I don't mean to be blunt or dismissive, but the pressure in the veins/arteries has nothing to do with (a) the thickness/elasticity of the wall tissue, (b) the diameter of the arteries/veins, or (c) the number of (branches of) arteries/veins.
This can either be caused by a more prominent maxilla (upper jaw) or a retruded mandible (lower jaw further back than it should be). This causes a discrepancy in how all teeth contact, and can manifest as an increased overjet. An increased overjet can also be caused by a discrepancy in the number of teeth, or the length of the arch.
Osteoarthritis and overloading of the joint are the most common causes of facet hypertrophy. The most common cause of overloading is degenerative disc disease, which causes the disc. height to shrink and consequently the bony components of the facet joint to place increasing pressure on each other.