Study design and subjects

This retrospective study addresses the oral health-related quality of life after maxillary sinus augmentation. Therefore, all patients that received an implantation after maxillary sinus augmentation in the Department of Oral and Maxillofacial Surgery of the University Medical Centre Mainz, Germany, between July 2002 and December 2007 were included in this study. There were no specific exclusion criteria. In this time period, 863 implants in 316 patients after sinus augmentation were inserted. One hundred forty-two of these patients (44.9%) were men and 174 (55.1%) women. Mean age of men was 57.4 years and mean age of women 55.2 years. Fifty-three patients (33 women and 8 men), with 157 dental implants remaining in situ, attended a clinical follow-up examination (Fig. 1). For these patients, plaque index, gingival index, probing depth, and width of keratinized mucosa were evaluated. The retrospective data analysis was conducted in accordance with the Helsinki Declaration of 1975, as revised in 2008, and all patients signed an informed consent. After consulting the local ethic committee, the decision was that due to the retrospective character of this study with no additional data acquisition, no ethical approval was needed according to the hospital laws of the appropriate state (Landeskrankenhausgesetz Rhineland Palatinate, Germany).

Measurement of OHRQoL

For evaluation of OHRQoL after sinus lift procedures, a modified version of the OHIP-G was applied. This modification was performed to adapt the questionnaire to the specific objective of our study, as we wanted to evaluate the oral health-related quality of life after sinus lift procedures. Therefore, for this treatment, specific questions like “Have you had a maxillary sinusitis” were added to the questionnaire. After providing informed consent, patients completed a questionnaire, consisting of the three subcategories (1) functional limitations, (2) physical and psychological disabilities, and (3) complaints due to the surgical procedure. The implemented questions are shown in Tables 1, 2, and 3. Responses were made on an ordinal 4-point adjectival scale (0=never, 1=occasionally, 2=fairly often, and 3=very often). OHRQoL is described by summary scores of the asked items. Higher scores imply a stronger negative influence on OHRQoL; in contrast, lower scores indicate better OHRQoL. The valuation periods were divided into “pre-operative” and “recently” for subcategories (1) and (2). For subcategory (3), valuation periods were classified into “pre-operative,” “post-operative,” and “recently.”

Statistics

The Kaplan–Meier survival function was applied for the description of survival rates. To examine the statistical difference between survival rates, a log-rank test was used. Implant-related data were calculated. For statistical comparison of the paired questions and the total scores, a Wilcoxon test was applied. The intention of this study was descriptive, exploratory without a primary hypothesis. Consequently, we show descriptive p values of tests and no adjustment to multiple testing was done. The analyses were conducted using SPSS version 20.0 (IBM, USA).