Fig. 3

Included studies presenting OHIP 14 values. The diagonally crosshatched bars represent modified OHIP mean values with regard to the rating (0–4 vs. 1–5) and/or the inverse interpretation (0 (“never”) vs. 5 (“never”)). For OHIP 14 findings of the three studies using a scale of 1–5, 14 points were subtracted. Furthermore, the inverse rating, which was 5 (“never”) to 1 (“very often”) was converted by subtracting 14 points first (50/56 instead of 64/70). Afterwards, the difference between the maximum (56) and detected score (50) was calculated (OHIP 14 of 6)