IM0210

Fig. 1g_Final aspect of the maxilla. See the abutments for immediate loading and the palatal position of the distal implant in the first quadrant. Fig. 2a_Metal-ceramic full-arch rehabilitation with four anterior im- plants and two zygomatic implants. Notice the palatal emergence of the zygomatic implants. Fig. 2b_Detail of the palatal emergence. implants2_2010 aline inside the sinus for a few minutes to prevent bleeding and deter mucosal tissue from blocking the view. _Technique modifications The main disadvantage of this technique is re- lated to the palatal emergence (Figs. 2a & b) of the implants that complicates the design of the pros- thesis, reduces the patient’s ability to speak and compromises the long-term health of the peri-im- planttissuesduetothedifficultythatpatientshave to clean this area. Secondly, due to the intrasinusal path of the implants the risk of sinus pathology de- velopment must be considered.2 Recently,someauthorshaveproposedmodifica- tionsoftheclassicaltechniquedescribedbefore.We would like to emphasize the following: Extramaxillary implants Basically, it consists of a modification of the im- plantentranceinthealveolarprocessanditstrajec- tory up to the zygomatic bone.14 In this technique, the implant emergence is located just in the middle ofthealveolarprocess,hencecorrectingthepalatal entrance of the Brånemark technique. In its trajec- torytothezygomaticbone,thefixturegoesthrough the lateral sinus wall keeping the Schneiderian membrane intact. This technique not only improves thedesignoftheprosthesisbutalsoseemstoreduce the incidence of sinusitis. Malo et al.14 and Aparicio etal.15 havealreadypublishedsomereportswithex- cellent results (98.5–100% survival rates). On the other hand, the main complaint would be the fact that the middle part of the implant rests in direct contact with the soft tissue of the cheek. Zygomatic implants without anterior standard implants Frequently, the high degree of maxillary atrophy of these patients forces the surgeon to perform bone grafting techniques in the anterior area of the maxilla in order to place four standard implants. A modification first described by Bothur et al.16 rec- ommended the placement of four to six zygomatic implants in order to avoid the need of anterior fix- tures and therefore to reduce the necessity of bone grafting in this area. In a study with 40 edentulous skulls, with atrophic alveolar processes and pre- maxillas, Rossi et al.17 measured the distances be- tweenthealveolarprocessemergenceatthecanine region and the premolar/molar region to the zygo- matic bone. The authors stressed the fact that the meanlengthofdistancebetweenthecanineregions to the zygomatic bone was 53.42 mm and the max- imum distance was 61.94 mm. Given that the longest commercially available implant is 52.5 mm, the authors emphasize the importance of a precise presurgical evaluation of the available distance when the placement of four zygomatic implants is planned. Sinus-slot technique Stella and Warner18 described this method in 2000. Mainly, the “slot technique” is a reduction of the sinus wall perforation doing a slot instead of a window. Likewise, this modification permits a good control of the drilling direction and insertion of the zygomatic fixture. Furthermore, according to the authors a higher amount of bone is preserved and also the flap size can be reduced, improving the pa- tients’ postoperative recovery. Peñarrocha et al.12 published in 2007 a series of 21 cases with the “Slot technique” with a 100% survival rate, but the Schneiderianmembranewasperforatedinallcases, even though the incidence of sinus pathology was low (two cases). Immediate loading Traditionally,thezygomaticimplantloadingpro- tocol has been a two-stage approach. Nowadays, justafewnumbersofauthorshavepublishedresults with an immediate loading protocol. To our knowl- edge, the first case-series was published in 2006 by Bedrossian et al.19 The review included a total of 28 zygomatic implants and 55 standard implants that were loaded immediately after surgery. The authors reported very good results with a survival rate of 100% and without any complications. Other recent studieshavealsoreportedsimilarfindingswithsur- vival rates ranging from 95.8% to 100%.4, 14, 15, 20-22 Fig. 1g Fig. 2a Fig. 2b

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