Abstract
The purpose of this study was to examine the longitudinal change of occlusion in children. The materials were study models obtained annually from 27 patients (17 boys and 10 girls) aged 4 to 12, having no history of significant tooth decay or orthodontic treatment. The interdental spaces in the primary dentition, the anterior occlusal relationship, the terminal plane, the relationship of the permanent first molar, and the change of occlusion from the primary dentition to the permanent dentition, were discussed.
The results of this study were as follows:
1. The majority of interdental spaces in the primary dentition was observed to be the developmental and primate space for both sexes.
2. The percentage of normal occlusion at 5 years of age was 47.7% for boys and 50.0% for girls; at 12 years of age it was 23.5% for boys and 30.0% for girls. The type of abnormal occlusion that increased mostly between the ages of 4 and 12 was crowding of teeth.
3. The terminal plane was most frequently observed for both the horizontal and vertical types. The most common type of occlusion for front molars was the Class I relationship, followed by the Class II and Class III relationships, in that order. The majority has been observed to shift from the vertical type to the Class I relationship.
4. Of the cases where there was normal occlusion in the primary dentition period,62.5% had normal occlusion for the permanent dentition. Most of the cases of overbite in the primary dentition period progressed to malocclusion.
Thusly, the percentage of those with normal occlusion decreases with age, and in many cases, malocclusion does not heal spontaneously. We can therefore conclude that this suggests the need to provide occlusal guidance concerning dental health of patients in childhood.
