Bulletin of Tokyo Dental College最新文献

We report a case of fixed prosthetic treatment for poor esthetics due to the position of the maxillary left lateral incisor in a 43-year-old woman. Initial examination revealed no carious lesions, but the tooth axis of the maxillary right canine showed mesial inclination of approximately 15°. Orthodontic treatment was first proposed but was declined by the patient as they did not wish to undergo a prolonged period of therapy. Therefore, recovery by extraction of the maxillary right lateral incisor and prosthetic treatment was proposed as an alternative. The method to be used for application of a 3-unit fixed partial denture and implant treatment was explained to the patient. She refused to give consent to this plan as well, however, due to concerns regarding the need to cut a lot from a non-problematic tooth and the length of time such treatment would require. Therefore, the problem was finally treated by application of a cantilever single-retainer fixed partial denture while giving sufficient consideration to extraction and occlusal contact. Lithium disilicate was used for the material of the prothesis. At 1 year after completion of treatment, no problem was observed with either the prosthetic appliance or the abutment teeth.

The primary aim of this study was to determine the prevalence of dental caries and its association with infant feeding and oral health-related behavior in Japanese children between the ages of 18 months and 3 years. A total of 387 infants were initially examined at the age of 18 months (or 19 months in some cases) and then again at 3 years (or at 3 years 1 month in some cases). The primary objective was to identify factors contributing to the prevalence of caries in children aged 18 months. The secondary objective was to follow up children with no caries at the age of 18 months to seek potential correlations between background factors and the increment of caries by the age of 3 years. In an adjusted multivariate logistic regression model, children who continued breastfeeding were approximately 7 times more likely to have dental caries at 18 months of age than those who did not. Infants brought in for an oral examination and consultation at around 12 months of age were less likely to develop dental caries at 18 months of age than those who were not. Multivariate logistic regression analysis revealed that infants who did not receive a dental check-up at 12 months of age showed a significantly higher incidence of dental caries at 3 years of age. The present results suggest that prolonged breastfeeding is a risk factor for early childhood caries at 18 months of age, and that infants in whom a regular oral care program is implemented from the age of 12 months are less likely to develop early childhood caries at 18 months or 3 years.

The objective of this study was to analyze the distribution and morphology of the valves in the human retromandibular vein. The retromandibular, internal thoracic, azygos, femoral, and brachial veins were harvested from 46 cadavers donated to the Department of Anatomy at Tokyo Dental College for dissection. The frequency of the valves in each vein, the length of the cusps, and the thickness of the vein itself were measured. Valves were present at high frequency (92.1%) in the veins of the limbs and had cusps at least twice as long as the internal diameter of the vein. Veins in the trunk contained a lower frequency of valves, with cusps that tended to be shorter (1.60±0.77) than those of the venous valves in the limbs (2.12±0.60). The valves of the retromandibular vein tended to resemble venous valves in the trunk in terms of both frequency and morphology. The main function of venous valves in the limbs is to prevent retrograde flow. Conversely, valves in the veins of the trunk and retromandibular vein play a role in retaining blood in the veins, and their relationship to other veins means that they can cause major hemorrhage.

This report describes a case of generalized chronic periodontitis requiring periodontal regenerative therapy. The patient was a 62-year-old man who presented with the chief complaint of gingival swelling in the molar region. An initial examination revealed that 31.6% of sites had a probing depth of ≥4 mm and 18.5% bleeding on probing. Radiographic examination revealed vertical bone resorption in #14, 25, 26, 27, 32, 37, 45, and 47, and horizontal resorption in other regions. Based on a clinical diagnosis of moderate chronic periodontitis, initial periodontal therapy consisting of plaque control and scaling and root planing was performed. Occlusal adjustment of premature contact sites was performed after inflammation was suppressed. Surgical periodontal therapy was subsequently performed at selected sites. Periodontal regenerative therapy using recombinant human fibroblast growth factor (rhFGF)-2 was performed on #14, 25, 26, 32, and 37. Combination therapy with rhFGF-2 and deproteinized bovine bone mineral (DBBM) was performed on #45 and 47. Other sites with residual periodontal pockets were treated by open flap debridement, and #27 was extracted due to a bone defect exceeding the root apex. Progress was then reevaluated and the patient placed on supportive periodontal therapy. Periodontal regenerative therapy using rhFGF-2 in combination with DBBM resulted in an improvement in clinical parameters and vertical bone resorption. This improvement has been adequately maintained over an 18-month period. The periodontal treatment provided resulted in a marked improvement in the patient's oral health-related quality of life.

Capnocytophaga ochracea possesses a type-IX secretion system that exports proteins which have a gliding motility-associated C-terminal (CTD) domain. This system is found in several species of the Bacteroidetes phylum. Hyalin, a large protein encoded by Coch_0033 in C. ochracea ATCC 27872, has a CTD domain and is posited to be involved in quorum sensing according to the database of the Kyoto Encyclopedia of Genes and Genomes. This suggests that it plays a role in biofilm formation via interbacterial communication. The aim of this study was to investigate the potential role of the hyalin-like protein coded by the Coch_0033 gene in gliding and biofilm formation of C. ochracea. A hyalin-like protein-deficient mutant strain of C. ochracea, designated mutant WR-1, was constructed through insertion of the ermF-ermAM cassette into the target gene. The spreading feature at the edge of the colony was lost in the mutant strain. Crystal violet and confocal laser scanning microscopy revealed no difference between the quantity of biofilm organized by the mutant and that organized by the wild-type strain. These data suggest that the hyalin-like protein encoded by the Coch_0033 gene is indeed involved in C. ochracea gliding activity.

