Using a controlled pre/post study design, we investigated the effects of professional mechanical cleaning of the oral cavity with benzethonium chloride, interdental brushes, and hydrogen peroxide on the number of oral bacteria and postoperative complications among esophageal cancer patients in an intensive care unit. Before surgery, 44 patients with esophageal cancer were recruited at Okayama Hospital from January through August 2015. The control group (n = 23) received routine oral hygiene care in the intensive care unit. The intervention group (n = 21) received intensive interdental cleaning with benzethonium chloride solution and tongue cleaning with hydrogen peroxide. The number of oral bacteria on the tongue surface and plaque index were significantly lower in the intervention group than in the control group on postoperative days 1 and 2 (P < 0.05). Additionally, the number of days with elevated fever during a 1-week period was significantly lower in the intervention group than in the control group (P = 0.037). As compared with routine oral hygiene, a new oral hygiene regimen comprising benzethonium chloride, interdental brushes, and hydrogen peroxide significantly reduced the number of oral bacteria and days with elevated fever in patients with esophageal cancer.

To evaluate the occlusion accuracy of a novel impression technique, excessively high occlusion and the occlusal contact area during lateral movements were compared between metal restorations (restorations) and removable partial dentures (RPDs) fabricated using conventional and novel techniques. Both restorations and RPDs were fabricated on the simulation model with the precise displacement of the remaining teeth and soft tissue. For the novel technique, functionally generated path (FGP) recording and impression under occlusal force were simultaneously performed using a custom tray with an FGP table. For the two conventional techniques, definitive casts were mounted on an average value articulator and a semi-adjustable articulator in the typical manner. Prostheses were placed on the simulation models, and excessively high occlusion in the intercuspal position and occlusal contact areas during lateral movements were measured. Statistical analyses were performed using Kruskal-Wallis and Steel-Dwass tests (α = 0.05). For both prostheses, conventional techniques showed significantly higher occlusion in the intercuspal position than the novel technique. Moreover, the new technique demonstrated better guidance contact during lateral movements than conventional techniques. This novel technique can be recommended for the fabrication of highly accurate prostheses with appropriate occlusal contact without corrections at delivery.

Brain and muscle Arnt-like protein-1 (BMAL1) knockout mice exhibit accelerated aging, abnormal glucose metabolism, and impaired adipocyte differentiation, among other phenotypes, which are effects associated with the BMAL1 gene. No study has investigated temporal changes in the deformation of the mandibular condyle and the presence of calcification in areas surrounding the mandibular condyle. In a study of 12 C57/BL strain mice under inhalation anesthesia, we collected images of the mandibular condyle at 6 weeks after birth and then every 5 weeks from 10 to 25 weeks after birth. At 25 weeks, deformation of the mandibular condyle was seen in 8 of 12 joints in BMAL1 knockout mice and in 2 of 12 joints in wild-type mice. At 20 and 25 weeks, deformation in areas surrounding the mandibular condyle, which are known to undergo calcification, was seen in 2 of 12 joints in BMAL1 knockout mice and in 0 of 12 joints in wild-type mice. BMAL1 knockout mice exhibited premature aging of the mandibular condyle, which suggests that circadian rhythms affect mandibular condyle morphology.

In oral lichen planus, extracellular matrix and basal cells are damaged by T-lymphocytes. As a consequence, changes in expression of collagen fibers within the connective tissue and cytoskeletons of the epithelial tissue can be observed. With the goal of examining the characteristic changes undergone by basal cells as a consequence of T-lymphocytes damage in oral lichen planus, we investigated protein expression in the epithelial-connective junction. We selected 20 cases of oral lichen planus and 5 control samples of buccal mucosa. Subsequently, we divided the oral lichen planus cases into thin and thick parts based on the mean values of epithelial thickness from the control samples, and counted the positive rate of collagen IV, keratin 19, desmoglein 1, and Ki-67. Collagen IV immune-reactivity partially disappeared or thickened in oral lichen planus. The keratin 19 positive rate in oral lichen planus cases was significantly lower than in the controls. Desmoglein 1 positive rate of the thick part was significantly higher compared to the thin part of oral lichen planus. Thus, modifications in basal cells with both reduced keratin 19 expression and alterations of desmoglein 1 expression suggest that in oral lichen planus, as a consequence of cell injury or regeneration in the interface area, there is a disappearance of the “true basal cell nature”.

This study investigated differences in periodontal health variables between buccally impacted maxillary canines (BIMC) and palatally impacted maxillary canines (PIMC) after surgical-orthodontic treatment with open technique. Nineteen patients were enrolled: 10 with unilateral BIMC (5 men, 5 women; mean age 18.50 ± 1.96 years) and 9 with unilateral PIMC (4 men, 5 women; mean age 19.44 ± 2.40 years). Probing depth and keratinized tissue were recorded 12 months after surgical-orthodontic treatment, and the differences between the 2 sides were analyzed as primary outcomes. In addition, data for BIMC and PIMC were directly compared. In the BIMC group, probing depths were significantly higher for lateral incisors than for the untreated side (P = 0.044), and keratinized tissue values were significantly lower for canines than for the untreated side (P = 0.006). No significant differences were observed in the PIMC group. In BIMC, surgical-orthodontic treatment with open technique resulted in loss of periodontal keratinized tissue in the treated tooth and periodontal attachment loss in adjacent lateral incisors. However, the periodontal status of PIMC was not affected by surgical-orthodontic treatment with open technique.

Once a tooth develops deep caries and the dental pulp tissue is irreversibly infected, the infected dental pulp tissue should be removed, and filling material should be placed in the root canal. Endodontically treated teeth are prone to root fracture or periapical periodontitis; however, dental pulp tissue has the potential to prevent root fracture or periapical periodontitis. Therefore, dental pulp regeneration after pulpectomy may help prolong tooth life. In this study, a new method of dental pulp regeneration was developed. Vascular endothelial growth factor-adsorbed collagen gel was injected into the root canal of a prepared root canal model, placed into the dorsum of a rat, and cultured for 3 weeks. After retrieving the implant, histological analysis was performed. It was found that rat somatic cells were recruited into the root apex of the transplanted root canal model. These findings suggest a new potential technique for engineering dental pulp tissue.