“…Scala et al [ 2 ] distinguished between primary (or idiopathic) BMS, when the underlying cause is not known, and secondary BMS, when the disorder is associated with systemic diseases and/or local factors. The etiology of burning mouth syndrome is complex and multifactorial, and has not been fully clarified to date [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].…”