Innervation Of Teeth Research Articles

Innervation of rat molar teeth: I. Distribution of neuronal cell bodies in the trigeminal ganglion from a mandibular molar tooth.

The cell bodies of neurons innervating a rat mandibular molar tooth were examined with respect to their location in the trigeminal ganglion. The study sought to determine if these cell bodies were restricted to a specific somatotopic location within the mandibular territory of the ganglion or if they were distributed throughout the entire mandibular territory. Horseradish peroxidase (HRP) pellets were placed in the cavity preparation of right first mandibular molar teeth for a 24-hour period. The animals were then perfusion fixed, and the right trigeminal ganglion was removed, sectioned and processed by the tetramethyl benzidine neurohistochemical technic. The four trigeminal ganglia constituting this experimental series demonstrated 129, 185, 236, 318 HRP-positive cell bodies. These cell bodies were dispersed throughout the extent of the mandibular territory. It was concluded from these observations that the distribution of cell bodies innervating a rat mandibular molar tooth is not restricted to a specific region of the mandibular territory of the trigeminal ganglion, but rather the distribution of these cell bodies is throughout all parts of the mandibular territory.

Histochemical evidence for strictly ipsilateral innervation of maxillary canine teeth in cats

Histochemical evidence for strictly ipsilateral innervation of maxillary canine teeth in cats

Histochemical evidence for strictly ipsilateral innervation of maxillary canine teeth in cats

Substantial efforts by various investigators have not shown conclusively that there is a peripheral crossed innervation of feline maxillary canine teeth. In addition, the number and location of afferent cell bodies innervating these teeth has not been adequately determined. Horseradish peroxidase (HRP) was used as a retrograde neuronal marker of the afferent fibers innervating the maxillary canine teeth in 11 cats. Cavity preparations were made in the ipsilateral canine tooth and then HRP was deposited in the cavity preparation. After survival periods of 18 to 72 h, the anesthetized animals were perfused and both the ipsilateral and contralateral ganglia were processed histochemically for the localization of the HRP reaction product. Both ganglia were studied for labeled cell bodies and their locus within the ganglia. All labeled cell bodies were in the maxillary division of the ipsilateral trigeminal ganglion. The greatest number of labeled cell bodies, in excess of 200, occurred 18 h after injection of the HRP, and was higher than reported in previous studies. The results from this study clearly indicate that the primary afferent innervation of the maxillary canine teeth in the cat is strictly ipsilateral, which casts doubt on the previous claims of a crossed or “transmedian” innervation of the maxillary canine teeth in that species.

A lack of peripheral transmedian innervation of feline mandibular canine teeth as determined by horseradish peroxidase

A lack of peripheral transmedian innervation of feline mandibular canine teeth as determined by horseradish peroxidase

