Yutaka Maruoka

National Center for Global Health and Medicine in Japan, Edo, Tōkyō, Japan

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Publications (41)77.5 Total impact

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    ABSTRACT: Oral care is important for oral and systemic health, especially for elderly institutionalized individuals and compromised patients. However, conventional mechanical plaque control is often difficult for these patients because of the pain or the risk of aspiration. Despite that antimicrobial photodynamic therapy (aPDT), which is considered an alternative or adjunct to mechanical means, has potential application as a less stressful method of daily plaque control, no clinical application has been reported. We chose the combination of toluidine blue O (TBO), and a red light-emitting diode (LED), and investigated the associated inhibitory effect on dental plaque formation in healthy volunteers. For determining the concentration of TBO, preliminary experiments were performed in vitro to evaluate the bactericidal effect of aPDT on Streptococcus oralis, and to clarify the safety in fibroblast cells. In order to survey the mechanism of TBO-mediated aPDT, the quality and quantity of reactive oxygen species (ROS) generated during aPDT were also examined using electron spin resonance (ESR) spectroscopy. Following the in vitro experiments, the inhibitory effect of the aPDT on dental plaque formation was investigated in eleven subjects as a clinical pilot study. The right or left side mandible premolars were randomly assigned to the treatment (with aPDT) or control (without aPDT) groups. In total, aPDT was applied six times (twice per day) to the test group teeth over a period of four days. On the fourth day, the study concluded and the analyses were performed. The results indicated that the combination of 500 or 1000 mug/ml TBO and LED irradiation for 20 s significantly decreased the number of colony forming unit of Streptococcus oralis. The cytotoxicity of aPDT was comparable to that of standard antiseptics used in oral cavity. Hydroxyl radicals were detected by ESR analysis, but not singlet oxygen. The randomized controlled trial demonstrated that aPDT with 1000 mug/ml TBO and red LED irradiation significantly suppressed dental plaque formation without harmful events to teeth or surrounding tissues. aPDT has the potential to be a promising novel technical modality for dental plaque control.Trial registration: This trial was registered with University Hospital Medical Information Network Clinical Trials Registry (number UMIN000012504).
    BMC Oral Health 12/2014; 14(1):152. DOI:10.1186/1472-6831-14-152 · 1.15 Impact Factor
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    ABSTRACT: So-called Progressive Condylar Resorption (PCR) is defined as diminishing condylar head volume with changes in shape, often discussed with decreased mandibular ramus height, mandibular retrusion and clockwise rotation resulting in progressive Angle's Class II basal bone in relation with anterior open bite, resulting in malocclusion. There are various clinical issues since the etiology of this disease is largely unknown. So far, we have investigated abnormal bone metabolism with condylar resorption similar to peR in CC chemokine receptor 5 (CCR5) null mice and CCR1 null mice, sharing chemokine ligands. Although practical application of a drug for the treatment of human immunodeficiency virus (HIV) using CCR5 which functions as a co-receptor of HIV has almost been achieved, the effects of the drug on the quality of life of patients with acquired immune deficiency syndrome (AIDS) such as abnormal bone metabolism and increased risk of fracture have not been evaluated. In a study last year, our group found a relationship between the pathology of PCR and chemokines based on the finding that chemokines such as RANTES (regulated upon activation, normal T-cell expressed and secreted) that are increasingly expressed in PCR patients can be effective biomarkers. The purpose of the present study is to develop a new reasonable definition of PCR including its name through collecting and analyzing both domestic and international cases, and to propose treatment measures for each case for further discussion, including predictability.
