It is generally accepted that perioperative management of oral function can help to prevent complications. Since fiscal 2016, perioperative management of oral function in palliative care patients has been covered by government health insurance. We conducted a clinical study of 171 palliative care patients who visited our department over the 3-year period from January 2013 to December 2015. We also studied the differences between the palliative care physicians and actual oral disease. A questionnaire survey was administered to 18 nurses working in palliative care units. In general, patients with end-stage disease are prone to a variety of oral problems. The survey revealed the current situation that they feel the need for oral care but cannot do enough. Currently, perioperative management of oral function for palliative care patients has achieved specific results. It is suggested that it is necessary to provide dental care as a prophylactic treatment rather than conventional symptomatic treatment in order to further improve the perioperative management of periodontic function.

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To investigate the effects of exercise stress on halitosis, we determined concentrations of cortisol and catecholamine in the blood and that of volatile sulfur compounds （VSC） in the expired gas. The experiments were conducted on healthy volunteers. All volunteers were measured for VSC （hydrogen sulfide, methylmercaptan, dimethylsulfide）, cortisol and catecholamine （adrenaline, noradrenalin, and dopamine） before and after a footstool elevation movement. We found significant increases in hydrogen sulfide in the volatile expired gas and cortisol, adrenaline, noradrenalin, and dopamine in the blood in a comparison of before and after exercise. In addition, a significant positive correlation was found between hydrogen sulfide and adrenaline, hydrogen sulfide and dopamine. These results suggest that induced exercise stress is a factor that increases the concentration of sulfur compounds. In particular, the results strongly suggested that adrenaline and dopamine are involved in the increase of hydrogen sulfide.

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Objectives: Oral management strategies for prevention of medication-related osteonecrosis of the jaw （MRONJ） in patients receiving bone-modifying agents （BMA） have not been established. Hence, we investigated the triggering events and prevention methods for MRONJ.
Methods: Eighty-six patients who developed MRONJ （33 with malignancies and 53 with osteoporosis） were examined retrospectively, focusing on the triggers for these cases.
Results: Tooth extraction was a trigger for MRONJ in 7 of 33 patients （21.2％） with malignancies, and 26 of 53 （49.1％） with osteoporosis. The occurrence of MRONJ due to tooth extraction was less frequent in the former group than in the latter because tooth extraction is typically avoided for those with malignancy as per the recommendation of a position paper. MRONJ frequently occurred in patients who underwent extraction of infected teeth, whereas no patients developed MRONJ after extraction of symptomless teeth. These findings suggest that the trigger of MRONJ is a local infection rather than surgery-related damage to the bone. Duration of BMA administration before the development of MRONJ was greater than 6months.
Conclusions: For prevention of MRONJ, we think that teeth that may be a source of infection in future should be extracted before long-term administration of BMA.

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Purpose: The objective of this study was to clarify the relationship between the bone resorption around dental implants and bone metabolism. Patients and Methods: Eleven post-menopausal female patients were enrolled in the clinical study. Twenty-three dental implants were inserted in the posterior mandibular edentulous region. Dental radiograms evaluated the alveolar bone absorption ratio （ABAR） of post-surgical peri-implant bone resorption. Bone alkaline phosphatase isoform （ALP） and bone metabolism marker （PICP and ICTP） in serum were measured before surgery as markers of bone synthesis and degradation. A semi-quantitative ratio of the bone uptake of a scintigraphic study at one month post-surgery was calculated. Results: ABAR was not correlated with serum PICP, ICTP, or ALP. However, the correlation between ABAR and the ICTP to PICP ratio representing bone formation was higher than that of each relation. ABAR increased with the magnitude of the bone uptake ratio of the scintigraphic study. There was a relation between PICP and bone uptake: uptake decreased with increasing PICP. Conclusion: Peri-implant bone resorption may be related with enhanced bone metabolism in the region of implant placement. Bone formation capacity is likely to be important for inhibiting post-surgical peri-implant bone resorption.

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Salivary gland tumors derived from minor salivary glands are relatively rare, but it is often difficult to distinguish between benign or malignant. Also, in the case of malignant tumor, treatment methods other than surgical resection are not established and it is often difficult to take measures. We report three cases of malignant salivary gland tumor that was thought to be derived from minor salivary glands clinically. The cases included a man and two women ranging in age from 32 to 65 years old; two patients had it on the retromolar site, and the other had it on the buccal mucosa. Histopathological diagnosis included two patients with mucoepidermoid carcinoma and the other with adenoid cystic carcinoma. In two cases, chemotherapy and radiotherapy were conducted as additional treatments after surgery. Subsequently, one case resulted in relapse or metastasis.

