Schwannoma is a relatively rare, benign peripheral nerve sheath tumor that affects the oro-maxillofacial region. The peripheral nerve tissues are known to be closely related to vascular tissues from viewpoints of morphology and physiology. Therefore, the authors speculate that schwannoma of peripheral nerve origin is also associated with vascular tissues ; however, the histogenesis with regard to vasculature is not fully understood. The authors investigated the localization of the blood and lymphatic vessels in schwannoma using histopathological and immunohistochemical methodologies. The tumor parenchyma consisted of a proliferation of relatively long spindle cells with nuclear palisading (Antoni A type), diffuse spreading with myxoid or edematous background (Antoni B type), and encapsulation with fibrous tissue (capsular tissue). In one case, the tumor exhibited multicystic growth. Dilation and hyperplasia of the vessels were observed in the Antoni A and B zones, the border of the Antoni A and B zones (border zone), and capsular tissue. With periodic acid-Schiff reaction-alcian blue pH2.5 staining, the myxoid matrix in the Antoni B zone was stained blue. Immunohistochemically, CD-34-positive blood vessels were found in all cases. The vessels were predominantly observed in the Antoni B zone, and only moderately in the Antoni A zone, border zone, and capsular tissue. Four cases showed that D2-40-positive lymphatic vessels were mainly observed in the Antoni B zone and capsular tissue, and only moderately in the Antoni A zone. In the other four cases, D2-40-positive lymphatic vessels were only indicated in the capsular tissue. In addition, positive immunoreactivity for D2-40 was found in the cyst-lining cells in the multicystic case. Microvessel density (MVD, numbers of blood vessels per unit area) was calculated for CD-34-positive blood vessels. MVD was 3.4±2.1 in the Antoni A zone, 6.0±1.7 in the border zone, 9.4±3.2 in the Antoni B zone, and 2.7±1.0 in the capsular tissue. In addition, lymphatic vessel density (LVD, numbers of lymphatic vessels per unit area) was calculated for D2-40-positive vessels. LVD was 0.2±0.5 in the Antoni A zone, 2.7±3.5 in the Antoni B zone, and 2.4±0.9 in the capsular tissue. These results suggest that the localization of the blood and lymphatic vessels was closely associated with the histogenesis of the Antoni B zone in schwannoma, not only by the degeneration and over-expression of the myxoid matrix but also by the edematous change from circulation disturbance in the tumor tissues during benign tumor growth and development.

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The nucleotide sequence of the glucosyltransferase (GTF) gene, which encodes a GTF enzyme that synthesizes a water-insoluble glucan (WIG), was determined in Streptococcus ratti FA-1 (GTC 00245^T). The gtf of S. ratti consisted of 4,350-bp that encoded for a 1,449 amino acid protein with a molecular weight of approximately 159.9 kDa and was revealed to be a gtfL type gene, which were first found in Streptococcus salivarius ATCC 25975. The deduced 35 amino acid sequence of the N-terminal was thought to be a signal peptide required for the secretion of GTF-L in S. ratti as it showed high similarity to a known GTF-L from S. salivarius. In addition, three major functional domains of GTF : an N-terminal variable region, a conserved catalytic site for sucrase activity, and C-terminal YG repeating units for glucan binding were also found in GTF-L from S. ratti. The percentage homology of the GTF-L amino acid sequences from S. ratti and S. salivarius was 99.7%. Although GTF-L were classified into the WIG-synthesizing GTF group, phylogenetic analysis suggested that GTF-L were positioned outside of the WIG-synthesizing GTF group of mutans streptococci.

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Objectives : Joint effusion in temporomandibular disorders is a pathological accumulation of synovial fluid caused by inflammatory conditions. The purpose of this study was to examine the relationship between cervical lymphadenopathy and the occurrence of joint effusion in patients with temporomandibular disorders. Methods : The study subjects were 133 patients with temporomandibular disorders who underwent MR imaging. MR imaging techniques used included oblique sagittal proton density and T2-weighted imaging and axial short TI inversion recovery (STIR) imaging. Joint effusion was classified by grading system on T2-weighted oblique sagittal images. On STIR axial images, the number of cervical lymph nodes and their short-axis diameter were observed on a workstation, and they were categorized into “without fluid” and “with fluid” groups on the basis of the presence or absence of joint effusion. Results : The results suggested a correlation between joint effusion and the mean number and size of spinal accessory nodes and Rouvière's lymph nodes, particularly among patients over 31 years. Conclusion : These findings suggest that the occurrence of joint effusion in patients with temporomandibular disorders increases the incidence of spinal accessory nodes and Rouvière's lymph nodes.

