• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.1
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• pp.122-128
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• 2021

Short root anomaly (SRA) is a rare dental condition with abnormally short and blunt root morphology. It mostly affects maxillary central incisors symmetrically and only has been observed in permanent teeth. A 9-year-old girl was referred from a local dental clinic for short root development in mixed dentition with no symptoms. Radiographic and intraoral examinations revealed SRA on upper and lower incisors and mandibular first molars along with other dental anomalies such as enamel hypoplasia and dens invaginatus. During long - term follow - up for 5 years, her mixed dentition has changed to permanent dentition and generalized SRA was observed in all permanent teeth. Cephalometric radiograph also revealed the calcification between the anterior and posterior clinoid processes described as a sella turcica bridge which was reported associating with dental anomalies. Early diagnosis of SRA is emphasized for successful management and prevention of root resorption and tooth loss. This report aimed to present a rare case of generalized SRA along with other dental anomalies and sella turcica bridging in a female patient through long - term follow - up.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.465-470
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• 2003

Transverse and oblique crown-root fractures constitute a major therapeutic problem, particularly in young dentitions. Because crown-root fracture may involve enamel, dentin, pulp, and periodontal tissues, management of the injuries must be modified accordingly. When the fracture line was located under the alveolar crest. there are several methods for crown-root fractured teeth with pulp exposure, such as extruding the root fragment with orthodontic force and restoring it, or intentionally extracting the tooth and replanting it to a position which it can be restored. This case, the fractured tooth is intentionally extracted atraumatically, and replanted by rotating approximately 180 degree into the original socket and fixing with an orthodontic wire. At the 8-month recall examination, the root still showed normal mobility and there was not observed any inflammatory or replacement root resorption in the periapical radiograph.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.245-252
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• 2009

The congenital missing of teeth is common, which takes place since the proliferation and differentiation are not allowed in that tooth bud fail to start development. The purpose of this study is to research incidence rate, number, and missing part of congenital missing teeth, and to study whether a person who has missing teeth has other abnormality of teeth or not. For this study, 1,520 subjects(aged 2.9$\sim$17) who had visited pediatric dentist department of Chonbuk national university dental hospital within 2 years were examined with an panoramic radiograph; exempting third molar missing state. The obtained results are as follows. 1. 8.88% among total subjects show missing teeth; male 9.05%, female 8.64% 2. The most frequently missing permanent teeth were the mandibular second premolars(22.3%). The most frequently missing primary teeth are mandibular lateral incisors(50%). 3. 43.3% patients have one permanent missing tooth, 34.3% have two, and 10.4% have more than six, respectively. In primary teeth, 86.7% patients have one missing tooth, and 13.3% have two missing teeth. 4. 18 patients(13.3%) have missing teeth as well as hyperdontia, while some patients have microdont, ectopic eruption, and fusion teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.90-96
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• 2012

Supernumerary tooth occurs most frequently at premaxilla area. Followed by mandibular premolar area, mandibular fourth molar area, maxillary paramolar area. Mesiodens are mainly impacted in the palatal area and surgical approach is made at palatal side. The time of surgery remains controversial. In case of inverted or horizontal impacted supernumerary tooth, intraosseous tooth movement and vertical growth of premaxilla makes surgical extraction more difficult. And also the more quantity of removed bone is, the higher degree of difficulty is. Inverted mesiodens of these cases were impacted superior to apex level of adjacent permanent incisor. Although CT examination revealed exact location of impacted tooth, surgical procedure including ostectomy may take a long time more than expected. So, before surgical extraction, it's need to be considered several factors such as necessity of CT taking, degree of difficulty, direction of surgical approach, necessity of general anesthesia etc.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.4
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• pp.683-690
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• 1998

The purpose of this study was to evaluate the reliablity of laser Doppler flowmeter on the permanent maxillary central incisors with open apex. Laser Doppler flowmeter and electric pulp tests were done in 35 elementary students aged between 8 and 9 years and 35 females and males aged between 23 and 24 years. Teeth with open apex were confined to root developmental stage 5 and 6 by Moorrees classification. The threshold of electric pulp tests was decided the time of tingling sensation. More than three different electric pulp tests applied on every teeth with more than 3 minutes interval between each teeth due to the false response. Laser Doppler flowmeter test stablilzation and observation stages took more than 5 minutes each LDF values and electric pulp test thresholds were analyzed with student t-test. The results were as follows: 1. The electric pulp test threshold on teeth with immature and mature roots showed 28.4% and 100% response respectively, and the the LDF values on teeth with immature and mature roots showed 100% response. 2. The EPT thresholds on teeth with immature roots were larger than thresholds on teeth with mature roots(p<0.01). 3. No significant differences were found in the LDF values on teeth with immature and mature roots.

