坂本 洋右

2010年1月～2020年12月に当院歯科・顎・口腔外科を受診した12歳以下の小児158名(男児97名、女児61名)を対象とする臨床的観察研究を行い、性別、年齢、受傷時刻、受傷原因、軟組織受傷、歯の外傷、顎顔面骨折の有無を調べた。年齢別にみると1歳と2歳児がそれぞれ20人と最も多く、低年齢児に多くみられ、0から5歳までが全体の60%を占めていた。受傷時刻は12時から18時の時間帯が73名(46.2%)と最も多く、受傷の原因は転倒が79名(50.0%)と大部分を占めていた。軟組織受傷は94名(59.5%)であり、受傷部位は口唇35名(37.3%)、歯肉24名(25.5%)、舌19名(20.2%)となっていた。歯の外傷は58名(36.7%)であり、3歳児に最も多くみられ(15.5%)、以下、4歳(13.8%)と5歳(13.8%)の順であった。顎顔面骨骨折は11名(7.0%)であり、下顎骨骨折が10名、上顎骨骨折が1名であった。

Circular RNAs (circRNAs), which form as covalently closed loop structures, have several biological functions such as regulation of cellular behavior by adsorbing microRNAs. However, there is limited information of circRNAs in oral squamous cell carcinoma (OSCC). Here, we aimed to elucidate the roles of aberrantly expressed circRNAs in OSCC. CircRNA microarray showed that circRNA-102450 was down-regulated in OSCC cells. Clinical validation of circRNA-102450 was performed using highly sensitive droplet digital PCR in preoperative liquid biopsy samples from 30 OSCC patients. Interestingly, none of 16 studied patients with high circRNA-102450 had regional lymph node metastasis (RLNM), whereas 4 of 14 studied patients (28.5%) with low expression had pathologically proven RLNM. Overexpressed circRNA-102450 significantly inhibited the tumor metastatic properties of cell proliferation, migration, and invasion. Furthermore, circRNA-102450 directly bound to, and consequently down-regulated, miR-1178 in OSCC cells. Taken together, circRNA-102450 has a tumor suppressive effect via the circRNA-102450/miR-1178 axis and may be a novel potential marker of RLNM in OSCC patients.

Supernumerary teeth (ST) are common clinical dental anomalies characterized by the presence of excessive teeth. It can cause diverse complications in the developing jaw and dentition, which could prevent the acquisition of normal oral functions. The presence of multiple ST is rare and commonly associated with genetic syndromes or developmental anomalies. In such cases, the related clinical problems should be considered along with the treatment of multiple ST. Then, it is important to pay attention to the craniofacial, skeletal, and other physical findings. Herein, we report a rare case of eight ST in a patient without any associated syndromes. Early diagnosis and successive radiographic evaluations are critical for preventing the complications caused by ST.

Pneumatosis intestinalis (PI) is characterized by the presence of gas in the bowel wall and is associated with a wide range of clinical conditions, such as pulmonary, gastrointestinal, infectious, and autoimmune diseases, and an immunosuppressive state such as that resulting from cancer chemotherapy. It is not a distinct disease but rather a physical or radiographic finding and can be categorized into types: primary and secondary. Primary PI is idiopathic, while secondary PI occurs as a result of an underlying disease. Several theories were suggested for the etiology of this condition. Intestinal gas, mucosal integrity, intraluminal pressure, and bacterial flora play interactive roles in the development of PI yet, the mechanisms involved remain unclear. PI can be seen in benign or life-threatening situations. Choosing an appropriate treatment owing to the various interpretations of the clinical significance of PI is difficult. An urgent surgical procedure is necessary for patients with signs of bowel perforation, peritonitis, or necrotizing enterocolitis. Potentially, these life-threatening conditions should be ruled out, based on the physical and radiographic findings of the patient. Herein, we report a rare case of PI in a 72-year-old woman who was administrated cisplatin and radiation as adjuvant chemoradiotherapy for oral cancer. During the therapy, free air was detected via chest radiography. Based on the physical and computed tomographic findings, the development of free air was considered as a non-life-threatening PI phenomenon caused by the cancer chemotherapy.