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Maltose-binding protein (MBP) produced by Escherichia coli acts as an adjuvant when fused to various antigens. In this study, the antigenic region of hemagglutinin A of Porphyromonas gingivalis with a molecular mass of 25 kDa (25k-hagA) was fused to MBP (25k-hagA-MBP) and the efficacy of the resulting fusion protein as a nasal vaccine was assessed. While nasal immunization with 25k-hagA induced no antibody responses, 25k-hagA-MBP elicited high serum IgG, IgA, and secretory IgA anti-25k-hagA antibodies in the saliva. When 25k-hagA-MBP was co-administered with an established mucosal adjuvant, cholera toxin, 25k-hagA-specific serum IgG and salivary IgA antibody responses were not further elevated. Interestingly, 25k-hagA mixed with MBP failed to induce 25k-hagA-specific antibody responses. These findings suggest that MBP must be fused to the target antigen for induction of antigen-specific antibody responses and that nasal administration of 25k-hagA-MBP may be an effective mucosal vaccine for the prevention of P. gingivalis infection.

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Beta-tricalcium phosphate (β-TCP) has been used for bone regeneration with satisfactory clinical results in accelerating bone formation. However, little is known about the molecular mechanisms enhancing the bone formation by β-TCP. To understand this mechanism, β-TCP was implanted into bone defects of the mandible in beagles and gene expression profiles were examined using DNA microarray technology. β-TCP altered many gene expressions ; among those genes, a significantly higher mRNA level of platelet-derived growth factor receptor beta (PDGFRB) was observed. The enhanced PDGFRB gene expression level was successfully confirmed by reverse transcription-polymerase chain reaction and real-time polymerase chain reaction. Immunohistochemical study using antibody against PDGFRB also demonstrated that PDGFRB protein expression was enhanced by β-TCP. Because PDGFRB is a potent regulator of mesenchymal cell function of wound healing and osteogenic differentiation, the enhancement of the PDGFRB gene expression by β-TCP may be an important mechanism in accelerating bone formation.

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It has been suggested that the dental characteristics of Papua New Guinea (PNG) Highlanders are unique. For example, the frequency of shovel shaped incisor is relatively low, but that of tubercle-shaped incisors is high. Also their dental arches are shorter and broader compared with other Pacific populations. They are considered to be closely related to Aboriginal Australians on the basis of genetic and archaeological studies. However, their dental characters are distinctively different to those of Australians. The purpose of this study is to describe the frequencies of these dental characters and to compare them with other Asian and Pacific peoples. Materials were dental impressions of 111 young adults from Kasi village, Wabag, Enga Province, PNG. Characters used in this study comprised 17 dental traits that were recorded using Arizona State University Dental Anthropology System. Conspicuous characters in PNG include : low frequency of shoveling and double-shoveling of maxillary incisors ; Cusp 6 in mandibular first molar ; Carabelli's trait ; high frequencies of hypocone reduction in maxillary second molars ; Cusp 5 in maxillary first molars ; protostylid in mandibular first molars ; and 4-cusped mandibular second molars. It is suggested that this unique set of dental characters in PNG was acquired by morphological reduction from the original Australian type of dental characters and by admixture with south Asian and Pacific peoples. The principal coordinate plot for these 17 sets of scores, based on Smith's MMDs and standard deviations, showed that the PNG Highlanders belong to the Sundadont group and were located in an extreme position on the right of the first axis and in relatively lower position in the second axis.

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It is well established that CD4⁺ T cells are major contributors to the induction and regulation of antigen-specific antibody responses in both mucosal and systemic compartments. However, our previous studies have demonstrated that oral immunization of CD4^-/- mice with soluble protein plus cholera toxin as adjuvant elicited antigen-specific IgA antibody responses in the gastrointestinal tract. In this study, we investigated whether oral delivery of live bacteria could elicit mucosal immunity in CD4^-/- mice. Oral immunization with recombinant Salmonella expressing fragment C of tetanus toxin resulted in serum IgG and IgA anti-tetanus toxoid antibody responses. Furthermore, CD4^-/- mice are capable of eliciting secretory IgA antibodies in the intestinal tract. Antibody-forming cell analysis confirmed the antibody titers by revealing significant numbers of tetanus toxoid-specific IgG- and IgA-forming cells in the spleen and IgA-forming cells in intestinal lamina propria. In addition, significant delayed-type hypersensitivity responses were detected in CD4^-/- mice given rSalmonella-Tox C. These results suggest that antigen-specific mucosal as well as systemic antibody responses can be induced in the absence of CD4⁺ T cells after oral immunization with Salmonella.

