Objective: To investigate the change of caries activity in children with fixed appliance.
Methods: 30 children of permanent dentition were treated with edgewise appliance. CAT was used to test the degree of caries activity before the orthodontic treatment, at the first week, at the first month, at the third month and at the sixth month of appliance bonding respectively.
Results: Compared with pre-treatment, there was a significant difference of CAT at the first, third and sixth month of treatment; compared with the first week of treatment, there was also a significant difference of CAT at the third and sixth month of treatment.
Conclusions: The CAT degree increases in children with fixed orthodontic appliance and these children are more sensitive to dental caries.