    12/2012; 22(4):S15-22. DOI:10.5927/jjjd.22.S15
  • International Journal of Oral and Maxillofacial Surgery 10/2011; 40(10):1148-1148. DOI:10.1016/j.ijom.2011.07.413 · 1.36 Impact Factor
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    ABSTRACT: o-called Progressive Condylar Resorption (PCR) is defi ned as diminishing condylar head vol-ume with changes in condylar shape, often discussed with decreased mandibular ramus height, the mandibular retrusion and counter clockwise rotation resulting in progressive Angle’ s Class II basal bone in relation with anterior open bite. PCR patient are known to have relatively small and retruded mandible. Because of it, those patients often undergo inappropriate treatment or unnecessary orthodontic procedures under misdiagnosis with maxillary protrusion and/or mandibular retrusion. Another discussion for the cause of condylar resorption is as post orthognathic surgery complication, following excessive traumatic burden to the temporomandibular joint known as TMJ. Other complication can be progressing malocclusion pain and jaw joint pain because PCR patients have difficulties in biting properly with front teeth, thus their molar region receive excess mechanical stress in periodontal tissues. ICR, known as idiopathic condylar resorption, might be indicated similar word, however, progressive condylar resorption (PCR) has been thought a more general term describing conditions, including those of known etiology (eg, juvenile rheumatoid arthritis, lupus erythematosis, trauma, steroid use). It is thought very hard to distinguish between PCR and ICR. There is no established mechanism known to cause these conditions yet. Some say aging and underlying ongoing systemic co-morbidity, and another known discussion is host adaptive capacity of the temporomandibular joint. Others argue that condylar resorption can be initiated by traction compression from joint orthognathic surgery with excessive force load on TMJ. There also are a few reports on young onset cases that had low mandibular growth rate to start with. There can be multiple mechanisms that result in these conditions. For clinical diagnosis, many confused concepts have been mixed and used in dealing with those symptoms, thus appropriate diagnostic criteria need to be established, and its pathologenesis has to be elucidated. Whereas, being advanced chemotherapy for HIV infection remarkably, the newly developed anti-HIV drug, that is chemokine receptor antagonists, are well investigated. Among them, CCR5, CC chemokine receptor 5, is known as the co-receptor for HIV virus with CD4. In a process to elucidate the secondary eff ect of the drug, we revealed in the CCR5-deficient mice, and CCR1-deficient mice an osteopenia due to impaired functions of osteoclasts and osteoblasts. Ccr1-/- mice have fewer and thinner trabecular bones and low mineral bone density in cancellous bones. The lack of CCR1 affects the diff erentiation and function of osteoblasts. Furthermore, there are something striking about both anterior open bite and deformity of the condyle in Ccr1-/- mice and Ccr5-/- mice. That is how this study all started. So, it was for that purpose that we established the research unit for the establishment for the criteria of the progressive condylar resorption, for pathologenesis, and for the eff ective and authorized therapy. First of all, we begun to have Japanese oral surgeons fi ll in a questionnaire about PCR/ICR: age, gender, chief complaint, disease sides, clinical diagnosis, physical complications, and therapy. Our research showed the female/male prevalence rate to be approximately 10 times higher for female, indicating the similar results as previous reports from Europe/United States and that at least 1000 patients are estimated to exist in Japan. The patients classified in two groups: idiopathic cases without any systemic complications in their teens and twenties in age and cases with autoimmune diseases above age 50. There were many reports that supported the eff ectiveness of stabilizing occlusion. In order to achieve it, occlusal splint therapy and orthognathic surgery can be selected. Our surveys found each agency employed in various diff erent ways treating patients presenting these conditions in Japan. It was pretty safe to conclude there has never been treatment standard guidelines for PCR/ICR. Then, for the patients benefi t we made attempt to establish the biomarker. Biomarkers from our patients’ blood and urine tests suggested strong indication of osteoporosis. In younger patient, the marker both bone metabolism and bone resorption is relatively high; indicate increased bone turnover. While, in senior patients, value indicated decreased bone turnover. And it strongly indicates non-infl ammatory cases can be one signifi cant piece of the entire PCR/ICR picture. To our surprise, in some kinds of chemokine ligands, the value indicated apparently diff erent from standard. Thus, we found the possibility to characterize PCR/ICR. We are in progress for increasing the case not only in Japan but also in the foreign agencyin order to verify the results.
