Occlusal contact changes after the active phase of orthodontic treatment

Occlusal contacts in maximum intercuspidation were recorded at the end of active orthodontic treatment and 3 months into the retention period. Hawley retainer, tooth positioner, and nontreated normal occlusion groups of 10 subjects were examined for change in the number and location of occlusal contacts. Soft silicone-base impression materials were used to make interocclusal registrations. The contacts were then transferred onto the study models, and standard photographs of each model were taken. To determine any locational changes, superimposition of the first registration photograph on the second one was done. Significant difference in the number of total contacts between the treated groups and the control sample was recorded at both time periods. Use of a tooth positioner as a retainer did not show any additional gain of contacts in the positioner group when compared with the Hawley retainer group. No significant change in the location of contacts occurred during the period of observation.