• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.693-702
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• 2005

Accurate timing and sequence of eruption of permanent teeth are indicies of growth and essential for pediatric dentistry and pediatric clinical orthodontics. From the children brought to the Yonsei Dental Hospital during 2001 to 2003, 654 boys and 542 girls, ranging in age from five to fourteen years, were selected and analysed. The following was concluded. 1. Eruption time of maxillary teeth is 6.81 years in boys, 6.78 years in girls for central incisor, 8.30 years in boys, 7.98 years in girls for lateral incisor, 10.28 years in boys, 10.04 years in girls for canine, 9.74 years in boys, 9.90 years in girls for first premolar, 10.87 years in boys, 10.41 years in girls for second premolar, 6.25 years in boys, 6.54 years in girls for first permanent molar, 12.21 years in boys, 12.03 years in girls for second permanent molar 2. Eruption time of mandibular teeth is 6.00 years in boys, 6.06 years in girls for central incisor, 6.99 years in boys, 6.74 years in girls for lateral incisor, 9.83 years in boys, 9.17 years in girls for canine, 9.92 years in boys, 9.75 years in girls for first premolar, 10.66 years in boys, 10.39 years in girls for second premolar, 5.99 years in boys, 5.75 years in girls for first permanent molar, 11.92 years in boys, 12.17 years in girls or second permanent molar. 3. The following eruption sequence was observed the first permanent molar erupted first, followed by the central incisor, the lateral incisor, the first premolar, the canine, the second premolar and the second permanent molar in the maxilla. The first permanent molar erupted first, followed by the central incisor, the lateral incisor, the canine, the first premolar, the second premolar and the second permanent molar in the mandible.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.574-578
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• 2002

Mesiodens is developmental tooth anomaly which is commonly found in clinical pediatric dentistry. however, it may cause many partial problem in tooth alignment when congenitally missing teeth was accompanied by mesiodens. The terms, concomitant hypodontia and hyperdontia' and oligo-pleiodontia' have been used to describe the condition in witch developmental absence of teeth and supernumerary teeth are present in the same individual. Only a few case reports of this rare condition which is opposite developmental phenomena exist in the literature. The purpose of this study is survey of congenitally missing teeth in mesiodens case and to compare previous literature of congenitally missing teeth in normal. The subjects were 310 children(247 male and 63 female) at the age from 5 to 12 years visiting the Department of Pediatric Dentistry, Pusan National University Hospital with mesiodens for last 3 years. With their pantomograms we studied congenitally missing teeth except permanent 3rd molar. 1. The preference of congenitally missing teeth in mesiodens cases was revealed to be 17.1%(53 out of 310 in total), and there was a higher prevalence in females(22.2%) than in males(15.8%). 2. The most frequently missing teeth were maxillary lateral incisors(22.7%) and mandibular second premolars(22.7%), followed by maxillary second premolar(17.3%), and mandibular lateral incisors(16.0%). There was no significant differences between maxilla(49.3%) and mandible(50.7%). 3. In number of congenitally missing teeth per person, 69.9% had one missing tooth, 22.7% had two missing teeth and 9.4% had three missing teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.310-317
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• 2009

Dens evaginatus is a dental anomaly involving an extra cusp or tubercle that protrudes from the occlusal surface of the affected tooth. The prevalence of dens evaginatus is 1 to 4 percent, and dens evaginatus is observed most commonly in premolars. It can be worn or fractured easily, resulting in pulpal exposure, pulpal infection, loss of vitality, facial infection and osteomyelitis. Since the tooth frequently has the immature apex when the tubercle is fractured, there is difficulty in treatment. Although calcium hydroxide is widely used for pulp treatment of an immature permanent tooth, several alternatives have been suggested to reduce patient's appointments. Mineral trioxide aggregate is considered biocom-patible and has excellent marginal sealing ability. In addition, it can minimize patient's visits. In this case report, apexification with MTA was attempted on the immature premolars in patients with cellulitis patient, caused by pulp necrosis due to dens evaginatus. Favorable clinical and radiologic results were achieved. In one case, continued root formation was observed.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.2
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• pp.196-203
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• 2002

