The blood vessel system in the periodontal ligament of the equine cheek teeth–part II: The micro-architecture and its functional implications in a constantly remodelling system.

The research article is an investigation into the microscopic vascular structure of the Periodontal Ligament (PDL) in horses’ cheek teeth, aimed at understanding its specific features and their functional implications within this constantly remodeling system.

Research Methodology

• The study involved examining the micro-vasculature of horse’s Periodontal Ligament (PDL) using a specific method known as corrosion casting followed by scanning electron microscopy.
• The sample for the research included specimens from eight healthy warm-blooded horses.

Findings from the Study

• Research revealed specific features of the equine PDL such as large ampullae with a diameter of up to 300 microm and blind vascular casts.
• The ampullae-shaped venules were found only in the peripheral layer and were formed at the confluence of several vessels.
• Two types of blind stumps were identified. The first was found in all three layers, while the second was exclusive to the peripheral layer.
• The study also found that there were no blood-flow-regulating structures in the equine PDL and no vascular valves. Therefore, blood could flow in all directions.
• The polydirectional shift was observed to extend to all the vascular layers.

Functional Implication of PDL Micro-architecture

• The study suggests that the vascular ampullae, only found in the peripheral layer, receive masticatory forces, indicating a functional feature of the PDL.
• Apart from its mechanical role, the vascular structure is adaptive to spatial changes. This adaptability is crucial due to the life-long eruption of horse’s cheek teeth.
• Vascular changes occur through processes such as vascular sprouting and intussusceptive vascular remodelling. The blind ending stumps of the corrosion casts indicate vascular sprouting.
• The large ampullae are seen as the first step in an intussusceptive process, a form of vascular remodeling.