The 2016 Kumamoto earthquakes were a series of earthquakes, including a foreshock with a magnitude 6.5 and a mainshock with a magnitude of 7.3. In this study, we discuss the clinical features of craniomaxillofacial fractures before and after large-scale disasters in a regional disaster-based hospital.

　We evaluated 179 patients with all types of bone fractures we encountered in our hospital during a month after the 2016 Kumamoto earthquakes. In addition, we compared 40 patients with craniomaxillofacial fractures who were involved in earthquakes during the 6 months after the disaster with 56 patients during the 6 months before the earthquakes.

　Overall, the number of patients after the earthquakes was twofold higher than that during the normal period. The department in which the patients were most frequently examined was orthopedics. In the craniomaxillofacial region, the two most common age groups were young adults (teens and twenties) and patients 70 years or older. Nearly half of the patients came to our hospital during the month after the earthquakes and were brought by ambulance. The number of patients with injuries who presented within 24 hours increased. Midfacial fractures were the most common fractures before the earthquakes, whereas mandible injuries increased after the disaster. Falling was the most frequent cause of craniomaxillofacial fractures. There were no differences between surgical treatment and non-surgical treatment.

　We found that the need for oral surgery became higher after an earthquake, but lack of human resources was a concern in hospital dentistry. Medical and dental cooperation can be effective not only at normal times but also during large-scale disasters. Therefore, it is important that we ordinarily cooperate with medical departments.

Radiographic opacity in the maxillary sinus is indicative of ailments such as fungal maxillary sinusitis, neoplastic disease, or isolated bone fragments. In this paper, we describe a case of a maxillary sinus polyp with ossification. The diagnosis was based on the histopathological findings and features of an excised specimen with a bone lesion in the maxillary sinus adherent to a dental root on one side. The patient, a 36-year-old woman, was referred to our department for further evaluation of a radiographic opacity in the right maxillary sinus. Our initial examination revealed no subjective symptoms and no organic abnormalities. However, panoramic radiography revealed an opacity in the apex of 6, which computed tomography revealed to be a 20 × 15 mm internally inhomogeneous calcification adhering to a palatal root. Surgical excision of the calcification and apicoectomy of 6 were performed. A lesion adhering between the anterior wall of the maxillary sinus and the palatal root of 6 was found. Histopathological examination of the excised specimen revealed that it was mature bone tissue covered by columnar epithelium. On reviewing these findings, the aforementioned diagnosis was made. Postoperative examinations at 3 years revealed no signs of recurrence.

We report a case of osseous dysplasia associated with a radiolucent cyst-like bone cavity in the molar region of the mandible. A 46-year-old Japanese woman visited our hospital because of a pain on the right side of the mandible. A bone biopsy of the lesion revealed osseous dysplasia. The cyst-like bone cavity lesion contained serous content. Branches of inferior alveolar nerve were observed, whereas no epithelial structure was found on the wall of the cavity. The radiopaque lesion was solid and contained fibrous bone, therefor we did not consider surgical intervention of this lesion. However, we considered surgical treatment for the cyst-like lesion by filling the bone cavity with platelet-rich plasma to stimulate bone healing. We concomitantly performed an apicoectomy for the involved teeth in the bone cavity. After a long-term follow-up (10 years), ossification was observed in the bone cavity in the molar region with no signs of recurrence, and the osseous dysplasia lesion in the premolar region was stable without showing signs of growth.

Clear cell odontogenic carcinoma (CCOC) is a rare intraosseous tumor of the jaw that was classified as a malignant odontogenic tumor by the WHO classification in 2005. Although 104 cases have been reported in the literature to date, there are no common treatments or prognostic factors. We report a new case of CCOC in a patient who underwent reconstruction using a vascularized free fibula flap.

　A 63-year-old man with tooth mobility and swelling of the middle lingual side of the mandible came to our clinic. He did not complain of pain. Enhanced computed tomography (CT) revealed a 45 × 35 × 33 mm tumor in the mandibular bone associated with an osteolytic lesion. Furthermore, invasion of the mylohyoid and genioglossus muscle was observed on magnetic resonance images (MRI). Since malignancy was suspected on biopsy, we performed wide tumor resection and reconstruction with a vascularized free fibula flap. Finally, CCOC was diagnosed on by histopathological examination. As of 3 years 10 months after the operation, neither recurrence nor metastasis was detected.

