• 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.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.

• The Journal of the Korean dental association
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• v.30 no.4 s.275
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• pp.323-326
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• 1992

• The Journal of the Korean dental association
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• v.30 no.6 s.277
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• pp.479-480
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• 1992

• The Journal of the Korean dental association
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• v.30 no.8 s.279
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• pp.625-627
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• 1992

• The Journal of the Korean dental association
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• v.30 no.9 s.280
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• pp.697-699
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• 1992

• The Journal of the Korean dental association
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• v.30 no.10 s.281
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• pp.771-773
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• 1992

• The Journal of the Korean dental association
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• v.30 no.7 s.278
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• pp.539-542
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• 1992

• The Journal of the Korean dental association
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• v.30 no.5 s.276
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• pp.411-412
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• 1992

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.251-255
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• 2005

Radiotherapy for head and neck tumors is a viable treatment modality. However, a wide range of potentially debilitating dental complications may be accompanied by this treatment. We report two cases of developmental disturbance of permanent tooth germs after radiotherapy. The one was that of a seven-year-old girl, who had congenitally missing teeth, and microdontia of permanent tooth germs. she had received radiotherapy for acute myelocytic leukemia at the age of 19 months. The other was that of a nine-year-old boy, in which congenitally missing teeth, microdontia, root hypoplasia, and enamel hypoplasia of permanent teeth were observed. He had undergone a course of radiotherapy for bilateral retinoblastoma at the age of 13 months.