Kokubyo Gakkai zasshi. The Journal of the Stomatological Society, Japan最新文献

In the Dental Hospital, Tokyo Medical and Dental University, an infection control team (ICT) has been formed to inspect each diagnosis department of clinics and wards in order to identify problems regarding nosocomial infection control. In this study, we analyzed the inspection reports and highlighted the following serious problems: 1) inadequate hygienic hand-washing for out- and in-patient treatment, 2) incomplete wearing of personal protective equipment (PPE) by dental health care workers, 3) necessity of environmental improvement in the clinics, and 4) cross-infection risk induced by. the continuous use of treatment devices without appropriate disinfection. The ICT provided feedback to the inspected departments, suggesting solutions to problems regarding nosocomial infection control. In order to enhance infection control in our hospital, dental healthcare practitioners must make further efforts on nosocomial infection control and prevention, and act according to their position by continuously educating students and enlightening hospital staff about the importance of infection control.

MicroRNAs (miRNAs) are endogenous small non-coding RNAs that negatively regulate gene expression via binding to the 3' -untranslated region (UTR) of transcripts. However, recent evidence suggests that miRNA can also bind to the open reading frame (ORF) region within transcripts for its down-regulation. On the other hand, a previous report demonstrated that miR-596 has a tumor suppressor function by targeting LGALS3BP via directly binding to its 3' UTR in oral squamous cell carcinoma (OSCC) cells. However, it is not clear whether this miRNA can bind to the ORF region of LGALS3BP. In this study, although four putative binding sites of miR-596 were included within the ORF region of LGALS3BP, it was found that miR-596 could not bind to those sites. Instead, the results showed that the expression of LGALS3BP might be in part negatively regulated by the proteasome system at the protein level. Thus, these findings may help clarify the molecular mechanism of the tumor-suppressive effect through down-regulation of LGALS3BP by miR-596 in OSCC cells.

Glucagon-like peptide 1 (GLP-1) is the gastrointestinal hormone released from L-cells of the small intestine and promotes insulin secretion by acting on the pancreas islet. GLP-1 receptor (GLP-1R) expression has been detected in many organs that are involved in carbohydrate metabolism, however its expression in the salivary glands, which participate in the first carbohydrate metabolism, has not been clarified yet. Furthermore, it is known that occlusion affects both the morphology and function of the salivary glands. Thus in this study, we focused on the expression of GLP-1R in the major salivary glands, and analyzed the changes of GLP-1R expression under the occlusal changes. Twenty-four male Wistar rats were used in this study. In the experimental group, all maxillary molars were extracted at 7 weeks old. The rats without molar extraction were used as the control group. The rats were sacrificed at 8 and 11 weeks old, then the parotid gland (PG), submandibular gland (SMG), and sublingual gland (SLG) were analyzed immunohistochemically for the presence of GLP-1R. Immunohistochemical staining showed GLP-1R to be localized in the ductal cells of PG, SMG, and SLG. In SLG, there were no differences in the intensity of GLP-1R staining in both the control and experimental groups at 8 and 11 weeks old. In PG and SMG, the intensity of GLP-1R staining in the experimental group was significantly weaker than in the control group at 11 weeks old, otherwise there were no differences at 8 weeks old. In conclusion, GLP-1R is expressed in rat PG, SMG, and SLG, and its expression can be influenced by molar extraction.

This paper reviews the introduction of a flipped class for fourth grade dentistry students, and analyzes the characteristics of the learning method. In fiscal 2013 and 2014, a series of ten three-hour units for removable partial prosthodontics were completed with the flipped class method; a lecture video of approximately 60 minutes was made by the teacher (author) and uploaded to the university's e-learning website one week before each class. Students were instructed to prepare for the class by watching the streaming video on their PC, tablet, or smartphone. In the flipped class, students were not given a lecture, but were asked to solve short questions displayed on screen, to make a short presentation about a part of the video lecture, and to discuss a critical question related to the main subject of the day. An additional team-based learning (TBL) session with individual and group answers was implemented. The average individual scores were considerably higher in the last two years, when the flipped method was implemented, than in the three previous years when conventional lectures were used. The following learning concepts were discussed: the role of the flipped method as an active learning strategy, the efficacy of lecture videos and short questions, students' participation in the class discussion, present-day value of the method, cooperation with TBL, the significance of active learning in relation with the students' learning ability, and the potential increase in the preparation time and workload for students.

Oral function improvement programs utilizing health behavior theories are considered to be effective in preventing the need for long-term social care. In the present study, an oral function improvement program based upon health behavior theories was designed, and its utility was assessed in 102 pre-frail elderly persons (33 males, 69 females, mean age: 76.9 +/- 5.7) considered to be in potential need of long-term social care and attending a long-term care prevention class in Sayama City, Saitama Prefecture, Japan. The degree of improvement in oral functions (7 items) and oral hygienic conditions (3 items) was assessed by comparing oral health before and after participation in the program. The results showed statistically significant improvements in the following oral functions: (1) lip functions (oral diadochokinesis, measured by the regularity of the repetition of the syllable "Pa"), (2) tongue functions, (3) tongue root motor skills (oral diadochokinesis, measured by the regularity of the repetition of the syllables "Ta" and "Ka"), (4) tongue extension/retraction, (5) side-to-side tongue movement functions, (6) cheek motor skills, and (7) repetitive saliva swallowing test (RSST). The following measures of oral hygiene also showed a statistically significant improvement: (1) debris on dentures or teeth, (2) coated tongue, and (3) frequency of oral cleaning. These findings demonstrated that an improvement program informed by health behavior theories is useful in improving oral functions and oral hygiene conditions.

