The purpose of this study was to determine the distribution of healthy elderly individuals undergoing regular dental check-ups and identify any environmental or associated oral factors. A cross-sectional questionnaire survey was used to interview 216 individuals attending 2 welfare facilities for the elderly, of whom 160 were included in the final analysis. Items comprised age, sex, number of residual teeth, frequency of teeth/denture cleaning, subjective chewing ability, denture use, oral status, regular dental check-ups, visitation of the same dentist, number of dental visits in the past year, General Oral Health Assessment Index (GOHAI) (Japanese version) score, living situation, and use of routine medication. Individuals undergoing regular dental check-ups were defined as those with a primary dentist whom they saw for dental check-ups at least once a year. The rate of individuals undergoing regular dental check-ups was 75.0% in men aged 60–74 years, 58.8% in women aged 60–74 years, 70.0% in men aged 75 years or over, and 45.3% in women aged 75 years or over. Logistic regression analysis revealed a higher number of residual teeth (odds ratio [OR]=2.664 in comparison with those with fewer than 20 teeth, p=0.0427); cleaning teeth/dentures 3 or more times per day (OR=2.546 in comparison with cleaning them twice per day or less, p=0.0157); and a higher GOHAI score (OR=2.742 in comparison with those with a GOHAI score of less than 58, p=0.0263) as factors significantly correlated with undergoing regular dental check-ups. In conclusion, the results revealed that individuals undergoing regular dental check-ups had 20 or more residual teeth, cleaned their teeth/denture 3 or more times per day, and had a higher GOHAI score. This indicates that the best predictive factor for undergoing regular dental check-ups in healthy elderly individuals is their GOHAI score.
The purpose of the present study was to investigate the relevance of the external morphology of the mandibular ramus, internal bone tissue structure, and maxillofacial morphology at the site for sagittal split ramus osteotomy among different facial skeletal patterns. A total of 80 patients with jaw deformities who underwent sagittal split ramus osteotomy were included in the study. The patients were divided into two groups based on facial skeletal type (skeletal Class II or skeletal Class III). A further 7 patients with no skeletal abnormalities were established as the control group (skeletal Class I). Computed tomography images obtained from these patients were 3-dimensionally reconstructed and the morphology of the mandibular ramus determined. Thickness at the mandibular foramen in Class II was greater than that in Class III, and showed the lowest value at the midpoint of the mandibular foramen and mandibular notch in Class I. Mandibular morphology showed change according to facial skeletal type. Correlations were also observed between the cephalometric analysis values and mandibular morphology.
Interleukin-34 (IL-34), an alternative ligand for macrophage colony-stimulating factor receptor, plays an important role in osteoclastogenesis. The aim of this study was to analyze the effect of smoking on IL-34 levels in gingival crevicular fluid (GCF) and plasma in individuals with healthy periodontium and chronic generalized periodontitis (CP). A total of 60 individuals ranging in age from 25 to 55 years were enrolled in the study. The participants were divided into 4 groups: Group A, 30 samples (15 GCF and 15 plasma) obtained from 15 non-smokers with healthy periodontium; Group B, 30 samples (15 GCF and 15 plasma) from 15 smokers with healthy periodontium; Group C, 30 samples (15 GCF and 15 plasma) from 15 non-smokers with CP; and Group D, 30 samples (15 GCF and 15 plasma) from 15 smokers with CP. The Gingival Index and probing depth scores, together with the Clinical Attachment Level, were assessed in each group as clinical periodontal parameters. Levels of IL-34 in GCF and plasma were quantified using enzyme linked immunosorbent assay. The results showed that the mean IL-34 concentrations in GCF and plasma were highest in Group D, followed by Group C, Group B, and Group A, and the difference among them was statistically significant (p<0.05). The relatively elevated IL-34 levels observed here in smokers with CP suggest that this cytokine offers a potential inflammatory marker of periodontal disease in smokers.
