한국인(韓國人) 아동(兒童)에 있어서 상악제1대구치(上顎第一大臼齒)의 위치부정맹출(位置不正萌出)에 관(關)한 고찰(考察)

CONSIDERATIONS ON ECTOPIC ERUPTION OF MAXILLARY 1ST. MOLAR OF CHILDREN IN KOREA.

The author has observed the ectopic eruption pattern on oblique cephalogram of 195 children. (5years: 78, 6 years: 58, 7 years: 59). The results were as follows; 1) Making a comparison between hold type and jump type of ectopic eruption, there are 4 cases in Hold type, 5 cases in jump type. 2) Making a comparison of ectopic eruptin between male and female, there are 7 cases in male, 2 cases in female. 3) Making a comparison of ectopic eruption between right side and left side, there are 5 cases at right side, 4 cases at left side. 4) Making a comparison of ectopic eruption among 5 years to 7 years, there are 4 cases in 5 years, 3 cases in 6 years, 2 cases in 7 years. 5) The prevalence of ectopic eruption of the maxillary first molar was 4.61%. 6) Normal eruption angle of the maxillary first molar is prevailing in $80^{\circ}{\sim}85^{\circ}$.