Vascular Fragility and the Endothelial Glycocalyx in the Tissues Lining the Healthy Gingival Crevice

The aim of this study is to investigate vascular fragility and endothelial glycocalyx (ECG) in images of the healthy gingival crevice (GC). The ECG is a surface layer lining the luminal walls of blood vessels composed of proteoglycans and glycoproteins with other components. Degradation of the layer has been shown to drastically affect microvascular flow, permeability, and immune function.

Videomicroscopic images from tissues lining the healthy GC in 20 healthy volunteers were analyzed to determine the presence of microhemorrhage related to branched dilated microvessels. Imaging of capillary ECG in human labial mucosa was achieved by the use of a 1-mm-diameter 0.5 numerical aperture gradient index objective lens and one-sided oblique illumination using light at 450 nm. This allows resolution of red blood cells within the capillary and the endothelial cell wall of the lumen. The cell-free plasma gap between the red cell and endothelial wall represents the ECG.

In the healthy GC there was no evidence of microhemorrhage in participants that had only simple capillary loops (seven of 20). Microhemorrhage was present in the majority of participants with branched dilated microvessels (11 of 13) (McNemar Test for equal distribution, P = 0.05). A cell-free plasma gap representing the ECG could be imaged in the superficial tissues lining the labial sulcus. No such cell-free plasma gap could be detected in the branched dilated microvessels in tissues lining the GC.

There is an association between the presence of vascular microhemorrhage and branched dilated microvessels in the tissues lining the clinically healthy GC. Loss of ECG might be part of the inflammatory process in these tissues.