Reliability and Characteristics of Current Perception Thresholds in the Territory of the Infraorbital and Inferior Alveolar Nerves

Aims: To estimate the intra- and interrater reliability of current perception threshold (CPT) evaluation, especially within the infraorbital nerve territory (ION) and inferior alveolar nerve territory (IAN) of the orofacial region, and to characterize the CPTs of ION and IAN in the normal population. Methods: Electrical stimulation (at 2,000 Hz, 250 Hz, and 5 Hz) was applied to ION and IAN to allow for CPT evaluation in 200 subjects, all of whom were healthy, had no systemic diseases, and were free from symptoms and history of neuropathic conditions. Twenty-five of the subjects were evaluated 3 times by 2 examiners to test reliability, and the remaining subjects were evaluated once for normative data. Results: The intraclass correlation coefficient of CPTs within examiner and between examiners ranged from 0.46 to 0.95. There were no significant differences between right and left sides in CPT evaluation within the ION and IAN territory. Gender and age did not affect the CPT values for ION and IAN in the normal population. There were significant differences between each of the 3 frequency-dependent (2,000 Hz, 250 Hz, 5 Hz) measures within ION and IAN (P 0.001). Conclusion: Evaluation of CPTs within ION and IAN revealed good intra- and interrater reliability. The study also provided normative data of CPTs of ION, IAN, and the between-site and within-site ratios of CPTs of ION and IAN. This should prove useful in the diagnosis of orofacial neuropathy.