When analysing the study groups in relation to risk factors, OPG rs2073617 (p = 0.034) was more frequent in patients with PI who smoked more than 10 cig/day, and BMP-4 rs17563 (p = 0.018) or FGF-3 rs1893047 (p = 0.014) in patients with PI and Type II diabetes mellitus (Table 4). Here, FGF3 is linked to type 2 diabetes mellitus.