    International Journal of Oral and Maxillofacial Surgery 10/2011; 40(10):1148-1149. DOI:10.1016/j.ijom.2011.07.414 · 1.36 Impact Factor
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    ABSTRACT: Chemokines are characterized by the homing activity of leukocytes to targeted inflammation sites. Recent research indicates that chemokines play more divergent roles in various phases of pathogenesis as well as immune reactions. The chemokine receptor, CCR1, and its ligands are thought to be involved in inflammatory bone destruction, but their physiological roles in the bone metabolism in vivo have not yet been elucidated. In the present study, we investigated the roles of CCR1 in bone metabolism using CCR1-deficient mice. Ccr1(-/-) mice have fewer and thinner trabecular bones and low mineral bone density in cancellous bones. The lack of CCR1 affects the differentiation and function of osteoblasts. Runx2, Atf4, Osteopontin, and Osteonectin were significantly up-regulated in Ccr1(-/-) mice despite sustained expression of Osterix and reduced expression of Osteocalcin, suggesting a lower potential for differentiation into mature osteoblasts. In addition, mineralized nodule formation was markedly disrupted in cultured osteoblastic cells isolated from Ccr1(-/-) mice. Osteoclastogenesis induced from cultured Ccr1(-/-) bone marrow cells yielded fewer and smaller osteoclasts due to the abrogated cell-fusion. Ccr1(-/-) osteoclasts exerted no osteolytic activity concomitant with reduced expressions of Rank and its downstream targets, implying that the defective osteoclastogenesis is involved in the bone phenotype in Ccr1(-/-) mice. The co-culture of wild-type osteoclast precursors with Ccr1(-/-) osteoblasts failed to facilitate osteoclastogenesis. This finding is most likely due to a reduction in Rankl expression. These observations suggest that the axis of CCR1 and its ligands are likely to be involved in cross-talk between osteoclasts and osteoblasts by modulating the RANK-RANKL-mediated interaction.
    Journal of Biological Chemistry 09/2010; 285(37):28826-37. DOI:10.1074/jbc.M109.099424 · 4.60 Impact Factor
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    ABSTRACT: Chemokines are characterized by the homing activity of leukocytes to targeted inflammation sites. Recent research indicates that chemokines play more divergent roles in various phases of pathogenesis as well as immune reactions. The chemokine receptor, CCR1, and its ligands are thought to be involved in inflammatory bone destruction, but their physiological roles in the bone metabolism in vivo have not yet been elucidated. In the present study, we investigated the roles of CCR1 in bone metabolism using CCR1-deficient mice. Ccr1−/− mice have fewer and thinner trabecular bones and low mineral bone density in cancellous bones. The lack of CCR1 affects the differentiation and function of osteoblasts. Runx2, Atf4, Osteopontin, and Osteonectin were significantly up-regulated in Ccr1−/− mice despite sustained expression of Osterix and reduced expression of Osteocalcin, suggesting a lower potential for differentiation into mature osteoblasts. In addition, mineralized nodule formation was markedly disrupted in cultured osteoblastic cells isolated from Ccr1−/− mice. Osteoclastogenesis induced from cultured Ccr1−/− bone marrow cells yielded fewer and smaller osteoclasts due to the abrogated cell-fusion. Ccr1−/− osteoclasts exerted no osteolytic activity concomitant with reduced expressions of Rank and its downstream targets, implying that the defective osteoclastogenesis is involved in the bone phenotype in Ccr1−/− mice. The co-culture of wild-type osteoclast precursors with Ccr1−/− osteoblasts failed to facilitate osteoclastogenesis. This finding is most likely due to a reduction in Rankl expression. These observations suggest that the axis of CCR1 and its ligands are likely to be involved in cross-talk between osteoclasts and osteoblasts by modulating the RANK-RANKL-mediated interaction.
