Abstract
The dental health examination of children at the age of one year and six months was conducted in nine areas (Iwamizawa, Morioka, Sendai, Suginami (Tokyo), Kanagawa, Ibarage (Osaka), Hiroshima, Tokushima, Fukuoka) of Japan. In this study, the superior labial frenum occupied one part of the examination. The following subjects were examined with each person, namely the frequency of the abnormal frenum, longitudinal change of the abnormal frenum and the relationship between the abnormal frenum and the upper mid-line space.
The subjects were 902 children who were examined every six months from one year and six months of age to three years and six months of age. The results were as follows.
1)The abnormal frenum was classified into the five types at one year and six months of age.
2)The maxillary abnormal frenum decreased in the higher age brackets. The abnormal frenum was observed in 27.3% of the subjects at the age of one year and six months,14.3% at the age of 2,9.3% at the age of 2 years and six months,6.4% at the age of 3 and 5.9% at the age of 3 years and six months.
3)Observating the longitudinal change of the abnormal frenum with the same persons, half of the children with an abnormal frenum returned to a normal frenum from the age 2.
4)The appearance of the upper mid-line space in the children with the abnormal frenum was most frequent among all the subjects, in each age bracket.
5)In the children with the abnormal frenum, over than half of the children with the upper mid-line space were observed, in each bracket, except at one year and six months of age.
6)In particular most of the children with the no changed abnormal frenum from one year and six months to three years and six months of age had the upper midline space.
7)It was considerated that the abnormal frenum was not the cause of origin the upper mid-line space, but was the result.
