Bulletin of Tokyo Dental College最新文献

Various pieces of information, including the age of the patient, the site involved, symptoms, intraoral findings, and X-ray findings are necessary in making a clinical diagnosis. This report describes a case in which the initial diagnosis was eruption sequestrum based on clinical information but which was later found to be a complex odontoma based on histopathological findings. The patient was an 8-year-old girl who presented at our hospital with the chief complaint of pain in the right mandibular molar region. The distal aspect of the right mandibular first molar, which had partially erupted, was covered with gingiva and hard tissue which were separated from the tooth itself. X-ray findings showing radiopaque hard tissue at this site indicated a clinical diagnosis of eruption sequestrum. After local infiltration anesthesia, the hard tissue was extracted and a gingivectomy performed. Histopathological examination of the excised material, however, indicated a diagnosis of complex odontoma.

This report describes a case of generalized aggressive periodontitis requiring periodontal treatment including regenerative therapy. The patient was a 34-year-old woman who visited the Tokyo Dental College Suidobashi Hospital with the chief complaint of pain in tooth #14. An initial examination revealed that 35.8% of sites had a probing depth of ≥4 mm, while 19.1% showed bleeding on probing. Radiographic examination revealed angular bone resorption in #14, 33, 36, and 46, with horizontal resorption in other areas. Based on a clinical diagnosis of Stage III Grade C periodontitis, initial periodontal therapy consisting of plaque control, and scaling and root planing was performed. After reevaluation, periodontal regenerative therapy using recombinant human fibroblast growth factor-2 (rhFGF-2) in combination with carbonate apatite (CO₃Ap) granules was performed for #14 and 33, while regenerative therapy using rhFGF-2 alone was performed for #46. Following reevaluation, the patient was placed on supportive periodontal therapy (SPT). During SPT, CAD/CAM crowns were placed on #26 and 46. Periodontal regenerative therapy using rhFGF-2 with CO₃Ap granules yielded a resolution of angular bone defects in #14 and 33. This improvement has been adequately maintained over a 30-month period.

The epithelial cell rests of Malassez (ERM) are located within the periodontal ligament. They are reportedly involved in maintaining homeostasis, particularly with regards to the thickness of the periodontal ligament. Their role in apical periodontitis lesions remains unclear, however. This study investigated the response of ERM to infection with Porphyromonas gingivalis. After being infected, the morphology of the P. gingivalis-infected cells was observed using confocal laser-scanning microscopy. The gene expression of P. gingivalis-infected and uninfected cells was investigated by RNA-sequencing analysis. Morphological observation showed the invasion and adhesion of P. gingivalis to the surface of ERM. The RNA analysis showed that the gene expression profile significantly differed between the infected and uninfected cells. At an expression level of ≥2 and false discovery rate of <0.1, the infected cells showed a decrease in 99 genes and an increase in 6 compared with in the non-infected cells. Most of the upregulated genes were unique to epithelial cells, such as endothelial cell-specific molecules and cytokeratin 5; the upregulated genes were associated with the immune response, however. These results indicate that ERM upregulate genes associated with epithelial cells and suppress those associated with the immune response following P. gingivalis infection.

The aim of this study was to analyze orthodontic data to investigate occlusal conditions, the relationship between malocclusion and the number of congenitally missing teeth, and occlusal support of maxillomandibular teeth in patients with oligodontia. The study included 66 patients with permanent dentition from two orthodontic clinics belonging to Tokyo Dental College who had received a diagnosis of oligodontia between 2003 and 2014. The materials used for the analysis comprised intraoral photographs, panoramic radiographs, and lateral cephalometric radiographs. The antero-posterior occlusal relationships, assessed by overjet, showed a high prevalence of anterior crossbite, while the vertical occlusal relationships, evaluated by overbite, indicated a predominance of deep bite. There were no significant differences in the total number of missing teeth in the three groups divided according to degree of overjet. The same tendency was observed in the case of overbite. The number of missing teeth in the maxilla was significantly higher than that in the mandible. The high occurrence of anterior crossbite in oligodontia is believed to be related to skeletal factors, such as deficiency of the maxillary apical base and a greater number of missing teeth in the maxilla compared to in the mandible. Based on their Eichner Index scores, 98.5% of cases were classified as Class B. Among these, B2 was the most prevalent (60.6%), suggesting that patients with oligodontia have low occlusal support. The average number of Occlusal Units (OUs) was 6.4 out of 12. Nearly half of the second deciduous molars were retained in both the maxilla and the mandible. When deciduous molars were treated as premolars, there was a significant increase in number of OUs. No significant differences were observed in the actual occlusal support score, however. Therefore, oligodontia with many defects in the premolar region resulted in a low level of occlusal support, and although the survival rate of the deciduous molars was high, they were not useful in providing occlusal support.