    Journal of Biological Chemistry 09/2010; 285(37):28826-28837. · 4.60 Impact Factor
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    ABSTRACT: This study was designed to evaluate the effect of recombinant human fibroblast growth factor-2 (rhFGF-2) on the amount and period of new bone formation in rabbit mandibular distraction models using beta-tricalcium phosphate (beta-TCP) as a bone graft substitute. Sixteen male Japanese White rabbits were divided into the following four experimental groups: 1, distraction alone; 2, distraction with beta-TCP granules; 3, distraction with rhFGF-2 (25 microg/50 microL) injected into beta-TCP granules; and 4, distraction with rhFGF-2 (100 microg/50 microL) injected into beta-TCP granules. The bones were harvested at 4 weeks after the operation and examined using soft radiography, micro-computed tomography (micro-CT), and peripheral quantitative computed tomography (pQCT). The dissected mandibles were stained using the Villanueva bone staining method, and the amount of new bone formed, bioresorption of beta-TCP, and new blood vessel formation were morphometrically calculated using bone histomorphometry. Radiopaque areas were observed more frequently in the distracted area of groups 3 and 4. Micro-CT analysis revealed partial new bone formation in the central region of the distracted area in groups 3 and 4. pQCT analysis revealed increased bone mineral density in groups 3 and 4. Histomorphometric analysis revealed increased newly formed bone and blood vessel areas in groups 3 and 4. In group 4, the number of osteoclasts around the beta-TCP granules had significantly increased. The present findings suggested that the combined use of rhFGF-2 and beta-TCP reduced the treatment period for distraction osteogenesis and accelerated the formation of a new high-quality bone.
    Congenital Anomalies 02/2010; 50(2):95-104. DOI:10.1111/j.1741-4520.2010.00272.x · 0.78 Impact Factor
  • Annals of the New York Academy of Sciences 06/2008; 785(1):274 - 277. DOI:10.1111/j.1749-6632.1996.tb56282.x · 4.31 Impact Factor
  • 01/2008; 54(11):616-620. DOI:10.5794/jjoms.54.616
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    ABSTRACT: Studies of changes in the surrounding soft tissue in association with distraction osteogenesis in the maxillofacial region, where various different kinds of tissue are tightly packed, are rare. In this study, we performed morphological and immunohistochemical investigations of muscle tissue during mandibular distraction osteogenesis. Japanese white rabbits were divided into 2 groups. In 1 group, the mandibular bone was distracted at a rate of 1 mm/day (DO group), whereas in the other group it was advanced by 10 mm all at once (O group). The cross-section of the anterior belly of the digastric muscle was examined using hematoxylin and eosin, periodic acid-Schiff (PAS), and proliferating cell nuclear antigen (PCNA) staining methods, as well as scanning electronmicroscopy (SEM). In the DO group, the cross-section of muscle bundle revealed no remarkable changes. In PAS staining, type II fibers gradually disappeared with distraction, but eventually reappeared after a period of consolidation. In the SEM photographs, striation-like laminated structures were evident in the control and the 3-mm distraction, ambiguous in the 6-mm distraction, and not evident in the 10-mm distraction. In contrast, the structure appeared to be restored in the consolidation for 1 week thereafter. In the PCNA immunostaining, the numbers of PCNA-positive nuclei increased during periods of distraction, but subsequently tended to decrease gradually. Although minute injuries were induced in muscle fibers in association with distraction osteogenesis, it is suggested that muscle fibers regenerate starting in the distraction period and thus can adapt to the environment.
