Quantitative study of the apical nerve fibers of adult and juvenile rat molars

Naftel, John P.; Bernanke, Jayne M.; Qian, Xiaobing

doi:10.1002/ar.1092380410

Cited by 24 publications

(5 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This was accomplished by use of immunohistochemical staining with anti‐neurofilament antibodies to facilitate tracing of small nerves through serial sections of mandibles. In addition, the numbers and sizes of axons composing the major dental branches were examined by electron microscopy first to correlate the present findings with the most detailed previous study of IAN branches (Johansson et al, 1992) and second to compare dental nerve composition with available quantitative data both on pulpal axons at the molar apex (Naftel et al, 1994) and on identified somas of molar afferents in the trigeminal ganglion (Aker, 1987; Fried et al, 1989; Qian and Naftel, 1996).…”

mentioning

confidence: 77%

“…These numbers are compatible with a ratio of one pulpal neuronal soma in the ganglion for each pulpal axon at the level of the posterior part of the mandibular canal. In contrast, an average of 1,038 axons traverse the four root apices of the 1st mandibular molar to enter the pulp, and only about 1/4 of these are myelinated (Naftel et al, 1994). We have observed further that the 3rd molar receives more than 300 axons, two‐thirds of which are unmyelinated (unpublished data).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Course and composition of the nerves that supply the mandibular teeth of the rat

et al. 1999

Self Cite

View full text Add to dashboard Cite

The rodent dentition has become an important model for investigations of interactions between dental tissues and peripheral neurons. Although experimental nerve injury has been widely used for such studies, there is uncertainty about the courses of nerve fibers supplying the mandibular teeth. In order to clarify this, we used a mixture of monoclonal antibodies against neurofilament proteins to enhance demonstration of nerve fibers so that small nerves could be readily traced in serial frozen sections of mandibles of Sprague Dawley rats ranging in age from embryonic day (E) 18 to postnatal day (P) 90. The 1st molar and anterior portion of the 2nd molar were innervated by small nerves that emerged as distinct branches of the IAN trunk at or near the mandibular foramen. In contrast, the nerve supply to the 3rd molar and posterior part of the 2nd molar was a branch of the lingual nerve that bypassed the mandibular canal altogether. The IAN trunk split into the mental nerve and a large branch to the incisor about 2 mm anterior to the mandibular foramen. Thick branches of the incisor nerve descended into the incisor socket to form a dense plexus of nerve fiber bundles extending along the length of the incisor periodontium. The sparse pulpal innervation of the incisor was provided by a few thin fascicles that emerged from the caudal portion of the periodontal plexus to enter the incisor apex. The dental branches of the IAN and lingual nerve seen in the adult were well established and readily identifiable at age E18 even though their targets were limited to the follicles of the developing teeth. These studies show that the trigeminal branches that supply the mandibular teeth can be identified at a wide range of ages as distinct nerves at a considerable distance proximal to their targets. This detailed information on the courses taken by the dental nerves can provide an anatomical basis for increased precision in characterization and perturbation of neural pathways from the molars and incisor.

show abstract

mentioning

confidence: 77%

Section: Discussionmentioning

confidence: 99%

Course and composition of the nerves that supply the mandibular teeth of the rat

et al. 1999

Self Cite

View full text Add to dashboard Cite

show abstract

“…Previous EM studies identified both myelinated and unmyelinated axons in dental pulp [19,20], but the authors did not elucidate where and how the morphology of the parent myelinated axons change between their origin in the TG and their target in the dental pulp, or within the dental pulp itself. It was shown that virtually all axons in the sensory roots of the TG that are immunopositive for parvalbumin (PV+) are myelinated [21].…”

Section: Morphological Features Of Axons Within the Dental Pulpmentioning

confidence: 99%

Morphological foundations of pain processing in dental pulp

Bae

Yoshida

2020

J Oral Sci

View full text Add to dashboard Cite

Dental pulp is densely innervated by sensory afferents that are primarily involved in nociception. Elucidating the type and properties of these afferents and their distribution patterns within the dental pulp is crucial for understanding the mechanisms of acute dental pain and dental hypersensitivity. Recent studies on the release of the transmitter glutamate and the expression of glutamate receptors and vesicular glutamate transporters (VGLUT) in the pulpal axons and trigeminal ganglion (TG) have suggested the possibility of a distinct glutamate signaling mechanism underlying the peripheral processing of dental pain. This review discusses recent findings on the innervation of dental pulp and glutamate signaling by pulpal axons. First, recent findings on the morphological features and types of axons innervating the dental pulp are summarized. Then, glutamate signaling in the dental pulp and changes in the expression of VGLUT1 and VGLUT2 in the pulpal axons and TG neurons following pulpal inflammation are explained. Finally, findings on glutamate release from odontoblasts are briefly described.

show abstract

“…For example, the conduction velocity of axons that innervate the dental pulp is higher in the extrapulpal than in the intrapulpal segment (5,6), and the proportion of myelinated to unmyelinated axons is higher in the inferior alveolar nerve than in the intrapulpal nerve (7,8). In addition, a large number of electron microscopic (EM) studies have reported that only 22%-45% of the intradental axons are myelinated in the radicular pulp of rats, cats, dogs, marmosets, and humans (9)(10)(11)(12)(13), whereas our previous study found that most axons innervating the rat dental pulp are myelinated at their site of origin in the trigeminal ganglion (TG) (14). Taken together, these results suggest that at least a large fraction of parent axons innervating the dental pulp lose their myelin between leaving the TG and entering the dental pulp.…”

mentioning

confidence: 99%