[Process of the tooth brushing habit formation in children. 1. Period of the start and present circumstances classified by age].

The purpose of this study was to investigate the process by which the tooth brushing habit was formed in children. The study is based on questionnaires about the habit of tooth brushing from mothers of kindergarten pupils aged from one to six years living in Nagoya and the suburbs. The results of this study were summarised as follows: 1. Period of the start: 1) The number of children who started tooth brushing before the age of one year and six months was 75.7%, and before the age of two, 88.3%. 2) The item of "Eruption of the teeth" showed the highest ratio (49.2%) regarding the motive for the start of tooth brushing. 3) The children who started tooth brushing with the motive which construction about caries prevention with mothers as the main tended to start the earliest. 4) The ratio of persons who actually brush the children's teeth were as follows, "mother brushes (51.6%)", "mother after her child (37.1%)" and "child brushes (6.8%)". 5) The number of children who started using a tooth-brush before the age of two years was 78.8%, and before the age of two years and six months, 92.5%. 2. Present circumstances classified by age: 1) The number of children whose teeth are brushed by themselves or their mothers more than once a day before they were six years old was 61.8%. 2) In all ages, the group of once or twice a day showed a high ratio for frequency of tooth brushing. 3) "mother brushes (47.4%)" for one year olds, and "mother helps her child's brushing (85.7-53.6%)" for two to five year olds, and "child brushes (64.8%)" for six years olds were the highest ratios regarding the persons who actually brush the children's teeth. 4) Co-operative attitude of the children towards their mother's help is bad for one year olds, but good above two years old. 5) Attitude of the children towards tooth brushing is negative under three years old, and positive above four years old. 6) There is little hope that children can brush well by themselves under two years old. 7) children who have experienced guidance in tooth brushing from their mothers before they were three years old numbered 84.7%, and from a dentist or dental hygienist before they were six years old numbered 49.8%.