Hiroo Miyazawa

Pilot study of facial soft tissue thickness differences among three skeletal classes in Japanese females

Facial reconstruction is a technique used in forensic anthropology to estimate the appearance of the antemortem face from unknown human skeletal remains. This requires accurate skull assessment (for variables such as age, sex, and race) and soft tissue thickness data. However, the skull can provide only limited information, and further data are needed to reconstruct the face. The authors herein obtained further information from the skull in order to reconstruct the face more accurately. Skulls can be classified into three facial types on the basis of orthodontic skeletal classes (namely, straight facial profile, type I, convex facial profile, type II, and concave facial profile, type III). This concept was applied to facial tissue measurement and soft tissue depth was compared in each skeletal class in a Japanese female population. Differences of soft tissue depth between skeletal classes were observed, and this information may enable more accurate reconstruction than sex-specific depth alone.

Dental Pulp and Periodontal Ligament Cells Support Osteoclastic Differentiation

Odontoclasts and cementoclasts are considered to play major roles in the internal resorption of dentin and the external resorption of tooth roots. In this study, we evaluated the osteoclast-inducing ability of human dental pulp and periodontal ligament cells, which are mesenchymal cells in dental tissues. These cells expressed RANKL and OPG mRNA constitutively. As osteoclast precursors, CD14+ monocytes derived from human peripheral blood were isolated, and incubated together with human dental pulp or periodontal ligament cells. Both cell types spontaneously induced the differentiation of CD14+ monocytes into osteoclasts without osteotropic factors. These results suggest that dental pulp and periodontal ligament cells are involved in regulating the differentiation and function of osteoclasts.

Facial soft tissue thickness in Japanese children

Facial reconstruction techniques used in forensic anthropology are based on mean soft tissue thickness measurements. Numerous studies of facial tissue thickness in adults have been published on a range of subjects from different ancestral backgrounds. Data on facial thickness in children derive primarily from Caucasoid, African-American, and Hispanic subjects. There are limited data from the few studies of Japanese children (male: skeletal class I only; female: all skeletal classes). The author has previously reported facial tissue thickness data for Japanese girls and boys with skeletal class I and for all three skeletal classes in Japanese girls. The present study reports facial soft tissue thickness data in Japanese children of all skeletal classes, within age subsets. With parental informed consent, diagnostic lateral cephalometric X-ray images were obtained from 339 Japanese children aged 7-18 years (male: 162; female: 177) who attended the Matsumoto Dental University Department of Orthodontics to undergo orthodontic treatment. Soft tissue and skeletal features were traced onto acetate sheets from the X-ray images, and 10 anthropological landmarks on the midsagittal line were measured. Means, SDs, and ranges were then calculated. Differences between male and female measurements in six age groups were compared using t-tests. Significant differences were observed at some landmarks in each age group. The findings were compared with data from other juvenile populations.

1α,25-Dihydroxyvitamin D3 inhibits osteoblastic differentiation of mouse periodontal fibroblasts

OBJECTIVE Periodontal ligament (PDL) is a non-mineralized tissue connecting cementum and alveolar bone. Recent studies have suggested that periodontal fibroblasts can differentiate into mineralized tissue-forming cells such as osteoblasts and cementoblasts. We elucidated the immunolocalization of vitamin D receptor (VDR) and the effects of vitamin D(3) (VD(3)) on mouse periodontal fibroblasts to clarify the role of VDR and VD(3) in the differentiation of periodontal fibroblasts. DESIGN Immunohistochemical analysis using anti-VDR antibody was performed in paraffin sections of mouse mandibles at E13, E14, E17, P10, and P35. The roles of VD(3) in osteoblastic differentiation and mineralization were estimated by alkaline phosphatase (ALP) and alizarin red (AR) staining. In addition, the mRNA expression of osteoblast markers and mineralization inhibitors was examined by real-time PCR. RESULTS At the bud, cap and early bell stages, immunoreactivity for VDR was scarcely seen in the cells of dental follicles. Labelling was detected in the nuclei of cemetoblasts, periodontal fibroblasts and osteoblasts during root formation. VD(3) inhibited ALP activity and AR-positive mineralized nodule formation of periodontal fibroblasts in osteogenic culture medium. Real-time PCR revealed that VD(3) down-regulated the levels of osteoblast markers. In contrast, VD(3) significantly up-regulated the level of periodontal ligament associated protein (PLAP)-1, a negative regulator of osteoblastic differentiation. CONCLUSION These results suggest that VD(3) negatively regulates the osteoblastic differentiation of mouse periodontal fibroblasts and prevents the periodontal ligament from mineralization via increase of PLAP-1.