Treponema denticola is frequently isolated together with Porphyromonas gingivalis from the lesions seen in cases of chronic periodontitis and is considered a major pathogen of this disease. It has several virulence factors, including a major surface protein (Msp) and a major surface protease, dentilisin. The effect of these virulence factors on the host immune response remains to be elucidated, however. Toll-like receptors (TLRs) in the host can recognize pathogen-associated molecular patterns. Bacteria stimulate TLRs and activate the pro-inflammatory nuclear factor-kappa B pathway. Therefore, the aim of this study was to investigate the effect of T. denticola on TLR pathways. Toll-like receptor 4 and TLR2 reporter cell lines, which secrete alkaline phosphatase in response to TLR signals, were infected with the T. denticola wild type, an Msp-deficient mutant, a dentilisin-deficient mutant, or their extracts obtained via sonication. Signals from TLR2 or TLR4 cells were evaluated by alkaline phosphatase activity. Toll-like receptor 2 signals were detected in all T. denticola strains and sonication extracts, while no TLR4 signal was detected. Infection with the dentilisin-deficient mutant induced the strongest TLR2 signal among the strains. Sonication extracts of the wild type and Msp-deficient mutant showed the same level of TLR2 signaling. The TLR2 signal in the sonication extracts from the wild type was inhibited by Sparstolonin B, an antagonist of TLR2, in a dose-dependent manner. These results indicate that T. denticola is recognized by epithelial cells mainly via TLR2. The outer sheath structure may conceal potential ligands for TLR2.

A condylar head fracture in the mandible is often misdiagnosed as a contusion of the temporomandibular joint (TMJ). Moreover, they are often overlooked by general practitioners as the fragments are small, making them difficult to identify. This report describes 2 cases of old mandibular condylar head fractures: one involving an 84-year-old woman referred to our dental office with suspected medication-related osteonecrosis of the jaw; and another involving a 23-year-old man who visited with the chief complaint of slight pain in the left TMJ. An old condylar head fracture with dislocation or displacement was coincidentally found on panoramic radiographs obtained during dental treatment in both cases. No disturbances in mouth opening or masticatory forces were observed in either case. Analysis of injury status and imaging with X-rays and computed tomography revealed that the relationship between the dislocated/displaced condylar head and the mandibular fossa changed as the bone structure and muscle positions stabilized.

Rather than focusing solely on cost-effectiveness and accessibility, it is also important to assess the quality of treatments available under Japan's Public Health Insurance System (PHIS). The purpose of this retrospective study was to assess the survival rate of metal crowns used to replace first molars in a clinical setting. Only metal crowns made of 12% gold-silver-palladium alloy placed on first molars and available under the PHIS were included. The endpoint was removal/separation of a crown or extraction of the tooth. A total of 603 crowns fitted at 20 dental offices were investigated. During the observation period, 133 of these crowns showed failure. The crown survival rate was 92.5% at 5 years, 80.8% at 10 years, 70.5% at 15 years, and 54.0% at 20 years as estimated using the Kaplan-Meier method. The estimated mean survival period was 20.6 years. The analysis revealed 3 risk factors: male (hazard ratio [HR]: 1.51), low gonial angle (HR: 1.74), and deep pockets around the abutment teeth (HR: 1.53). The main reasons for crown failure were extraction of an abutment tooth (22.6%), separation from an abutment tooth (21.8%), root fracture (18.8%), and caries (15.8%). The results showed that metal crowns available under the PHIS at dental offices have a long survival period, and that plaque control and measures to prevent separation from the abutment teeth are important for their longterm survival.

