A sympathetic adrenergic vascular control exists in
the dental pulp.
Mediators presently known are
noradrenaline and neuropeptide Y. The sympathetic
nerve fibres originate from the cervical sympathetic
ganglion, and after joining the trigeminal nerve at its
ganglion, most of them follow the course of the sensory
nerves to the teeth, or they possibly travel via the blood
vessels. Sympathetic vasoconstriction is typically
activated by stress stimuli and by painful stimuli directed
at almost any part of the body. Sympathetic vaso
constriction may modulate the excitability of the sensory
nerves. In the compromised pulp, sympathetic vaso
constriction is attenuated. Local sensory vasodilation
becomes predominant, which may contribute to further
progression of pulp inflammation.