The deterioration in masticatory function often seen in older adults rules out the consumption of hard foods, while a common decline in autonomic nervous response often observed in older adults may result in maladjustment to environmental stresses. The purpose of this study was to investigate whether autonomic nervous activity in older adults increased during the mastication of soft foods compared to at rest. The participants comprised 9 volunteer nursing home residents aged 78 to 100 years. All consumed soft rice as a grain dish and coarsely chopped food as side dishes. The coefficient of variation of R-R intervals (CVRR) and high-frequency (HF) power on electrocardiograph (ECG) served as indices of parasympathetic nervous activity, while the low-frequency (LF)/HF ratio served as an index of sympathetic nervous activity. Total power, reflecting the level of autonomic nervous activity, was also measured. We measured autonomic nervous activity while nursing home residents were eating lunch. HF was 3,457.4±3,037.5 ms2 at rest and 4,085.1±3,697.7 ms2 during mastication. The CVRR was 26.8±16.9% at rest and 26.1±16.1% during mastication. No significant difference was observed in HF or CVRR. On the other hand, the LF/HF ratio was 0.77±0.24 ms2 at rest and 31.0±3.77 ms2 during mastication (p=0.011). A significant difference was observed in the LF/HF ratio between the resting and masticating conditions. Total power was 6,244.1±5,752.5 ms2 at rest and 8,417.7±7,266.4 ms2 during mastication (p=0.038). A significant difference was also observed in total power between resting and masticating conditions. These results suggest that mastication of soft foods stimulates autonomic nervous activity in older adults. In conclusion, autonomic nervous activity increased during chewing soft foods compared to that during the resting level in older adults.
Treponema denticola, an anaerobic spirochete found mainly in the oral cavity, is associated with periodontal disease and has a variety of virulence factors. Although in vitro studies have shown that T. denticola is able to penetrate epithelial cell monolayers, its effect on the epithelial barrier junction is not known. Human gingival epithelial cells are closely associated with adjacent membranes, forming barriers in the presence of tight junction proteins, including zonula occludens-1 (ZO-1), claudin-1, and occludin. Tight junction proteins are also expressed by Madin-Darby canine kidney (MDCK) cells in culture. In this study, the MDCK cell profile was investigated following infection with T. denticola (ATCC 35405) wild-type, as well as with its dentilisin-deficient mutant, K1. Basolateral exposure of MDCK cell monolayers to T. denticola at a multiplicity of infection (MOI) of 104 resulted in a decrease in transepithelial electrical resistance (TER). Transepithelial electrical resistance in MDCK cell monolayers also decreased following apical exposure to T. denticola (MOI=104), although this took longer with basolateral exposure. The effect on the TER was time-dependent and required the presence of live bacteria. Meanwhile, MDCK cell viability showed a decrease with either basolateral or apical exposure. Immunofluorescence analysis demonstrated decreases in the amounts of immunoreactive ZO-1 and claudin-1 in association with disruption of cell-cell junctions in MDCK cells exposed apically or basolaterally to T. denticola. Western blot analysis demonstrated degradation of ZO-1 and claudin-1 in culture lysates derived from T. denticola-exposed MDCK cells, suggesting a bacteria-induced protease capable of cleaving these tight junction proteins.
The aim of this study was to obtain basic data that might serve as criteria in the diagnosis of delayed eruption of the permanent teeth. The synchronicity of the eruption of corresponding contralateral teeth was determined. Data were obtained on both the deciduous and permanent dentition based on records made every 2 months at the Department of Pediatric Dentistry of Tokyo Dental College. These data were then used to investigate bilateral differences in the timing of eruption of the permanent teeth. Over 80% of incisors, first molars, mandibular canines, and maxillary first premolars erupted within 4 months of their contralateral counterparts, while this occurred in 75% of maxillary canines, mandibular first premolars, and mandibular second molars, 70% of maxillary and mandibular second premolars, and 65% of maxillary second molars. Bilateral differences in the timing of permanent tooth eruption varied depending on type of tooth, and these differences tended to be smaller for teeth erupting at an earlier point in the order of eruption, and greater for those erupting at a later point. These results suggest that the failure of a contralateral tooth to erupt within 4 months of its counterpart might serve as a criterion in a diagnosis of suspected delayed eruption of a permanent tooth.
