• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.192-204
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• 2023

This study aimed to determine the criteria for quantifying developmental defects of enamel in primary teeth in premature babies and to investigate the severity of developmental defects according to the gestational age, birth weight, systemic complications, and treatments received after preterm birth. Birth information, a history of complications, the duration of parenteral nutrition, and endotracheal intubation were investigated by retrospectively reviewing the admission and discharge records of premature babies in the neonatal intensive care unit. The Preterm Developmental Defects of Enamel (PDDE) index was designed by modifying the existing developmental defects of enamel index. Based on PDDE index, the evaluator scored developmental defects of enamel by classifying them as enamel hypomineralization and hypoplasia. The PDDE scores in the extremely preterm and extremely low birth weight groups were significantly higher than those in other groups. Furthermore, PDDE scores of premature babies with bronchopulmonary dysplasia, rickets, intraventricular hemorrhage, or necrotizing colitis were significantly higher than those in the control group. In addition, more than 50 days of endotracheal intubation and more than 20 days of parenteral nutrition were associated with significantly higher PDDE scores than those in the control group and were risk factors for developmental defects of enamel. This study provides basic information for identifying risk factors for developmental defects of enamel in premature babies.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.2
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• pp.218-224
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• 2010

The prevalence of developmental defects of enamel and lesios by post-orthodontic decalcification has been reported with increasing frequency. Even though there have been increasing interests and clinical challenges in esthetic improvement of these lesions, few of studies were reported for using non-invasive approach which is a very significant matter for child and young adults. This study was conducted to assess clinical effect on the improvement in color of these lesions via resin infiltration method developed as minimum invasive technique for white spot. For the 38 maxillary anterior teeth with calcification problem, the changes in color between before- and after- infiltration treatment, were evaluated and summarized as following. 1. A week after infiltration, 25% of developmental defects and 61% of decalcification lesions were improved in color as the value of ${\Delta}E $ below 3.7. 2. 40% of the developmental defects and 6% of decalcification lesions showed no significant change. 3. The developmental defects showed more remarkable changes in color 1 week after infiltration rather than immediately after the treatment. From our study results, it is considered that the amount of color improvement depended on the depth of lesion. In other words, for the lesion having more depth than the depth infiltrant resin can penetrate into, infiltration treatment showed no significant effect. Therefore, for clinical indication of resin infiltration treatment, further research on precise measurement technique of lesion depth is strongly required.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.255-260
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• 2001

Trauma to the primary incisors may cause developmental or eruptional disturbance of the permanent successors. Two cases illustrate developmental disturbances of arrested root formation, dilaceration, and eruptional disturbances of impaction, ectopic eruption of permanent successors caused by traumatic injury to deciduous incisors. The patient of the first case suffered trauma at the age of 4 years 7 months, causing alveolar bone fracture including the maxillary right primary central and lateral incisors that were immedi-ately extracted. The second patient had trauma episodes at the age of 3 years. Avulsion of the maxillary primary right central and lateral incisors were occurred due to trauma. After such trauma, regular follow-up including radiographs is necessary to detect early any possible interference with normal eruption of permanent successors.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.159-166
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• 2008

The dental caries can be recovered or worse depending on the velocity of de- and remineralization of tooth. It is possible to remineralize the lesions by fluoride agent, but the results can be distinguished according to one's salivary flow rate, quantity of ion contents, and pH of the saliva. This article presents good results after applying the CPP-ACP paste for the patients who have incipient enamel caries. We instructed the patients to apply the paste everyday in the customed tray. We observed the white spot lesions without getting worse and reducing the size of lesions. After applying the CPP-ACP paste for 6 weeks, we concluded that; 1. It was possible to remineralize the incipient caries without preparation of the teeth. 2. CPP-ACP paste was successful for recovery of the demineralized lesions, especially for mild and moderate caries lesions, not for the severe developemental defects or chronic lesions. 3. CPP-ACP paste was efficient for pediatric patients, and the custumed tray was very useful for patients to apply the paste. 4. The ability of the patients for caring their oral hygiene was improved by routine check up and instructions.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.4
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• pp.322-327
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• 2014

Regional odontodysplasia (RO) is a rare and nonhereditary dental malformation. It is a dental alteration of unknown etiology, involving both mesodermal and ectodermal dental components, which is characterized by clinical, radiographic, and histologic features. The maxilla is more often involved than the mandible (especially the left side), and there is no racial predilection, but females are affected twice as often as males. The affected teeth are clinically hypoplastic and hypocalcified, presenting a "ghost-like" appearance radiographically. The present case features a male patient aged 4 years and 6 months who was diagnosed with regional odontodysplasia in the maxilla on the right side, confirmed by clinical and radiographic examination, with a follow up of 5 years. Since teeth affected by RO have a poor prognosis due to the fragile tooth surface and open apices, the long-term treatment strategy depends on periodic clinical and radiological observations.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.305-309
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• 2009

