Other studies have reported the presence of problems with oral tissue in the region of the zygomatic implants, including infection and swelling, usually associated with loss of implant apical osseointegration. Hirsch et al. have reported the presence of hyperplasia, mucositis, and infection in eight patients in a total of ten throughout the monitoring period.

Although certain criteria to evaluate osseointegration were considered, the study used the concept of survival of the implants instead of the success. Survival is a more general term, considering only the implant is still in the oral cavity, without analyzing the quality of its function and maintenance of its support. The success rate is applied to those fitting into established and applied criteria of installed implant. Due to various factors, from the type of test, as well as the difficulty to access all implants and characteristics inherent when working with atrophic maxilla without reconstruction, we found that survival, which is a concept widely used in the literature, would fit best for this research.

The possibility of zygomatic implants causing or favoring sinus disease due to the exposure of the implants within the maxillary sinus is an important issue. A number of studies describe the occurrence of maxillary sinusitis in patients with zygomatic implants. This finding has been attributed to perforation of the sinus membrane, a lack of contact between the implant and the surrounding bone crest, the migration of bacteria from the oral cavity to the maxillary sinus due to communication between these structures, and preexisting sinus conditions from the clinical and radiographic standpoint.

According to Stiévenart and Malevez, the incidence of sinusitis ranges from 14 to 30 %. In a previous retrospective study involving patients submitted to the Stella and Warner’s technique, Peñarrocha et al. found two cases of sinusitis among the 42 implants; one case was treated with antibiotics and the other was submitted to the removal of the implant.