Pain transmission and associated mechanisms

Pain transmission and central control mechanisms have evoked considerable interest in recent years. Extensive research has been and is being done into the subject, and the following three articles written by D. Bowsher, J. M. Mumford and F. T. Monks, who have had a long standing interest in this field, review the present concepts and cover, to some extent, the ideas of recent years that have led up to the present understanding of the subject. Dental pain, its production and the early part of its path o f transmission, is still a matter that is ill-understood. Both J. M. Mumford and F. T. Monks in their papers indicate this difficult problem from differing stand points. Is any part of the dentine innervated or not? Fearnhead and Lumsden (1956) and Fearnhead (1961) in their work on the innervation of teeth used a staining technique for nerve fibres on mature teeth. Their stain was based on silver nitrate which is notoriously capricious and must raise the problem of reliability. Monks (1951) used a silver protein compound, having first assessed its reliability, in a series of elegant histological investigations and came to the conclusion that nervous tissue was not present in the primitive pulp until after odontogenesis was firmly established and felt that under such circumstances it is unlikely for nervous tissue to be subsequently trapped in the advancing calcified dentine. Anderson (1976), in considering the transmission of stimuli across dentine regards the hydrodynamic theory of transmission as highly questionable considering the variable flow rates induced in dentinal tubules by a variety ofiso-osmotic solutions. Yet it is acknowledged that freshly cut dentine in the presence of a normal pulp is surprisingly insensitive. Sensitivity of dentine appears to be associated with pulpal oedema, yet it has not been emphasised that as the pulp is enclosed in a rigid box, and when under pressure, as in situations of oedema, it is likely that although a minimal fl0w of fluid in a tubule will produce a small stimulus at a receptor, the threshold level may be so lowered, it will result in the excitation of the afferent nerve. The fact that different iso-osmotic solutions give different flow rates in dentinal tubules would appear to be irrelevant in conditions of oedema but may be significant for their variable effect on the normal pulp. Speed of conduction across dentine is impressive clinically. Mechanical stimulation would produce a pressure wave in the tubules (rigid walled tubes) travelling at a speed of about 17 metres per second (Bradley, 1976) which is approximately the speed of conduction in a C pain fibre. Even if nervous tissue did penetrate the dentine to some extent, as Mumford suggests, the relationship of the odontoblast and its process with the nervous system is still not known. Would it be too far fetched to consider that the odontoblast and its process is a mechano-receptor and the afferent nerves merely synapse with the surface of the odontoblast in the predentine layer ? Or is the process a pressure effect in the pulp mediated by the liberation of a histamine-like substance as Monks suggests in his article. Recent work by Kollar and Lumsden (1979) suggests very early innervation of the pulp, contrary to Monks (l 951) findings who did demonstrate, however, early innervation of the follicle and sub-epithelial layer. The answers to many of these questions are still awaited, but reading these articles makes one feel that we are a little nearer the truth than we were: teeth are peculiar structures anatomically, embryologically and to some extent, physiologically.

Anatomic evidence revealing extensive transmedian innervation of feline canine teeth

Three anatomic techniques were used to study the transmedian innervation of the canine teeth of felines. They were (i) the Fink-Heimer II staining technique for degenerating axons, (ii) the cobalt, cut-axon technique, and (iii) the examination of retrograde chromatolysis in trigeminal ganglion cells following tooth pulp extractions. It was clearly demonstrated, using all three techniques, that canine teeth receive an extensive transmedian innervation, although the ipsilateral innervation exceeds the transmedian innervation. Approximately 199 trigeminal ganglion cells project to an ipsilateral canine tooth, whereas approximately 138 cells project to a contralateral canine tooth. These figures represent 0.5 and 0.3% of the cells in the trigeminal ganglion, respectively.

Sensory mechanisms in mammalian teeth and their supporting structures.

Sensory mechanisms in mammalian teeth and their supporting structures.

The distribution of nerves in human primary teeth.

AbstractHuman primary teeth in the stages of late root formation, root completion and root resorption were impregnated with silver to allow study of the distribution of nerves in the pulp.Neural trunks composed of many individual, myelinated nerve fibers enter the apical foramen of primary teeth and pass in a coronal direction, often in close association with blood vessels. Neural trunks in the crowns of the teeth divide into smaller branches, which divide further into myelinated nerve fibers, which become interwoven to form the parietal layer (plexus of Raschkow). An occasional unmyelinated fiber leaves this zone and passes into the odontoblastic layer of cells where it appears to terminate with no specialized ending apparent. No nerves were seen to enter the predentin or dentin.As primary teeth begin to undergo root resorption, degenerative changes such as thickenings, varicosities and fragmentation appear in the nerves. The quantity of neural tissue also decreases. The greater the amount of resorption, the greater are the degenerative changes. In teeth in which the roots are almost completely resorbed, only a small number of nerves remain.The pattern of distribution of nerves in primary teeth is observed to be similar to that of permanent teeth. The density of the innervation of the primary teeth, however, is not found to be as great as that of permanent teeth.

