Functional characterization of collaterals in the human gingiva by laser speckle contrast imaging

Abstract

Objective The rate of blood flow between the various areas of the gingiva in resting position and under challenge is unknown. In this study, the LSCI method was used to map spatial and temporal changes in gingival blood flow after transient compression. Methods Horizontal, vertical, and papilla base compressions were applied on the attached gingiva in 21 healthy patients (13 women, 8 men). LSCI was used to determine dynamic changes in regional blood flow during a five‐second occlusion interval and subsequent reperfusion for twenty minutes. Results Resting blood flow in the attached gingiva apical to the papillae was higher as compared to that in the midbuccal area of the teeth. During short‐term horizontal compression, ischemia was greater coronal than apical to the occlusion line. Postocclusive hyperemia was observed not only in the regions affected by ischemia but encompassed a wider area. Hyperemic response was more pronounced and prolonged in male than in female patients. Conclusions Blood flow in the attached gingiva shows spatial differences. Our findings corroborate the apicocoronal orientation of blood circulation. Periodontal and papillary collaterals may have little role in the blood supply of the adjacent attached gingiva under physiological conditions.

Evidence of spreading vasodilation in the human gingiva evoked by nitric oxide

“…The apical direction of spreading vasodilation reaffirms the priority of the plexus of the alveolar mucosa in blood supply to the keratinized gingiva in physiological conditions and during regular flap elevation or wounding . It also concurs with the ascending feature of flow‐mediated vasodilation.…”

“…In some regions, there was a tendency of reduction in GBF at the control site, which may be explained by the slight drop in gingival temperature and in mean arterial blood pressure during the blood flow measurement. A slight drop (marginally significant) in blood pressure was also observed in another LSCI study where the patient was in relaxed position for 30‐40 minutes and no vasoactive drug was applied suggesting that the observed decrease in blood pressure may not due to the systemic effect of Nitromint. The drop is probably caused by the prolonged relaxed position with an open mouth.…”

“…Vasodilation mainly spreads upstream of the arteriolar network to effectively ensure blood supply to the active site . The two known mechanisms of supplying upstream apical remote vasodilation are conducted vasodilation via retrograde propagated hyperpolarization of endothelial cells and vascular smooth muscle and flow‐mediated vasodilation via shear stress‐induced endothelial NO release . The former has an onset within a few seconds, while the latter has a lag of 10‐40 seconds and is responsible for sustained vasodilation .…”

Blood flow kinetics of a xenogeneic collagen matrix following a vestibuloplasty procedure in the human gingiva—An explorative study

“…Interestingly, papillary blood flow remained unchanged after the horizontal incision. In a previous study (Fazekas et al, ), compression at the base of the papilla caused a 55% drop in blood flow at the marginal gingiva of the nearby teeth. This suggests that papillary collaterals (intraseptal, lingual) contribute significantly to the blood supply of the marginal gingiva and may readily supply the coronal area after horizontal incision, which explains our unexpected finding.…”

“…The relative contribution of these anastomoses to maintaining blood supply in physiological and pathophysiological conditions has been less well researched. In a challenging situation induced by short‐time horizontal compression of the gingival vessels, the compensatory blood comes from the alveolar mucosa (Fazekas et al, ). This apico‐coronal direction was also confirmed in a series of case studies by Mormann (Mormann & Ciancio, ; Mormann, Meier, & Firestone, ), who found that marginal gingival perfusion is sensitive to the horizontal incision.…”