Tokyo Dental College

Animal studies suggest that periodontopathic bacteria induce gut dysbiosis and related pathology, possibly connecting periodontitis to non-oral diseases. However, the effects on the gut ecosystem in periodontitis patients are not fully understood.

We conducted a comprehensive analysis of the salivary and gut microbiota using 16S rRNA sequencing in periodontitis patients before and after treatment, comparing them to healthy participants. Serum metabolites were also analyzed.

Periodontitis patients showed high alpha diversity in both salivary and gut microbiota with a strong correlation. Significant differences were also observed in the gut microbiota composition between patients before treatment and healthy participants, irrespective of the ectopic colonization of periodontitis-associated bacteria in the gut. Co-abundance group analysis demonstrated that the gut microbiota of healthy participants was enriched with short-chain fatty acid producers. Changes in the gut microbiota coincided with alterations in the serum metabolite profile. While periodontal therapy improved salivary microbiota, it did not significantly affect gut microbiota.

Gut dysbiosis of periodontitis patients may impact systemic metabolite profiles. Given that periodontal therapy alone did not substantially improve the gut microbiota, adjunctive strategies targeting the gut microbiome may be effective in reducing the risk of periodontitis-associated diseases.

The jawbone contains a large number of unnamed epithelial rests that are remnants of the tooth-forming process. One of these uniquely extends naturally along neurovascular bundles, and was originally described at least 100 years ago as "epithelial nests in the bone nerve canal." As this concept has been forgotten in the years since then, any association of epithelial rests with the nerve has remained diagnostically enigmatic.

In jawbone sections, we have found common resting squamobasaloid and rare proliferating ameloblastic nests within neurovascular bundles. The latter type of large organoid follicle, when viewed in isolation, closely resembles ameloblastoma, but notable immunohistochemical differences are evident, suggesting classification as ameloblastomatoid hyperplasia.

Recognition of challenging intraneural epithelial rests in marrow spaces within cancellous bone as a normal microanatomic finding may help prevent diagnostic confusion and misdiagnosis. (Oral Surg Oral Med Oral Pathol Oral Radiol YEAR;VOL:page range).

Digital transformation is being applied in dentistry, and its usefulness in improving three-dimensional spatial awareness has begun to attract attention in studies using head-mounted displays rather than conventional flat monitor studies. This study reports the effectiveness of a new virtual reality (VR) educational system on learning comprehension to teach hygienic handwashing, sterile glove application, and gowning techniques to fourth-year dental students before clinical practice.

We undertook a cross-sectional study of fourth-year dental students who underwent VR learning. The students were evaluated using before and after tests involving 10 questions concerning hygienic handwashing. As a secondary outcome, a nine-item survey was administered to determine their opinions regarding VR learning.

The study comprised 135 students. In the pretest, mean scores were 54.9 (SD = 13.2); however, in the posttest, the scores increased significantly to a mean of 83.9 (SD = 13.7) (p = 1.37E-40 < 0.001). The survey results showed that there was an increase in positive opinions about learning in VR. The number of students who considered VR simple to operate increased from 51 to 122 pre- and post-VR learning, respectively. Concerning whether dizziness and nausea would occur with VR use, 33 (24%) students either disagreed or did not agree at all, but increased to 56 (41%) respondents after VR learning.

The new VR education system improved student knowledge in hygienic handwashing in an actual operating room. This system can be used at any time and place, standardizing learning opportunities based on actual clinical practice and allowing repeated learning; thus, offering a new approach in dental education.