BACKGROUND:Periodontal ligament (PDL) healing and long term prognosis of replanted avulsed teeth should rely on several factors including length of extra-oral dry time and type of the storage medium. The status of periodontal ligament is critical for the healing of replanted teeth. Different substances have been used for root surface treatment to promote formation of PDL and increase the survival of avulsed teeth submitted to replantation.AIM:The purpose of this study was to assess the effect of recombinant basic fibroblast growth factor 2 (bFGF) and enamel matrix derivative (EMD) on root resorption after delayed replantation.DESIGN:18 freshly extracted single-rooted incisor and premolar teeth were extracted from the beagle dogs and immersed in whole bovine milk for 45 and 60 min (n = 3 each). Following storage period, sockets washed and teeth were treated with bFGF and EMD and replanted into the sockets. After 8 weeks, dogs were sacrificed, specimens processed to 4-μm thick serial sections for histopathologic examination and morphometric assessments. Thus, the proportions of the roots that exhibited signs of surface resorption, inflammatory resorption, and replacement resorption, that is, ankylosis and normal PDL were noted.RESULTS:The percentage of root resorption was in the following order: EMD>milk>bFGF for 45 min and milk>EMD>bFGF for 60 min. For all groups, teeth stored 60 min showed significantly higher incidence of PDL resorption than those stored for 45 min (P < 0.01). The highest incidence of replacement resorption was observed in teeth treated with EMD for 60 min. After 8 weeks, the least resorption was found in bFGF-treated group (P < 0.01).CONCLUSIONS:The findings of this study suggest that use of bFGF favored the formation of new periodontal ligament; prevent ankylosis and resorption process following delayed replantation of teeth while EMD shows replacement resorption, which may turn to ankylosis.

Purpose: The present survey examined the need for dental treatment for caries among Cambodian children as well as the living environments of such children. Then, based on the results we assessed whether education programs aimed at caries prevention are required in Cambodia.Methods: Between 2010 and 2012, 1893 children (age: 3, 5, or 12 years), who were living in Siem Reap Province or Phnom Penh, the capital of Cambodia, were subjected to oral examinations and a survey. Then, the relationship between the prevalence of caries among the children and living environment factors was examined based on the survey data.Results: There was no significant difference in the prevalence of caries between Siem Reap Province and Phnom Penh. The mean prevalence rate of caries and the children's mean df tooth index (dft) and decay-missing-filled tooth (DMFT) scores were higher than those seen in Japan in all age groups. The proportion of treated teeth was low in all age groups, which suggested that a number of children had not consulted dentists. Many of the children regularly ate snacks containing sugar, which are closely associated with caries.Conclusion: Providing dental health education for parents and appropriate brushing advice for children would probably reduce the incidence of caries among Cambodian children. It is necessary to establish systems for preventing dental disorders in Cambodia as promptly as possible. Copyright (Cc) 2014 The Japanese Society of Pediatric Dentistry. Published by Elsevier Ltd. All rights reserved.

Tooth agenesis is the most common developmental anomaly of the human dentition. Epilepsy-like disorder (EL) mice, which have a 100% incidence of agenesis of the third molars, may be a good model for the genetic study of human tooth agenesis. Our previous congenic breeding strategy using EL mice confined a major locus for agenesis of M3, designated am3, within an approximately 1 Mega base pair (Mbp) interval on chromosome 3, which contains five known genes; Lef1, Hadh, Cyp2u1, Sgms2 and Papss1. The aim of this study was to identify the strongest candidate for am3 among the five genes using real-time PCR analysis. The tooth germs of M3 in the bud stage of EL and control mice were dissected out, and total RNA was extracted. In real-time PCR analysis, a significantly low level of expression of Lef1, which is one of the essential transcription factors for early tooth development, was observed in M3 of EL mice. In addition, a significantly low level of expression of Fgf4, which is a direct transcriptional target for LEF1 in early tooth development, was observed in M3 of EL mice. Our results suggest that the cause of M3 agenesis of EL mice may be a low level of Lef1 expression in M3 in the bud stage of EL mice.

