Statistica 12.0

The measurements from each site (4 points per implant) were used for statistical analysis. The variable evaluated in all tests was the distance between gingival margin and the abutment shoulder. To assess a relationship between qualitative variables, a Chi-Square Test of Independence and Fisher’s exact test were done. Normal distribution was verified by a Kolmogorov-Smirnov test combined with Lillefors amendment and Shapiro-Wilk test. No normal distribution of quantitative variables analyzed was found. Quantitative variables without normal distribution involving two dependent variables were compared in a nonparametric Wilcoxon matched pairs test. A Spearman’s rank order correlation coefficient was also determined. The results were statistically significant at p < 0.05. The statistical software was Statistica 12.0 StatSoft (StatSoft. Tulsa, OK, USA).

Shapiro-Wilk test was used to check the consistence of empirical distribution of evaluated variables with normal distribution. Levene test was applied to assess the homogeneity of variance. The one-way analysis of variance (ANOVA) was used for the assessment of differences between the age groups. To evaluate the significance of differences between the sexes in each age group the Cochran Cox test was used. The measured dimensions were compared with the previously established measurements in the control group of 153 children (Cochran Cox test). The statistical difference between groups has been assessed at the level of p≤0.05.
The “Reduction” of the measured parameter between patients and controls (last column) was calculated as follows: the percentage of reduction is the difference between the average dimension in healthy children and the average dimension in children with craniosynostosis, expressed as the percentage of the average value in healthy children.
The following software was used for the calculation and visualization of results: Statistica 12.0 StatSoft® and MS Excel 2013.