Dermoid cysts have been classified into the following three types based on pathological cellular components: epidermoid, dermoid, and teratoid cysts. We describe an extremely rare case of a dermoid cyst associated with cartilage in the tongue. A 51-year-old man was referred to our hospital because of a small mass on the dorsal surface of the tongue. Initial clinical examinations revealed a soft elastic mass with a smooth surface that measured 2 × 2 mm. Magnetic resonance imaging (MRI) showed a solid mass with a lipoid component in the deep region of the dorsum of the tongue. The mass measured 7 × 5 × 4 mm. Resection of the mass was performed with the patient under general anesthesia, and the histological diagnosis was a dermoid cyst containing squamous epithelium, sweat glands, sebaceous glands, and cartilage. Recurrence has not occurred as of 2 years 6 months after surgery.

Case reports describing mandibular fractures associated with external auditory canal fractures without condylar fractures are extremely rare. We report a case of mandibular and external auditory canal (EAC) fractures. A 56-year old man was referred to our department because of pain on opening and closing of the jaw. He had hypertension, diabetes mellitus, sleep apnea syndrome, and familial myoclonus epilepsy. In January 2014, he bruised his chin and precordial region when he fell down because of orthostatic hypotension. He was transported to a nearby general hospital and underwent treatment for a laceration on the chin. He was introduced to our department to receive treatment for hemorrhage from both the EAC fracture and mandibular fracture. Local examination showed disturbed mouth opening due to jaw pain and bloody discharge from both auditory canals. There was also a laceration on the chin. Computed tomography (CT) disclosed a fracture line at the mandibular symphysis and both EACs, but the auditory ossicles were not separated. The patient was treated by packing both auditory canals in consultation with the Department of Otolaryngology. We performed open reduction and internal fixation (ORIF) surgery with the patient under general anesthesia, and intermaxillary fixation (IMF) was secured for 1 week. The patient was followed up for 1 year, and healing was satisfactory with no subsequent stenosis of the auditory canal.

We report on the maxillofacial growth in two patients with Pierre Robin Sequence (PRS) who received mandibular distraction osteogenesis (MDO) in infancy. Bilateral MDO was performed at 9 months of age in patient 1 and at 7 months of age in patient 2. The mandible was bilaterally lengthened by 15 mm (patient 1) and 18 mm (patient 2). Computed tomography was performed before distraction and every year after MDO. Distance/angle measurements and morphological/functional assessments were performed using three-dimensional Multi-Planar Reforming images from the data of Digital Imaging and Communication in Medicine (DICOM). In distance/angle analysis, growth of the mandible as well as the maxilla and cranial base was confirmed. The enlarged upper airway was maintained without apnea symptoms. Morphological assessments showed that the temporomandibular joints were free of damage, and the permanent molars were formed normally. Early MDO was considered a useful option for improving severe airway obstruction in babies with PRS.

Cetuximab produces antitumor effects by inhibiting the epidermal growth factor receptor (EGFR) -mediated signal transmission route of tumor cells. However, monoclonal-antibody-administration-related infusion reactions (IRs) or anaphylaxis may appear. We report a case of cetuximab-induced anaphylaxis in a patient with mandibular gingival cancer in whom beef-specific IgE antibodies were detected.

　The patient was an 81-year-old woman with gingival cancer (cT2N2bM1, adenocarcinoma, NOS low grade). To reduce bone-metastasis-related neurological symptoms, radiotherapy was performed. To treat the primary lesion and metastatic cervical lesions, cetuximab monotherapy was selected. On serum IgE antibody testing, beef-specific IgE was detected, and treatment was begun, given the possibility of anaphylaxis related to cetuximab administration. Anaphylactic symptoms, such as a decrease in blood pressure, urticaria, and loss of consciousness, appeared 20 minutes after the initial administration. Rapid infusion, oxygen administration, and vasopressor administration led to the resolution of shock. Subsequently, the additional administration of cetuximab was not conducted, and palliative radiotherapy (30 Gy/10 fractions) for cervical/thoracic vertebral metastases was performed, resulting in pain relief. The patient was discharged 24 days after admission. Among IRs, IgE-mediated allergic reactions should be pathophysiologically differentiated from standard infusion reactions (SIRs), which are associated with hypercytokinemia. The onset of IgE-mediated allergic reactions may be avoided by discontinuing administration to patients in whom IgE antibody is detected on a beef-specific IgE antibody test before treatment.