Observations of pulpotomy in rats using in vivo Micro-CT —The changes after treatment of formocresol and calcium hydroxide pulpotomies or CO2 laser irradiation—

Abstract In general, pulpotomy is evaluated by pathological examination of sacrificed animals at each observing stage. Not only lots of small animals have to devote itself to experimentation, but also the result of research is lacking about the serial observation of an individual experimental animal. The aim of this study was to compare the relative effectiveness of the calcium hydroxide, formocresol and CO 2 laser using the R_mCT ® . Twenty male Wistar rats, 8 weeks of age, were used and imaged in present study. They were serially observed using the R_mCT ® on days 0, 3, 10, 30, 50 after pulpotomy, followed pathohistological examination. The R_mCT ® images revealed that the pulp capping agents were partly absorbed and a hard tissue-like was observed immediately beneath it, especially in the CO 2 laser group. Pathohistological examination showed a hard tissue-like appearance and inflammatory cell infiltration. The R_mCT ® images agreed with pathohistological finding on the days 50 after pulpotomy. Our research suggested that the R_mCT ® has made it possible to scan serial imaging of small animals such as experimental rats under anesthesia. Since its higher resolution enables clear observation of the entire hand of the rat, it is possible not only to compare the effectiveness of each pulpotomy method, but also to serially observe a single experimental animal during the process post-pulpotomy healing, growth, and aging. This study answered well for the animal protective law that to use the least of animal to got the best result.

Assessment of the esthetic smile in young Japanese women

Abstract Introduction The aim of the present study is to evaluate an esthetic smile in young Japanese women, which is not yet clear. Materials Thirty orthodontically treated female patients formed Group 1 and the same number of female models, Group 2. Methods All smile photos and slides were digitalized for analysis in an image-processing program. As the photos in Group 2 had a different size, the output image size was not considered. Five visual and four quantitative evaluations of a smile were studied for each subject. The smile arch and index, buccal corridor spaces (BCSs) and relationship between BCS and maxillary dental arch widths were studied. Statistics Standard errors of the measurements were calculated. Independent students t-tests were used to compare statistically the measurements of Group 1 patients and Group 2 model samples, and also those of BCS and the widths of the upper dental arch (UAW). Mean and standard deviation were calculated and p < 0.05 was significant. Results and conclusion The average smile, smile curve arch line without touching the lower lip, parallelism of the upper incisal curve with the inner curvature of the lower lip, no display of the 1st molar, 1:1 ratio of the widths of nose and upper cuspid, a minimum buccal corridor with no significant relation in widths of the upper dental arch all corresponded to ideal smile.

Micro-CT observation of rat dental pulp healing after pulpotomy in in vivo study

Abstract We report the newly developed Micro-CT, which allows us to observe the individual animal over a long experimental period and to compare changes in pulp tissue in relation to growth and aging without considering individual differences. Further, we used pathological examination to prove similar the result observing from Micro-CT. We have examined wound healing of teeth after pulpotomy in rats, and could clearly observe histopathological changes in the affected teeth and the absorption of temporary filling material and pulp capping agents. In cases with breakage of the dental crown, the CT images agreed with the pathological observations, and it was possible to estimate the time of breakage. In vivo Micro-CT is possible to apply in continuous recording of small experimental animals, such as rats, under anesthesia and the result is sufficiently high. High-quality image was obtained in of the entire head region of the rat. It was suggested that this method can be used for long-term continuous observation of changes in the teeth conditions after pulpotomy in experimental animals. We report the newly developed Micro-CT, which allows us to observe the individual animal over a long experimental period and to compare changes in pulp tissue in relation to growth and aging without considering individual differences.

