Characteristics of periodontal mechanoreceptors reinnervated after freezing the inferior alveolar nerve.
Previous electrophysiological investigations have shown that reinnervated periodontal mechanoreceptors, 12 weeks after crushing or sectioning the inferior alveolar nerve, have altered discharge properties. These alterations may have resulted from the regeneration of axons along inappropriate endoneurial sheaths distal to the injury site and this possibility was investigated by comparing the properties of reinnervated mechanoreceptors after nerve crush with those after nerve freeze (after which endoneurial sheath guidance is not lost). In 4 cats, 67 periodontal mechanosensitive units supplying the lower canine were examined 12 weeks after freezing the inferior alveolar nerve. When compared with controls, they were found to have significantly smaller arcs of sensitivity, raised force thresholds, lower discharge frequencies and reduced dynamic indices. These characteristics were, however, similar to those of units examined after nerve crush. These results suggest that the alterations in receptor properties after nerve injury cannot be attributed to a mismatch between the regenerating axons and their receptors.
Loescher
A R
AR
Department of Oral and Maxillofacial Surgery, University of Sheffield School of Clinical Dentistry, Charles Clifford Dental Hospital, U.K.
Robinson
P P
PP
D000818:Animals; D001369:Axons / Q000502:physiology; D002415:Cats; D004558:Electric Stimulation; D005615:Freezing; D008340:Mandibular Nerve / Q000502:physiology*; D008465:Mechanoreceptors / Q000502:physiology*; D009409:Nerve Crush; D009416:Nerve Regeneration / Q000502:physiology*; D010519:Periodontium / Q000294:innervation*