Extent of tooth wear: the average number of pathological wear buccal surface: 0.36 ± 1.5, the average number of pathological wear lingual surface: 0.76 ± 2.25, the average number of pathological wear occlusal surfaces / incisal edges: 8.22 ± 7.99, the average number of pathological wear teeth cervical: 1.98 ± 3.61.