• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.447-455
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• 2005

The purpose of this study was to examine the effect of Nd:YAG laser irradiation for sensory nerve conduction change. Nd:YAG laser was irradiated to mental region for 5 minutes with the parameters that 10 Hz and 20 Hz of 100 mJ/pulse. Target size of irradiation was 30 mm diameter of circle and target-tip distance was about 10 mm. Therefore, the power density were 212 $mW/cm^2$ and 424 $mW/cm^2$. Sensory nerve conduction was evaluated with $Neurometer^{\circled}$ CPT/C before and after Nd:YAG laser irradiation. As an outcomes, the current perception threshold(CPT) and pain tolerance threshold(PTT) were obtained. We made a comparison of these two values and the results were as follows. 1. There was no significant difference in CPT at 1W, 10 Hz and 2 W, 20 Hz Nd:YAG laser irradiation. 2. There was no significant difference in PTT at 10 Hz, 20 Hz of 100 mJ/pulse Nd:YAG laser. 3. There were no significant differences in CPT and PTT between 1 W, 10 Hz group and 2 W, 20 Hz group. Therefore, We can make a conclusion that Nd:YAG laser irradiation to mental region have no effect on mental nerve conduction in our study model.

• Journal of Oral Medicine and Pain
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• v.36 no.2
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• pp.131-137
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• 2011

Current Perception Threshold (CPT) using Neurometer($Neurometer^{(R)}$ CPT/C) is thought as one of easy and noninvasive QST(qunatitative sensory testing) tools for A${\beta}$, A${\delta}$ and C fibers within a relatively short time. However, conflicts about its reliability still exist. This study aimed to evaluate the reliability of CPTs evaluation and find a way to increase its reliability. Two examiners separately tested CPTs at each side of the mandibluar nerve areas for ten healthy male adults (average age of 22.4 years) three times with an intervals of a week during three weeks. Mean CPTs were compared between the right and left sides of the mandibular nerve area and between the three examinations on the each side. While CPTs at 2000 Hz(A${\beta}$ fiber) showed statistically significant side differences in all three examinations (p<0.05), significant side difference was found in only one examination at 250 Hz(A${\delta}$ fiber) and no difference at 5 Hz(C fiber). Comparing CPTs on the each side of the mandibular nerve area, all examinations at all sensory nerve fibers showed the least CPTs at the 1st examinations. CPTs at 250 Hz(A${\delta}$ fiber) and 5 Hz(C fiber) were significantly different between the first and the following examinations (p<0.05) and there was no significant difference between 2nd and 3rd examinations. The results of this study indicated that CPTs at 250 Hz(A${\delta}$ fiber) and 5 Hz(C fiber) are reliable but CPTs at 2000 Hz(A${\beta}$ fiber) is not appropriate for evaluation of side differences in the mandibular nerve area. In addition, it is suggested that repeated examination be helpful to increase reliability of the CPT evaluation.

• Journal of Oriental Medical Thermology
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• v.3 no.1
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• pp.60-66
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• 2004

Purpose This study is to examine of Neurometer for the diagnosis of cold hypersensitivity Method Among patients who visited the oriental gynecological department in Kangnam Korean Hospital from October. 2000 to December. 2000, 37 women were diagnosed as cold hypersensitivity by D.I.T.I. We measured the limbs' temperature by D.I.T.I. and Current perception threshold(CPT) of median N., ulnar N., radial N., peroneal N., sural N., tibial N., saphenous N. by neurometer Patients were divided into mild and severe group depending on the temperature difference between proximalis and distalis in limbs Result and Conclusion 1. In severe group, CPT of median N., ulnar N., radial N. was higher on 250Hz and 200Hz. 2. In severe group, Mean CPT of peroneal N., sural N., tibial N., saphenous N. was higher on every Hz.

• Journal of Oral Medicine and Pain
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• v.36 no.3
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• pp.199-205
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• 2011

During root canal treatment, overinstrumentation with hand or mechanically driven files can perforate the mandibular canal, allowing the extrusion of endodontic sealers, dressing agents, and irrigant solutions out of the tooth and into the canal. The patient may report symptoms such as pain, hyperesthesia, hypoesthesia, anesthesia, dysesthesia and paresthesia. Such problems must be resolved as quickly as possible to avoid irreversible sequelae caused by certain neurotoxic materials that form part of endodontic sealants. Although there have been no controlled trials of treatment protocols involving endodontically related injuries to the inferior alveolar nerve, the normal therapeutic sequence for this complication is the control of pain and inflammation and, whenever possible, the surgical elimination of the cause. However, total resolution of pain and reduction in or disappearance of paraesthesia after a non-surgical management have been reported. Antiepileptic drugs such as gabapentin or pregabalin have been used for the treatment of neuropathic pain. This article describes a case of inferior alveolar nerve(IAN) damage after endodontic treatment of a mandibular right second molar and the treatment with non-surgical approach using prednisone and gabapentin medication, monitoring the patient's condition with clinical neurosensory examination and current perception threshold test(Neurometer).