• The korean journal of orthodontics
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• v.25 no.4
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• pp.403-414
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• 1995

The purpose of this study was to investigate the histologic changes in mandibular periodontium during overbite closure for openbite treatment by continuous arch wires and anterior vertical elastics. Two female monkey(Macaca nemestrina) with permanent dentition were used. Posterior bite block was fixed to each of their maxillae, which made the animal temporary anterior openbite as well as stabilized the whole maxillary anchorage. In each mandible, all the teeth except the second molars which had been extracted, were prepared for cast crowns. 018 inch Standard brackets were welded on these crowns. After cementation, two types of the $016{\times}022$ inch continuous arch wires, the plain ideal arch to the control animal and the MEAW(multiloop edgewise archwire) to the other experimental one were inserted. Then anterior vertical elastics were applied for two weeks. The overbite depth changes in the monkeys and histologic examinations of the mandibular periodontiums suggested the following conclusions. 1. During two weeks of the experimental period, the overbite increased + 0.3 mm in the control and + 1.3 mm in the experimental one. 2. In both the control and the experimental animal, histologic examinations showed that incisors, canines and first premolars were subject to extrusive force and the rest of posteriors were subject to intrusive one. 3. In periodontiums of the extruded incisors of the experimental one, reorientation of the periodontal fiber structures reflected the direction of force and the alveolar bone surfaces including apical and crestal areas which had been subject to tension, were the front of new bone formation. 4. In periodontiums of the extruded incisors of the experimental one, neither excessive hyalinization nor gross root resorption was observed. 5. Alveolar bone remodeling of anteriors and posteriors was more remarkable in the experimental one than the control.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.654-660
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• 2001

Dentinogenesis imperfecta is an example of an inheritable dentinal defect originating during the histodifferentiation stage of tooth development, with involvement of the primary and permanent teeth. Shields, Bixler and El-Kafrawy proposed three types of Dentinogenesis imperfecta : Type I, II, III. Witkop reported a prevalence of 1 in 8000 with the trait, and no significant difference between male and female. Affected teeth have red-brown discoloration often with distinctive wearness of occlusal surface of posterior teeth and incisal surface of anterior teeth. Once enamel seperated from underlying defective dentin, the dentin demonstrates significantly acclerated attrision. Radiographically, the teeth have thin roots, bulbous crown, cervical constriction, and obliteration of the root canals and pulp chambers. In primary dentition periapical lesions or multiple root fractures are often observed. In successive generations the phenotypes of discoloration and wearness of teeth occurred, and one of the patient's subships, 10 year-old sister, showed general discoloration of her teeth and mild wearness. In this case, a 4 year-old male reported to the Yonsei University Pedodontics clinic, with a chief complaint of discolored teeth. The teeth showed generally yellowish-brown discoloration and moderate wearness. In radiographic features, obliteration of pulp, bulbous crown, and short roots were observed. It was diagnosed as Dentinogenesis imperfecta. The posterior teeth were restored with Stainless Steel Crown, and defective incisors including left upper primary central incisor which was extracted due to a root fracture with Open-faced Stainless Steel crown.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.4
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• pp.642-651
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• 2008

