IM0210

implants2_2010 1. Light to moderate bone atrophy in the anterior region of the maxilla, with a posterior resorp- tion of the alveolar process: This situation al- lows the placement of two to four implants in the anterior region, but the resorption of the posterior maxilla makes the placement of stan- dard fixtures in this area unfeasible. In this case two zygomatic implants will be placed, one for each side. 2. Advanced atrophy of the maxilla (anterior and posterior): In this case two options are avail- able: the use of bone grafting techniques in the anterior region can be performed and the placement of two zygomatic implants for the posterior region; or the placement of four zy- gomatic implants, two on each side without any anterior standard implants. _Presurgical evaluation Maxilla, maxillary sinus and zygomatic bone arethethreemainstructurestobeconsideredbe- fore surgery. A panoramic radiography, a com- puted tomography (CT), as well as an adequate clinical examination are paramount to perform a correct diagnosis and treatment planning of the case (Figs. 1a & b). The presence of sinus pathology might com- promisethefinalresultandthesurvivalofthezy- gomatic implants, so it is essential to treat this kind of conditions before the surgical proce- dure.6 _Surgical procedure General anaesthesia in conjunction with the administration of a local anaesthetic is the tradi- tional recommendation for the management of patient undergoing zygomatic implants place- ment.Morerecently,someauthorshavealsoused intravenous conscious sedation techniques for the same purpose.12 Blocks of the alveolar superior nerves, infraor- bitary nerves, and palatal nerves2 are required. A buccal approach using the traditional Le Fort I incision, can be made between the first mo- lar regions1 (Fig. 1c). Another option is to perform a crestal incision allowing improved palatal ac- cessforimplantplacement.2 Afterraisingthemu- coperiosteal flap, soft tissue dissection has to be extended along the inferior and frontal lateral surfaces of the zygomatic bone, with identifica- tion of the infraorbital foramen. Special care has to be taken to avoid invasion of the orbit or sec- tioning the insertion of the masseter muscles in excess, as important bleeding could occur. The palatal mucosa has then to be detached, espe- ciallyinthezoneofthesecondpremolar/firstmo- lar. Afterwards, a 10 x 5 mm infrazygomatic win- dow in the lateral wall of the maxillary sinus should be created to keep the Schneiderian mem- brane intact (Fig. 1d). This window should allow the observation of the drilling sequence as well as the implant placement (Figs. 1 e–g). Brånemark et al.1 recommend to place a gauze soaked in adren- Fig. 1a_Preoperative panoramic radiography of a 54-year-old male with total maxillary edentulism. Fig. 1b_ Preoperative aspect of the maxilla. Fig. 1c_Raising of the mucoperio- steal flap up to the zygomatic arch. Fig. 1d_Performing a lateral sinus window with a bone scraper. Fig. 1e_Drilling from the 2nd premo- lar- 1st molar region to the zygomatic bone. Fig. 1f_The machined surface zygo- matic implant. Notice that the main anchorage site is the zygomatic bone and the residual crestal bone. Fig. 1a Fig. 1b Fig. 1c Fig. 1d Fig. 1e Fig. 1f