In mammals, the salivary glands （SGs）, which produce 0.5-1.5 liters of saliva daily, comprise major （submandibular, sublingual, and parotid） and minor SGs. Saliva contains 99.5％ water, 0.3％ proteins （1.5-4.5g）, and 0.2％ ions. Acinar cells are responsible for the production and secretion of proteins such as amylase, mucins, and immunoglobulins, which are important for lubrication, buffering, food digestion and taste, and prevention of oral diseases. A failure during any of the steps in the secretion process （exocytosis） in the SGs results in altered secretion of salivary proteins. Recent studies show that salivary protein content is altered in patients with diabetes and obesity as well as in patients with oral health issues. In addition, the secretion of salivary proteins is reduced, and the contents of saliva are changed, in several pathological conditions, including Sjögren’s syndrome. Despite the importance of the process of salivary protein secretion, the regulatory mechanism（s） of exocytosis in the SGs remains unclear. A detailed understanding of these mechanism（s） would identify novel targets for therapeutics and contribute to new tools for diagnosing exocytosis defects, not only in the SGs but also in other secretory organs, in physiological and pathological conditions. In this review, we discuss recent findings related to molecular mechanisms of exocytosis and diseases associated with exocytosis defects.
Purpose: The purpose of this study was to clarify the activated regions in the human brain caused by low-level clenching and tooth separation, focusing on their differences. Methods: For creating functional magnetic resonance images（fMRI）, echo planar and T1-weighted images were obtained using a 3T MRI apparatus. Six healthy volunteers clenched with 10％ and 40％ of the maximum bite force as vertical stimulation（Task 1）, and 10 volunteers bit at 60, 120 and 180 seconds after the insertion of a brass contact gage as horizontal stimulation together with vertical stimulation（Task 2）. Results: At 10％ clenching, the supplementary motor area, frontal association cortex and cerebellum were activated, whereas the primary sensorimotor cortex and temporal association cortex were added to the activated regions at 10％ clenching. In addition to the activated regions in Task 1, the parietal association cortex, thalamus, hippocampus, putamen and insula were activated in the biting after the insertion of the brass gage. Conclusion: The hypothalamic area was confirmed to be activated due to biting with the gage in addition to the regions activated in low-level clenching. Brain fMRI might provide useful information to clarify the relationship between various intra-oral stimulations and brain activities.
Although the mechanism of systemic complications due to the oral environment in the perioperative period and oral complications due to treatment have been elucidated, it has become clear that improving the oral environment can prevent perioperative complications. Though the necessity of multi-professional collaboration is widely known to promote safer perioperative and higher quality medical care, few facilities have well-systematized oral management. Thus, in September 2014, our hospital established a perioperative management team to provide safe perioperative and high-quality medical care. Our department focuses on intraoral management in the perioperative period. Therefore, we report here the current status and usefulness of the management of perioperative oral function in our hospital. From September 2014 to March 2018, a total of 4297 patients visited our department for perioperative oral function management. To investigate the usefulness of this management, we analyzed the number of cases of pneumonia, surgical site infection, and bloodstream infection. No significant differences were found in the total number of medically associated infections between the group of patients with dental intervention under perioperative oral function management and the non-intervention group; however, the incidence of pneumonia was significantly decreased in the intervention group. An investigation of clinical indicators associated with postoperative complications among high-risk patients revealed a high percentage of patients in the medical infection group with low preoperative albumin levels, long surgery, hemodialysis, and steroid use. Based on these findings, introducing perioperative oral function management may promote improved safety during surgery and the prevention of postoperative complications, and hospital dentistry appears to play a major role in perioperative medical care; therefore, dentists should utilize their specialized knowledge about oral hygiene to make positive contributions to perioperative medical care．
An angioleiomyoma is a benign tumor derived from the smooth muscle cells of the vascular wall and tends to arise in the soft tissues of the lower extremities. It may rarely arise in the hard palate, and there are a few reports of this tumor accompanied with palatal bone defect. We herein report a case of angioleiomyoma of the hard palate with bone defect in a 79-year-old woman. She had complained of painless swelling of the hard palate. The lesion was a dark purple, elastic soft hemispheric mass, measuring 10mm in diameter. CT and MRI revealed that the tumor was accompanied with palatal bone defect. After biopsy, the tumor was resected under general anesthesia. Histopathologically, the tumor consisted of hyperplastic, mature smooth muscle cells, and included numerous blood vessels with hypertrophic walls and narrow lumens. The histopathological diagnosis was angioleiomyoma. Tumor recurrence has not been observed for over 5years after the surgery.