• Journal of Oral Medicine and Pain
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• v.32 no.2
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• pp.187-200
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• 2007

This study attempted to contribute to the clinical application of implant operation by making a quantitative nerve examination using a neurometer for the evaluation of sensory disturbances that could be incurred after the implantation in the dental clinics, and it intended to establish an objective guideline in the evaluation of sensory nerve after the operation of implant. An inspection was performed with the frequencies of 2000Hz, 250 Hz and 5 Hz before and after the operations of tooth implant using $Neurometer^{(R)}$ CPT/C (Neurotron, Inc. Baltimore, Maryland, USA) for 44 patients who had performed an implant operation among the patients coming to Daejeon Sun Dental Hospital in 2006 and 30 people for control group. The measuring sites were maxillary nerve ending and mandibular nerve ending of trigeminal nerve according to the implant operating regions. The current perception threshold (CPT) by each nerve fiber was specifically responded under the electric stimulation of 2000 Hz in case of $A{\beta}$ fiber and of 250 Hz in case of $A{\delta}$ fiber and of 5Hz in case of C fiber. The CPT test could be performed to assess the damages of peripheral nerve in the trigeminal nerve area and it stimulated selective nerve fibers by generating the electricity of specific frequency in the peripheral nerve area. The nerve fibers with varied thickness were responsive selectively to the electric stimulation with different frequencies; accordingly, they applied the electric stimulation with different frequencies and the reaction threshold of $A{\beta},\;A{\delta}$ and C fibers selectively responsive to each electric current could be individually evaluated. In the assessment through the CPT, the increase and decrease of the CPT could be measured so that sensory disturbances such as hyperaesthesia or hypoaesthesia could be diagnosed. This study could obtain the following results after the assessment of the CPT before and after the implant operation. 1. In the assessment before and after the implant operation, the CPT in the frequencies of 2000 Hz, 250 Hz, 5 Hz for maxillary branch increased on the whole after the operation and the CPT for mandibular branch in the $A{\beta}$-fiber(2000 Hz) and C-fiber(5 Hz )after the operation increased statistically significantly. 2. For the groups of patients with medically compromised or its subsequent medicinal prescription, there were no significant differences before and after the implant operation and for the control groups, significantly high CPT was shown after the implant operation in the left $A{\beta}$-fiber(2000 Hz) and C-fiber(5 Hz). 3. In the comparison of the measured value of the CPT before the operation between the control group and the implant operation group, the latter group had a significantly high measured value of the CPT in the right $A{\beta}$-fiber(2000 Hz) and C-fiber(5 Hz) and there were significant differences in $A{\beta}$-fiber(2000 Hz) in the CPT assessment after the implant operation for the control group. 4. Male participants had higher CPT than female counterparts; however, there were no statistic significances. In the CPT evaluation before and after implant operation, there were no statistical differences in the male group while the right C-fiber(5 Hz) and left $A{\beta}$-fiber(2000Hz) were significantly high in the female group. 5. In the comparison between the group who complain sensory disturbance and the other group, the CPT increased on the whole in the former group, but there were no statistical significances. In the groups, whom there was an increase in VAS, the CPT after the implant operation in the right C-fiber(5 Hz) increased significantly; meanwhile, in case that the VAS mark was '0' before and after the operation, the CPT after the operation in the left $A{\beta}$-fiber(2000 Hz) increased significantly. This study suggested that the CPT measurements using $Neurometer^{(R)}$ CPT/C, provide useful information of objective and quantitative sensory disturbances for tooth implantation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.5
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• pp.355-364
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• 2011

Introduction: This study evaluated nerve recovery through retrospective study of patients with lingual nerve damage. Patients and Methods: The patients who visited Seoul National University Dental Hospital for an injury to the lingual nerve from April 1988 to August 2009 were enrolled in this study (n=41). The relevance of various factors including the causes of damage, age, etc. was analyzed by the subjective improvement based upon questionnaires and the clinical records. The evaluation variants were a subjective assessment and neurosensory examination composed of the direction, contact threshold, two-point discrimination, pin prick, thermal discrimination and current perception threshold. Results: The causes of lingual nerve damage were an extraction of the lower third molar (75.6%), local anesthesia (9.7%), incision and drainage (4.88%), trauma (2.44%). The evaluation of subjective prognosis exhibited no difference in sensory improvement depending on the cause, age and gender. Based upon the subjective evaluation, 44.7% of patients showed sensory improvement. The first hospital visit from injury was shorter in the group showing subjective improvement (3.41 months) than those showing no improvement (5.24 months) (P=0.301). Thirty six out of 41 patients were treated with only conservative therapy and 5 patients were treated by surgical intervention. Neurosensory examinations revealed improvement, although not statistically significant, and the degree was higher in the subjectively improved group. The contact threshold discrimination showed the highest correlation with subjective improvement (P=0.069). Most of the sensory recovery was gained within 12 months and the degree of improvement at the tip of the tongue was higher than that of the dorsum (P<0.001). Conclusion: The damaged lingual nerve improved at a rate of 44.7% and mostly within 12 months after the incident. There was no difference between the subjective prognosis and neurosensory examination depending on the cause of damage, age and gender, whereas the contact threshold discrimination was the best variant that reflected the subjective prognosis statistically.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.13.1-13.7
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• 2015

