Caroliene Meijndert

86 Chapter 5 Statistical analysis All the data was checked for normality using QQ-plots and the Shapiro-Wilk test in order to determine the appropriate statistical method. Ordinal and not-normally distributed continuous data was analysed using the Wilcoxon signed rank test to determine any significance between time intervals. The normally distributed data was analysed using the Paired T-test to determine any significance between time intervals. The McNemar’s test was used for the questions in the questionnaire. A p-value of 0.05 was considered to indicate statistical significance. All the analyses were performed using SPSS (PASW Statistics 23.0, SPSS Inc.; IBM Corporation, Chicago, IL, USA). Results A total of 30 participants was included. The characteristics of the study population are depicted in Table 1 . No patients dropped out or were lost to follow-up. Table 1. Characteristics of the study group at the start of the study Number of participants 30 Mean age in years mean±SD (range) 43±16 (18-74) Sex (male/female) 16/14 Labial bone wall defect in mm, mean (range) 8.6 (5-12) Implant location (I 1 /I 2 /C/P 1 ) 24/5/1/0 Implant length, mm (10/12/14) 0/19/11 Implant diameter, mm (3.3/4.1) 4/26 Labial bone wall defect In all cases the defect of the labial bone wall after removing the tooth was U-shaped. Five participants had also a fistula at the labial mucosa. The origin of the bone (donor site) to preserve the alveolar ridge was the maxillary tuberosity in 14 cases and the retromolar area in 16 cases. The choice for the retromolar area was made in case wisdom teeth were present in the maxilla. When maxillary wisdom teeth are present, usually, less bone can be harvested in these areas.