Most dentigerous cysts are solitary. Bilateral and multiple dentigerous cysts are rare and occur typically in association with a number of syndromes such as Maroteaux-Lamy syndrome, Hunter's syndrome, Basal cell nevus syndrome, Marfan syndrome, cleidocranial dysplasia. The presented case is of bilateral nonsyndromic, dentigerous cysts associated with mandibular right and left first premolars. A marsupialization procedure may be a choice of treatment for a large sized dentigerous cyst rather than an enucleation. The marsupialization procedure is recommended during the age when the erupting force of the teeth is still strong. We can expect the unerupted tooth to erupt normally. Although most of bilateral or multiple dentigerous cysts which are not associated with syndromes are rare, a bilateral dentigerous cyst without syndrome is seen. Therefore, it is wise to explain a possibility of development of new one to patient / parents in advance.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.2
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• pp.185-193
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• 1992

The purpose of this study was to evaluate the prevalence and distribution of tooth number anomaly by means of the analysis of panoramic radiographs in 6,531 patients visited the Dental Infirmary of Kyungpook National University Hospital from January 1983 to May 1992. The results were as follows: 1. The prevalence of congenitally missing teeth except third molar was revealed to be 10.8%, and there was a hihger prevalence in females(44.6%) than in males(55.4%). Mandibular 2nd premolars(23.2 %) were absent most frequently, followed by maxillary lateral incisors(18.4 %), mandibular lateral incisors(18.3%), and maxillary second premolars(15.4 %) in descending order of frequency. As to the number of congenitally missing teeth, the percentage of missing one tooth was 48%, missing two teeth was 35.4 %, missing three teeth was 6.6%. 2. he prevalence of congenitally missing third molars was revealed to be 39.7%. There was a higher prevalence n the maxilla(60.3%) than in the mandible(39.7%). Maxillary right 3rd molars(30.6%) were absent most frequently, followed by maxillary left 3rd molar(29.7%), mandibular right 3rd molar(202%), mandibular left 3rd molar(19.5%) in descending order of frequency. 3. The prevalence of supernumerary teeth was revealed to be 4.2%, and there was a higher prevalence in males(65.7%) than in females(34.3 ). They were ound most frequently in maxillary central incisor area(64.8%), followed by maxillary lateral incisor area(132%), posterior area of maxillary third molar(8.7%) in descending order of frequency. As to the number of supernumerary teeth; The percentage of one supernumerary tooth was 79.9%, two supernumerary teeth was 8.9%, three supernumerary teeth was 1.2 %.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.3
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• pp.312-319
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• 2020

Precocious puberty (PP) is defined as the early development of secondary sexual characteristics (before the ages of 8 years in girls and 9 years in boys). The aim of this study is to identify characteristics of the dental maturity in girls with PP that discriminate them from normal healthy girls. This study included 99 girls aged 6 - 8 years with PP and 99 girls without past medical history of same chronological age (control group). The study was performed on 198 panoramic radiographs (99 PP girls, 99 control group girls). Demirjian method was used to evaluate the panoramic radiographs and determine dental maturity. Difference in dental maturity score and tooth formation stages between the two groups were analyzed. The PP group showed significant higher maturity score than control group. Among mandibular teeth, mandibular 2nd premolar and 2nd molar were significantly more mature in the PP group than control group. Logistic regression analysis showed that mandibular 2nd molar was only significant predictor for PP girls.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.327-337
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• 1999

Patients with skeletal class III can be succesfully treated by either orthognathic surgery or orthodontic treatment owing to unavoidable circumstances. Systers were treated , elder syster by orthognathic surgery and younger one by compromised treatment. For the ideal treatment goal, orthognathic surgery will be inevitable in skeletal problem case, but by the patient's private situations orthodontist cannot help doing compromised treatment. It could be another option if correct biomechanical approach is used.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.281-302
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• 1987

