2000 Fiscal Year Final Research Report Summary
Clinical examination of thecranio-facial pain associated with tooth pulppathosis and the neuronal hyperresponsiveness observed in animal with experimentally induced pulpitis
| Project/Area Number |
10470403
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Conservative dentistry
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
SUNAKAWA Mitsuhiro Graduate School, Pulp Biology and Endodontics Tokyo Medical and Dental University Senior Lecturer, 大学院・医歯学総合研究科, 講師 (30179288)
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| Co-Investigator(Kenkyū-buntansha) |
SUDA Hideaki Graduate School, Pulp Biology and Endodontics Tokyo Medical and Dental University Professor, 大学院・医歯学総合研究科, 教授 (00114760)
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| Project Period (FY) |
1998 – 2000
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| Keywords | pulpitis / mustard oil / medullary dorsal horn / brain stem reticular formation / tooth pulp-dreiven neuron / central sensitization / jaw muscle EMG activity / axon reflex |
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| Research Abstract |
We have tried to analyze the physiological changes of thcranio-facial regionsin patients suffering from thepulpitis and/or periradicular pathosis, and to compare the data recorded in the periods of before and afterendodontic treatment. It was, however, difficult to getcooperations of patients who were complaining of severe pain. We thought that it was necessary to perform the physiological examination of the patients with pain suffering frompulpal diseases, but it remained difficult situations of getting theinformed-consent for the examination from them.
The application of "mustard oil : MO" to the tooth pulp as a chemical conditioning stimulation produced the alterations of the neurophysilogical and neuropharmacological response prccperties in the peripheral and central nervous system. Respccnsiveness of the tooth pulp-driven neurons in themedullary dorsal horn (Vc) or brain stem reticular formation (RF), which had the receptive field in theoro-facial region, showed different pattern of hyper excitation. Especially, a significant increase in the responsiveness of the RF tooth pulp-driven neuron was observed with elapse after MO conditioning stimulation, and systemic administration of naloxone produced a significant rekindling effect in its responsiveness. A statistical significance was found in the responsiveness changes between the Vc tooth pulp-driven neuron and the RF one. These neuronal responsiveness changes may be closely related to the increase of reflex-induced jaw muscle EMG activities by MO tooth pulp application.
Mustard oil application to a tooth pulp produced both hyperexcitation of the afferent fibers and increase of the blood flow in the pulp of neighboring teeth as well as in the MO applied one. These phenomena may be caused by the axon reflex of the branched afferents innervating the plural teeth pulp, which suggests that thepulpal inflammation in a single tooth has a possibility of inducing the clinical symptoms in the plural teeth.
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