Naomi Kanno

Mandibular reconstruction using plates prebent to fit rapid prototyping 3-dimensional printing models ameliorates contour deformity

BackgroundRecently, medical rapid prototyping (MRP) models, fabricated with computer-aided design and computer-aided manufacture (CAD/CAM) techniques, have been applied to reconstructive surgery in the treatment of head and neck cancers. Here, we tested the use of preoperatively manufactured reconstruction plates, which were produced using MRP models. The clinical efficacy and esthetic outcome of using these products in mandibular reconstruction was evaluated.MethodsA series of 28 patients with malignant oral tumors underwent unilateral segmental resection of the mandible and simultaneous mandibular reconstruction. Twelve patients were treated with prebent reconstruction plates that were molded to MRP mandibular models designed with CAD/CAM techniques and fabricated on a combined powder bed and inkjet head three-dimensional printer. The remaining 16 patients were treated using conventional reconstruction methods. The surgical and esthetic outcomes of the two groups were compared by imaging analysis using post-operative panoramic tomography.ResultsThe mandibular symmetry in patients receiving the MRP-model-based prebent plates was significantly better than that in patients receiving conventional reconstructive surgery.ConclusionsPatients with head and neck cancer undergoing reconstructive surgery using a prebent reconstruction plate fabricated according to an MRP mandibular model showed improved mandibular contour compared to patients undergoing conventional mandibular reconstruction. Thus, use of this new technology for mandibular reconstruction results in an improved esthetic outcome with the potential for improved quality of life for patients.

MicroRNA-155-5p is associated with oral squamous cell carcinoma metastasis and poor prognosis.

BACKGROUND Abnormal miRNA expression was recently implicated in the metastasis of oral squamous cell carcinoma (OSCC) and with a poor prognosis. The initiation of the invasion-metastasis cascade involves epithelial-mesenchymal transition (EMT). Our aim was to clarify how miRNA, especially miR-155-5p misexpression contributes to OSCC metastasis through EMT. METHODS We collected tumor samples from 73 subjects with OSCC. The samples were analyzed by quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and correlations between miR-155-5p levels and clinical characteristics were investigated. OSCC cell lines were analyzed by miRNA microarray and by transfection with a miR-155-5p mimic or inhibitor, followed by proliferation and wound-healing migration assays. qRT-PCR analyses of EMT makers in cells transfected with miR-155-5p inhibitor were performed. RESULTS We found high miR-155-5p expression in tissue samples from subjects with OSCC that had metastasized to cervical lymph nodes. HSC-3 cells also strongly expressed miR-155-5p. The epithelial marker E-cadherin was strongly expressed in HSC-3 cells transfected with miR-155-5p inhibitor, and we observed elevated SOCS1 and decreased STAT3 expression in these cells. CONCLUSIONS Our results suggest that miR-155-5p causes OSCC to metastasize, and could serve as a novel therapeutic target for OSCC.

MicroRNA-205-5p suppresses the invasiveness of oral squamous cell carcinoma by inhibiting TIMP‑2 expression

MicroRNAs (miRNAs or miRs) play important roles in carcinogenesis. The miRNA, miR-205-5p, has been reported to suppress the growth of various types of tumor; however, its functional contribution to oral squamous cell carcinoma (OSCC) is not yet clear. Thus, this study was conducted to determine the miRNA expression signatures in OSCC and to investigate the functional role of miR‑205‑5p in OSCC cells. We measured miR‑205‑5p expression by RT-qPCR, and examined the function of miR‑205‑5p by transfecting a miR‑205‑5p mimic or inhibitor into OSCC cells and measuring cell proliferation, migration and invasiveness. Genes targeted by miR‑205‑5p were identified using the TargetScan database and verified by western blot analysis, luciferase reporter assay and ELISA. We found that miR‑205‑5p was significantly downregulated in OSCC cell lines and tissue specimens. Following transfection of miR‑205‑5p mimic or inhibitor into the cancer cell lines, miR‑205‑5p overexpression significantly suppressed cancer cell migration and invasion. We further demonstrated that miR‑205‑5p directly targeted and regulated the tissue inhibitor of metalloproteinases‑2 (TIMP‑2) gene. The silencing of TIMP‑2 suppressed cancer cell invasion and the activation of pro‑matrix metalloproteinase‑2 (pro‑MMP‑2). These results suggest that TIMP‑2 promotes tumor progression, and that miR‑205‑5p directly regulates TIMP‑2, thereby suppressing pro‑MMP‑2 activation and inhibiting OSCC cell invasiveness. Our data describing the pathways regulated by miR‑205‑5p provide new insight into the mechanisms responsible for OSCC development and metastasis.

