BMP4 and periodontitis: Although we could not find any differences in local gingival BMP-2 and BMP-4 levels between patients in the acromegaly and control groups, the unexpectedly low frequency of severe periodontitis and the finding of increasing levels of gingival BMP-2 levels as the degree of periodontal tissue problem decreases in acromegalics, suggested a protective role for BMP-2 in acromegalics.