    Journal of Oral and Maxillofacial Surgery 09/2007; 65(8):1517-25. DOI:10.1016/j.joms.2006.10.041 · 1.28 Impact Factor
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    ABSTRACT: We investigated distracted keratinized epithelium to elucidate any proliferative and degenerated changes and to estimate the stability of the gingival tissues in mandibular distraction osteogenesis in a rabbit model. Twenty-two rabbits were subjected to unilateral vertical osteotomy. After a latency period of 4 days, devices were activated 3, 6, and 10 days at a rate of 1 mm/day. We additionally investigated the recovery of the distracted gingiva in consolidation periods for 3 weeks. The animals were examined by histologic and immunohistologic methods using proliferating cell nuclear antigen (PCNA), single-stranded DNA (ssDNA), and keratin. Atrophy of distracted gingiva was observed characterized by loss of rete ridges, acanthosis, vacuolation in the prickle cell layer, and cleavage of the keratin layer. Proliferating cell nuclear antigen-positive cells and ssDNA-positive cells were observed in the basal and prickle layers, respectively. During consolidation periods, slight recovery of rete ridges, thinning of the keratin layer, and immature epithelial layer was observed. Proliferative and degenerated changes occurred to compensate for cell death and distracted space. Thickness of gingival tissues was maintained by high mitotic activity and delay in the rate of cell maturation. Immature epithelial layer was related to sensitive and weak resistance against various stimulating factors, such as cleavage of the keratin layer among distracted gingival tissues.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 07/2007; 103(6):738-44. DOI:10.1016/j.tripleo.2006.12.019 · 1.46 Impact Factor
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    ABSTRACT: To evaluate the diagnostic accuracy of cone-beam CT compared with panoramic images in predicting neurovascular bundle exposure during extraction of impacted mandibular third molars. Cone-beam CT and panoramic images of 142 impacted mandibular third molars were prospectively evaluated to assess tooth relationship to the mandibular canal. These interpretations were then correlated with intraoperative findings. The sensitivity and specificity of the 2 modalities in predicting neurovascular bundle exposure at extraction were calculated and compared. The diagnostic criterion for panoramic images was defined using multivariate logistic regression analysis. In predicting the exposure, the sensitivity and specificity were 93% and 77% for cone-beam CT, and 70% and 63% for panoramic images, respectively. Cone-beam CT was significantly superior to panoramic images in both sensitivity and specificity. Cone-beam CT was significantly superior to panoramic images in predicting neurovascular bundle exposure during extraction of impacted mandibular third molar teeth.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 03/2007; 103(2):253-9. DOI:10.1016/j.tripleo.2006.06.060 · 1.46 Impact Factor
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    ABSTRACT: To examine neurosensory changes in the chin following bilateral sagittal split ramus osteotomy (BSSRO) using the heat flux technique. Twelve healthy adults (C-group) and 23 patients undergoing BSSRO (P-group) were examined. The warm sense threshold (WHF) and cold sense threshold (CHF) in the chin of these patients were measured by the heat flux technique. In the P-group, touch sensation also was measured with a visual analog scale (VAS) and the Semmes-Weinstein monofilament test (SW test). Both WHF and CHF were significantly larger in the P-group than in the C-group (P = .024). Touch sensation (VAS and SW test) were damaged in some patients of the P-group. However, no correlation was revealed between thermal sensation (WHF and CHF) and touch sensation (VAS and SW test) in the P-group. These results suggest that the thermal sensation in the chin was damaged after BSSRO. The heat flux technique appears to be one of the useful methods for the examination of neurosensory disturbance in the chin.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 01/2007; 102(6):719-24. DOI:10.1016/j.tripleo.2005.11.001 · 1.46 Impact Factor
  • Yutaka Maruoka, Hiroyuki Harada, Ken Omura
    01/2007; 53(9):549-552. DOI:10.5794/jjoms.53.549
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    ABSTRACT: Gene-activated matrix (GAM) is a matrix, such as collagen-containing plasmid vector, that encodes a protein to stimulate tissue regeneration. In the original GAM system, gene transfer efficiency was extremely low. We have recently reported that modifying GAM with calcium-phosphate precipitates (CaP) enhances the efficiency of gene transfer. The purpose of this study was to evaluate the effects of our modified GAM on tissue regeneration. We prepared critical size segmental bone defects in rat tibiae and transplanted GAM consisting of bovine atelocollagen and expression plasmid vector (bmp2), which encodes human BMP2, with or without CaP. The tibiae were later examined radiographically, histologically, and mechanically. Implantation of bmp2-CaP-collagen at 12 microg bmp2 bridged the bone defect at 4 weeks, and the strength of the bone was comparable to that of an intact tibia at 6 weeks. Implantation of bmp2-collagen at the same dose of bmp2 bridged the defect to a smaller extent. Neither collagen alone nor vacant vector-CaP-collagen bridged the defect. These results indicate that our modified GAM with CaP has the potential to be effective in tissue regeneration at lower plasmid DNA doses than used in previous studies.