FUNCTIONAL ORGANIZATION OF TACTILE CUTANEOUS AFFERENTS WITHIN THE SEMILUNAR GANGLION AND TRIGEMINAL SPINAL TRACT OF THE CAT.

ArticlesFUNCTIONAL ORGANIZATION OF TACTILE CUTANEOUS AFFERENTS WITHIN THE SEMILUNAR GANGLION AND TRIGEMINAL SPINAL TRACT OF THE CATI. Darian-Smith, Patricia Mutton, and Robyn ProctorI. Darian-Smith, Patricia Mutton, and Robyn ProctorPublished Online:01 Jul 1965https://doi.org/10.1152/jn.1965.28.4.682MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByCurrent understanding of trigeminal ganglion structure and function in headache10 July 2018 | Cephalalgia, Vol. 39, No. 13Stable synchronized high-frequency signals from the main sensory and spinal nuclei of the pig activated by Aβ fibers of the maxillary nerve innervating the snoutBrain Research, Vol. 959, No. 1Musculotopic organization in the motor trigeminal nucleus of the reeler mutant mouseBrain Research, Vol. 666, No. 1Histamine actions and comparison with substance P effects in trigeminal neuronsNeuroscience, Vol. 55, No. 2Responses of cat C1 spinal cord dorsal and ventral horn neurons to noxious and non-noxious stimulation of the head and faceBrain Research, Vol. 555, No. 2Cervical Spinal Cord Neurons Receiving Sensory Input from the Cranial Vasculature7 November 2016 | Cephalalgia, Vol. 11, No. 2Topographic study of the feline trigeminal ganglion via the horseradish peroxidase tracer methodBrain Research, Vol. 476, No. 2Somatotopic organization of tooth pulp primary afferent neurons in the catBrain Research, Vol. 477, No. 1-2Electrophysiological responses of trigeminal root ganglion neurons in vitroNeuroscience, Vol. 24, No. 2Somatotopic Organization and Transmedian Pathways of the Rat Trigeminal Ganglion8 November 2016 | Journal of Dental Research, Vol. 63, No. 11Accessory innervation of mandibular anterior teeth in cats: a horseradish peroxidase studyBrain Research, Vol. 298, No. 2A horseradish peroxidase study of feline mandibular incisorsBrain Research, Vol. 260, No. 2The sensory representation of the dura mater in the trigeminal ganglion of the catNeuroscience Letters, Vol. 31, No. 3Peripheral and central substrates involved in the Rostrad transmission of nociceptive informationPain, Vol. 13, No. 1Peripheral and central pathways in painPharmacology & Therapeutics, Vol. 14, No. 3Histochemical evidence for strictly ipsilateral innervation of maxillary canine teeth in catsExperimental Neurology, Vol. 70, No. 1Motor and sensory centers for the innervation of mandibular and sublingual salivary glands: A horseradish peroxidase study in the dogBrain Research, Vol. 189, No. 2A lack of peripheral transmedian innervation of feline mandibular canine teeth as determined by horseradish peroxidaseBrain Research, Vol. 179, No. 2Further observations on transganglionic degeneration in trigeminal primary sensory neuronsBrain Research, Vol. 162, No. 1Topography of cutaneous spinal ganglion cells in the frog(Rana esculenta)Brain Research, Vol. 156, No. 1Ectopic action potential generation in peripheral trigeminal axonsExperimental Neurology, Vol. 62, No. 2Location of feline trigeminal ganglion cells innervating maxillary canine teeth: A horseradish peroxidase analysisExperimental Neurology, Vol. 57, No. 1Afferent excitability compared using pulsating versus constant direct current electroanalgesia in cat tooth pulpExperimental Neurology, Vol. 53, No. 2Location of cat trigeminal ganglion cells innervating dental pulp of upper and lower canines studied by retrograde transport of horseradish peroxidaseBrain Research, Vol. 99, No. 1The selective vulnerability of evoked potentials in the trigeminal sensory root to graded thermocoagulationExperimental Neurology, Vol. 49, No. 1Trigeminal influences on extensor muscles of the neckExperimental Neurology, Vol. 47, No. 2Transmedian innervation of canine tooth pulp in catsExperimental Neurology, Vol. 44, No. 1Excitability changes at the intramedullary terminals of lingual mechanoreceptor afferents induced by volleys in the cat's lingual nerveBrain Research, Vol. 57, No. 1Somatotopic organization of the trigeminal ganglion in the ratArchives of Oral Biology, Vol. 18, No. 4Respones of trigeminal ganglion and brain stem neurones in the cat to mechanical and thermal stimulation of the faceBrain Research, Vol. 42, No. 2A histological study of chromatolytic cell groups in the trigeminal ganglion of the ratArchives of Oral Biology, Vol. 17, No. 3Extraocular muscle proprioception and the descending trigeminal nucleusExperimental Neurology, Vol. 33, No. 1Tactile direction sensitivity of area 2 oral neurons in the rhesus monkey cortexBrain Research, Vol. 27, No. 2Location of the neurons innervating tendon spindles of masticator musclesExperimental Neurology, Vol. 25, No. 4Coding of somatic sensory input by vibrissae neurons in the rat's trigeminal ganglionBrain Research, Vol. 12, No. 1Peripheral pathway of eye muscle proprioceptionExperimental Neurology, Vol. 22, No. 1Interaction of peripheral and central input in the main sensory trigeminal nucleus of the catExperimental Neurology, Vol. 17, No. 2Eye muscle proprioception and the semilunar ganglionExperimental Neurology, Vol. 16, No. 2 More from this issue > Volume 28Issue 4July 1965Pages 682-694 https://doi.org/10.1152/jn.1965.28.4.682PubMed14347628History Published online 1 July 1965 Published in print 1 July 1965 Metrics

