Medication-related osteonecrosis of the jaws (MRONJ) still is increasing in Japan according to the reports from the Japanese Society of Oral and Maxillofacial Surgeons at 2022. New MRONJ Japanese position paper released at 2023 emphasizes cooperation between physicians and dentists to prevent MRONJ. Japan Osteoporosis Society (and Adequate Treatment of Osteoporosis Research Group) conducted questionnairebased survey regarding cooperation between them at 2014, 2015 and 2018. We investigated new questionnairebased survey at 2022 and compared the results at 2022 with those of previous surveys. The rates of physicians who requested oral health care by a dentist before antiresorptive agent therapy and reported cooperation between physicians and dentists were 72.7％ and 42.4％ in 2022 compared with 32.9％ and 24.8％ in 2015, respectively. The rates of cooperation among the 47 prefectures in Japan were significantly different, ranging from 10.0 to 83.3％. A further increase of a similar magnitude in cooperation across Japan would be necessary to prevent MRONJ.

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　In this revision of the position paper, medication-related osteonecrosis of the jaw (MRONJ) was chosen as the name, because of the number of causative agents for ONJ has increased. These drugs include angiogenesis inhibitors, tyrosine kinase inhibitors, and mTOR inhibitors, which have recently been increasingly used as main anticancer drugs. However, most ONJs in anticancer drug treatment are used in combination with antiresorptive agents (ARA), and the greatest risk of developing the disease remains the administration of ARA, bisphosphonates and denosumab (Dmab). For cancer bone metastases, not only anticancer drugs but also high doses ARA are administered from an early stage of metastasis detection, which is the standard treatment for preventing pathological fractures. Fracture prevention is because fractures not only lead to a decrease in quality of life, but also worsen the prognosis of life. Therefore, in principle, the ARA that was started will not be interrupted during cancer treatment.
　Another bone problem in cancer treatment is cancer treatment-related bone loss (CTIBL) which occurs almost with adjuvant therapy to prevent recurrence of the cancer. Breast cancer and prostate cancer, for which hormonal therapy is particularly effective, have an increased risk of CTIBL, requiring long-term administration of low doses ARA in combination with cancer treatment.
　In this way, the risk of MRONJ in cancer patients is thought to be increasing. At MRONJ, it is important to maintain good oral hygiene for prevention, and it is recommended to visit the dentist regularly before and after starting anticancer drug treatment. The higher the dose of ARA and the longer the administration period, the greater the risk of ONJ, but the combination drug and oral conditions are also greatly affected. So medical, dental and phalmacological collaboration is essential.

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　We report a rare case of odontogenic infection accompanied by various complications, including left temporal fossa and infratemporal fossa abscess, left intracranial subdural empyema, bacterial meningitis, acute cerebral infarction, and septic pulmonary embolism. A 74-year-old female was referred to us due to trismus with painful swelling in the left temporal region. CT and MRI scans revealed left temporal fossa and infratemporal fossa abscesses, and a left intracranial subdural empyema. Surgical drainage of the abscesses was performed and intravenous antibiotics were administered. All of these complications were improved by continuous antibiotics therapy. The patient recovered and was discharged from hospital three months later.

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　Gorham-Stout disease (GSD) is a rare lymphangitic disease that causes continuous and destructive dissolution of bone. It is extremely rare for it to occur in the maxillofacial bone.
　A 21-year-old male patient visited his family dentist due to discomfort on the right side of his mandible. Panoramic radiographs revealed a radiolucency in the right mandible, and the patient was referred to the Department of Oral and Maxillofacial Surgery in our hospital for further examination and treatment. CT images showed bone resorption from the right side of the mandible to the base of the skull, and together with pathological findings, the patient was diagnosed with GSD. After the commencement of treatment with zoledronic acid, denosumab and sirolimus, the lesion decreased in size and the osteolytic lesion improved.
　The findings indicate that antiresorptive agents and mTOR inhibitors may serve to stabilize this disease and facilitate gradual improvement in prognosis.

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　This paper describes a rare case of pleomorphic adenoma originating from an accessory submandibular gland. A 28-year-old woman presented to our hospital with a mass in the left submandibular area. Imaging revealed an irregularly-shaped mass, approximately 20 mm in size, in contact with the anterior surface of the left submandibular gland. A thin layer of fat was observed between the submandibular gland and the mass, with no evident continuity, suggesting an extramandibular gland tumor. Additionally, the submandibular lymph node was enlarged, exhibiting a signal pattern similar to that of a tumor. The diagnosis was benign tumor; however, due to the possibility of malignancy, tumor excision and a neck lymphadenectomy of the Level IB region were performed. Pathohistological examination confirmed the presence of a pleomorphic adenoma, and tissue similar to that of a normal submandibular gland was present in the outer capsule of the pleomorphic adenoma. No recurrence has been observed in the nine years following surgery.

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