[The research and analysis on the fused primary teeth regarding to the permantent dental dentition-10 years follow up]

36 cases with unilateral mandibular fused primary teeth have been followed up and analysed for 10 years.The result showed that the fused primary teeth obviously affect the secondary permanent teeth and permanent dental dentition.In this series,there was one secondary permanent tooth lost in all of 19 cases.The secondary permanent tooth was also fused tooth in 3 cases.The length of permanent dental dentition and the width of dentition in front of the second cuspids in the cases with one secondary permanent tooth lost were extremely shorter than that in the cases with secondary permanent teeth.In addition,the mandibular dental dentitions were towards the fused teeth side.Comparing to the synonymic teeth,the mesial and distal steps and the height of secondary permanent teeth of fused primary teeth were no difference from normal side.