Revisiting the vascularity of the keratinized gingiva in the maxillary esthetic zone

Abstract

Background The active arterial-to-arterial collaterals are a significant factor in the prevention of ischemia and extensive tissue necrosis in the case of arterial blockage of various tissues. The present study investigates the mucogingival vasculature in the maxillary esthetic zone mucosa in human cadavers and functionally evaluates the area, which is supplied by the terminal arterioles, on the individual level. Methods In the human cadaver study, macroscopic arterial analyses of the anterior maxillary vestibule in 7 specimens were scrutinized by latex milk injection. The tracks of the mucosal branches in relation to the mucogingival junction were investigated. In the functional study, individual gingival blood flow (GBF) changes were measured by laser speckle contrast imaging (LSCI) in 31 young subjects with healthy gingiva before and during 30-s compressions. This was conducted with a ball-shaped condenser. The data was analyzed by the linear mixed model. Results The vertically aligned branches of the superior labial artery (SLA) divided into small, slightly deviating sub-branches near the mucogingival junction. These arteries created collateral plexuses and supplied the attached gingiva. The compression of these branches resulted in ischemia coronally with significant individual variation. The ischemia was either apico-mesial, apico-distal, or straight apical to the compression. A significant correlation was found between the ischemic area and the magnitude of the decrease in GBF (r = 0.81, p < 0.001). In males, 77% of the subjects, and 50% of the female subjects had an ischemic response in either region. The horizontal extension of the ischemic area ranged between 0.26 mm and 8.76 mm. Males had significantly higher baseline GBF and larger ischemia than females. At the base of the papilla, significant restoration of GBF was observed during compression in males, but not in females. Conclusion The arcade anastomoses formed by the small arteries in the keratinized gingiva of the upper esthetic zone explain the consequences of vertical incisions. The considerable individual variations in ischemic responses might be the reason for unexpected surgical outcomes in some cases. Furthermore, there is increasing evidence that men have different vascular reactivity and/or regulation of collateral circulation than women, which may affect wound healing.

Sex-related differences in endothelium-dependent vasodilation of human gingiva

“…In gingivitis, some studies [ 47 – 49 ] found higher resting GBF, which could lessen the vasodilator capacity. In the current and previous study [ 31 ], men had higher gingival baseline blood flow than women. We could only speculate that higher gingival blood flow and endothelial reactivity of males in healthy gingiva is also true for periodontitis.…”

“…Both endothelium-dependent and independent local hyperemia elicited spreading vasodilation. The vestibule contains the upstream (supply) arteries of the attached and marginal gingiva as demonstrated by morphology [ 30 , 31 ], by wounding study [ 32 ] and by occlusal test [ 5 , 31 ]. Therefore, the observed spreading vasodilation was upstream in nature.…”

“…The larger arterioles are more sensitive to shear stress than the small ones [ 18 ]. In gingiva, the larger arterioles localized apically [ 30 , 31 , 44 ]; therefore, this might explain the lack of decay of the NitroPOHL effect.

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Osseous topography in biologically driven flap design in minimally invasive regenerative therapy: A classification proposal

“…The utilization of magnification devices with coaxial illumination, such as OMs, will refine minimally invasive efforts when approaching infrabony defects 23 . Awareness of macrovascular and microvascular tracks during incision tracing and flap design will translate into proper angiogenesis and wound healing 24,25 …”

Periodontal Wound Healing and Tissue Regeneration: A Narrative Review

“…Vertical incision, such as a coronally advanced flap in vertical bone augmentation, is unavoidable, and the incision should be placed at the mesial side of the flap to avoid the interruption of vascular flow from the posterior end to the anterior end of the scar [ 37 ]. Additionally, long time periodontal surgery with a vertical incision and additional local anesthetics such as epinephrine can induce ischemia in the mucogingival flap [ 38 , 39 ].…”