The International Journal of Oral & Maxillofacial Implants 1049 ©2014 by Quintessence Publishing Co Inc. Anatomical Study of the Pterygomaxillary Area for Implant Placement: Cone Beam Computed Tomographic Scanning in 100 Patients Xavier Rodríguez, MD, PhD 1 /Federico Rambla, DDS 2 /Luis De Marcos Lopez, DDS 3 / Víctor Méndez, DDS 4 /Xavier Vela, DDS, MD 5 /Jaime Jimenez Garcia, DDS, PhD 6 Purpose: The aim of this study was to describe the average angulation and dimensions of the pterygomaxillary area in the atrophic maxilla to facilitate the orientation of pterygoid implants during their placement. Materials and Methods: A retrospective radiologic study was made. A virtual pterygoid implant, 13, 15, or 18 mm long, was placed in the pterygomaxillary area following the axis of the bone, with a distance of at least 2 mm maintained between the artery and palatine nerve and the implant. The long axis of the implant was inclined slightly toward the palatal to follow the cortical palatal bone. The angles between the long axis of the virtual implant and Frankfort horizontal were measured in both sagittal and frontal views. To calculate the average length of the pterygomaxillary area, the virtual long axis of the implant was measured from the alveolar crest to the pterygomaxillary suture. Results: The average anteroposterior axis inclination of the pterygomaxillary area was 72.5 ± 4.9 degrees relative to Frankfort horizontal. The average angulation of the palatal vestibule was 81.3 ± 42.8 degrees relative to Frankfort horizontal. The average length of the pterygomaxillary area was 22.5 ± 4.8 mm. Conclusion: Pterygoid implant placement requires thorough knowledge of each patient’s anatomy and individual needs. The mean position of the pterygomaxillary buttress axis was 72.5 ± 4.9 degrees to the distal and 81.3 ± 2.8 degrees to the palatal relative to Frankfort horizontal. Placement of pterygoid implants in this inclination may increase accuracy of implant placement. The average length from the tuberosity to the most apical point of the pterygoid apophysis was 22.5 ± 4.8 mm. These results suggest that an implant 15 to 18 mm in length would ft in the pterygomaxillary area to reach the cortical bone. INT J ORAL MAXILLOFAC IMPLANTS 2014;29:1049–1052. doi: 10.11607/jomi.3173 Key words: atrophic maxilla, implant angulation, pterygoid implant, pterygomaxillary region, radiologic assessment, tilting R ehabilitation of the atrophic maxilla is a challenge in dental practice. Alveolar crest resorption, the presence of the maxillary sinus, and the poorer miner- alization of the posterior atrophic maxilla render it dif- fcult to restore this area by means of dental implants. 1,2 The sinus grafting technique is a popular method to restore the posterior atrophic maxilla. However, this technique requires a bone graft, and time for the graft to mature must also be allowed. 1,2 Pterygoid implants may make it possible to avoid sinus elevation and re- store the posterior area more quickly, with only 2 to 3 months needed for osseointegration of the implants. 3,4 The pterygoid implant placement technique requires thorough knowledge of each patient’s anatomy and their individual needs. Thus, dental implant place- ment must respect the pterygomaxillary anatomy of each patient. The pterygoid implant must enter at the level of the maxillary tuberosity and travel lengthwise through the palatine bone until it is inserted in the pterygoid apophysis. 5,6 Some authors state that the pterygoid implant must be placed on the anteroposte- rior axis with a 45-degree angulation relative to Frank- fort horizontal plane. 7–9 Another study found that the implant angulation was around 70 degrees relative 1 Private Practice in Barcelona and Madrid, Spain; Member of the Barcelona Osseointegration Research Group (BORG); Professor, Implantology Department of the International University of Catalonia, Barcelona, Spain; Professor, Implantology Department of the European University of Madrid, Madrid, Spain. 2 Assistant Professor, Implantology, European University of Madrid; Member of the Barcelona Osseointegration Research Group (BORG). 3 Assistant Professor, Implantology, European University of Madrid. 4 Member of the Barcelona Osseointegration Research Group (BORG). 5 Professor, Implantology, European University of Madrid; Member of the Barcelona Osseointegration Research Group (BORG). 6 Chairman, Implantology, European University of Madrid. Correspondence to: Dr Xavier Rodríguez, Implantology, BORG Center, Mare de Déu de Sales, 67C, Viladecans, 08440 Spain. Email: borgbcn@borgbcn.com © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.