Changes in tooth contacts following orthodontic treatment.

Occlusal contacts in maximum intercuspation were examined in 38 patients at the end of the active phase of orthodontic treatment and again 3 months into the retention phase to assess the initial posttreatment occlusal changes. The sample consisted of 23 patients with conventional retainers and 15 patients with gnathological rubber tooth positioners. Polyether rubber impression bites were used to record occlusal contacts. The locations of the contacts were then transferred to study models. In the combined sample (N = 38), the total number of contacts increased 14% over the 3-month period. This was due entirely to an increase in the number of contacts on posterior teeth (premolars and molars). Those cases with fewer teeth in contact at the end of treatment developed more teeth in contact over the 3-month period. Although the group retained with positioners demonstrated a greater gain in the total number of teeth in contact over time when compared with the group with conventional retainers, the additional gain was minimal.