Reconsideration of Leeway Space Calculated Using Models from Same Patients at Different Growth Stages.

In this study, original leeway space was determined using plaster models prepared from the same individuals over successive years and compared with that reported in an earlier study. The plaster models used for measurement were prepared from a normal dentition group comprising 64 patients and a crowded dentition group comprising 29. The mesiodistal crown width of the deciduous canines, deciduous first molars, and deciduous second molars, as well as that of the canines, first premolars, and second premolars was measured.

Melatonin suppresses the antiviral immune response to EMCV infection through intracellular ATP deprivation caused by mitochondrial fragmentation.

Melatonin, a sleep hormone derived from the pineal gland, has an anti-inflammatory effect on the immune system in addition to modulating the brain nervous system. Previous studies have shown that melatonin suppresses signaling pathways downstream of multiple pattern recognition receptors on the innate immune cells during pathogen infection, but the specific mechanism of suppression has not been well understood. Using an encephalomyocarditis virus (EMCV) infection model in macrophages, we investigated the effects of melatonin on the antiviral response in innate immunity and found that melatonin attenuated the uptake of viral particles into macrophages.

The concurrent stimulation of Wnt and FGF8 signaling induce differentiation of dental mesenchymal cells into odontoblast-like cells.

Fibroblast growth factor 8 (FGF8) is known to be a potent stimulator of canonical Wnt/β-catenin activity, an essential factor for tooth development. In this study, we analyzed the effects of co-administration of FGF8 and a CHIR99021 (GSK3β inhibitor) on differentiation of dental mesenchymal cells into odontoblasts. Utilizing Cre-mediated EGFP reporter mice, dentin matrix protein 1 (Dmp1) expression was examined in mouse neonatal molar tooth germs.

Molar incisor hypomineralization: A review and prevalence in Japan.

Molar incisor hypomineralization (MIH) is defined as hypomineralization of systemic origin of one to four first permanent molars, and incisors are also frequently affected. This disorder is a serious concern in pediatric dentistry. Teeth affected by MIH have many dental problems, such as hypersensitivity, poor aesthetics, and rapid progression of dental caries.

Caries and Its Association with Infant Feeding and Oral Health-related Behavior in 18-month and 3-year-old Japanese Children.

The primary aim of this study was to determine the prevalence of dental caries and its association with infant feeding and oral health-related behavior in Japanese children between the ages of 18 months and 3 years. A total of 387 infants were initially examined at the age of 18 months (or 19 months in some cases) and then again at 3 years (or at 3 years 1 month in some cases). The primary objective was to identify factors contributing to the prevalence of caries in children aged 18 months.

Investigation of the potential regulator proteins associated with the expression of major surface protein and dentilisin in .

is involved in 'chronic' periodontitis pathogenesis. The mechanism underlying the regulation of the expression of its virulence factors, such as major surface protein (Msp) and prolyl-phenylalanine specific protease (dentilisin) is yet to be clarified. We determined the gene expression profiles of Msp- and dentilisin-deficient mutants of to identify the regulation network of gene expression concomitant with the inactivation of these virulence genes.

Microbiomes of colored dental biofilms in children with or without severe caries experience.

Background: Biofilm coloration can compromise maturation and increase the risk of oral disease in adulthood, though children with colored biofilm do not always demonstrate a poor oral health status.

Aim: The microbial compositions of colored and white biofilms in children were compared.

Design: Thirty-two dental biofilm samples from 16 children (age < 13 years) were analyzed using 16S rRNA pyrosequencing, then the subjects were divided into severe caries and healthy (caries-free) groups.

High-Level Expression of Alkaline Phosphatase by Adeno-Associated Virus Vector Ameliorates Pathological Bone Structure in a Hypophosphatasia Mouse Model.

Hypophosphatasia (HPP) is a systemic skeletal disease caused by mutations in the gene encoding tissue-nonspecific alkaline phosphatase (TNALP). We recently reported that survival of HPP model mice can be prolonged using an adeno-associated virus (AAV) vector expressing bone-targeted TNALP with deca-aspartate at the C terminus (TNALP-D); however, abnormal bone structure and hypomineralization remained in the treated mice. Here, to develop a more effective and clinically applicable approach, we assessed whether transfection with TNALP-D expressing virus vector at a higher dose than previously used would ameliorate bone structure defects.