The relationship between public health expenditure and number of teeth was investigated in patients with diabetes mellitus using data obtained from the Japanese National Database of Health Insurance Claims and Specific Health Checkups. Data on medical, dental, and pharmacy claims generated between April 2015 and March 2016 were analyzed in patients with diabetes mellitus aged 50-74 years who used outpatient services during this period. Patients initiating medical and pharmacy claims related to diabetes mellitus were defined as having diabetes mellitus. Number of teeth was defined as number of teeth in conjunction with periodontitis due to the nature of the data source. Descriptive statistics were used to investigate the association between number of teeth and public health expenditure. Data on a total of 1,017,758 patients with diabetes mellitus were analyzed. Patients with the fewest teeth incurred higher medical expenses. The largest mean difference in medical expenditure was observed between patients with 5-9 teeth and those with over 28 teeth. The results of this study suggest that public health expenditure on patients with diabetes mellitus differs based on number of teeth.

Many cases of immunoglobulin G4-related disease (IgG4-RD) involve swelling of the salivary glands, often affecting the parotid and submandibular glands in the head and neck region, in addition to the lacrimal glands. Cases of IgG4-RD characterized by swelling of the palatal glands, however, are extremely rare. Here, we describe a case of IgG4-RD involving bilateral swelling of the palatal glands. An 83-year-old man presented at our hospital with bilateral swelling of the lacrimal and submandibular glands. A solid bilateral swelling of normal colour and unclear boundaries was observed in the hard palate. The lesion was diagnosed as IgG4-RD and steroid therapy initiated. A subsequent decrease in swelling of the palatal, lacrimal, and submandibular glands was confirmed by magnetic resonance imaging. These results indicate that dentists should suspect IgG4-RD in patients presenting with bilateral swelling of the palatal glands.

A range of experimental designs have been used in destructive testing of composite resin CAD/CAM crowns. Various materials have been adopted for the abutment in such tests, including human or bovine dentin, stainless steel, PMMA, and composite resin, the selection of which is made in accordance with study objective or preference of the researcher. The purpose of this study was to determine how the material selected for the abutment material affected fracture load and maximum displacement. Destructive tests were conducted on composite resin crowns of the same design. Three types of material were used for the abutments together with 2 types of adhesive material. Images of each sample were acquired before destruction using a microfocus X-ray CT scanner to confirm the feasibility of a non-destructive test.The load required to fracture the composite CAD/CAM resin crowns depended on the abutment material used, with a decrease being observed in the order of composite resin, stainless steel, and PMMA. Maximum displacement decreased in the order of PMMA, composite resin, and stainless steel. Differences in the material used for setting (adhesive resin or polycarboxylate cement) showed no effect on fracture load. These results indicate that the load required to achieve destruction of resin CAD/CAM crowns varies according to the abutment material used.

Candida albicans is the primary candidiasis-causing fungal pathogen in humans, and one of its most important virulence factors is the ability to form biofilms. Moreover, these biofilms are often resistant to antifungal agents, so there is a need to develop alternative elimination strategies and therapeutic agents for such infections. The antifungal activity of resveratrol, a phytoalexin polyphenolic compound, impairs the morphological transition of C. albicans under various hypha-inducing conditions and inhibits growth of the yeast-form and mycelia. The purpose of this study was to investigate the effect of resveratrol against C. albicans biofilm formation. The developmental, sustained, and mature stages of biofilm formation were affected or inhibited by resveratrol. Exposure to resveratrol at the developmental stage inhibited growth of C. albicans in a dose-dependent manner. A >30% reduction was observed in sustained biofilm growth in the presence of 200 μg/ml resveratrol in comparison with in its absence. In terms of disruption of matured biofilm, 6.25-100 μg/ml resveratrol significantly reduced cell viability of C. albicans compared with in a control sample (p<0.05). The present results indicate that resveratrol has the potential to serve as an anti-Candida treatment and preventive tool which functions by inhibiting existing or under-forming C. albicans biofilms.

An ameloblastic fibroma (AF) is a proliferative mixed tumor which includes components of both odontogenic epithelium and mesenchymal tissue. It is a relatively rare neoplasm, accounting for approximately only 1.5－4.5% of odontogenic tumors. This case report describes an AF that occurred in the mandibular anterior tooth region in a 9-year-old girl who presented with the chief complaint of swelling in the left mandibular anterior tooth region. Intraoral examination revealed a swelling along the labial gingiva, extending from the left mandibular lateral incisor region to the left mandibular canine. Upon palpation, the swelling appeared to comprise a hard tissue. Computed tomography revealed a supernumerary impacted tooth; soft tissue density in the bone surrounding the region extending from the left mandibular lateral incisor to the left mandibular canine; labial bone expansion; and thinning of the labial cortical bone. A biopsy was performed under local anesthesia and the lesion subsequently diagnosed as an AF. Tumor resection and extraction of the supernumerary impacted tooth were carried out under general anesthesia. At 2 years postoperatively the prognosis is good. Although relapse with an AF is rarer than that with an ameloblastoma, strict follow-up is required, as malignant transformation to an ameloblastic fibrosarcoma has been reported in relapsed cases.