Innervation of teeth and periodontium after enzymatic removal of collagenous elements

1. 1. The innervation of human and monkey teeth and their periodontium was studied by Pearson's silver gelatin method. The jaws and teeth were fixed in a formol-acetic acid-alcohol mixture, decalcified, dehydrated, and embedded in nitrocellulose in the usual manner. The embedded specimens were sectioned at 25 to 100 micra, and the cut sections were exposed to enzymatic hydrolysis before silver impregnation. 2. 2. The common pulpal nerve arises as a union of the branches of the various dental nerves which enter the apical periodontal membrane of all the surfaces surrounding the tooth. In the coronal portion of the pulp the common pulpal nerve breaks up into cuspal nerves which course toward the cuspal horns. The termination of these nerves is mainly in the odontoblastic layer; however, a few nerves enter the predentine, where they form a loop to return to the odontoblastic layer. 3. 3. The nerve supply to the periodontal membrane arises from the dental and interalveolar nerves, branches of the alveolar nerves. The dental nerve fibers supply the periapical region and pass gingivally to form a united bundle with the perforating branches of the interalveolar nerves. 4. 4. Two types of nerve endings are found in the periodontal membrane. (1) Nonmedullated nerve fibers may unite at their terminals to form an arborization. Fine delicate fibrils arise from this network to end as “free nerve endings” among the stroma cells, cementoblasts, and cementum. (2) Medullated fibers may lose their myelin sheath, and the naked fibrils terminate into an elongated spindlelike structure. 5. 5. Gingival innervation is derived from two sources: (1) fibers arising from the nerves of the periodontal membrane and (2) fibers originating from the labial or palatal nerves. As these fibers pass through the connective tissue, terminal twigs are given off which supply the tunica propria. Intrapapillary and intraepithelial nerve endings are scarce in the epithelial attachment and marginal gingiva. On the other hand, attached gingiva contains both types of nerve endings.

Innervation of the continuously growing incisor.

