• 대한구순구개열학회지
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• 제4권2호
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• pp.19-27
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• 2001

This study was performed to determine the prevalence of hypodontia and hyperdontia of permanent teeth among Korean schoolchildren, and to compare differences in the prevalence between Korea, other country, and other ethnic groups. The sample consisted of 346 girls aged 6.9～0.3 yr and 375 boys aged 6.8～0.4 yr on whom a panoramic radiograph was taken at Yeonchun-Gun community in Korea. The prevalence of congenitally missing teeth (third molars excluded) was 6.7% in boys and somewhat higher, 9.5% in girls, and 8.0% for both sexes combined. On the average, number of missing teeth per affected child was 1.9 teeth. The most commonly congenitally missing teeth were the mandibular second premolar (32.7%), followed by the mandibular incisor (28.7%), the maxillary second premolar (16.7%), and the maxillary lateral incisors (10.2%). The prevalence of supernumerary teeth was 2.1 % in boys, 1.4% in girls, and 1.8% for both sexes combined. The most common supernumerary teeth were the mesiodens (76.9%), followed by the supernumerary premolar (23.1 %). The affected male-female ratio was 1.6: 1.0. The prevalence of congenital missing teeth in this study was similar to in studies of Japanese, Danish, American and German. The frequency of hyperdontia was lower in this study than in studies of Chinese children, Japanese and American.

• Imaging Science in Dentistry
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• 제44권1호
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• pp.7-13
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• 2014

Purpose: This study was performed to evaluate the prevalence of all types and subtypes of dental anomalies among 7- to 35-year-old patients by using panoramic radiographs. Materials and Methods: This cross-sectional study was conducted on 1649 people in Hamadan City, in 2012-2013. The prevalence of four types and 12 subtypes of dental anomalies was evaluated by two observers separately by using panoramic radiography. Dental anomalies were divided into four types: (a) shape (including fusion, taurodontism, and dens invagination); (b) number (including hypodontia, oligodontia, and hyperdontia); (c) structure (including amelogenesis imperfecta, dentinogenesis imperfecta, and dentin dysplasia); and (d) position (including displacement, impaction, and dilacerations). Results: The reliability between the two observers was 79.56% according to the Kappa statistics. The prevalence of dental anomalies diagnosed by panoramic radiographs was 29%. Anomalies of position and number were the most common types of abnormalities, and anomalies of shape and structure were the least in both genders. Anomalies of impaction (44.76%), dilacerations (21.11%), hypodontia (15.88%), taurodontism (9.29%), and hyperdontia (6.76%) were the most common subtypes of dental anomalies. The anomalies of shape and number were more common in the age groups of 7-12 years and 13-15 years, respectively, while the anomalies of structure and position were more common among the other age groups. Conclusion: Anomalies of tooth position were the most common type of dental anomalies, and structure anomalies were the least in this Iranian population. The frequency and type of dental anomalies vary within and between populations, confirming the role of racial factors in the prevalence of dental anomalies.

• 대한소아치과학회지
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• 제29권4호
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• pp.574-578
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• 2002

소아치과 임상에서 정중 과잉치는 비교적 흔히 볼 수 있는 치아의 발육이상이다. 그런데, 이와 더불어 인접 치아가 선천 결손된 경우에는 배열상에 국소적으로 여러 문제점을 유발하기도 한다. 이처럼 동일 개체에서 과잉치와 선천 결손이 동시에 나타난 경우를 'hypo-hyperodontia' 또는 'oligo-pleiodontia'라고 부른다. 발생학적으로는 반대 현상인 이 두 가지 치아이상이 병발된 증례에 관해서는 지금까지 소수의 증례보고가 발표된 바 있다. 본 고에서는 정중 과잉치를 가지고 있는 환아 중에서 치아의 선천 결손이 나타난 발생양상을 조사하고, 치아의 선천 결손에 관한 기존의 역학 자료와 비교해 보았다. 지난 3년간 부산대학교병원 소아치과에 과잉치 발거를 주소로 내원한 $5{\sim}12$세 아동 310명 (남아 247명, 여아 63명)을 대상으로, 이들의 파노라마사진을 통하여 제 3대구치를 제외한 선천 결손치의 분포를 조사하여 다음과 같은 결과를 얻었다. 1. 정중 과잉치를 가진 증례 중 치아의 선천 결손 발생빈도는, 남자 247명중 39명(15.8%), 여자 63명중 14명(22.2%)으로, 전체적으로는 310명중 53명(17.1%)이었다. 2. 치아별 선천 결손의 분포는 상악 측절치와 하악 제 2소구치에서 각각 22.7%, 상악 제 2소구치 17.3%, 하악 측절치 16.0%로 나타났다. 상하악의 분포는 상악에서 49.3%, 하악에서 50.7%로 나타났고, 통계학적으로 약간의 차이는 없었다. 3. 결손치의 갯수는 1개인 경우가 67.9%, 2개인 경우가 22.7%, 3개인 경우가 9.4%로 나타났다.