We investigated the oral condition of patients who underwent full medical checkups at Matsumoto Dental University Hospital （our university hospital） and requested dental health checkups for 1 year from April 2022 to March 2023. The male-to-female ratio of consultations was 62％ males and 38％ females, and 51.8％ of the visits were in the same city as the university hospital. The most common age group for consultation was patients in their 50s （35.9％）, and 90％ of patients currently had 25-32 teeth. Concerning the age groups for consultations, significant differences were observed in smoking status. Regarding the number of current teeth, the average number of times of teeth brushing, use of auxiliary cleaning tools, and chewing during meals exhibited significant differences.

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A metastatic tumor from colorectal carcinoma is very rare. There have been no previous reports of colorectal carcinoma metastasis with bone formation in the oral and maxillary regions. We report a case of suspected metastasis at the left temporomandibular condyle from colorectal carcinoma, which showed bone formation on computed tomography.
A 74-year-old man was referred to our department for oral examination from the Department of Surgery. He had a past history of colorectal carcinoma, and underwent right hemicolectomy and lymphadenectomy. Post-operative chemotherapy was performed for recurrence and metastasis. In our department, computed tomography of the head and neck region showed swelling and calcification at the left mandibular condyle. We performed fine needle aspiration cytology. The results showed atypical cells similar to the characteristics of adenocarcinoma. A review of previous and recent magnetic resonance imaging confirmed multiple metastases to the skull and the appearance of a tumor around the left mandibular condyle. FNA and CT/MRI examination results led us to suspect metastatic colorectal carcinoma with bone formation at the left temporomandibular condyle.

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Adenomatoid odontogenic tumor （AOT） is defined as a benign epithelial odontogenic tumor in the WHO classification of odontogenic and maxillofacial bone tumors. We experienced a case of AOT in the mandibular anterior tooth complicated with odontoma. The patient was a 46-year-old male who visited our department with a chief complaint of dislocation of the temporomandibular joint. Panoramic radiographs and computed tomography （CT） showed impacted teeth and transmission images in the anterior mandibular region of the mandible. Excision was performed under general anesthesia. On histopathological examination the lesion was diagnosed as AOT.

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After removal of a mandibular alveolar nerve sensory disturbance caused by drug overflow into the mandibular canal during root canal treatment of a mandibular molar. We report a case of mandibular alveolar nerve paresthesia that was evaluated by trigeminal sensory elicitation potential measurement （TSEP）, and improvement was observed. The patient was a woman in her 40s. After root canal treatment of the left mandibular second molar （M2） at a local dental clinic, left-sided hypersensitivity was observed; the proximal root of M2 was extracted and a foreign body was removed by osteotomy from the extraction socket to the mandibular canal. Two weeks postoperatively, TSEP and SWMT showed marked recovery. We report our experience of objectively evaluating inferior alveolar nerve palsy due to a foreign body outside the mandibular canal, which resulted in improvement of paresthesia.

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A simple bone cyst is a pseudocyst that frequently occurs in long bones, such as the humerus and femur. However, the process of development is poorly understood, including causes and pathology. In the jawbone, a frequent site of occurrence is the area from the mandibular canine to the wisdom tooth, whereas this type of cyst is rarely seen in the mandibular ramus. Here, we report a patient with a simple bone cyst extending from the mandibular molar region to the coronoid process. An 11-year-old female came to our clinic for detailed examination and treatment of the right lower jawbone. Panoramic radiograph imaging showed extensive radiolucency extending from the right mandibular molar region to the coronoid process. In computed tomography findings, buccolingual bulging in the corresponding area of the jawbone was confirmed, and the cortical bone appeared to have become thin and the septal walls separated. A cystectomy was performed under general anesthesia. During surgery, no cyst wall was found and the inner cavity was found to continue to the coronoid process. The interior wall of the cavity was removed by scraping, then suturing was performed to complete the procedure. The histopathological diagnosis was a simple bone cyst.

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