Central nervous system mechanisms
Both structural and functional changes in the Central nervous system occur following peripheral nociceptor activation in response to tissue damage and inflammation. These changes become more visible in prolonged pain and can lead to constant changes in those parts of pain pathways that are involved in the regulation of pain impulse transmission from the periphery to the higher centers of the brain. The results of psychophysiological research and neurophysiological experiments show that the Central regulation is also important in various dental pain conditions.
Human experiments Sigurdsson and Maixner (55), showed that the radiation of pain in the pulpit through secondary hyperalgesia of Central sensitization. The air conditioning painful stimulation hands, secondary hyperalgesia may be cancelled, and the main source of the pain more precisely localize.
Electrophysiological studies have shown that the harmful stimulation teeth results in discrete cytochemical answer a second-order neurons trigeminal nuclei of the brain stem intermediary Orofacial pain (12, 13).
These morphological changes are evident within a few hours after stimulation of peripheral nociceptors and may represent the first signs of the initial sensitisation Central pain pathways. Injury dental nerves caused by the removal of teeth and pulpotomies has been shown to cause long-term functional changes in the trigeminal of neurons in the brain stem (53). Neurons show an increase in spontaneous activity and increased peripheral receptive field, indicating that they formed a connection to peripheral neurons, which, as a rule, do not activate them.
In summary stated that the inflammation and injury to peripheral tissues can lead to changes in the transmission of impulses in Central pain pathways. It is not known to what extent the Central mechanisms play an important role in dental pain conditions, but they may be significant, especially in cases of prolonged pain...