M Beerens

48 CHAPTER 3 In order to defined the baseline similarity DMFS and bleeding on probing was assessed. The median DMFS scores were 1 (range 0 - 11) for the WSL group and 1 (range 0 - 3) for the group without WSL (p = 0.101, Mann-Whitney U). The median bleeding on probing percentages were 30% (range 10% - 80%) for the WSL group and 10% (range 0% - 30%) for the group without WSL (p < 0.001, Mann-Whitney U). No significant gender or age differences were detected in the occurrence of WSL. Therefore, the data presented below were not separated based on gender or age. The median duration of the orthodontic fixed appliance treatment was 31.9 months (range 14.6 - 155.8 months) for the WSL group and 31.9 months (range 17.4 - 39.7 months) for the group without WSL (p= 0.69, Mann-Whitney U). Results DGGE band detection Band patterns determined by visual detection of bands and automated band detection settings were compared for one gel comprising three marker lanes and ten sample lanes. The highest level of agreement between visual band detection and automated band detection settings was found for minimum profiling of 4% absolute to the most intense band, 0% grey zone, minimum area between 0.1% and 0.5% and shoulder sensitivity 0 (ICC p= 0.914). The highest level of agreement between visual band detection and automated band detection settings for minimum profiling relative to the most intense band (ICC p= 0.800) were found for a minimum profiling of 15% relative to the most intense band, 0% grey zone, minimum area 1% and shoulder sensitivity 0 and these settings were used for analysis of the DGGE patterns of subjects undergoing orthodontic treatment with fixed appliances. The DGGE banding patterns of the 4 duplo samples showed a good but not perfect match with Pearson correlations varying from 0.82 to 0.94. The numbers of bands detected were the same for each of the 4 duplo comparisons, although some differences were visible by eye in the relative intensity of bands. The DGGE banding patterns and the dendrogram grouping of the individual profiles based on similarity for automated band detection withminimumprofiling of 4% absolute to themost intense band, 0% grey zone, minimum area 0.1% and a shoulder sensitivity 0 are presented in Figure 1. The dendrogram is host-specific, i.e. showed large differences between the individual banding patterns for both groups, and the groups could not be