The first molar will play a key role in the formation of permanent dentition and also is easy to be caries. In this series, 7968 cases 4-6 yrs old children are investigated and the eruption and caries of first molar a...The first molar will play a key role in the formation of permanent dentition and also is easy to be caries. In this series, 7968 cases 4-6 yrs old children are investigated and the eruption and caries of first molar are analysed. The results are as follows: The eruption rate of first molar in 7968 cases 4-6 yrs old children is 22.13%. The mean number of molar erupted is 0.55+1.17. Both are in very signiflicant sexual difference. The eruption in girls is earlier than that in boys. The eruption rates are 1.01% in 4 yrs old group and 59.00% in 6 yrs old group. In the per centage of the molar erupted, (?) is 66.26% with symmetrical rate 69.31%, 6 is 33.74% with symmetrical rate 33.24%. The incidence rate of caries in 1763 cases 4-6 yrs old children with first molar erupted is 1.76% with dft 0.02±0.15. The dft in cases of caries is 1.26±0.63. There are two molars with caries of Degree IV in 5 yrs old group. The eruption and caries of the first molar in childhood are analysed. The importance of prevention dnd treatment of first permanent molar in childhood is indicated.展开更多
文摘The first molar will play a key role in the formation of permanent dentition and also is easy to be caries. In this series, 7968 cases 4-6 yrs old children are investigated and the eruption and caries of first molar are analysed. The results are as follows: The eruption rate of first molar in 7968 cases 4-6 yrs old children is 22.13%. The mean number of molar erupted is 0.55+1.17. Both are in very signiflicant sexual difference. The eruption in girls is earlier than that in boys. The eruption rates are 1.01% in 4 yrs old group and 59.00% in 6 yrs old group. In the per centage of the molar erupted, (?) is 66.26% with symmetrical rate 69.31%, 6 is 33.74% with symmetrical rate 33.24%. The incidence rate of caries in 1763 cases 4-6 yrs old children with first molar erupted is 1.76% with dft 0.02±0.15. The dft in cases of caries is 1.26±0.63. There are two molars with caries of Degree IV in 5 yrs old group. The eruption and caries of the first molar in childhood are analysed. The importance of prevention dnd treatment of first permanent molar in childhood is indicated.