This study was carried out to give basic information of traumatic injuries of primary and permanent teeth which can be used for diagnosis and management of injured teeth. From January 2003 to July 2007, 570 children with 1394 teeth who came to pediatric dentistry and emergency center of Chonnam National University Hospital due to the traumatized teeth participated in this study. The following data were investigated. : age, sex, causes and places of trauma, position of injured teeth, types of injury, and treatment at the first visit. 1. Trauma prevailed at the age of 1, $6{\sim}8$, $17{\sim}18$ and the rate of males was more likely to be higher than the rate of females(1.9 : 1). 2. The main cause of injury is a fall-down injury for primary and mixed dentition, but is a traffic accident and fighting for permanent dentition, respectably. The place of injury for primary dentition is mainly home(45.3%), while street for mixed and permanent dentition. 3. The position of injured teeth according to the area in the mouth is mainly maxillary anterior teeth in both case of primary and permanent teeth and especially, the ratio of central incisors is high. 4. The periodontal tissue injury occurred the most frequently in the primary and the permanent teeth, but the ratio of hard tissue injury in the permanent teeth increased, compared with the primary teeth. 5. Among treatments at the first visit, observation without actual treatment comprised 75.6% in the primary teeth and 55.4% in the permanent teeth, respectably. The pulp necrosis occurred in 20.3% of the primary teeth and 26.6% of the permanent teeth in the case of the periodontal tissue injuries, respectably.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.74-81
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• 2014

Purpose: While studies have examined microleakage in endodontically treated teeth restored with posts, microleakage among post and adhesive systems remains a concern. This study compared the sealing properties of 3 adhesively luted post systems. Materials and methods: Thirty-six endodontically treated permanent maxillary central incisors were divided into 3 groups: Zirconia-glass fiber, Quartz-glass fiber, Polyethylene fiber posts. Post space was prepared and each post was adhesively luted with 3 systems. The specimens were separately immersed in freshly prepared 2% methylene blue solution for 1 week. The cleaned specimens were then embedded in autopolymerizing acrylic resin. The root portion of tooth were horizontally sectioned into three pieces (apical, middle, and coronal portions). An occlusal view of each section was digitally photographed with a stereomicroscope. The methylene blue-infiltrated surface for each specimen was measured. Dye penetration was estimated as the ratio of the methylene blue-infiltrated surface to the total dentin surface. Results: No significant differences were found among post types. The variables of middle section and 3-stage adhesive produced significant differences in microleakage between the following post pairs: zirconia-glass fiber versus quartz-glass fiber, zirconia-glass fiber versus polyethylene fiber, and quartz-glass fiber versus polyethylene fiber (P<.05). There were significant differences between the apical and coronal sections of each post type, and between apical versus middle sections of quarze-glass fiber and polyethylene fiber posts (P<.05). Conclusion: No significant differences were found among post types. The 3-stage adhesive produced significant differences in microleakage between the following post pairs.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.247-254
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• 2001

There is a growing tendency for injury and it is essential to know about the epidemiology of the injured teeth for proper and timely treatment. Through empirical data analysis of 120 children who came to pediatric dentistry of Kangnung National University Dental Hospital, this study purposes to give an understanding about the injury and analyzes the frequency by children's sex and age, the number of injured teeth according to the area in the mouth, the types of injury, causes and places of injury, the frequency occurred by month and hour, the position of injured teeth, and the elapse of time. The main findings of this study are summarized as follows: 1. The frequency analysis by sex shows that the rate of boys is more likely to be higher than girls(1.6:1). 2. The frequency analysis by age shows that the ratio of children between aged 2~4 and 8~10 are high. 3. The number of injured teeth is generally one(51.7%). 4. Periodontal tissue injury is the main cause for the primary teeth. In case of permanent teeth, the ratio of hard tissue injury which is much increased than the case of the primary teeth, is similar to that of periodontal tissue injury. 5. The main cause of injury is fall for both dentition; In case of permanent dentition, the ratio of injury by sports is increased. 6. The place of injury for primary teeth is mainly home(38.8%); Street and school for permanent teeth(42.5% and 35%, respectively). 7. The frequency by month shows that the injury is most frequently occurred in July. 8. The frequency analysis by hour shows that injury for primary teeth mostly happens in the morning; in the afternoon for permanent teeth. 9. The position of injured teeth according to the area in the mouth is mainly maxilla anterior in both case of primary and permanent teeth and especially the ratio of central incisors is high, 10. More than half(59.2%) of patients came to the hospital within one day and the seriously injured were likely to come within one day than the slightly injured.