Finite element analysis of three zygomatic implant techniques for the severely atrophic edentulous maxilla Hailin Wen, DDS, PhD, a Weihua Guo, DDS, PhD, b Rui Liang, ME, c Lin Xiang, DDS, PhD, d Gang Long, DDS, PhD, e Tingting Wang, MSD, f Meng Deng, MSD, g and Weidong Tian, DDS, PhD h Sichuan University, Chengdu, China Statement of problem. A variety of zygomatic implantation techniques currently exist; however, a consensus regarding the most suitable method has not yet been reached. Purpose. The purpose of this study was to evaluate and compare 3 zygomatic implantation techniques and to clarify the optimal number and position of zygomatic and dental implants for the reconstruction of the severely atrophied edentulous maxilla. Material and methods. A 3-dimensional finite element analysis craniofacial model was constructed from the computed tomography data of a selected patient with a severely atrophic edentulous maxilla. Modeled zygomatic implants were inserted into the craniofacial model with 3 surgical techniques (classic Brånemark, exteriorized, and extramaxillary), and with 3 model variations that involved the number and position of zygomatic and dental implants. The zygomatic implants were loaded with a vertical force of 150 N and a lateral force of 50 N. The stresses on and deformations of the bones and implants were then observed and compared. Results. No obvious differences in the amount and distribution of stress on the external craniofacial bones were detected in the models. The lowest stresses on the zygomatic implants were observed in the exteriorized technique group. The lowest deformations of the bone that surrounds zygomatic implants and dental implants were observed in the exteriorized technique and classic Brånemark technique groups. For the exteriorized technique group, the model with 1 dental implant in the site of the maxillary lateral incisor exhibited the lowest stress on the zygomatic implants and the least deformation of the bone surrounding the zygomatic and dental implants. This study was supported by National Basic Research Program (China, 2010CB944800), National High-Technology Research and Development Program (China, 2011AA030107), International Cooperation Program of China (China, 2013DFG32770 and 2011DFA51970), Nature Science Foundation of China (China, 81271095, 81271119 and 81200792), Doctoral Foundation of Ministry of Education of China (20110181120067 and 20110181110089), Key Technology R&D Program of Sichuan Province (2012SZ0013 and 12ZC0493) and Basic Research Program of Sichuan Province (2011JY0125 and 12JC0212). a Postgraduate student, Department of Oral and Maxillofacial Surgery, West China College of Stomatology, Sichuan University; National Engineering Laboratory for Oral Regenerative Medicine, West China Hospital of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University. b Associate Professor, Department of Pedodontics, West China College of Stomatology, Sichuan University; National Engineering Laboratory for Oral Regenerative Medicine, West China Hospital of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University. c Postgraduate student, College of Architecture and Environment, Sichuan University; National Engineering Laboratory for Oral Regenerative Medicine, West China Hospital of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University. d Postgraduate student, Department of Implantology, West China College of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University. e Postgraduate student, Department of Implantology, West China College of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University. f Postgraduate student, Department of Endodontics, West China College of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University. g Postgraduate student, Department of Endodontics, West China College of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University. h Professor and Director, Department of Oral and Maxillofacial Surgery, West China College of Stomatology, Sichuan University; National Engineering Laboratory for Oral Regenerative Medicine, West China Hospital of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University. Wen et al