RESUMEN
OBJECTIVE: To evaluate the biomechanic changes of craniofacial complex with rapid maxillary expansion using implant anchorage. METHODS: Rapid maxillary expansion using implant anchorage was simulated with MSC. Marc. Mentat software, restrained at the region around the foramen magnum and the anterior middle point of parietale and foramen. In the area of implant surface, forces of 80 N were applied with rapid maxillary expansion. Different numbers and positions of implant anchorage were chosen. Their influences on the craniofacial complex were analysed. RESULTS: The stress distribution and displacement trend of the craniofacial complex under different conditions were approximate. The greatest stress appeared on the areas along the frontonasal suture, zygomaticomaxillary suture, nasomaxillary suture and pterygopalatal suture. Two halves of palatine were separated in a "V" shape. Maximal stress and displacement were found when the implant was located between maxillary canine and first premolar. CONCLUSION: The numbers of implant are not associated with the size of stress and displacement. Greater stress and displacement occur when the implant position is in the front.