We measured the face breadth and the maxillary arch width of a total of 230 mice from 21 SMXA recombinant inbred (RI) mouse strains and their parental strains SM/J and A/J, and investigated genetic factors associated with these parameters. The coefficient of variation between maxillary arch width and face breadth within the same strain was low, suggesting that this is strictly governed by genetic factors. Maxillary arch width and face breadth exhibited a continuous size distribution within the 23 strains, suggesting the involvement of multiple genes rather than a single gene. In the 21 strains of SMXA RI mice and strains SM/J and A/J, there was a significant correlation between face breadth and maxillary arch width in male mice, with a correlation coefficient of 0.52. We performed a genome-wide scan for quantitative trait loci (QTL) determining maxillary arch width and face breadth. With respect to face breadth, the logarithm of odds (Lod) score for D11Mit229 on chromosome 11 was significant for both males and females, suggesting that the genes determining face breadth are located in this region. Although no loci exhibiting a significant Lod score were detected for maxillary arch width, the highest Lod scores were detected for the same loci as for face breadth. These findings suggest that some of the genes that determine face breadth may be the same genes that determine maxillary arch width.

The head and neck region is one of the most common sites for malignant lymphoma;however, pediatric oral lymphoma is very rare. We discovered a case of a malignant lymphoma that developed in the right mandibular molar region of a child and we are now reporting the summary. A 3 and a half year old boy came in to the Nihon University Hospital in Matsudo with a chief complaint of swelling of the right mandibular gingiva. The biopsy results revealed a malignant lymphoma by an H-E stain. Afterwards, we informed the parents of the necessity of systemic treatment and referred them to a comprehensive medical care center.

In order to study the relations of malocclusion formation and feeding behavior as a scientific research project, we measured the 3-D morphology of 31 healthy newborns within 7 days of birth and 1 month later using dental casts. Nine characteristics were selected and the developmental changes were analyzed using specialized software for investigating palatal development in detail. The results revealed that the palatal width, 3 palatal characteristics relating to depth, maximum slope location, and mean slope increased significantly during the 1 month, but there were no significant changes observed in palate length, cuspid ratio, and maximum slope. There was a significant correlation between palate depth and maximum depth point location, suggesting that the deeper points tended to be located further back. No significant correlations were observed between newborns within 7 days of birth and 1 month after birth for cuspid ratio, maximum depth point location, and maximum slope. Our observation of inter-characteristics correlations revealed 7 significant (P < 0.01) combinations out of a total of 33 combinations were observed in newborns within 7 days of birth, while only 4 were observed in 1-month-old infants. This appears to have been because of morphological changes occurring between individuals due to growth. Thus, it was clarified that not only size but shape (cuspid ratio, maximum slope point location, and the mean slope) also changes over the first month after birth. (C) 2013 The Japanese Society of Pediatric Dentistry. Published by Elsevier Ltd. All rights reserved.

EL/Sea mice are characterized by 100% incidence of agenesis of the third molars (M3). In a previous study, chromosomal mapping of the ninth generation EL/Sea congenic strains revealed a major locus for agenesis of M3, designated am3, in the 125-137 Mbp region of chromosome 3. In the present study, to determine the precise location of the am3 locus, we produced further generations of the EL/Sea congenic strains for am3 in which the restricted interval on chromosome 3 of EL/Sea was replaced by a MSM/Msf-derived homolog. The eleventh generation congenic mice that were either heterozygous or homozygous for the MSM/Msf-derived interval exhibited a significant decrease in the incidence of M3 agenesis (p < 0.00001). Results confined the am3 locus to an interval of 1 Mbp on chromosome 3, demonstrating that Lef1, one of the essential transcription factors for early tooth development, is the strongest candidate for am3.

