Abstract
It has been stated that 40-50% of the cases with fusion of deciduous teeth showed congenitally missing of one of the permanent successors. In other studies however, differences in prevalences were observed when comparing the types of fused deciduous teeth. The purpose of this study was to investigate the fused deciduous teeth and their relationship with the permanent successors in order to this apply as a good referenced at the public dental health services for children.
The sample consisted of 152 children (79 boys and 73 girls). Total of 182 fused deciduous teeth (boys: 100 cases, girls: 82 cases) were found during routine clinical examination. Dental radiographs were obtained from each child and all of the children were observed longitudinally until their permanent successors erupted.
1) The prevalence of congenitally missing permanent successors differed considerably among the types of fused teeth.
2) Cases with fusion of a mandibular central and lateral deciduous incisor (ab-type) showed a 11.1% of prevalence congenitally missing of those permanent successors. However,71.1% of the cases with fusion of a mandibular lateral deciduous incisor and deciduous canine (bc-Type)showed congenitally missing of a permanent tooth.
3) Cases with the fusion of a maxillary central and lateral deciduous incisor (ab-type) showed a 70.6% prevalence of congenitally missing successors and when they existed, many cases showed malformed crowns such as peg-shaped teeth. It is therefore reasonable to assume that this type of fusion nearly always affects the permanent dentition.
4) Statistically, there was a significant prevalence of mandibular ab-types occurring in boys and mandibular bc-types occurring in girls. No significant difference based on sex was observed however in the prevalences of congenitally missing permanent tooth.
5) No bilateral difference was observed in the prevalence of congenitally missing permanent tooth.