A 38-year-old woman with a history of systemic lupus erythematosus presented at our university hospital with fever, fatigue, and oral pain and was urgently admitted based on a diagnosis of septic shock. Initially, dental infection was suspected based on the symptoms and clinical presentation of purpura accompanied by severe tenderness along the marginal gingiva in the maxilla and mandible. However, subsequent investigations, including an oral examination, radiographic studies, and blood cultures, ruled out dental infection as the cause of the septic shock. The patient received antibiotic therapy and was discharged on Day 16 after admission, with no definitive source of the infection yet being identified. The gingiva around where the purpura was observed on Day 1 gradually necrosed and detached, leading to ulcer formation by Day 8 and gingival recession by Day 15. Gingival necrosis was attributed to septic shock-induced neutropenia and circulatory disturbances, indicating the severity of the systemic conditions. Follow-up after discharge revealed no recurrence. This case underscores the importance of recognising oral symptoms as potential precursors to severe systemic conditions such as septic shock. Timely intervention and interdisciplinary collaboration are essential in effectively managing such cases. Further research is warranted to elucidate the relationship between oral health and systemic diseases to enable clinicians to provide optimal patient care.

Sialolithiasis is a common disease of the salivary glands. This report describes a rare case of a submandibular gland sialolithiasis that grew over an extended period. The patient was a 72-year-old woman who presented with a mass in the right submandibular gland that had remained untreated for approximately 34 years. She had noticed the mass from the beginning, but had ignored it as it had caused no pain. She was eventually referred to our hospital, however, because panoramic X-ray images taken at another facility showed that it had grown over the previous 10 years. Extraoral findings at our clinic revealed a hen egg-sized, elastic, hard mass in the right submandibular region, strongly suggesting intraglandular sialolithiasis of the right submandibular gland. Extraction of the right submandibular gland was performed under general anesthesia. The size of the sialolith inside the submandibular gland was 42×22×15 mm, with a visually rough and yellowish-white surface. Histopathological findings showed a lamellar structure with basophilically stained bacteria in the hard material at the core, a finding typical of sialoliths. Therefore, the diagnosis was intraglandular sialolithiasis of the right submandibular gland. This report describes a case of a rare giant sialolith located within the right submandibular gland.

Rheumatoid arthritis (RA) is characterized by chronic inflammation in the synovial membrane, leading to matrix destruction of cartilage and bone. While various types of immune cell are found in inflamed synovium in RA, macrophages and osteoclasts also play important roles in joint destruction. Peripheral blood monocytes migrate to synovial tissue and differentiate into macrophages and osteoclasts in RA. Synovial macrophages are classified into two subsets: M1 (proinflammatory macrophages) or M2 (anti-proinflammatory macrophages). Human circulating monocytes have also been divided into three subsets according expression level of CD14 and CD16: CD14⁺CD16^- (classical); CD14^brightCD16⁺ (intermediate); or CD14^dimCD16⁺ (non-classical). Many recent studies have investigated the involvement of each subset of synovial macrophages and circulating monocytes in the pathophysiology of RA. On the other hand, several distinct human cell populations originating in circulating monocytes have the capacity to differentiate into non-phagocytic cells, including endothelial cells and adipocytes. This review summarizes the role of circulating monocytes in the pathophysiology of RA as precursor cells of not only phagocytes, such as macrophages and osteoclasts, but also non-phagocytes, such as endothelial cells and adipocytes. Furthermore, there is a growing body of evidence showing a significantly positive association between periodontopathic bacterial infection and the pathophysiology of RA. Therefore, the role of periodontopathic bacteria in the development of RA is also discussed.