We report a rare case of high-grade MEC developed in the palate. Myoepithelial carcinoma (MEC) is an uncommon malignant tumor, which is also known as malignant myoepithelioma. It generally occurs in major salivary glands. A 79-year-old female presented complaining a painless swelling on the left side palate which grew rapidly in 3 weeks. A soft and pendulous mass with approximately 42 × 30 mm in diameter with ulceration was observed in the palate.Radiological imaging analyses (e-CT, e-MRI and FDG-PETCT) showed an irregular mass of the left palate with bone invasion into the palatal bone and suggested potential metastases in submandibular lymph nodes. A biopsy was performed and diagnosed as MEC of the palate. Surgical tumor resection and radical neck dissection were performed under general anesthesia. Pathologic evaluation showed that the lesion was mainly consisted of atypical cells with abundant eosinophilic cytoplasm including a mixture of spindled or epithelioid cells. Immunohistochemically, the lesion included specifically and diffusely positive for S-100, CD10, calponin, GFAP, and p63. Cell proliferation activity assessed by the Ki67 labeling index was 55 %. From these findings, the lesion was finally diagnosed as MEC of the palate. The patient has been followed for 6years without a recurrence.

The main symptom of Kimura disease (KD), a rare, chronic inflammatory disorder of unknown etiology, is painless granulation preferentially developing in the head and neck region's soft tissues, especially in the parotid and submandibular glands and neck lymph nodes. KD is characterized clinically by peripheral blood eosinophilia and elevated serum immunoglobulin E (IgE) levels and histopathologically by high capillary vascularization and lymphoid follicle formation with eosinophil infiltration in the connective tissues. Angiolymphoid hyperplasia with eosinophilia (ALHE), a rare benign tumor of unknown etiology, also occurs in the head and neck frequently as single/multiple angiomatous papules/nodules varying from light brown to pink. Histopathologically, accelerated endothelial cell proliferation and high lymphocyte and eosinophil infiltration are observed. Due to KD's and ALHE's similar clinical and pathological symptoms, differential diagnosis is challenging. Their manifestations include a painless head/neck subcutaneous swelling. Here, we have described a case involving a 44-year-old man who presented with an upper lip mass that increased in size for 1 year. Laboratory studies revealed leukocytosis and eosinophilia. Computed tomography and magnetic resonance imaging examinations revealed a submucosal lip mass. Suspect minor salivary gland malignancies and lymphomas were surgically excised. Histopathologically, we observed marked lymphoid follicle proliferation with inflammatory cell, including eosinophil infiltration, capillary proliferation, and a developed vessel not normally present in the lip. Because differentiating between KD and ALHE is difficult, clinical differentiation was our focus. The Asian male patient with lymphadenopathy, eosinophilia, and high IgE levels was finally diagnosed with KD that has not recurred in 1 year.

Semaphorin family members (Semaphorins SEMAs) consist of a large family that includes both secreted and membrane-associated proteins that are originally found to provide axon guidance in selected areas for neural development. The SEMAs have diverse biologic activities such as neuronal cellular migration, axon guidance, vasculogenesis, branching morphogenesis, and cardiac organogenesis. Recent studies have reported that SEMAs also play crucial roles in various carcinomas. However, the association and their role in oral squamous cell carcinoma (OSCC) are still poorly understood. In this study, we evaluated SEMAs mRNA expression in OSCC-derived cell lines using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis and revealed the altered gene expression profile of the SEMAs in OSCC cell lines compared with human normal oral keratinocytes. We found that tendency for up-regulation of SEMA3E, 4C, 5A, 6B, and 7A in OSCC-derived cell lines. Especially, SEMA3E and SEMA7A mRNA were significantly up-regulated in all OSCC-derived cell lines. On the other hands, SEMA3A, 3C, 3F, and 6A mRNA were significantly down-regulated in all OSCC-derived cell lines. The expression and role of SEMAs in OSCC depend on the forms and may provide novel insights and therapeutic target for OSCCs.