Schwannoma originate in the Schwann sheath of peripheral nerves; the incidence of schwannoma in the oral and maxillofacial region is low. We describe our experience with a patient who had a schwannoma that showed high uptake on a FDG-PET/CT scan. A 64-year-old woman underwent FDG-PET/CT imaging to evaluate primary lung cancer in depth. The scan demonstrated high uptake of FDG (SUVmax = 4.7) in the right side of the mouth floor, and the patient was therefore referred to our hospital. Echography and CT revealed an oval mass with smooth margins (diameter, 20 mm) in the vicinity of the sublingual gland in the right side of the mouth floor. Based on the clinical diagnosis, we resected the oral floor mass with the patient under general anesthesia in June 2015. In the intraoperative assessment, the tumor had a coat, but was contiguous with the lingual nerve and partly adhered to the sublingual gland. The histopathological diagnosis was schwannoma. On immunohistochemical staining, the tumor was GLUT-1 and GLUT-3 positive, suggesting that GLUT expression was involved in the high uptake of FDG. At 2 years of follow-up, we found no evidence of recurrence.

Solitary fibrous tumor (SFT) is a fibrous mesenchymal tumor that was first reported on the pleura by Lietaud in 1767, followed by Wagner in 1870 and Klemperer and Rabin in 1931. SFT is rare in the oral cavity, and some studies reported that SFT can arise in the buccal region and tongue. However, there is only one report of SFT arising in the soft palate in Japan. The patient was an 82-year-old woman with 20 × 10 mm and 8 × 8 mm elastic masses on the right side of the soft palate. MRI revealed two well-circumscribed masses on T1-weighted images, which had the same intensity level as the muscle, and on T2-weighted images, which had uneven high signal intensity. Because a biopsy specimen was diagnosed as SFT, we performed tumor resection with the patient under general anesthesia. The patient had no signs of recurrence or metastasis as of 1 after surgery, and is still under follow-up.

Human myiasis is a parasitic infestation caused by fly larvae. There are many case reports of parasitic infestations in the digestive tract, ears, and sites of traumatic injury, but few reports of infestation inside the oral cavity. We report a case of human myiasis arising in the anterior maxillary gingiva.

　A 91-year-old woman was admitted to our hospital in October 2016 because of pneumonia. She started to receive antimicrobials after being hospitalized and her pneumonia symptoms were resolving, when five larvae were observed in the maxillary gingiva during oral care on hospital day 19. The larvae were extracted and sent to Japan’s National Institute of Infectious Diseases (Ministry of Health, Labour, and Welfare) for identification. They were identified as the third instar larvae of Sarcophaga similis. Based on the growth cycle of Sarcophaga similis, our patient is believed to have contracted the infestation after hospitalization. Regular, strict oral care was provided, and no insect larvae were found thereafter. Her pneumonia and oral health status improved, and she was transferred to another hospital on hospital day 35.

Despite the fact that radiation is one of the standard therapies in patients with oral cancer, tumor can recur even in the early stages of the disease, negatively affecting outcomes and the quality of life. We previously found that CD11b⁺ bone marrow-derived cells (BMDCs) were recruited into human glioblastoma multiforme (GBM), leading to re-organization of the vasculature and tumour regrowth. However, it is not yet known how these cells contribute to tumour vascularization. In the present study, we investigated the role of infiltrating CD11b⁺ myeloid cells in the vascularization and recurrence of oral squamous cell carcinoma (OSCC). In a xenograft mouse model, local irradiation caused vascular damage and hypoxia in the tumor and increased infiltration of CD11b⁺ myeloid cells. These infiltrating cells showed characteristics of M2 macrophages (M2Mφs) and are associated with the promotion of vascularization. M2Mφs promoted tumor progression in recurrence after irradiation as compared with non-irradiated tumours. In addition, we found that CD11b⁺ myeloid cells, as well as CD206⁺ M2Mφs, are increased during recurrence after radiotherapy in human OSCC specimens. Our findings may lead to the development of potential clinical biomarkers or treatment targets in patients with irradiated OSCC.