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Odontogenic myxofibroma is a rare and locally invasive benign neoplasm, which is a variant of odontogenic myxomas. Odontogenic myxofibromas contain considerable amounts of collagen fibers, dispersed within a myxoid stroma. The radiographic features of odontogenic myxofibromas are variable, and so it is difficult to diagnose this condition. We present a case of odontogenic myxofibroma in the right maxilla of an 18-year-old woman.
An operation was performed to carry out tumor extraction and curettage; during this procedure, a residual tumor in the pterygopalatine fossa region was noted. This residual tumor was removed during a second surgery via a Le Fort type I osteotomy. The patient has reported no tumor recurrence during the 5 years post-operation.

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We report a case in which a silicone implant was removed from the chin region using silicone implantation at about 50 years postoperatively due to odontogenic infection. A woman in her 70s was referred to our clinic with a chief complaint of pus discharge in the gingiva and the chin region. CT showed a radiopaque lesion in the mental region and it was attached to apical periodontitis in lower canine teeth. Under general anesthesia we removed the silicone implant and the teeth that caused the infection and unviable teeth with a clinical diagnosis of implant infection, and the postoperative course was uneventful.

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We report a case of sialolithiasis in the parotid glands that passed spontaneously during follow-up with some discussion based on the literature. The patient was a 62-year-old male who visited our hospital with the chief complaints of spontaneous pain and swelling around the left auricular area. Swelling and tenderness in the outer part of the left parotid gland area as well as redness and swelling with pus discharge with compression in the left parotid orifice were found during examination. Panoramic radiography showed relatively well-circumscribed shapeless opacities in the distal left second molar of the upper jaw. MR imaging revealed significant swelling in the left parotid gland area with low signal intensity on the T1-weighted image, low to moderate signal intensity on the T2-weighted image, moderate to high signal intensity on the fat-suppressed T2-weighted image, approximately 1-cm oval area with no signal within the buccal gingival soft tissue of the left molar of the upper jaw, and behind there, significant expansion of the parotid duct. A hard material, probably sialolithiasis, passed spontaneously during brushing in the morning of the next day of the initial examination, and the patient visited the hospital with the excretion. The sialolithiasis was almost round, yellowish-white, somewhat rough, and 11×7mm in size. For this case of sialolithiasis in the parotid glands, a CT examination was not performed and images could not be accurately obtained at the initial examination. It is therefore important to perform a comprehensive diagnosis, from clinical diagnosis to imaging diagnosis including panoramic radiography, CT examination, MR imaging, or ultrasonography.

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This article reports on subcutaneous emphysema with extensive bleeding caused by root canal therapy of a left maxillary first molar. A woman in her 60s visited the otolaryngology department of our hospital for treatment of maxillary sinusitis but was transferred to our department and underwent root canal treatment of the left maxillary first molar because of dental focal infection.
After washing by H₂O₂ and NaClO, she claimed a sense of incongruity of the left gena. She suffered sudden swelling of the left buccal region afterwards. Left gena subcutaneous emphysema and extensive bleeding were found by CT. She was hospitalized for follow-up because of intense pain and trismus. She suffered dyspnea after hospitalization and was given a steroid dosage, which immediately improved the dyspnea.
It is important to recognize that serious symptoms can be accidentally caused by root canal treatment, to consider ways to prevent occurrence, and to devise a counterplan in case of occurrence.

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There have been few reports on cases of spindle cell squamous cell carcinoma of the oral cavity. In this paper, we report a case of spindle cell squamous carcinoma arising in the tongue. A 76-year-old male with tongue squamous cell carcinoma was referred to our hospital. After two courses of neoadjuvant chemotherapy, subtotal resection of the tongue, unilateral radical neck dissection, and reconstruction with free transverse rectus abdominis myocutaneous flap were performed. Pathological diagnosis of the surgical specimen was spindle cell squamous carcinoma （pT3N0M0, Stage Ⅲ）. Recurrence of primary tumor was detected about four months after the operation and it showed extremely rapid growth. Palliative radiotherapy （two courses with 24Gy/8 fractions and 20Gy/5fractions） effectively controlled the patient’s quality of life. It is thought that although spindle cell squamous carcinoma clinically shows a response to radiotherapy or chemotherapy, some tumor cells （low sensitivity cancer stem cells） may resist and survive. So, radical resection with wider surgical free margin may be essential.

