Characteristics of the pain tolerance threshold induced by electrical stimulation of the alveolar ridge

Verification of the reliability of current perception threshold and pain threshold testing by application of an electrical current stimulus to mandibular mucosa in young adults

BACKGROUND

There is little evidence regarding the reliability of CPT and PT measurements to gauge mandibular perception. Thus, this study aimed to evaluate the test-retest reliability of CPT and PT values obtained from the mandibular oral mucosa and to test the bilateral differences in CPT and PT values obtained from the mental foramen region and buccal shelf region by a single operator.

METHODS

CPT and PT values were obtained from the mental foramen and buccal shelf regions of 20 volunteers (10 males and 10 females; average age: 26.4 ± 2.6 years) by using the Neurometer CPT/C® device to deliver electrical stimulation.

RESULTS

Relative and absolute reliabilities were confirmed over two measurements of CPT and PT over a 7- to 10-day measurement interval. Intra-class correlation coefficients (ICCs) for CPT and PT table obtained from the mental foramen region were >0.8, while most ICC for the buccal shelf region were <0.8. Standard error of measurement, minimal detectable change and Bland-Altman analyses showed that the CPT and PT measurements had no systematic error and could serve as useful methods. At all frequencies, the bilateral difference in CPT and PT values at the mental foramen and buccal shelf region was not significant.

CONCLUSION

CPT and PT measurements using a custom-made device that applied an electrical current to the mental foramen region have appropriate reliability to assess intra-oral sensitivity to electrical stimulation in young adults.

Electrostimulation of the lingual nerve by an intraoral device may lead to salivary gland regeneration: A case series study

Background

Salivary gland function is controlled by the salivary reflex, whose efferent arm is composed by the parasympathetic and the sympathetic divisions of the autonomic nervous system. Parenchymal injury is the main salivary gland involvement of Sjögren’s syndrome and head and neck radiotherapy, but neural damage has been reported as well. Recently an intraoral device for electrostimulation of the lingual nerve in vicinity to the lower third molar has been introduced. At this point this nerve carries efferent fibers for the innervation of the submandibular, sublingual and several minor salivary glands and afferent fibers of the salivary reflex. Therefore, excitation of these fibers potentially leads to increased secretion of all salivary glands. Thus, the study objective was to assess whether comprehensive neural activation by electrostimulation of the lingual nerve carries the potential to induce the regeneration of damaged salivary glands.

Material and Methods

The device was tested on three patients with no collectable resting and stimulated secretion of saliva during a double blind, sham controlled period of two months and nine open-label months.

Results

All three subjects developed the capacity to spit saliva, not only in direct response to the electrostimulation but also after free intervals without electrostimulation. In addition, their symptoms of dry mouth severity and frequency improved.

Conclusions

This recovery is probably due to the combined effect of increase in secretory functional gland mass and regain of nervous control of the secretory elements and blood vessels. Both are phenomena that would contribute to gland regeneration.

Key words:Xerostomia, dry mouth, saliva, electrostimulation, regeneration.

Measurement reliability of current perception threshold and pain threshold in parallel with blood sampling

The irritation and pain associated with oral blood sampling necessary to monitor glycemic control can alter oral sensation, but no studies have measured the reliability of oral sensation testing when performed concurrently with blood sampling. The primary and secondary aims of this study were to verify the measurement reliability of current perception threshold (CPT) and pain threshold (PT) tests performed before and after blood sampling and to investigate the differences in CPTs/PTs obtained from the oral cavity, hand, and foot, respectively. CPT/PT measurements were obtained from the oral mucosa and the tips of fingers and toes of 18 volunteers (10 males and 8 females, average age = 26.3 years) using electrical stimulation at frequencies of 5, 250, and 2,000 Hz. Participants also provided blood samples by pricking their own index fingers with a small needle. All subjects completed the following 3 conditions at once-weekly intervals as follows: (a) sensory measurements followed by blood sampling (SB block); (b) blood sampling followed by sensory measurements (BS block); (c) sensory measurements without blood sampling (CO control block). Cronbach's α coefficients were over 0.78 for the SB, BS, and CO blocks, and are considered to be acceptable for assuring measurement reliability. The oral cavity had significantly lower CPT/PTs than both hands and feet, such that the threshold increased in the order oral cavity < hand < foot. CPT and PT measurements performed concurrently with blood sampling are both reliable and region specific, and for which the oral cavity is the most sensitive testing region.