Background: This study evaluated Somatosensory evoked potentials (SEP), Quantitative sensory testing (QST), and thermography as diagnostic methods for nerve injury. Methods: From 2006 through 2011, 17 patients (mean age: 50.1 years) from ${\bigcirc}{\bigcirc}{\bigcirc}{\bigcirc}$ Hospital who sought care for altered sensation after dental implant treatment were identified. The mean time of objective assessment was 15.2 months after onset. Results: SEP of Inferior alveolar nerve(IAN) was $15.87{\pm}0.87ms$ on the normal side and $16.18{\pm}0.73ms$ on the abnormal side. There was delayed N20 latency on the abnormal side, but the difference was not statistically significant. In QST, the abnormal side showed significantly higher scores of the current perception threshold at 2 KHz, 250 Hz, and 5 Hz. The absolute temperature difference was $0.55^{\circ}C$ without statistically significance. Conclusion: These results indicate that QST is valuable as an objective method for assessment of nerve injury.

• Journal of Oral Medicine and Pain
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• v.24 no.3
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• pp.301-313
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• 1999

구강안면동통 환자의 치료법으로 널리 쓰이는 전기요법은 연조직과 신경계 구조물에 대한 치료 시 중요한 역할을 담당하고 있다. 저자는 현재 구강안면동통의 치료법으로 널리 쓰이고 있는 전기요법들 중 경피성 신경자극(Transcutaneous electric nerve stimulation)과 전기침자극요법(Electroacupuncture stimulation therapy)이 각각의 신경섬유에 미치는 효과를 평가하고자 정상 성인 남녀 29명에게 경피성 신경자극 및 전기침자극을 시행하고 시행 전 및 시행 후 삼차신경 영역의 3가지 종류($A{\beta}$, $A{\delta}$, C fiber)의 신경섬유의 전류인지역치(CPT) 변화를 측정하여 그 차이점을 분석하였으며 이를 대조군과 비교하였다. 경피성 신경자극 및 전기침자극 모두에서 대조군에 비해 삼차신경 영역의 모든 신경섬유에 걸쳐 고른 전류인지역치의 증가를 나타내었으며, 경피성 신경자극과 전기침자극 후의 전류인지역치 변화량은 서로 유의할만한 차이를 나타내지 않았다. 이는 경피성 신경자극 과 전기침자극 모두 3가지 종류($A{\beta}$, $A{\delta}$, C fiber)의 감각신경섬유의 전류인지역치에 영향을 미치며, 구강안면동통의 감소에 효과적으로 사용될 수 있으리라 생각된다.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.249-256
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• 2019

A full-scale test line was established to verify the electrical environmental interferences caused by the HVDC ±500 kV Double Bipole overhead transmission line with metallic return conductor, which is scheduled for construction in Korea and the fullscale test was conducted for one year. And through the human perception test of the DC electric-field under the HVDC Double Bipole line, the threshold value at which the human detects DC electric field was investigated to verify the validity of the design guide for the HVDC ±500 kV Double Bipole overhead transmission line. The polarity configuration of the HVDC ±500 kV Double Bipole test line was arranged diagonally with the same polarity in terms of the electrical environment disturbance and operation. The test line utilized the 6-bundle arrangement to prevent the corona discharge taking into account the domestic social acceptability. The test results show that the HVDC ±500 kV Double Bipole transmission line generated very little corona discharge from the conductors. Therefore, both DC electric field and ion current density met the domestic design guide for DC overhead transmission lines. Also, the human perception test of DC electric fields under the test line showed that 70% of participants did not recognize the DC electric field even when exposed to 23 kV/m.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.3
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• pp.43-60
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• 2005

In september 2004, a new pilot certificate scheme referred to as Sport Pilot Certificate was declared official and standardized in the US. The designation of Light-sport aircraft and the details of the relevant pilot certificate policy was announced out of the perception that a new regulation is required to be applied whereby the limitations on the manufacturing process enhancements and current aviation rules are considered the triggering factors. US Federal Aviation Regulation retains a comprehensive range of airworthiness certificates and aircrafts are managed systematically in accordance with FAR 21, 103. The airworthiness are further segregated into sub categories, which allows differentiated management. Korean Aviation Law classify aircraft into five different categories and powered air vehicle that weighs more than 150kg(19liters fuel capacity) for one seat, 225kg for two seats(38liters fuel capacity) while the systems that fall under a specific mass threshold level are known as ultralight vehicle. The research discusses the policy of the sport pilot certificate and the light-sport aircraft ratings announced official by the Federal Aviation Administration in an intuitive fashion with the analysis of the operations providing the evidence as to the viability of adopting the policy in local grounds. Based on the findings, the report discusses the case for introducing the light-sport aircraft and make recommendation on a strategy of applying the policy in Korea with respect to the pilot certificates, safety agenda, and the written test for the pilot certificate, and operating efficiency.