THE ROENTGENOGRAPHIC STUDY OF THE RELATIONSHIP BETWEEN ERUPTION AND CALCIFICATION OF THE MANDIBULAR PERMANENT TEETH IN KOREAN.

한국인 하악 영구치 석회화와 맹출의 상호 관계에 관한 방사선학적 연구

  • Kim, Soon-Joo (Department of Pedodntics College of Dentistry yensei University) ;
  • Lee, Jong-Gap (Department of Pedodntics College of Dentistry yensei University)
  • 김순주 (연세대학교 치과대학 소아치과학 교실) ;
  • 이종갑 (연세대학교 치과대학 소아치과학 교실)
  • Published : 1979.01.01

Abstract

The purpose of this study was to finding out the relationship between the tooth calcification and eruption of the mandibular permanent teeth in Korean. This study was undertaken in 592 children at ages from 3 to 13 years who had good oral condition by means of panoramic roentgenographic analysis. The following results were obtained. 1. The mean ages of crown completion were as follows; Canine 1st. Premolar 2nd. Premolar 1st. Molar Male 6yrs. 4mos. 6yrs. 8mos. 7yrs. 6mos. 7yrs. 6mos. Female 5yrs. 11mos. 6yrs. 5mos. 7yrs. 2mos. 3yrs. 3mos. 2. Each tooth started to move toward occlusion at approximately stage 6 or after crown completion. 3. The highest increment in eruption rate was at about 1/3~1/2 completion of root and ages at 10-11 years in male, 9-10 years in female. 4. Eruption period of both sexes were as follows; Canine: 6-12years 1st. Premolar: 7-12 years 2nd. Premolar: 7-13 years 1st. Molar: 3-7 years 5. The eruption was completed before the root completion. 6. The sequence of eruption and calcification was 1st. Molar-Canine-1st. Premolar-2nd. Premolar in both sexes.

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