Developmental studies on the acquisition of perception conducting pathways via TRP channels in rat molar odontoblasts using immunohistochemistry and RT-qPCR.

Odontoblasts act as dentin formation and sensory receptors. Recently, it was reported that transient receptor potential ankyrin (TRPA) 1, TRP vanilloid (TRPV) 4 and pannexin 1 (PANX-1) play important roles in odontoblast sensory reception. However, it is not known when odontoblasts begin to possess a sense reception function.

Expression of Cytokeratin in Experimentally Created Inflammatory Cyst in Vivo and in Vitro.

The purpose of this study was to investigate the behavior of epithelial lining derived from Malassez's epithelial rest (MER) cells in experimentally created inflammatory cysts in vivo and in vitro. Porcine MER cells were cultured in vitro with or without interleukin (IL)-1β (1 ng/ml) or IL-6 (1 ng/ml). Cell proliferation was assessed and expression levels of CK19 and CK13 mRNA determined using RT-PCR.

Treatment of Child with Four Lost Maxillary Incisors due to Traffic Injury.

Tooth injury is frequently encountered in pediatric clinical practice. A clinician may be requested to not only respond at the time of injury, but also properly diagnose how such injury will affect the teeth and dentition. Here, we present a case of a child who lost 4 bilateral maxillary incisors due to a traffic accident, and in whom marked mesial inclination of the bilateral maxillary canines and bilateral maxillary first premolars would subsequently occur.

Difference in Bilateral Timing of Eruption of Permanent Teeth.

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.

Development of Jaw and Deciduous Teeth in Japanese Children -Comparing Size of Crown and Alveolar Area between Today and 40 Years Ago.

The purpose of the present study was to investigate change in the size of the jaw and deciduous teeth in Japanese children over the past 40 years by performing measurements on plaster models of the dental arch obtained from children born between 2007 and 2009 (2000s group) and children born between 1968 and 1974 (70s) group. A total of 61 children were enrolled in the 2000s group, comprising 25 boys (average age, 4 years 5 months) and 36 girls (average age, 4 years 4 months), and 93 children in the 70s group, comprising 45 boys (4 years 6 months) and 48 girls (4 years 4 months). The mesiodistal width of the crown, dental arch width, dental arch length, dental arch height, and available arch length in these groups were measured using a 3D measurement system and the sums of the mesiodistal width of the crown and tooth size-arch length discrepancies calculated.

Intentional Partial Pulpotomy for Treatment of Immature Permanent Maxillary Incisor with Talon Cusp.

We report the successful morphological correction of a maxillary lateral incisor with a talon cusp and the preservation of vital pulp by employing an intentional partial pulpotomy. A talon cusp is a comparatively rare morphological tooth anomaly that may cause multiple clinical problems. An 11-year-old girl was referred to our department for morphological correction of a maxillary lateral incisor with a talon cusp prior to orthodontic treatment.

Relationship between Interdental Spacing and Colonization by Streptococcus mutans in Children.

The purpose of this study was to investigate the relationship between interdental spacing in the upper incisors and other associated factors with colonization by Streptococcus mutans in children. A total of 47 children aged between 24 and 36 months with no decayed cavities were enrolled in the study. Models were obtained to evaluate interdental spacing in the upper anterior region.

Alveolar Growth in Japanese Infants : A Comparison between Now and 40 Years ago.

To investigate differences in alveolar growth during the primary dentition period among different age groups, dental arch width, length, and height were measured in 93 dental arch plaster models obtained from 4-year-olds born between 1968 and 1974, 88 from 5-year-olds born between 1968 and 1974 (70s group), 61 from 4-year-olds born between 2007 and 2009, and 56 from 5-year-olds born between 2006 and 2008 (2000s group). A comparison was also performed to determine whether there was any difference in change between 4 and 5 years of age. The results showed age- and sex-dependent differences in growth patterns in primary dental arch width, length, and height.