의치상 재료 종류에 따라 의치, 점막 및 하악골에 발생되는 변위 및 응력을 연구하기 위하여 컴퓨터를 이용한 수치적 해석인 2차원 유한 요소법을 이용하였다. 2차원 유한 요소 모형으로선 표준 크기의 하악골 및 의치를 고려하여 231개의 사변형 요소 및 268개의 절점으로 분할한 후 각 구성 성분의 물리적 성질인 탄성률 및 프와송비를 대입시켰다. 사용된 의치로서는 일반 합성수지의치, 2mm후경의 탄성재를 의치상 하부에 이장한 합성수지의치, 2mm후경의 탄성재를 치아와 의치상 중앙에 삽입한 합성수지의치 및 0.5mm후경의 금속상의치의 4종류였으며, 하중시에 하악의 고정 부위로선 생체와 동일 조건을 부여하기 위하여 교근, 내측익돌근, 측두근등의 하악 폐구근이 부착되는 하악각 부위 및 하악 근돌기 부위의 16절점을 고정점으로 하였다. 하중 조건으로선 하악 제1대구치의 일점에 10kg의 수직 집중하중, 하악 중절치의 일점에 7kg의 수직 집중하중 및 하악 제 1소구치로 부터 하악 제2대구치까지의 교합면에 10kg의 수직 분산하중을 부여하여 분석한 결과는 다음과 같다. 1. 하중이 의치 교합면위의 가해진 부위에 따라 다양한 의치 회전 및 강하 현상을 보였으며, 탄성재를 이장 및 삽입한 합성 수지 의치의 변위가 일반 합성수지의치 및 금속상 의치의 변위보다 더 컸다. 2. 주응력을 고려할때 점막 부위에는 주로 압축 응력이 작용하였으며 치조제 부위는 압축응력과 인장 응력이 함께 작용하였다. 3. 탄성재를 삽입한 합성수지의치에 최고 등가 응력이 집중되었으며 그 다음은 탄성재를 이장한 합성수지의치, 일반 합성수지의치의 순이였으며 금속상의 경우는 금속을 따라서 높은 등가 응력이 넓게 분산되었다. 4. 의치상 종류에 관계없이 동일 하중 조건하에선 점막에 나타나는 등가 응력의 크기 및 분산양태는 유사하였다. 5. 하악골에서 등가 응력은 의치지지 부위에만 국한되지 않고 넓게 분산 되었으며 의치상 종류 및 하중 조건에 관계없이 치조제 후방 및 하악연의 후방 부위에 특히 높은 등가응력이 집중되었다. 6. 하악 중절치의 일점에 수직 하중을 가한 경우가 다른 하중 조건에 비하여 지지점과의 거리차이로 인하여 하악골에 가장 높은 등가 응력을 유발하였다. 7. 의치상 재료에 따른 하악 골에 발생되는 응력의 크기 및 분산에는 큰 차이가 없으나 금속상의 경우가 교합압을 분산하는데는 효과적이었다.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.79-86
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• 2012

In most patients with severe crowding or lip protrusion, orthodontic treatment with tooth extraction is done. In these patients, even though space is closed after orthodontic treatment, gingival invagination is observed on the extracted site. Since there are possibilities of space recurrence and regional periodontic problems occurrence, periodontic treatment is necessary on the gingival invagination region. This case was a 16 year old female with a chief complaint of crooked teeth. Since her maxillary premolars were already extracted a few years ago at a local dental clinic, orthodontic treatment was done by extracting mandibular premolars. Unlike maxillary premolar regions, gingival invagination occurred in mandibular premolar regions and gingival flattening was done by excising the gingival invaginated region. Gingival flattening was done once on the left side, twice on the right side and showed stable results. This is a case report of a patient that was prone to gingival invagination after orthodontic treatment with extraction and was treated with gingival flattening.

• Journal of dental hygiene science
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• v.9 no.5
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• pp.563-570
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• 2009

This study carried out the survey of the actual condition targeting 303 patients with execution of treatment after medical examination among patients who visited from January 2, 2008 to December 31, 2008 at dental hospital where is located in K region, and analyzed by using a program of SPSS13.0. The ratio of treatment in posterior was high with 76.9% in central incisor, 62.3% in the 1st bicuspids, and 45.3% in the first permanent molars as for health in the right teeth of maxillary, and with 77.9% in central incisor, 64.4% in the 1st bicuspids, and 47.6% in the first permanent molars as for the left teeth. In the lower jaw, the ratio of treatment in posterior was high with 92.1% in central incisor, 73.9% in the 1st bicuspids, and 42.6% in the first permanent molars as for health in the right teeth, and with 92.1% in central incisor, 75.9% in the 1st bicuspids, and 43.2% in the first permanent molars as for the left teeth. The upper left cuspid was treated in older patients by age(${\chi}^2=32.33$, p=0.000), in the more patients with high blood pressure(${\chi}^2=12.60$, p=0.000), and in case of systemic disease. The significant difference was shown(${\chi}^2=6.37$, p=0.012). The older patients led to being treated cuspid among right teeth in the lower jaw. The significant difference was shown according in the more patients with high blood pressure(${\chi}^2=8.26$, p=0.004). The left cuspid in the lower jaw was treated in the older patients by age the statistically significant difference was shown(${\chi}^2=12.10$, p=0.007).