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Cellular and molecular mechanisms of the immune system influencing oral bone metabolism remain to be elucidated. In this study, we characterize the mucosal cytokine production by CD4⁺ T cells in the inflamed gingiva of mice infected with Porphyromonas gingivalis (P. gingivalis). A murine periodontal disease model with alveolar bone loss showed significant levels of FimA-specific salivary secretory IgA and plasma IgG Ab responses. Further, IL-6 and TNF-α production was elevated when compared with sham-infected mice. The frequencies of Th1 (IFN-γ), Th2 (IL-4) and Th17 (IL-17) producing CD4⁺ T cells were also increased in P. gingivalis infected mice. Among these cytokines, a significantly higher frequency of IFN-γ producing CD4⁺ T cells was noted. The kinetics of intracellular cytokine analyses revealed a significantly increased frequency of IFN-γ-, IL-4- and IL-17-producing CD4⁺ T cells one day after infection. Further, the frequency of IFN-γ producing CD4⁺ T cells was maintained throughout the experimental period. Although IL-4 and IL-17 production was intact until 15 days after the infection, the numbers of CD4⁺ T cells producing these cytokines were reduced thereafter. These results indicate that Th1-type CD4⁺ T cells play distinct roles in the induction and regulation of periodontal disease when compared with Th2- and Th17-type cytokine-producing CD4⁺ T cells.

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Candida dubliniensis was first isolated from the oral cavity of AIDS patients as an emerging pathogen. As C. dubliniensis is very closely related to Candida albicans, it is difficult to separate these species from individual clinical samples. Differences in the expression of putative virulence factors and in antifungal susceptibility among different Candida species have raised the need for species-level identification. A novel selective medium for distinguishing C. dubliniensis from C. albicans was developed on the basis of susceptibility to micafungin. The minimum inhibitory concentrations of micafungin were more than 16 μg/ml for C. dubliniensis and less than 0.015 μg/ml for C. albicans. C. dubliniensis grew well, and the average growth recovery of the strains on the selective medium was 66.0% (23.9-97.7%). However, C. albicans did not grow on the medium. Even when C. dubliniensis was treated with saliva, no effects were observed on the growth recovery on the medium. In clinical samples from oral cavity, C. dubliniensis was detected from 3 of 13 denture-wearing subjects using the selective medium. When C. dubliniensis was detected in these 3 subjects, C. albicans always coexisted in the samples. In this study, new selective medium was suggested to be useful for the isolation of C. dubliniensis from oral cavity in clinical samples.

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Our previous study showed that nasal immunization with glucosyltransferase-I (GTF-I) produced by Streptococcus sobrinus elicits serum IgG, serum IgA, and salivary IgA antibody responses that provide protection against dental caries caused by S. sobrinus infection. In this study, to develop an effective vaccine for the prevention of dental caries, we assessed T helper (Th) cell responses in systemic and mucosal compartments when GTF-I was administered nasally. When CD4⁺ T cells isolated from the spleen or cervical lymph nodes of mice immunized with GTF-I alone or GTF-I plus unmethylated cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODN) were re-stimulated with GTF-I in vitro, significant levels of proliferative responses were induced. Analysis of Th1 (IFN-γ) and Th2 (IL-4) cytokine responses showed that GTF-I-specific Th cells from mice given GTF-I alone produced a significant level of IL-4 with low IFN-γ. On the other hand, CD4⁺ T cells from mice given GTF-I plus CpG ODN produced increased levels of IFN-γ when compared with those of mice given GTF-I alone, whereas the IL-4 production was not changed. The IgG subclass responses confirmed the cytokine profile, showing that while nasal GTF-I elicited mainly IgG1 antibodies, GTF-I plus CpG ODN further enhanced IgG2a and IgG2b, but not IgG1, antibody responses. These results suggest that nasal immunization with GTF-I elicits GTF-I-specific Th2 cytokine responses in both mucosal and systemic lymphoid tissues and that CpG ODN as an adjuvant enhances Th1-type cytokine responses to co-administered GTF-I.

