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Development of Sinusitis After Sinus Floor Elevation Surgery: A Systematic Review

Background: Maxillary sinusitis can arise after sinus floor elevation surgery and should be treated immediately to prevent further complications which included dental implants failure, graft lost, and oro-antral fistula. This is the first systematic review to assess the incidence, causes, and treatment of sinusitis after sinus lift surgery. Materials and methods: An electronic search included MEDLINE (PUBMED) data base site was carried out for articles involving development of sinusitis after sinus lift surgery from September 1997 up to April, 8, 2017. The search was done and reviewed by two independent authors. Results: The total results of electronic search were (182) abstracts and articles, the extracted articles which involved development of sinusitis after sinus lift surgery were (25) studies. Of the 25 articles only (8) articles fit the inclusion criteria. Maxillary sinusitis was calculated for all selected studies and it was ranged from 2.12% to 12.7% with average of 5.4 %. Conclusion: Maxillary sinusitis could be developed after sinus lift surgery with average of 5.4 % and the patients with previous maxillary sinus disease showed to be at increased risk of sinusitis after sinus lift surgery.


INTRODUCTION
One of the major postoperative complications after sinus floor elevation surgery is sinusitis. The post-surgical sinusitis etiology can arise from two origins; either from earlier chronic infection of the maxillary sinus which is triggered by post-surgical inflammatory changes or from communication with bacteria of oral cavity via perforation of Schneiderian membrane (1) . It is very important to treat sinusitis after maxillary sinus lift surgery as soon as possible because the infection may spread to other paranasal sinuses. In addition to that sinus infection may cause oro-antral fistula, loss of graft material and failure of dental implants (2)(3)(4)(5)(6) .
The aims of this study were to present the results of the previous studies which involved development of sinusitis after sinus lift surgery and to assess the incidence of the maxillary sinusitis after sinus floor elevation surgery. The search process is demonstrated in diagram 1. Exclusion criteria: 1-Case reports and case series with less than 10 patients.

2-Studies published in other languages than
English.

3-Experimental studies (on animals). 4-Studies involving complications after sinus lift
other than maxillary sinusitis. 5-Studies with less than 6 months follow-up period. 6-Patient with systemic diseases that may had an effect on maxillary sinus health.

Selection of studies
Titles and abstracts of the articles were examined initially by two independent reviewers (authors) for the chance of inclusion in this systematic review.

RESULTS
The total results of electronic search were 182 abstracts and articles. The reviewed abstracts were 130, the extracted articles which involved development of sinusitis after sinus lift surgery were 25 studies. Of the 25 articles 17 studies were excluded and only 8 articles which fit the inclusion criteria were involved in this research. The characteristic data for each study was summarized in table 1. The average of sinusitis was calculated for all studies and it was 5.4 %.
Seventeen articles were excluded from this research because of the following points: 1-Five articles were excluded because they were case reports. 2-One study excluded because it was involving various types of localized lateral alveolar ridge and/or sinus floor augmentation procedures performed before implant placement. 3-Seven articles were excluded because of missing data and not standardized criteria. 4-Three articles were excluded because they written in German language. 5-One article was excluded because the sinusitis complication was not related only to sinus lift surgery but to other causes like odontogenic causes.

DISCUSSION
Development of sinusitis after sinus lift surgery among the selected studies in this research ranged from 2.12% to 12.7% (10,14) .
Causes of sinusitis (according to the authors in the selected studies) were as follow: 1-Sinusitis due to sinus membrane perforation as mentioned in two studies (10,12) . Nolan et al. (10) reported Sinusitis with percentage of (12.7%) in his study. Of the sinuses presented with sinusitis, 85% have Schneiderian membrane perforation. In contrary three other studies reported that the most common intraoperative complication was Schneiderian membrane perforation, which did not show any relation to postoperative sinusitis (7,9,14) . 2-Sinusitis due to assumed long implant [10][11][12][13][14][15][16] mm as reported in one study (8) . 3-The risk of postoperative sinusitis was increased in patients who had previous chronic sinusitis and in cases in which a large amount of graft was used for sinus augmentation as reported in one study (11) 4-Risk of postoperative sinusitis was associated with sinus elevation width, smoking and sinus membrane perforation (12) .

CONCLUSION
According to this research, sinusitis can developed after sinus lift surgery with average of 5.4 %. Patients with previous maxillary sinus diseases appeared to be at increased risk of sinusitis development after sinus lift surgery.