Computer anchorage analysis of digitized picture of modified typodont

In contemporary orthodontic treatment, the extraction of a premolar is freq uently indicated, followed by canine retraction with bodily movement. The m ain. problem is how to prevent the mesial movement of first molars (loss of anchorage) and loss of the space obtained by extraction. The aim of the st udy was to evaluate the anchorage capacity of posterior teeth using SW (str aight wire) appliances after extraction of first premolars and to determine Goshgarian transpalatal arch as anchorage reinforcement. All experiments w ere recorded by video-camera, and the analogue signal has been. digitized a nd saved on PC. Computer animation visualised the direction. and the amount of tooth movement. Very significant loss of anchorage was found (in the co ntrol experiment), when molars and premolars were reinforced. No significan t difference between the active and non-active transpalatal arch has been p erceived in the sense of lateral anchorage stabilization.