APICAL ROOT RESORPTION DURING ORTHODONTIC TREATMENT OF PATIENTS WITH MULTIPLE APLASIA - A STUDY OF MAXILLARY INCISORS

The aim of this study was to evaluate the risk of root resorption duri ng orthodontic treatment of patients with aplasia, and to analyse the relative importance of some anamnestic and treatment variables. The su bjects comprised 68 orthodontically treated patients with 1-16 congeni tally missing teeth. The age of the patients was 11-20 years (mean 15 years). All patients were treated with fixed edgewise appliances. The purpose of the orthodontic treatment varied: to create optimal conditi ons for prosthetic restorations or osseointegrated implants, or to ach ieve aesthetic and functional alignment of teeth in less severe cases. The degree of root resorption was assessed before and after treatment from intra-oral radiographs of the maxillary incisors using a scale o f 0-4. in all, 186 maxillary incisors were evaluated. The degree of ap ical root resorption was significantly greater in cases of multiple ap lasia (4-16 missing teeth) than in those with only one to three missin g teeth. Root form, treatment time with rectangular wires and intermax illary elastics, and total treatment time were significantly related t o root resorption. Discriminant analysis disclosed that the following variables were the most important determinants of root resorption: num ber of missing teeth, root form, and time with rectangular archwires a nd intermaxillary elastics. It is concluded that there is a high risk of apical root resorption during orthodontic treatment in patients wit h multiple aplasia (four or more teeth), in particular in teeth with a n abnormal root form and lengthy treatment with elastics and rectangul ar archwires.