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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

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

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.

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 0.414 ppm during Condition 1, 0.158 ppm during Condition 2, 0.252 ppm during Condition 3, and 0.091 ppm during Condition 4. FA levels at the dentist were 0.115 ppm during Condition 1, 0.042 ppm during Condition 2, 0.081 ppm during Condition 3, and 0.028 ppm during Condition 4. FA levels at the dental assistant were 0.067 ppm during Condition 1, 0.038 during Condition 2, 0.059 ppm during Condition 3, and 0.025 ppm 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.

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.

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.

Hypodontia of permanent teeth was evaluated from orthopantomograms of 2072 apparently healthy pediatric patients at The Hospital of Nihon University School of Dentistry at Matsudo. The prevalence of congenitally missing teeth (CMT) was 8.7% in boys and 10.8% in girls, and 9.4% for both sexes combined. Most cases (67.8%) involved either one or two missing teeth. There were in total 574 CMT, and on average 2.8 teeth were missing per child. The most commonly absent tooth was the mandibular second premolar. On the other hand, no first molars were missing in any case. A high frequency of CMT mandibular incisors (18.82%) was observed, and this seems to be a characteristic peculiar to individuals of Asian ethnicity. Oligodontia (6 or more CMT excluding the third molar) ranged from 6 to 14 teeth, with a prevalence of 1.4% in general: 1.8% for girls and 0.9% for boys. Symmetry of CMT was predominant: 214 pairs for bilateral symmetry and 107 pairs for symmetry between two antagonistic quadrants. The distribution of CMT between maxillary and mandibular hypodontia in the right and left quadrants for boys and girls no had significant association (P < 0.05).

Apatite is considered to be effective for bone regeneration when it contains calcium carbonate and β -TCP. In the present study, we made 3 different apatite preparations, hydroxyapatite, hydroxyapatite containing calcium carbonate, and hydroxyapatite containing β -TCP, using spark plasma sintering and compared their abilities for osteoinduction. For elucidation of bone regeneration, evaluations are generally made after euthanasia of experimental animals. However, the present R_mCT ® procedure allowed such evaluations while the animals were alive. Our results showed that sintered HAP containing β -TCP was more effective for guided bone regeneration than the other test materials.

I-cell disease is a rare autorecessive metabolic disorder that is classified as one of the lysosomal storage diseases. Gingival enlargement is a representative oral manifestation of patients with I-cell disease. This report describes a case with a satisfactory prognosis after gingivectomy for gingival enlargement accompanying I-cell disease in a 2-year-old boy. The chief complaints were both eating disorders and night terrors accompanied by gingival enlargement of both the maxillary and mandibular alveolar gingivae, especially in the region of the first deciduous molars. Although it was supposed that there were various hazards associated with gingivectomy caused by aortic incompetence, sigmoidal spinal curvature and hypertrophy of the laryngopharynx, gingivectomy with an internal bevel incision was performed under general anesthesia to improve the chief complaints. A piece of the enlarged gingivae dissected during the operation was examined histopathologically, and the histopathological diagnosis was gingival hyperplasia. The patient's signs and symptoms of the eating disorders and night terrors have improved since the gingivectomy operation. Recurrence of the gingival enlargement has not been identified up to 18 months after the surgery. It is therefore concluded that gingivectomy for gingival enlargement accompanying I-cell disease was effective for this 2-year-old boy.

The purpose of this study was to investigate whether the lesion of incipient caries was associated with morphological differences between the molars of C3H/HeJ and C57BL/6J mice. The caries scores for C57BL/6J and C3H/HeJ at 35 days old were 3.8±2.5 and 0±0 (mean±SD), respectively. The caries scores for C57BL/6J and C3H/HeJ at 49 days old were 42.4±8.3 and 4.2±2.4 (mean±SD), respectively. There was a 10-fold difference between C57BL/6J and C3H/HeJ in terms of caries progress. Incipient caries then appeared at the second fissure of lower M1. The central region of the second fissure of lower M1 in C57BL/6J was deeper and rougher than the same region in C3H/HeJ. The Ca/P ratios of the fissure for C57BL/6J and C3H/HeJ were 1.69±0.27 and 1.71 ±0.25 (mean±SD), respectively. The total data showed no significant difference between C57BL/6J and C3H/HeJ.In conclusion, it was found that incipient caries appeared at the second fissure of lower M1. Moreover, it is suggested that the morphology of the fissure as well as the immune responses may be responsible for the dental caries caused by stagnation of bacterial plaque.

The purpose of this study was to compare the production of interleukin-1β (IL-1β) by peptidoglycan from Lactobacillus casei (L. casei) in human pulp-derived fibroblasts from deciduous (DHPF) and permanent teeth (HPF). DHPF and HPF were collected from 6 noncarious deciduous teeth (6-9 year-old individuals) and 6 noncarious permanent teeth (20-25 year old individuals) extracted in the course of orthodontic treatment. Both IL-1β protein production and IL-1β mRNA levels from peptidoglycan- treated DHPF and HPF were clearly enhanced, compared to IL-1β protein production and IL-1β mRNA levels from peptidoglycan-non-treated DHPF and HPF that were not treated by peptidoglycan. Furthermore, IL-1β protein production and IL-1β mRNA levels from peptidoglycan-treated DHPF showed clearly lower levels, compared with IL-1β protein production and IL-1β mRNA levels from peptidoglycan-treated HPF. These findings suggest that pulpitis in deciduous teeth was less induced than pulpitis in permanent teeth, and that L. casei- peptidoglycan stimulated IL-1β production through enhancement of IL-1β mRNA expression from DHPF and HPF.

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. (J Oral Sci 53, 121-124, 2011)

Tooth agenesis or hypodontia is one of the most common anomalies of the human dentition, characterized by the developmental absence of one or more teeth. Many studies have reported that the prevalence of congenital absence of permanent teeth varies from 3% to 11% among European and Asian populations. Recent advances in the fields of molecular biology and human genetics have improved our understanding of the cause of tooth agenesis. In this review, we assess the previous literature on prevalence of tooth agenesis comparing the Japanese with other racial populations, and describe the recent genetic studies associated with hypodontia in human and mouse models.