Dens evaginatus is a dental anomaly most commonly seen in premolar teeth in which a tubercle or protuberance projects from either the center of the occlusal surface or the buccal triangular ridge. These tubercles are easily fractured from mastication as the tooth erupts and frequently leads to pulp necrosis as a common complication. To prevent these sequelae, prophylactic treatment soon after the tooth starts erupting is essential. These preventive treatments include, selective grinding and protection of the tubercle by pit and fissure sealant. When the tooth does shows signs of pulp necrosis and apical periodontitis, endodontic procedures are needed. Apexification and apexogenesis are usually the treatment of choice for the affected teeth which have immature apices. Apexogenesis is a vital pulp therapy procedure performed to encourage continued physiological development and formation of the root end. It involves removal of the inflamed pulp and the placement of calcium hydroxide on the remaining healthy pulp tissue. This case report describes an atypical apexogenesis of a mandibular premolar which showed to be a dens evaginatus. The tooth which was treated with calcium hydroxide shows good results and is planned for permanent root canal filling.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.15 no.1
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• pp.89-93
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• 2019

Preterm infants have higher possibility of undergoing endotracheal intubation after birth than normal children due to medical conditions. Developmental disturbances of primary incisors following intubation can occur as crown malformation, enamel defects, delayed eruption, displacement of dental follicle in crypt, groove formation of palate or alveolar ridge, acquired cleft palate, and dental arch distortion. This clinical report presents the effect of intubation on primary dentition of preterm infants. A 2-year-old girl with cerebral palsy and premature birth history visited our clinic with chief complaint of unerupted primary upper incisor. A 1-year-old boy with cerebral palsy, status epilepticus and premature birth history visited our clinic due to crown malformation. Developmental disturbances of primary incisors in these cases were not related to the patients' systemic disease, and there were no history of dental trauma. A long term endotracheal intubation prior to tooth eruption might have caused local trauma on alveolar ridge. It is very important to monitor dental problems of preterm infants who had experienced endotracheal intubation during neonatal period. Due to influences on both primary and permanent teeth, periodic re-evaluation of affected areas and establishment of comprehensive treatment plans are necessary.

• Applied Microscopy
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• v.29 no.2
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• pp.189-193
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• 1999

The response of ameloblast to long term (3 weeks) exposure to fluoride was examined in continuously erupting mandibular incisors of pregnancy rats as compared to control rats receiving a similar diet (Teklad L-356) but no sodium fluoride in there drinking water. Rats were started on water containing 0 ppm, 100 ppm, 200 ppm, and 300 ppm NaF at the beginning of pregnancy. To examine on the ultrastructural changes of the ameloblast, electron microscopy was used. The results indicated that rat incisors expressed two major changes in normal amelogenesis that could be attributed to chronic fluoride treatment. The fluoride produces marked alteration in the fine structure of ameloblast from teeth of young rats, such as large confluent distensions of the endoplasmic reticulum and swelling of isolated mitochondria, in particular on the morphology of the rough-surfaced endoplasmic reticulum. A graded series of alterations to these organelles were produced, and the severity of the changes would seem to be dependent on dose and time. This experimental data suggested that exposure prolonged of animal to high level of fluoride appears to induce morphological changes in the normal appositional growth and initial mineralization of enamel created during amelogenesis.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.2
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• pp.138-146
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• 2017

The aim of this study was to estimate time of biomineralization in developmental stages of rat lower incisors. Eruption length was measured. Four stages of incisor development were identified on histologic and microscopic computerized tomography (micro-CT) sections: (1) preodontoblast, (2) dentin matrix secretion, (3) enamel matrix secretion, and (4) enamel calcification. The overall eruption rate of the rat lower incisor was $600{\pm}70{\mu}m/day$ ($mean{\pm}SD$; n = 12). The length of the enamel secretion was $4.59{\pm}0.75mm$ in histologic section, was $3.64{\pm}0.63mm$ in radiographic section, which converts to $180.4{\pm}30.0hours$, $145{\pm}25hours$ respectively (n = 24). These findings suggested that the four biomineralizing developmental stages of the rat incisor took only several days. The significance of this animal study was to provide understanding for the rapid biomineralization process of developing rat tooth germ by analysis of tooth forming period.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.96-101
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• 2009

Regional odontodysplasia(ROD) is relatively rare localized developmental anomaly of tooth formation in which hard tissue is affected. The maxilla is typically affected than the mandible, and especially the maxillary left quadrant is the most commonly involved. Females are affected twice as often as males, and there is no association with race. Its etiology remains undetermined, but local circulatory disorders, somatic mutations, virus infections, local trauma, hyperpyrexia, irradiation, metabolic disturbances, and hereditary transmission are considered as possible etiologic factors. The affected teeth are likely to be small, hypoplastic, brown, and grooved. Eruption failure or delay is frequently seen as well as abscess or fistulae formation in absence of caries. Radiographically, there is a lack of contrast between the enamel and dentin, both of which are less radiopaque than unaffected counterparts. Moreover, enamel and dentin layers are thin, giving the teeth a “ghost-like appearance”. The pulp chambers and canals are large, the roots seem like to be short and indistinct. A 2-year-3-month old boy came to the department of pediatric dentistry, Yonsei University, with the chief complaint of delayed eruption and abnormal tooth shape on the lower left quadrant. He was diagnosed as regional odontodysplasia based on the clinical and radiographic findings.