To my knowledge, the development of the innervation of the teeth has not yet been systematically investigated. There have been sporadic remarks ; for example, Holland1 writes : “As far as nerve tissue is concerned, it is believed that there is no direct connection or hookup with the parent sensory nerve ganglion until the tooth erupts and until root formation is nearly completed”. Different authors, for example, Powers2, in her studies of tooth innervation, has given illustrations of the rat-pulp for myelinated fibres but only from the molar teeth and illustrations of the periodontal nerve supply from the continuously growing incisor of the same species. In several animals (dog, calf, pig) I have found that in the earlier stages of the tooth development, for example, the period before the root begins to grow, there are in the pulp only unmyelinated (presumably vegetative) fibres. Later the myelinated sensory fibres appear. The pulp of the continuously growing incisor of the rat shows a similar situation. There are only unmyelinated fibres differing in size and branching. These are mainly in the neighbourhood of the vessels (see Fig. 1) and do not reach the odontoblastic layer.

The Innervation of Teeth

The Innervation of Teeth

The innervation of the teeth in the albino rat with some observations on the finer structure of the dental pulp

The innervation of the teeth in the albino rat with some observations on the finer structure of the dental pulp

The Innervation of Teeth

The author, using the staining methods of Bielschowski, Gross, Beckwith, Weigert-Pal and Cajal in frozen and serial paraffin and celloidin sections, has investigated the dental innervations of man, monkey, dog, cat, and guinea-pig in health and disease. He discusses the anatomy and physiology of the dental innervation and the effect of section of the inferior dental nerve on the trophic, vasomotor, protective, and sensory functions, with special reference to the relation between dental disease and neuropathies. He describes the innervation of the tooth germ and the nature of the growing fibrils seen before calcification in the dentinal papilla and draws attention to the innervation of the periodontal membrane. He has found that these nerves anastomose across the crest of the interdental septa with their fellows and demonstrates coiled sub-cemental nerve-endings. He has been unable to find any difference in the eruption and casting of teeth after section of the inferior dental nerve, and does not find degeneration of the nerves of deciduous teeth prior to casting to be inevitable. He discusses the effect of local anaesthesia on the dental pulp, some of the causes of odontalgia and neuralgia and the effect of old age and general disease on the dental innervation. He has failed with lethal or continued sublethal doses of ethyl and methyl alcohol, lead or tetanus and diphtheria toxins, using the oral, gastric, subcutaneous and intravenous route, to produce dental neuronic change. The effects of fracture of teeth and jaws, the introduction of arsenic into the pulp chamber and amputation and extirpation of the pulp are examined. The vital resistance of the pulp and the significance of granulomata as a protective mechanism are discussed. The author has found that after extraction although there is at first degeneration of the nerve-fibres concerned, there may subsequently be regeneration, sometimes in the form of plexiform neuroma. He has produced degenerative changes in both the nerves and the Gasserian ganglia on both the operated and unoperated sides by the introduction of tetanus and diphtheria toxins into extraction sockets, where the neuronic involvement is proportionate to the degree of trauma with which the extraction is effected. The rôle of innervation in tooth movement during eruption and orthodontic correction, and after the extraction of anterior teeth, has been investigated, the latter by roentgencinematography.

Some Aspects of the Innervation of the Teeth

Some Aspects of the Innervation of the Teeth

Identification of the cells and fibers concerned in the innervation of the teeth

Journal of Comparative NeurologyVolume 39, Issue 3 p. 325-343 Article Identification of the cells and fibers concerned in the innervation of the teeth William F. Allen, William F. Allen Department of Anatomy of the University of Oregon Medical School, Portland, OregonSearch for more papers by this author William F. Allen, William F. Allen Department of Anatomy of the University of Oregon Medical School, Portland, OregonSearch for more papers by this author First published: December 1925 https://doi.org/10.1002/cne.900390302Citations: 19AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume39, Issue3December 1925Pages 325-343 RelatedInformation

The innervation of palatal taste buds and teeth of Amblystoma

The innervation of palatal taste buds and teeth of Amblystoma