with cervical lymph node metastasis of colon adenocarcinoma.

Cervical lymph node metastasis is an extremely rare event in oral verrucous carcinoma. Isolated cervical lymph node metastasis of colon cancer is also rare. This article describes a case of maxillary verrucous carcinoma accompanied by colon adenocarcinoma that metastasized to a cervical lymph node in a 69-year-old Japanese woman.

Stimulatory effect of hydrothermally synthesized biodegradable hydroxyapatite granules on osteogenesis and direct association with osteoclasts.

Calcium-deficient hydroxyapatite (HA) granules with a unique spherical shape were prepared using an applied hydrothermal method. Spherical stoichiometric HA granules were also prepared by normal sintering and both granules were used for implantation into rat tibiae to compare the biological responses to each implant. Twelve and 24 weeks after implantation, the volume of calcium-deficient HA granules was significantly less than that of stoichiometric HA granules, and the biodegradability of calcium-deficient HA granules was confirmed.

Predictability of lymph node metastases by preoperative nuclear morphometry in squamous cell carcinoma of the tongue.

Aim: This study was undertaken to assess the predictability of lymph node metastases by analyzing preoperative nuclear morphometry of squamous cell carcinoma of the tongue.

Methods: Twenty-eight cases of well-differentiated squamous cell carcinoma (13 cases with metastasized lymph nodes, 15 node-negative cases) were examined. Using a computerized image system, the mean nuclear area, the nuclear perimeter, the circular rate, the largest to the smallest dimension ratio (LS ratio) of the nuclei, and the coefficient of variation of the nuclear area (NACV) were measured.