StomatologyEduJournal1-2015 | Page 59

ZYGOMATIC IMPLANT COMPLICATED WITH RECURRENT ORO-ANTRAL COMMUNICATION Figure 9. 6 months postoperative, frontal view disappeared. Initially a further surgical thinning of the flap was planned, but due to the favorable development, this was abandoned. The flap got thinner with tight fitting skin around the implant. The patient is satisfied with the result (Fig.8, Fig. 9, Fig. 10) and is able to keep the region clean. He was discharged from surgical follow-up and referred to his dentist for the prosthetic and implant followup. Discussion In recent systematic reviews of survival and complications of zygomatic implants, both Chrcanovic and Goiato e.a. find a cumulative survival rate of 96,7% after 36 months.3,8 Postoperative complications include maxillary sinusitis, soft tissue infections, paresthesia and oro-nasal fistulas.3 Maxillary sinusitis is the most common complication, ranging from 1.5% to 18.42%.9 Maxillary sinusitis, both acute and chronic, are the main reasons of failure of zygomatic implants.10 Removal of the zygomatic implants from the infected area is often performed, if antibiotics cannot resolve the infection, arguing that the implants act as a foreign body and maintain the infection. Other reasons why zygomatic implants can cause maxillary sinusitis are given by Davó11: the invasiveness of the surgery to the sinus, the persistence of an oro-nasal communication, mainly in absence or loss of the thin palatal bony wall. Resorption of the thin palatal boneplate that covers the zygomatic implant leads to oro-antral fistula followed by implant loss.12 Bedrossian reported on three patients with zygomatic implants and persistent sinus infections refractory to oral antibiotic treatments, in which a Functional Endoscopic Sinus Surgery (FESS) procedure completely resolved the sinus infections without removal of the zygomatic implants.13 De Moraes reported on the successful use of the buccal fat pad technique to resolve an oro-antral communication;14 this procedure however was reported concomitant with the placement of zygomatic implants and did not resolve an oroantral communication secondary to an infectious process. Peñarrocha-Oltra (2015) reported on the successful use of the buccal fat pad to close an oro-antral communication with an accompanying maxillary sinusitis in one patient. Their procedure involved the removal of the zygomatic implant.15 Figure 10. 6 months postoperative, facial frontal view The reported follow-up period was 6 months. Stella and Warner advocated the sinus slot technique in 20007 as an alternative to the original technique introduced by Bränemark in 1998.16 In both techniques the sinus is penetrated. Bränemark explicitly states : “The sinus mucosa was then reflected and no special effort was made to keep it intact” (Bränemark e.a., 2004).16 The third alternative is the exteriorized technique avoiding passage through the maxillary sinus.17,18 Chrcanovic e.a. (2013) compared the three surgical techniques and concluded that neither claimed to cause sinusitis.19 Adverse complications as for example an oroantral communication secondary to surgical treatments with zygomatic implants however do occur. Visscher e.a., in a review of the literature concluded that surgical closure of oro-antral communications by a buccal or palatal flap therefore remain the treatment of choice.20 Even in the absence of dental implants, the recurrence rate after surgical closure of oro-antral communications is high at about 10%.21 The risk of recurrence is 15 times higher with maxillary sinusitis at follow-up. After two failed surgical attempts to