Multiple supernumerary molars are an uncommon occurrence. In this case report, six molars were observed unilaterally in the maxilla of a 7-year-old patient. An erupted supernumerary molar was found palatal to the permanent upper right first molar. On computed tomogram examination, four unerupted molars were clearly identified distal to the permanent upper right first molar. This dental anomaly is rarely encountered and this may be the first case in which four supernumerary molars were observed in a quadrant with no identifiable pathology.

PURPOSE:Cherubism is a rare autosomal dominant syndrome characterized by abnormal bone tissue in the lower part of the face. Mutations in the gene coding for SH3BP2 have been identified in about 80% of people with cherubism. The aim of this study was to determine whether a mutation in the SH3BP2 gene was the molecular basis of cherubism in two unrelated families.METHODS:Two cases of the aggressive form of Cherubism were described in two Turkish families with extensive bilateral swelling in the mandible, typical pathological features and familial history. Genomic DNA was extracted from six affected and three unaffected individuals from two families, and mutations in the SH3BP2 were detected by PCR, and direct DNA sequencing was carried out.RESULTS:In the first family, a missense mutation Arg415Gln was found in exon 9 of the SH3BP2 in all affected individuals. The unaffected individuals did not have this mutation. In the second family, another missense mutation Pro418Thr was identified in exon 9 of the SH3BP2 in the patient and his mother with cherubism.CONCLUSIONS:We detected the point mutations in the SH3BP2 gene in the patients with multiple affected individuals. Genotype-phenotype association studies in individuals with cherubism are necessary to provide important knowledge about molecular mechanisms of the disease.

The purpose of the present study was to determine whether different consistency of diet and malocclusion induced by the extraction of molar teeth on the masticatory organs modulated gastric acid secretion, gastric emptying and intestinal transit in young and elder rats. Male Wistar rats (young, 5weeks; elder, 1.5years) were used in this experiment, and were divided into 2 groups. Group one (G1) was maintained with solid diet, Group two (G2) with mud diet. Further, the mandibular molar teeth of G2 were extracted. The experimental period was 10weeks. The effect of aging and malocclusion on the parameters of gastric secretion was examined using pylorus-ligated rats. The gastric emptying rate (GER) and small intestinal transit rate was determined in rats by evans blue from the stomach and charcoal from the small intestinal, respectively. In pylorus-ligated rats, Young-G2 rat of gastric juice volume, acid output and pepsin secretion remarkably showed significant decrease in comparison with Young-G1 group, but there was not significant difference between Elder-G1 and Elder-G2. GER of Young-G2 rat group was 44.2±7.9%, significantly lower than that of Young-G1 rat group (61.6±8.8%, P<0.01), but Elder-G1 rat group were not significantly different than those of rats of Elder-G2 group. In small intestinal transit rates of charcoal meals, G1 and G2 of young were 73.3±9.1 and 55.1±8.6%, respectively, and Elder groups were 61.7±9.8 and 52.6±7.7%, suggesting an insignificant effect on diet. These results suggest that the diet and malocclusion, induced by extraction of mandibular molar teeth of young rat groups, may have a great influence compared to elder rat groups.

Streptococcus mutans plays an important role in biofilm formation on the tooth surface and is the primary causative agent of dental caries. The binding of S. mutans to the salivary pellicle is of considerable etiologic significance and is important in biofilm development. Recently, we produced NOD/SCID.e2f1(-/-) mice that show hyposalivation, lower salivary antibody, and an extended life span compared to the parent strain: NOD.e2f1(-/-). In this study we used NOD/SCID.e2f1(-/-) 4 or 6 mice to determine the roles of several salivary components in S. mutans colonization in vivo. S. mutans colonization in NOD/SCID.e2f1(-/-) mice was significantly increased when mice were pre-treated with human saliva or commercial salivary components. Interestingly, pre-treatment with secretory IgA (sIgA) at physiological concentrations promoted significant colonization of S. mutans compared with sIgA at higher concentrations, or with human saliva or other components. Our data suggest the principal effects of specific sIgA on S. mutans occur during S. mutans colonization, where the appropriate concentration of specific sIgA may serve as an anti-microbial agent, agglutinin, or an adherence receptor to surface antigens. Further, specific sIgA supported biofilm formation when the mice were supplied 1% sucrose water and a non-sucrose diet. The data suggests that there are multiple effects exerted by sIgA in S. mutans colonization, with synergistic effects evident under the condition of sIgA and limited nutrients on colonization in NOD/SCID.e2f1(-/-) mice. This is a new animal model that can be used to assess prevention methods for dental biofilm-dependent diseases such as dental caries.