An abnormal maxillomandibular ridge relationship frequently hinders oral implant treatment in patients with jaw deformities. Here, we describe a patient who was experiencing difficulty using dentures due to multiple maxillary tooth loss and mandibular prognathism. Treatment comprising sagittal splitting ramus osteotomy and alveolar ridge augmentation using bone grafts harvested from the mandibular ramus followed by implant treatment yielded good outcomes. The patient was a 47-year-old woman presenting with an unstable upper partial denture. Although prior prosthetic treatment for mandibular prognathism had resulted in normal overbite, she had since lost an increasing number of teeth due to advanced periodontal disease, impairing support for the denture. She was referred to the Department of Oral Implantology at the Tokyo Dental College Chiba Hospital in October 2008. Subsequent treatment comprised implant treatment following maxillary alveolar ridge augmentation and sagittal splitting ramus osteotomy to correct the maxillary-mandibular relationship. In January 2010, sagittal splitting ramus osteotomy and alveolar bone augmentation using a bone graft from the mandibular ramus were performed under general anesthesia. In July and August 2010, a total of 7 implants were placed in the maxilla and implant superstructure preparation started after 3 months. Taking both the patient's wishes and ease of maintenance into account, retrievable superstructures made of Auro Galvano Crown were fitted in April 2011. The jaw-to-jaw alveolar ridge relationship was improved by sagittal splitting ramus osteotomy, rendering subsequent treatment, from implant placement to superstructure preparation, feasible by conventional methods. The use of surplus bone generated during sagittal splitting ramus osteotomy for bone augmentation avoided the need to harvest bone from another area.
Disseminated carcinomatosis of the bone marrow (DCBM) is characterized by diffuse metastasis to bone marrow and sudden mortality. To the best of our knowledge, no studies to date have reported progression of oral squamous cell carcinoma to DCBM. Herein, we report a case of squamous cell carcinoma in the maxillary gingiva suspected of progressing to DCBM. A 64-year-old woman presented with white lesions on the left maxillary gingiva. The lesions were diagnosed as squamous cell carcinoma (T2, N0, M0), and partial maxillectomy performed. Two years and 5 months after surgery, metastasis was noted in the left cervical lymph node and left radical neck dissection carried out. The subsequent diagnosis was right cervical lymph node metastasis and multiple bone metastases. The patient also presented with thrombocytopenia, anemia, and elevated levels of alkaline phosphatase, probably due to metastatic bone disease. Although various antitumor therapies were administered, the patient died 6 months after diagnosis of multiple bone metastases.
An iliac block graft is the most commonly used biomaterial for reconstruction following resection of the mandible. Its use has some disadvantages, however, including limitations on the amount of bone that may be harvested, and the subsequent increase in burden on the iliac bone. Therefore, recently, free vascularized fibular grafts have been used as an alternative in some cases. Here, we report the advantages of, and issues related to reconstruction using free vascularized fibular grafts observed at Tokyo Dental College Chiba Hospital. Eight patients undergoing mandibular reconstruction using free vascularized fibular grafts between January 2003 and January 2017 were investigated. Of these, 6 were men, and 2 were women. Age ranged from 38 to 74 years (average, 54 years). Primary diseases comprised malignant tumor in 3 patients, benign tumor in 3, and radiation osteomyelitis of the mandible in 2. The defects were classified as follows according to the CAT system (Condylar Head, Mandibular Angle, Mental Tubercle): 3 cases of Body, 2 of AT, and 1 case each of TT, ATTA, and CATT. The resection range of the mandible was 5–16 cm (average, 10 cm). The single barrel technique was used in 7 cases, and the double barrel technique in 1. In terms of the flap survival ratio, complete engraftment was achieved in 6 out of the 8 cases. Two cases of radiation osteomyelitis of the mandible, with necrosis caused by vascular breakdown after wound infection, were observed, however. While the advantages of mandibular reconstruction by this method include comparatively safe conditions and functional recovery, there were also some problems. It was inappropriate for cases of radiation osteomyelitis of the mandible; those where anti-inflammatory therapy was ineffective; and those where greater resection of the soft tissue was required. Further study is needed to clarify the criteria for selecting this procedure.