    Tissue Engineering 04/2006; 12(3):489-97. DOI:10.1089/ten.2006.12.489 · 4.25 Impact Factor
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    ABSTRACT: Trichorhinophalangeal syndrome (TRPS) type I is characterized by slowly progressing systemic osseous dysplasia, exhibiting craniofacial and other skeletal deformities. However, there have been few reports describing this syndrome after undergoing orthognathic surgery. In this report, we present a patient with TRPS I who successfully underwent orthognathic surgery. In addition, we examined the skeletal stability of the patient for 2 years after the surgery.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 03/2006; 101(2):e23-7. DOI:10.1016/j.tripleo.2005.07.014 · 1.46 Impact Factor
  • 01/2006; 16(1):8-11. DOI:10.5927/jjjd1991.16.8
  • International Journal of Oral and Maxillofacial Surgery 01/2005; 34:104-104. DOI:10.1016/S0901-5027(05)81279-2 · 1.36 Impact Factor
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    ABSTRACT: Gnathodiaphyseal dysplasia (GDD) is a rare skeletal syndrome characterized by bone fragility, sclerosis of tubular bones, and cemento-osseous lesions of the jawbone. By linkage analysis of a large Japanese family with GDD, we previously mapped the GDD locus to chromosome 11p14.3-15.1. In the critical region determined by recombination mapping, we identified a novel gene (GDD1) that encodes a 913-amino-acid protein containing eight putative transmembrane-spanning domains. Two missense mutations (C356R and C356G) of GDD1 were identified in the two families with GDD (the original Japanese family and a new African American family), and both missense mutations occur at the cysteine residue at amino acid 356, which is evolutionarily conserved among human, mouse, zebrafish, fruit fly, and mosquito. Cellular localization to the endoplasmic reticulum suggests a role for GDD1 in the regulation of intracellular calcium homeostasis.
    The American Journal of Human Genetics 07/2004; 74(6):1255-61. DOI:10.1086/421527 · 10.99 Impact Factor
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    ABSTRACT: Here we report that successful bone formation with a vascular flap inside a cylindrical mold was induced from fat tissue with the use of recombinant human bone morphogenetic protein-2 in rats. Fat tissue connected to blood vessels was prepared to fit into the mold and implanted intramuscularly into the hind leg in Wistar rats. RhBMP-2 (20 micro g) was applied in a collagen sheet previously placed on the inside surface of the mold. Bone formation was confirmed radiologically and morphologically at 2, 4, and 8 weeks after the surgery. In the control group without rhBMP-2 or the group with ligation of the blood vessels before the implantation, bone formation was not observed. Our success in bone formation having a definite size, shape, and blood supply may lead to a therapeutic approach to effective bone reconstitution. The present study is the first report on bone induction from fat tissue by rhBMP-2 in vivo.
    Journal of Dental Research 09/2003; 82(8):581-4. DOI:10.1177/154405910308200802 · 4.14 Impact Factor

Publication Stats

494 Citations
77.50 Total Impact Points

Institutions

  • 2011–2014
    • National Center for Global Health and Medicine in Japan
      Edo, Tōkyō, Japan
  • 1994–2007
    • Tokyo Medical and Dental University
      • • Department of Oral Restitution
      • • Department of Maxillofacial Surgery
      • • Department of Biochemistry
      Edo, Tōkyō, Japan
  • 1997
    • Japan Women's University
      Edo, Tōkyō, Japan