Abstract
This study was conducted to calrify the relationship between oral habits and malocclusion. The subjects were 238 children who were born during the period from May 1985 to November 1988, and who underwent oral health examination at one and a half, two, two and a half and three years of age. The prevalence of oral habits and malocclusion, the duration of the appearance and disappearance of finger sucking as well as the nursing environment were investigated.
The results were as follows:
1) The ratios of the prevalence of oral habits at one and a half, two, two and a half and three years of age were 33.6%,36.2%,38.1% and 44.3%, respectively. They increased with age. The ratios of the prevalence of finger sucking at one and a half, two, two and a half and three years of age were 24.1%,27.2%,25.0% and 23.4%, respectively. It did not significantly change with age.
2) The ratios of the prevalence of malocclusion at one and a half, two, two and a half and three years of age were 50.0%,54.8%,52.1% and 45.8%, respectively. They did not significantly change with age. Maxillary protrusion protrusion increased, deep bite, mandibular protrusion, cross bite and crowding decreased, and open bite and edge to edge coclusion did not change with age.
3) The prevalence of open bite or maxillary protrusion in children with finger sucking was significantly higher than in children without finger sucking. The children with finger sucking continuously more than one year until two and a half years of age showed a significantly high frequency of open bite or maxillary protrusion at three years of age.
4) The probability of open bite or maxillary protrusion at three years of age was significantly higher in the child who was an only child, whose father and/or mother was an office worker, who lived without grandparent(s) and/or who nursed in a day care center or kindergarten.