The purpose of this study was to investigate new patients who had already received treatment with dental implants. The subjects were patients who visited the clinic for oral implants at Tokyo Medical and Dental University Hospital from April 1995 to March 2012. The results were as follows: 1) Of the total number of patients, there were 2,419 patients (14.0%) with dental implants. 2) Of the 2,419 patients, 252 patients (10.4%) had been referred from operating doctors or operating clinics. 3) There were 1,516 (62.7%) patients with complaints related to the implant therapy. 4) There were 1,367 (56.5%) patients who had ill feelings toward their attending doctors. 5) There were 1,112 (46.0%) patients with biological complications. 6) Regarding patients with or without a referral from the doctor who had performed their dental implant, those patients who had been referred showed significantly higher occurrence of loss of implants, neurological symptoms, doctor's recommendation, prosthetic problems, and surgical problems. Almost implant therapies were treated with other treatments for natural teeth, including surgical treatment, prosthetic treatment, periodontal treatment and maintenance. These were too complex to enable the results to be forecast before treatment, therefore unpredictable symptoms often occur in patients with implant therapy. Informed consent including patient education is important, but the results of this study suggest that it is insufficient at present.

According to the shortened dental arch concept, missing molars should not always be restored with prosthetic treatment. A shortened dental arch with missing molars is associated with a decrease in masticatory function. However, it is not known whether a shortened dental arch influences brain activity during chewing. This study aimed to clarify the effect of posterior arch length of mandibular bilateral distal extension removable partial dentures (RPDs) on brain activity during chewing. Eleven subjects with bilaterally missing mandibular molars (mean age, 66.1 years) participated in the study. RPDs with full dental arch and shortened dental arch were fabricated and brain activity during gum chewing under each dental condition was measured using functional magnetic resonance imaging. Brain activation during gum chewing with the full dental arch was observed in the middle frontal gyrus, primary sensorimotor cortex extending to the premotor cortex, supplementary motor area, putamen, insula and cerebellum. However, activation of the middle frontal gyrus was not observed during gum chewing with the shortened dental arch. The results of this study suggest that human brain activity during chewing in the middle frontal gyrus may be associated with chewing in the presence of the molar region.

Candida albicans is a commensal fungus that commonly colonizes human mucosal surfaces. When the host immune defenses are impaired, C. albicans triggers recurrent infections of the oral mucosa and tongue. We previously reported that the characteristics in NOD/SCID. e2f1(-/-) mice that have naturally decreased saliva and T and B cells that do not develop increase the susceptibility of oral bacterial infection in the oral cavity. Next, we sought to establish a C. albicans infection model in NOD/SCID. e2f1(-/-) mice. C. albicans yeast forms were introduced by wiping a cotton swab moistened with C. albicans solution on the tongue after disinfection by 0.2 Chlorhexidine for the first time. After an interval of 60 min, the inoculation was performed by pipette 2 or 4 times at an interval of 60 min. The number of C. albicans colonized on the tongue significantly increased but there were no significant difference between NOD/SCID. e2f1(+/+) mice and NOD/SCID. e2f1(-/-) mice at 120-240 minutes. However, a significant difference between these mice was observed at 24 hours after the last inoculation. Moreover, 5 inoculations/day were also performed for 2-4 days and significant differences between mice arose, and the maximum level of infection was found at 24 hours after consecutive inoculation for 3, 4 and 5 days, but the levels were reduced after 48 h. It is suggested that the saliva volume and flow are important for preventing 24-hour colonization of C. albicans. NOD/SCID. e2f1(-/-) mice are a relevant mouse model for 24-hour colonization on the tongue.

The epidermal growth factor receptor (EGFR) is one of the receptor tyrosine kinases. Some EGFRs are transferred from membrane to nucleus upon ligand binding and an increase of this translocation causes high-level expression of nuclear EGFR. The high-level expression of nuclear EGFR was reported to be a poor prognostic factor in various cancers such as breast cancer, ovarian cancer, gallbladder cancer, prostate cancer and oropharyngeal cancer. Regarding oral cancers, one report indicated that nuclear EGFR is detected in oral squamous cell carcinoma (OSCC) on immunohistochemical staining, but did not mention the clinicopathological prognostic value in detail. Therefore, we investigated the expression of nuclear EGFR in OSCC cell lines and primary tumor specimens of tongue SCCs to see whether nuclear EGFR could be a useful prognostic value. We verified the expression level of nuclear EGFR in OSCC cell lines and observed an increase in the amount of nuclear EGFR upon EGF stimulation with the expression level reaching its peak after 15 minutes. Nuclear EGFR positive tumors were found in 23 patients (28.0%) with tongue SCCs. However, we could not find any correlation between clinicopathological factors and the expression of nuclear EGFR in patients with tongue SCCs.

Pronunciation requires speed and accuracy, like many other fundamental activities such as breathing, eating, and walking. People can pronounce almost automatically without paying much attention to correctness, also like other activities. However, people may have to focus carefully on pronunciation when learning a foreign language, wearing dental appliances or rehabilitating after an injury or disease that affects speech. In the present study, we investigated neural changes underlying the process of learning new movement patterns of pronunciation in such cases. Nine healthy adults participated in the study. Difficulty of pronunciation was evaluated and cortical activity was measured under three conditions (overt and covert speaking, and silent reading) by fMRI three times after they wore orthodontic appliances. We found that the right superior temporal gyrus (STG) was involved in the auditory feedback control of pronunciation with the appliances, and the activity of the right STG was well correlated with the subjective difficulty of pronunciation and its time-dependent reduction. On the other hand, neural changes related to somatosensory feedback control and motor control of pronunciation did not show any time-dependent change. Our findings indicate that auditory feedback control of pronunciation is more important than motor control and somatosensory feedback control for learning new movements related to pronunciation.