Laugier-Hunziker-Baran (LHB) syndrome is an acquired, macular hyperpigmentation of the lips, and oral mucosa, often associated with pigmentation of the nails, palms, and fingertips. LHB syndrome is considered to be a benign disease with no systemic manifestation or malignant potential. Normally, no treatment is required for this condition, unless for esthetic reason, mainly due to pigmentation on the lip mucosa. Here we present a case of LHB syndrome, 32-year-old male, whose pigmentations on his tongue, buccal mucosa, palate, and ventral surface of fingertip, diagnosed by clinical and dermoscopic findings.

Basaloid squamous cell carcinoma (BSCC) is a histologically distinct variant of squamous cell carcinoma (SCC). In this report, we present a case of a 67-year-old man diagnosed with BSCC in the mandibular gingiva. The patient underwent resection of the gingival tumor with a partial mandibulectomy and a functional neck dissection. The mandibular gingiva was reconstructed with forearm free flap. The patient remained in good general health and free of disease for 44 months.

Basaloid squamous cell carcinoma (BSCC) is a histologically distinct variant of squamous cell carcinoma (SCC). In this report, we present a case of a 67-year-old man diagnosed with BSCC in the mandibular gingiva. The patient underwent resection of the gingival tumor with a partial mandibulectomy and a functional neck dissection. The mandibular gingiva was reconstructed with forearm free flap. The patient remained in good general health and free of disease for 44 months.

Ameloblastic carcinoma (AC) is an odontogenic malignant tumor which combines the histological features of ameloblastoma and cytologic atypia. The key point of the diagnosis and clinical characteristics of AC have not been well defined, as it is a rare type of tumor. Hence, in this study, we present’ for better clarity the diagnostic flowchart for AC, ameloblastoma, and metastasizing ameloblastoma.

Drug resistance to anti-cancer agents is a major concern regarding the successful treatment of malignant tumors. Recent studies have suggested that acquired resistance to anti-epidermal growth factor receptor (EGFR) therapies such as cetuximab are in part caused by genetic alterations in patients with oral squamous cell carcinoma (OSCC). However, the molecular mechanisms employed by other complementary pathways that govern resistance remain unclear. In the current study, we performed gene expression profiling combined with extensive molecular validation to explore alternative mechanisms driving cetuximab-resistance in OSCC cells. Among the genes identified, we discovered that a urokinase-type plasminogen activator receptor (uPAR)/integrin β1/Src/FAK signal circuit converges to regulate ERK1/2 phosphorylation and this pathway drives cetuximab-resistance in the absence of EGFR overexpression or acquired EGFR activating mutations. Notably, the polyphenolic phytoalexin resveratrol, inhibited uPAR expression and consequently the signaling molecules ERK1/2 downstream of EGFR thus revealing additive effects on promoting OSCC cetuximab-sensitivity in vitro and in vivo. The current findings indicate that uPAR expression plays a critical role in acquired cetuximab resistance of OSCC and that combination therapy with resveratrol may provide an attractive means for treating these patients.

Dermoid cysts, which are lined by ectoderm elements, typically arise in skin, testicles, and ovaries. These cysts mostly occur during the second or third decade of life and rarely present in children. We describe a rare case of a dermoid cyst in a 6-year-old Japanese girl. Examination showed a smooth, well-defined cystic swelling approximately 30 × 20 mm2 in the midline of the oral floor. The cyst was excised via the intraoral approach under general anesthesia. The histopathologic diagnosis of a dermoid cyst was made. The clinical outcome was satisfactory without postoperative complications during the 26-month follow-up period.