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In this study, we report a case of a patient with medication-related osteonecrosis of the jaw （MRONJ） with maxillary sinusitis. The patient was successfully evaluated using ^99mTc-bone scintigraphy combined with panoramic radiography and computed tomography, enabling early diagnosis and surgical treatment. The inflammation was limited to the maxillary antrum at the bottom of the jawbone and mandibular bone; therefore, we performed sequestrectomy for the maxilla and mandibular bone. As a result, the patient is now at postoperative 1 year and 8 months and the course remains good. We adopted imaging techniques to positively determine the treatment strategy for this MRONJ case, and we will repeat this approach depending on clinical conditions to further examine outcomes in future.

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It has become clear that there is not only BRONJ （bisphosphonates; BPs-related osteonecrosis） but also DRONJ （denosumab-related osteonecrosis）. Both are collectively referred to as ARONJ （antiresorptive agents-related osteonecrosis） in a Japanese position paper published in 2016.
We report a successful case in which we conservatively treated osteonecrosis of the maxilla which had developed in connection with a bisphosphonate intravenous agent that had been administered for multiple myeloma and observed a good course in congenital sequestration.
A 78-year-old woman, who was being treated for multiple myeloma, had been intravenously administered zoledronic acid hydrate totaling 52.8mg over a period of 15 months. With the cooperation of her family, oral hygiene after each meal had been done thoroughly, but 8 months after the discontinuation of her medication, we observed the onset of ARONJ. We continued with the maintenance of good oral hygiene, the administration of antibiotics and once-a-week local cleaning. Nine months after the onset of ARONJ, sequestration occurred. The sequestrum-dropout portion was covered by mucous membrane, and even now we have not observed any spread in new bone exposure or in the perforations. We believe that it is crucial to continue to maintain good oral hygiene, prevent relapse and perform long-term follow-up.

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We report a case with seven supernumerary teeth. The patient was a 29-year-old man, who visited the Department of Oral and Maxillofacial Surgery, Tokyo Dental College, for a medical examination of supernumerary teeth. The dental panoramic radiograph and CT scan showed seven supernumerary teeth located from both sides of the mandibular canine to the premolar region （three）, and on both sides of the maxillary third molar region （four）. The supernumerary teeth were extracted under local anesthesia and general anesthesia. The supernumerary tooth extracted from the maxilla was a microdont and presented an eternal tooth form as well as an almost similar form with the lower jaw. In addition, the tooth showed a graft organization of supernumerary teeth, as observed by an optical microscope and a soft X-ray photograph; the presented teeth-like structure and observations made were suggested after birth. No supernumerary teeth were identified during the 1.5-year follow-up of the patient after the surgical extraction.

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Objective: The needs of intraoral radiography are increasing for home care and especially for victim identification after the Great East Japan Earthquake. In this study, we evaluated the characteristics of output X-rays and measured air kermas of stray radiation from three battery-powered portable intraoral X-ray units.
Materials and Methods: The air kermas of stray radiation, generated from an IEC CT dosimetry head phantom and the X-ray units, which included DEXICO ADX4000, DEXICO ADX4000W, and DEXICO DX3000 （10DR Japan）, were measured using Pitman 37D and the 350cc ionization chamber attached （Pitman）.
Results: If an operator works in a sectioned area with a central angle of 180±60 degrees and a radius of 0.5m, the mean stray radiation was 0.353μGy for the ADX4000, 0.297μGy for the ADX4000W, and 0.288μGy for the DX3000 per 1mGy at the cone tip of each unit.
Discussion: In the event of a large-scale disaster, an operator would be taking many radiographs for victim identification each day. Therefore, this can be done by setting up a control area that ensures a sufficient distance from the radiation source, wearing a lead apron and using a protection board.

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We conducted a clinical research on the prognoses of 42 patients who were treated for medication-related osteonecrosis of the jaw （MRONJ） in our department, over an 8-year period from November 2008 to May 2016, and obtained the following results. Statistical analysis showed significant differences between the groups of cancer treatment and dosage career of injections.
Furthermore, the surgical treatment group showed improvements in symptoms in 80％ of the cases, while the conservative treatment group showed improvements in symptoms in 32％ of the cases. This research suggests the validity of the surgical approach for treating MRONJ.

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