Anchorage effect of palatal implants under various forces: A finite element study

The palatal implant can be used with a transpalatal arch (TPA) connected with the second premolar to provide anchorage. The purpose of this study was to analyze the anchorage effects of a palatal implant by using a finite element analysis. Four models (Model 1 with a 6-mm implant, Model 2 with a 4-mm implant, Model 3 without an implant, Model 4 without TPA or an implant) were created according to the clinical situation. Stress induced in three dimensions (mesial, transversal, and vertical) was investigated. The results showed that a 6-mm palatal implant could reduce periodontal ligament stress significantly (average stress was reduced 14.44% for the mesial force, 17.31% for the vertical force, and 60.28% for the transversal force separately). The 4-mm palatal implant showed almost the same anchorage effect as the 6-mm implant. TPA showed significant anchorage effect (average stress was reduced 8.16%) only when the second premolars were subjected to transversal force. These results suggest that the anchorage effect of palatal implants was related to the direction of the forces and that a 4-mm implant might have the same anchorage effect as a 6-mm implant. (C) 2006 Elsevier Ltd and the Japanese Orthodontic Society. All rights reserved.