A Case of Primary Combined Squamous Cell Carcinoma with Neuroendocrine (Atypical Carcinoid) Tumor in the Floor of the Mouth

The combined squamous cell carcinoma (SCC) with neuroendocrine (atypical carcinoid (AC)) tumor is extremely rare in the head and neck. We present here the first case of SCC with AC arising in the floor of the mouth of 65-year-old man. The tumor is comprised of two components of SCC and AC in the biopsy specimen. Neuroendocrine tumor component was classified as AC from the punctate necrosis and 2–10>/10 HPF. Immunohistochemical staining was HMW-CK/34B (+) and P63 (+) in SCC and synaptophysin (+) and CD56 (+) in AC. The pathological diagnosis of SCC with AC was made from both the morphological and immunological exam. Concurrent chemoradiotherapy was performed with radiotherapy 70.2 Gy and chemotherapy of CDDP and VP-16. Although the treatment effect was complete response both of primary tumor and of neck metastases, the recurrence of the primary tumor was after 6 months. Bilateral modified radical neck dissection and tumor resection of the floor of the mouth with reconstructive surgery of anterior lateral thigh free flap were performed. Although the primary and neck tumor did not recur, the multiple lung metastases and mediastinum lymph node metastases occurred at 6 months after surgery.

A Case of Brain Abscess Caused by Medication-Related Osteonecrosis of the Jaw

Reports of brain abscesses caused by medication-related osteonecrosis of the jaw (MRONJ) are very rare. We here present the case of a 76-year-old man with terminal-stage prostatic carcinoma and a brain abscess caused by MRONJ at the maxilla. The patient had been treated with zoledronic acid and denosumab for bone metastasis. For the brain abscess, an antibiotic regimen based on ceftriaxone and metronidazole and a sequestrectomy contributed to a successful outcome. In the case of maxillary MRONJ extending to the maxillary sinus, active resection of the infected bone should be considered to prevent the spread of the infection beyond the maxillary sinus, into the ethmoid sinus, and into the brain.

Medication-Related Osteonecrosis of the Jaw

Osteonecrosis of the jaw (ONJ) is a common side effect of antiresorptive drugs that are administered to cancer patients for bone metastasis, multiple myeloma, and osteoporosis. Since both bisphosphonate (BP) and denosumab show anti-bone resorption effects with ONJ, antiresorptive agent-related ONJ (ARONJ) has been suggested as a comprehensive term encompassing both BP-related osteonecrosis of the jaw (BRONJ) and denosumab-related osteonecrosis of the jaw (DRONJ). The term medication-related osteonecrosis of the jaw (MRONJ) is proposed as ARONJ with the antiangiogenic inhibitors or molecularly targeted drugs-related ONJ. Suppression of bone remodeling may contribute to the development of osteonecrosis and results in inadequate osteoclast activity to allow healing of the extraction socket. Infection is a major factor in the development of MRONJ. The major treatment goals for patients at risk of developing or who have MRONJ are prioritization and support of continued oncologic treatment in patients receiving antiresorptive and antiangiogenic therapy. To minimize the development of MRONJ in patients at risk, regular dental examinations are encouraged. Oral hygiene should be improved and local infection is managed as early as possible. The use of antibiotics before and after oral surgical procedures has been demonstrated to lower the risk of MRONJ.

A Rare Primary Neuroendocrine Tumor (Typical Carcinoid) of the Sublingual Gland.

A typical carcinoid is extremely rare in the oral cavity. We here present a case of a typical carcinoid arising in the sublingual gland of a 62-year-old woman. The tumor was removed by primary excision with 10 mm surgical margins and submandibular dissection. Examination of the tumor showed medium-sized tumor cells that were positive for CD56 and chromogranin A, with no necrosis, and with a mitotic count less than 1/10 HPF. A pathological diagnosis of typical carcinoid was made from both morphological and immunological examinations. One year after excision surgery, there was no tumor recurrence or neck metastasis.