The first disease that comes to a dentist’s mind during diagnosis is thought to be due to intuition. It is a function of “system one,” the area of the brain responsible for the storage of short-term memories. On the other hand, “system two” is responsible for analytical thinking that follows a logical thought process. This area functions during hypothesis formation to create a list of differential diagnoses based on the patient’s history and during hypothesis verification to examine the probability of the patient having a disease from that list. However, its disadvantage is that it takes time. The dual process theory describes the cognitive process of clinical reasoning as an interaction between the fast, subconscious “system one” and time-based, conscious “system two”. This theory is based on the idea that it is useful to think using both systems simultaneously to solve problems. However, it has been found that this leads to the occurrence of a variety of cognitive errors. Dentists should be familiar with the cognitive processes involved in diagnosis and take measures to prevent and correct errors.

抄録全体を表示

We report a case of a woman in her 60s who presented with numb chin syndrome as the initial symptom; she had a history of breast cancer. Based on CT, MRI, and PET-CT imaging findings, we suspected mandibular osteomyelitis. She received medication for a long time but did not show improvement. We performed a pathological examination under general anesthesia. Herein, we report a case of breast cancer metastasizing to the mandible bone.

抄録全体を表示

The incidence of impacted supernumerary teeth in the median maxillary region is 1.48〜5.17％. Most patients present with one impacted tooth （62.5〜85.7％）, although there are some rare cases with two （16.48〜37.5％） or three （0.02〜1.8％） impacted teeth. In the present study, we report the rare case of a patient who presented with three impacted supernumerary teeth in the median maxillary region. The patient was an 8-year-old boy who was referred to our clinic to undergo detailed examination and treatment for impacted supernumerary teeth in the median maxillary region. XP revealed the presence of three impacted teeth, which were subsequently removed under general anesthesia. The patient recovered well postoperatively.

抄録全体を表示

Sialoliths commonly occur in the submandibular gland, but parotid gland stones are rare. We report a case of extraductal parotid gland stone caused by repeated inflammation. A 49-year-old male with left buccal swelling was referred to our department for endoscopic removal to avoid removal by the extraoral approach after a diagnosis of parotid gland stone at another hospital. Computed tomography showed that the left stone was 6.2×5.2×3.4mm in size. The patient underwent removal of the stone. Because sialendoscopy revealed an extraductal stone caused by inflammation, a buccal skin incision through the fistula was made and the stone was removed. There was no recurrence or stenosis more than 1 year after removal of the parotid gland stone.

抄録全体を表示

Surgical resection or brachytherapy has been used for curative treatment of oral cancer. Although only limited facilities perform brachytherapy, treatment results are as good as those of surgical resection and allow functional preservation. We report here the use of high-dose-rate brachytherapy with a remote after-loading system for mold irradiation for buccal mucosal cancer, in which function is expected to be impaired by surgical treatment. The patient was a woman in her 80s who visited a dental clinic complaining of pain in the left buccal mucosa. She was referred to our department, where a tumor with a rough surface of 39 mm×22 mm was found on the left buccal mucosa. Computed tomography showed a contrast-enhanced soft-tissue mass on the left cheek, with a thickness of 20 mm. Subsequent biopsy of the lesion revealed squamous cell carcinoma, and the tumor was classified as cT2N0M0 （stage Ⅱ）. Surgical resection would be expected to cause dysfunction through the skin on the cheek, therefore simultaneous chemoradiotherapy was planned. The thickness of the oral mucosa should be less than 15 mm, but was 20 mm in this case, making brachytherapy unsuitable. We therefore created a mold device using the occlusion plate to extend the buccal mucosa and maintain contact with the source of radiation, allowing irradiation of the tumor. Mold irradiation was performed using 192-Ir at a total dose of 60 Gy. The patient remains recurrence-free as of 2 years 6 months after mold irradiation.

抄録全体を表示

Actinomycosis is an uncommon chronic granulomatous infection. Typical symptoms of this infection are multiple abscess formation, plate-like induration and trismus. Recently, this infection has been difficult to diagnose because of the lack of typical symptoms. We report a rare case of actinomycosis mimicking the clinical appearance of a benign tumor in the lower lip.
The patient was an 85-year-old man who noticed a swelling and spontaneous pain in the left lower lip region. The mucosal surface of the left lower lip was white in color with a small yellow, elastic hard tumor, measuring 11mm in diameter. We diagnosed a tumor of the left lower lip and performed excisional biopsy of the region. Histopathologically, actinomycotic colonies were identified, and actinomycosis was diagnosed. However, the mass persisted even after the surgical treatment. An amoxicillin formulation was therefore administered until the mass disappeared. At 3 months postoperatively, there was no sign of any recurrence.

抄録全体を表示

We report a case of acantholytic squamous cell carcinoma of the mandibular gingiva. A 63-year-old man with a localized indurative mass in the lower gingiva was referred to our department for consultation. Under the clinical diagnosis of carcinoma of the lower gingiva, mandibular segmental resection and neck dissection were performed. Histological and immunohistochemical examinations confirmed the diagnosis of acantholytic squamous cell carcinoma. Metastasis occurred after postoperative radiotherapy, and the patient died of respiratory failure 10 months after surgery.

抄録全体を表示

Odontoma is one of the most common benign odontogenic tumor but rarely occurs in the wall of the maxillary sinus. We report a rare case of an isolated odontoma, complex type which was located in the medial wall of the maxillary sinus.
A 64-year-old man visited a dental clinic because of pain and swelling of his left-side maxillary gingiva. Radiographic examination showed a radiopaque mass in the left maxillary sinus. He was referred to our department for further investigation of the lesion in the left maxillary sinus. Computed tomography revealed thickening of the maxillary sinus mucosa surrounding a tooth-like structure in the left medial wall of the maxillary sinus and soft tissue density in the left maxillary sinus containing the impacted first and second molars.
He was given a provisional diagnosis of odontoma in the maxillary sinus and infected dentigerous cyst associated with impacted first and second molars. He underwent surgical removal of the tooth-like structure in the maxillary sinus, followed by creation of a nasoantral window and extraction of the impacted first and second molars, followed by surgical enucleation of the cyst under general anesthesia. Histopathological examination of the tooth-like structure confirmed the diagnosis of odontoma, complex type. No evidence of postoperative recurrence of the left maxillary sinus has been observed.

抄録全体を表示