Although using Buckley's Solution of formocresol (FC) in pulpotomy procedures is becoming less common in pediatric dentistry. This study measured concentrations of formaldehyde (FA) evaporated during fixing and investigated safe procedures for FC pulpotomy. Methods: Ten measurements were taken for each of the conditions described below. Locations measured for each condition were 1) at a position equivalent to the patient, 2) at a position equivalent to the dentist, and 3) at a position equivalent to the assistant dentist. Condition 1 used no peripheral equipment. Condition 2 used an intraoral air evacuator, Condition 3 used extraoral air evacuators, Condition 4 used both extraoral and intraoral air evacuators. At the patient's FA levels were 0.414ppm during Condition 1, 0.158ppm during Condition 2, 0.252ppm during Condition 3, and 0.091ppm during Condition 4. FA levels at the dentist were 0.115 ppm during Condition 1, 0.042ppm during Condition 2, 0.081ppm during Condition 3, and 0.028ppm during Condition 4. FA levels at the dental assistant were 0.067ppm during Condition 1, 0.038 during Condition 2, 0.059ppm during Condition 3, and 0.025ppm during Condition 4. Exposure concentrations of FA during FC pulpotomy might have using of an extraoral, intraoral air evacuator during FC pulpotomy reduces formaldehyde exposure to patient, dentist, and dental assistant.

The aim of this study was to identify the chromosomes harboring candidate causative gene(s) for dental attrition using pools of DNA from two strains mice with different susceptibilities to attrition. Attrition scores in F2 mice aged 260 days obtained by genetic crossing of C3H/HeJSlc and C57BL/6JSlc mice ranged from low to high. DNA from four F2 mice with high attrition scores and four F2 mice with low attrition scores was pooled. The 53 Mit markers used in this study were determined as informative markers, being polymorphisms between C3H/HeJSlc and C57BL/6JSlc, and were distributed among all auto chromosomes in mice. This suggests that the candidate chromosomes harboring causative gene(s) for attrition are linked with D4Mit13 and D13Mit9, which were identified as homozygous alleles of C3H in Pool High DNA and homozygous alleles of C57BL/6 in Pool Low DNA.

We determined the number of reacted and unreacted 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) molecules with calcium during the demineralization process of hydroxyapatite or dentin by 10-MDP-based one-step (Clearfil Tri-S Bond, TS) or two-step self-etch adhesive (Clearfil SE Bond Primer, SE). We then examined the effects of the number of reacted and/or unreacted 10-MDP molecules on the initial bond strength and bond durability of the resultant adhesive layer. The null hypotheses were that (1) the etching efficacy of tooth apatite by 10-MDP used in TS was the same as that in SE, and (2) the unreacted 10-MDP polymer included within the adhesive layer does not affect bond durability. Addition of hydroxyapatite or dentin to the TS and SE resulted in decreases in the NMR peak intensities for 10-MDP. The peak intensity for 10-MDP showed a greater reduction in SE than in TS, consistent with the observation that SE provided significantly higher initial mean bond strengths than TS. Further, the unreacted 10-MDP polymer within the adhesive layer did not decrease the mean bond strength, despite the application of 20,000x thermo-cycling.

