Jun Sato

We would like to comment on the recently published article by Retuerto et al

Burning mouth syndrome (BMS) is a chronic oral pain disorder. There is a theory that BMS is a form of nociplastic pain. A standard treatment for BMS has not yet been established. Kampo medicine is a traditional oriental medicine. The purpose of this study is to evaluate the effectiveness of Rikkosan—a traditional Japanese herbal medicine (Kampo)—in the treatment of BMS. A single-center retrospective study was conducted on 20 patients who were diagnosed with BMS and treated with Rikkosan alone (total daily dose; 7.5 g) three times daily for approximately 4 weeks (29.5 ± 6.5 days). Rikkosan was dissolved in hot water and taken internally. They had an average age of 63 years, and 90% were being treated for other illnesses, but their medication status was the same during this study period, except for Rikkosan. No adverse events were observed in patients. Numerical rating scale (NRS) or visual analog scale (VAS)/10 scores decreased significantly between the time of the initiation of Rikkosan and one month after (−2.1 ± 1.2, p < 0.05). Rikkosan has a short-term effect of reducing NRS by two levels in BMS patients.

Burning mouth syndrome (BMS) is a chronic oral pain disorder. There is a theory that BMS is nociplastic pain. Standard treatment for BMS has not yet been established. Kampo medicine is a traditional oriental medicine. The purpose of this study is to evaluate the effectiveness of rikkosan—a traditional Japanese herbal medicine (Kampo)—in the treatment of BMS. A single-center retrospective study was conducted in 20 patients who were diagnosed with BMS and treated with rikkosan alone (7.5 g) three times daily for approximately 4 weeks. They were treated with rikkosan alone approximately 4 weeks (29.5 ± 6.5 days) for the initial treatment. They had an average age of 63 years and 90% were being treated for other illnesses, but their medication status was the same during this study period, except for rikkosan. No side effects were observed in patients. Numerical rating scale (NRS) or visual analogue scale (VAS)/10 scores decreased significantly between the time of the initiation of rikkosan and the one-month after (-2.1 ± 1.2, p < 0.05). Rikkosan has a short-term effect of reducing NRS by two levels in BMS patients.

Background: Carcinoma cuniculatum (CC) is a rare subtype of squamous cell carcinoma that is difficult to diagnose owing to the lack of cellar atypia and/or associated oral epithelial dysplasia. The prognosis is good given proper resection, but it often has a poor prognosis with recurrence. We present the case of a 78-year-old man who visited our department with an ulcer around the implant in tooth 35. With Nikolsky’s phenomenon in the gingiva, a detailed examination revealed pemphigus vulgaris. Steroid administration remarkably improved the oral symptoms but caused osteomyelitis and rapid bone destruction, leading to pathological fracture. After multiple biopsies, mandibular segment resection was performed with a diagnosis of mandibular osteomyelitis, and no malignant findings were found. Four months later, the wound reopened, a white keratinized lesion appeared, and a biopsy revealed CC. Unresectable tumor infiltration was already observed, but the patient died of aspiration pneumonia 15 months after diagnosis. Conclusions: It took 20 months to make a definitive diagnosis of CC in this case. Pemphigus vulgaris may have made the diagnosis particularly difficult. Since other CCs are often diagnosed with osteomyelitis or odontogenic keratocyst preoperatively, we recommend keeping in mind the possibility of CC in refractory cases.

This study describes the use of ¹⁸F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) to detect a chronic odontogenic infection as the possible origin of a brain abscess (BA). A 74-year-old man with esophageal carcinoma was referred to our department to determine the origin of a BA in his oral cavity. He had no acute odontogenic infections. The BA was drained, and bacteria of the Staphylococcus milleri group were detected. Whole body FDG-PET revealed that the only sites of definite uptake of FDG were the esophageal carcinoma and the left upper maxillary region (SUV_max: 4.5). These findings suggested that the BA may have originated from a chronic periodontal infection. Six teeth with progressive chronic periodontal disease were extracted to remove the possible source of BA. These findings excluded the possibility of direct spread of bacteria from the odontogenic infectious lesion to the intracranial cavity. After extraction, there was no relapse of BA.

Hypoxia, a prognostic factor in many types of cancer, can be detected by ¹⁸F-fluoromisonidazole (FMISO) positron emission tomography (PET). It is unclear whether hypoxia reflects the response to chemotherapy in patients with oral squamous cell carcinoma (OSCC). The correlations of FMISO-PET and FDG-PET with histological response to preoperative chemotherapy were therefore assessed in patients with OSCC.