Protein kinase A enhances lipopolysaccharide-induced IL-6, IL-8, and PGE2 production by human gingival fibroblasts

ObjectivePeriodontal disease is accompanied by inflammation of the gingiva and destruction of periodontal tissues, leading to alveolar bone loss in severe clinical cases. Interleukin (IL)-6, IL-8, and the chemical mediator prostaglandin E2 (PGE2) are known to play important roles in inflammatory responses and tissue degradation.Recently, we reported that the protein kinase A (PKA) inhibitor H-89 suppresses lipopolysaccharide (LPS)-induced IL-8 production by human gingival fibroblasts (HGFs). In the present study, the relevance of the PKA activity and two PKA-activating drugs, aminophylline and adrenaline, to LPS-induced inflammatory cytokines (IL-6 and IL-8) and PGE2 by HGFs were examined.MethodsHGFs were treated with LPS from Porphyromonas gingivalis and H-89, the cAMP analog dibutyryl cyclic AMP (dbcAMP), aminophylline, or adrenaline. After 24 h, IL-6, IL-8, and PGE2 levels were evaluated by ELISA.ResultsH-89 did not affect LPS-induced IL-6 production, but suppressed IL-8 and PGE2 production. In contrast, dbcAMP significantly increased LPS-induced IL-6, IL-8, and PGE2 production. Up to 10 μg/ml of aminophylline did not affect LPS-induced IL-6, IL-8, or PGE2 production, but they were significantly increased at 100 μg/ml. Similarly, 0.01 μg/ml of adrenaline did not affect LPS-induced IL-6, IL-8, or PGE2 production, but they were significantly increased at concentrations of 0.1 and 1 μg/ml. In the absence of LPS, H-89, dbcAMP, aminophylline, and adrenaline had no relevance to IL-6, IL-8, or PGE2 production.ConclusionThese results suggest that the PKA pathway, and also PKA-activating drugs, enhance LPS-induced IL-6, IL-8, and PGE2 production by HGFs. However, aminophylline may not have an effect on the production of these molecules at concentrations used in clinical settings (8 to 20 μg/ml in serum). These results suggest that aminophylline does not affect inflammatory responses in periodontal disease.

Transcriptional regulation of the salivary histatin gene: finding of a strong positive regulatory element and its binding protein.

Histatins are salivary proteins found and expressed in human salivary glands. They play a role in the non-immune system of antimicrobial defense, for instance, against Candida albicans. The transcriptional regulatory sequences of the histatin gene, HIS1, have remained obscure for a long time. Here, we cloned the putative promoter from human genomic DNA and tested it in a luciferase reporter system. This promoter is much more active in salivary gland cells than in other cell types. Analysis of deletion mutants revealed that the region encompassing -2254 to -1748 is a strong positive transcriptional element, and its functional core sequence (termed HTN27 box) works in correct and reverse orientations in synergy with downstream sequences, the region spanning -680 to +28 and a proximal promoter. The plus single-stranded HTN27 box is specifically bound by a 100 kDa protein that is present in HSG cells, but not in HeLa cells. These findings indicate that the regulation of the histatin gene expression may be intricate, and it seems to have a cell-type preference in the salivary gland cells.

Estimation of nasal tip position using lateral cephalometric X-ray images in Japanese male children : Applications in facial reconstruction

Abstract Facial reconstruction is a forensic anthropological technique based on a database of facial soft tissue thickness; however, the information available is generally insufficient to completely reconstruct facial features. While most soft tissue in the craniofacial region is strongly adherent to the bony surface, a few areas, such as the ears, nose, and lip regions, are not. Yet these are vital features for forensic identification and are used in everyday life in facial recognition. For such features, forensic anthropologists investigating age, sex, ancestry, and facial appearance must often rely upon bony information alone. Determination of nasal tip position in adults from the skull has been reported by several researchers. However, data for determining nasal tip position from the juvenile skull have not been reported. The aim of this study was to establish and apply a simple discriminative method of identification of nasal tip location in unidentified juvenile human skeletal remains through an investigation of the cranial base in the current Japanese juvenile population. The result would be applicable for not only the research described above but also estimation of growth of mid facial profile (i.e. estimation of patterns of bony and cartilaginous framework of the nose by diseased palatal clefts etc.) and aesthetic standards. Lateral cephalometric X-ray images were used to measure soft tissue thickness in subjects undergoing orthodontic treatment. Two reference planes were set on the skull radiograph (one had already been set at the beginning of facial reconstruction). After tracing the facial profile and plotting soft tissue and bony landmarks, nine dimensions of distances (length and length ratio) and angles between these landmarks and the nasal tip were measured. A prediction function for the nasal tip was derived from these measurements. This study reports a simple and reliable method of nasal tip prediction for use in forensic facial reconstruction from incomplete human juvenile skulls.