We describe the dental and craniofacial anomalies of 2 ethnically distinct patients with Goldenhar syndrome, which is characterized by hemifacial microsomia, facial asymmetry, and ear and dental abnormalities. A 7-year-old Japanese girl and 12-year-old Turkish boy with Goldenhar syndrome were examined clinically and radiographically; both had symptoms of hemifacial microsomia. Multiple organ involvement can limit surgical correction of deformities and affect patient management. Therefore, long-term regular follow-up by a multidisciplinary team is important to monitor the growth and development of patients.

Hypophosphatasia (HPP) is an inherited systemic skeletal disease caused by mutations in the gene encoding the tissue-nonspecific alkaline phosphatase (TNALP) isozyme. The clinical severity of HPP varies widely, with symptoms including rickets and osteomalacia. TNALP knockout (Akp2(-/-)) mice phenotypically mimic the severe infantile form of HPP; that is, TNALP-deficient mice are born with a normal appearance but die by 20 days of age owing to growth failure, hypomineralization, and epileptic seizures. In this study, a lentiviral vector expressing a bone-targeted form of TNALP was injected into the jugular vein of newborn Akp2(-/-) mice. We found that alkaline phosphatase activity in the plasma of treated Akp2(-/-) mice increased and remained at high levels throughout the life of the animals. The treated Akp2(-/-) mice survived for more than 10 months and demonstrated normal physical activity and a healthy appearance. Epileptic seizures were completely inhibited in the treated Akp2(-/-) mice, and X-ray examination of the skeleton showed that mineralization was significantly improved by the gene therapy. These results show that severe infantile HPP in TNALP knockout mice can be treated with a single injection of lentiviral vector during the neonatal period. (C) 2011 American Society for Bone and Mineral Research.

Proper understanding of the orofacial development and deformities associated with various syndromes is important for planning appropriate dental treatment and improving the craniofacial features. However, it is quite difficult to take cephalometric radiographs of patients with severe mental retardation or behavioral disorders, since patient co-operation and stability of body movement are necessary while taking the radiographs. Computed tomography (CT) is potentially a better tool for the diagnosis and treatment planning of complex maxillofacial deformities than conventional lateral cephalograms. CT images of patients with mental retardation can be taken under general anesthesia. The absorbed dose of radiation in 128 slice multi-detector row computed tomography (MDCT) used in this study is established as CTDI vol. 17.24 mGy, which is less than that of conventional CT (65 mGy). However, the use of MDCT for cephalometric analysis in pediatric dentistry has not been reported. Hence, the aim of the present study was to compare the reliability and difference of angle and linear measurements of craniofacial form using the landmarks on conventional and MDCT lateral cephalograms of human skulls. The results of this study showed that angular and linear measurements recorded from conventional and MDCT lateral cephalograms were similar. In conclusion, there were no significant differences in the mean and standard deviation of angular and linear measurements between conventional and MDCT lateral cephalograms of human skulls. Angular and linear analysis on MDCT cephalogram might show good precision for craniofacial analysis.

In pediatric dentistry, examination of the development of crown or tooth root is essential to determine the physiological development age. Measurements of the tooth size and dental arch width are also required to predict normal occlusion and oral function, and to plan appropriate dental treatment. Some dental anomalies are keys to identify congenital malformation syndromes. In patients with behavioral disorders, it is quite difficult to take diagnostic dental models and pantomographs, since patient co-operation and stability in body movement for a few minutes is necessary while taking the dental impression and pantomographs. For patients with severe mental retardation and behavioral disorders, performing computed tomography under general anesthesia or deep sedation is easier than taking pantomographs while awake. The aim of the present study was to compare the tooth development stage on pantomographs and mesiodistal diameter measurements of tooth size and dental arch width of dry human skulls with the images of those on 128 multi-detector row computed tomography (MDCT). Based on the results, the measurements of tooth development stage, tooth size and dental arch width on MDCT images were clinically precise.