Influence of lyophilization factors and gelatin concentration on pore structures of atelocollagen/gelatin sponge biomaterial.

This study aimed to investigate influences of lyophilization factors and gelatin concentration on pore structures of ACG sponge. ACG sponges of different freezing temperatures (-30, -80 and -196C), freezing times (1, 2 and 24 h), gelatin concentrations (0.6%AC+0.

Influence of Lifestyle Factors on Risk of Dental Caries among Children Living in Urban China.

The prevalence of dental caries has been decreasing among kindergarten children in Shanghai, China, over recent years, although it still remains at an unacceptably high level. The purpose of this study was to identify which factors were important in providing oral health guidance and achieving further improvement in the oral health status of kindergarten children in urban China. A survey was conducted on dental caries in 128 Japanese and 368 Chinese kindergarten children and a questionnaire given to their parents/guardians on each child's lifestyle and dietary habits from birth to the present.

Characterization of a potential ABC-type bacteriocin exporter protein from Treponema denticola.

Background: Treponema denticola is strongly associated with the development of periodontal disease. Both synergistic and antagonistic effects are observed among bacterial species in the process of biofilm formation. Bacteriocin-related genes have not yet been fully characterized in periodontopathic bacteria.

Dentilisin involvement in coaggregation between Treponema denticola and Tannerella forsythia.

Periodontitis arises from a biofilm consisting of gram-negative anaerobic rods and spirochetes. Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, termed the Red complex, have been co-isolated with high frequency from chronic periodontitis lesions, and these microorganisms are thought to be major pathogens of the disease. Coaggregation is an important strategy in the colonization of dental plaque biofilm by these bacteria.

Association between feeding methods and sucking habits: a cross-sectional study of infants in their first 18 months of life.

The aim of this study is to investigate infant feeding patterns and to analyze the influence of breast-feeding methods on the prevalence of non-nutritive sucking habits in a sample of Japanese infants. A random sample of 353 mothers of infants of 18 months of age was interviewed at a public health facility in "K" city. The prevalence and duration of infant feeding patterns categorized as breast-feeding, partial breast-feeding, and bottle-feeding, were determined.

Longitudinal investigation of relationship between developmental changes in sagittal occlusion and caries in lower first permanent molars.

The aim of the present study was to investigate the relationship between developmental changes in sagittal occlusion and the presence of caries on the occlusal surface of the lower first permanent molars. Dental casts were taken from 60 children at 2-monthly dental examinations after the emergence of the lower first molars through to when they reached 22 years of age. Data on the state of the occlusal surfaces of 120 lower first permanent molars were collected from these examinations and each occlusal surface classified into one of the following two categories: (1) sound, or (2) caries (filled).

Identification, characterization, and expression of dentin matrix protein 1 gene in Xenopus laevis.

Dentin matrix protein 1 (DMP1) is an acidic extracellular matrix protein expressed mainly in bone and dentin, and is a member of the small integrin-binding ligand N-linked glycoprotein (SIBLING) family. The DMP1 gene, however, appears to evolve rapidly in comparison with other SIBLING genes, even though such functionally important molecules usually evolve more slowly than less important ones. The purpose of this study was to identify and characterize an ortholog of the DMP1 gene in an amphibian (Xenopus laevis; X.

Effects of different combinations of fused primary teeth on eruption of the permanent successors.

Purpose: The fusion of primary teeth may be associated with the absence of 1 of the 2 permanent successors. Moreover, even if both successors erupt, developmental disturbances such as microdontia or delayed tooth formation may occur. The purpose of this study was to elucidate the effects of different combinations of fused primary teeth on the eruption of permanent successors.

Organization of Mhc class II A and B genes in the tilapiine fish Oreochromis.

Perch-like fishes of the family Cichlidae are models for the study of speciation. An important tool in these studies is the major histocompatibility complex (Mhc) and its organization. The present study takes the first step toward the elucidation of the Mhc class II gene organization in the tilapiine fish Oreochromis niloticus (Orni).