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In this study, to clarify the effects on dental caries susceptibility of mouse chromosome 2 in vivo, we used chromosome 2 substitution mice (termed consomic mice), B6-Chr2^C3H. The consomic mice used in this study were based on high dental caries susceptibility strain C57BL/6CrSlc (B6), and only chromosome 2 from the low dental caries susceptibility strain C3H/HeSlc (C3H) was substituted. We induced dental caries in three inbred mice strains : B6, C3H and B6-Chr2^C3H. All mice were weaned at 21 days, were fed on Diet#2000, and were infected with Streptococcus mutans JC-2 to induce dental caries. The mandible bones were extracted at 49 days and observed by microscope and Micro-focus X-ray computed tomography images. The caries status was evaluated by calculating the dental caries score using the modified Keyes method. Mean dental caries scores of B6-Chr2^C3H, B6 and C3H were 8.1±3.4 (mean±S.D.), 46.5±1.3 and 2.2±1.0, respectively. Statistical analysis revealed that the dental caries score of B6-Chr2^C3H was significantly low compared with the score of B6 and there was no difference in dental caries score between C3H and B6-Chr2^C3H. The first fissures of the first molar in B6 and B6-Chr2^C3H were similar having a slight fossa at center area and which were differ from that of C3H. However, there was no significant difference in dental caries score at the fissure among B6-Chr2^C3H, B6 and C3H. And, the amount of saliva of B6-Chr2^C3H was significantly low than C3H, and significantly high than B6. These results suggested that the major genetic factor responsible for dental caries susceptibility is located on mouse chromosome 2.

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Capillary hemangioma, pyogenic granuloma and cavernous hemangioma, benign vascular lesions affect in the oral regions. There have been some studies of them, but their pathological status is still controversial. The aim of the present study was to reveal the characteristic histopathological and immunohistochemical features such as cell proliferation activity, vascular proliferation factors and mesenchymal marker of these lesions in order to understand the pathological status of them. In histopathological findings of the present study, capillary hemangioma consisted of proliferating capillaries having endothelial cells and ovoid or spindle cells and associated with mast cells and lobular structures circumscribed with PAS-positive matrices. Pyogenic granuloma exhibited proliferation of the capillaries having endothelial cells and a few perivascular mesenchymal ovoid or spindle cells beneath erosive and ulcerative lesions and inflammatory changes. Cavernous hemangioma was composed of remarkably dilated and hyperplasic blood vessels. Immunohistochemically, Ki-67 labeling index of capillary hemangioma and pyogenic granuloma was higher than that of cavernous hemangioma. Positive immunoreactivity for CD34, CD105 and Tie2 was observed in some perivascular ovoid cells supported to be endothelial precursor cells. Capillary hemangioma exhibited that positive immunoreactivity for VEGF was found in the perivascular cells, mast cells and/or macrophage, whereas pyogenic granuloma showed that the positive reactivity was also seen mainly in the endothelial cells. Positive immunoreactivity for α-smooth muscle actin was identical to perivascular spindle cells, and was supposed to be pericytes. Conclusively, the present study indicated that capillary hemangioma and pyogenic granuloma showed different histopathology and immune-profiles of vascular proliferation factors, suggesting they would have different pathological status.

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Temporomandibular joint (TMJ) ankylosis or hypomobility involves fusion of the mandibular condyle to the base of the skull. It is most frequently caused by trauma, presents with restriction in mouth opening in early stages and, in children, it may result in facial growth retardation. Various methods are available for surgical correction, such as autogenous grafts, gap arthroplasty, and prosthetic reconstruction. However, such techniques present several disadvantages and may lead to relapse, decrease in the vertical height of the posterior mandible and, in the case of prosthetic reconstruction, be contraindicated for the treatment of pediatric patients. The aim of this paper is to present a case of bilateral TMJ ankylosis in a 9-year-old patient treated by the technique of vertical sliding osteotomy, a simple surgical procedure indicated for the treatment of TMJ ankylosis in children, with the results after a 3-year follow-up.

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Erratum to : revised the error of the title.
Title : Transcutaneous Ultrasonographic Assessment of Submucosal Fibrosis in Oral Submucous Fibrosis : A Preliminary Study

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