• Journal of Korean Dental Science
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• 제6권2호
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• pp.58-66
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• 2013

Purpose: The inferior alveolar nerve (IAN) can be damaged as a result of minor oral surgical procedure such as third molar extraction or implant placement. Repair of the injured IAN involves difficulty of access, and research studies are limited to elucidating the process of regeneration by surgical methods. This study sought to establish the rabbit animal model to apply polymeric membrane functionalized with nerve growth factor after a crush lesion for the evaluation of nerve regeneration using the electrophysiologic method. Materials and Methods: The IAN of 2 adult male New Zealand white rabbits (4 nerves) were exposed bilaterally, and crush injury rendered by jeweler's forceps was applied. Nerve conduction velocity was examined electrophysiologically using electromyography before, after, and 4 weeks after the crush injury. To evaluate the regeneration, the pattern of action potential of IAN was recorded, and the characteristics of neurons were histologically observed. Result: After the crush injury, afferent activity decreased in the injured group. Electromyography could not be recorded after four weeks because tissues surrounding the injured nerve collapsed. Decrease in the mean number of axons was observed in the injured part with membrane. Conclusion: Despite the limited result, the present animal model study may provide a possible way to research on the methods of enhancing the recovery of nerve injuries in clinical situations. For clinically widespread acceptance, however, it should gain more consecutive and scientific evidences.

• The Korean Journal of Physiology and Pharmacology
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• 제9권3호
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• pp.143-147
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• 2005

Following peripheral nerve injury, excessive nociceptive inputs result in diverse physiological alterations in the spinal cord substantia gelatinosa (SG), lamina II of the dorsal horn. Here, I report the alterations of excitatory or inhibitory transmission in the SG of a rat model for neuropathic pain ('spared nerve injury'). Results from whole-cell recordings of SG neurons show that the number of distinct primary afferent fibers, identified by graded intensity of stimulation, is increased at 2 weeks after spared nerve injury. In addition, short-term depression, recognized by paired-pulse ratio of excitatory postsynaptic currents, is significantly increased, indicating the increase of glutamate release probability at primary afferent terminals. The peripheral nerve injury also increases the amplitude, but not the frequency, of spontaneous inhibitory postsynaptic currents. These data support the hypothesis that peripheral nerve injury modifies spinal pain conduction and modulation systems to develop neuropathic pain.

• 대한치과의사협회지
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• 제54권11호
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• pp.874-879
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• 2016

Damage to the inferior alveolar nerve(IAN) is a relatively infrequent complication in endodontic treatment. However, endodontic overfilling involving the mandibular canal may cause an injury of the inferior alveolar nerve resulting in sensory disturbances such as pain, dysesthesia, paresthesia or anesthesia. Two mechanism(chemical neurotoxicity and mechanical compression) are responsible for the IAN injury. When absorbent materials overfilled, it can be treated as a non-surgical procedure. But early surgical intervention required when mechanical, chemical nerve damage expected. We report surgical removal of overfilled gutta-percha and IAN decompression through sagittal split osteotomy in case of dysesthesia after overfilling of endodontic material into the mandibular canal. Dysesthesia recovered 3 months after surgical treatment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권2호
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• pp.200-206
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• 2008

A variety of mechanisms may generate pain resulting from injury to the peripheral nervous system. None of these mechanisms is disease-specific, and several different pain mechanisms may be present simultaneously in any one patient. Diagnosis of neuropathic pain is often easily made from the information gathered on neurologic examination and from patient history. Evidence of sensory disturbances elicited by examination combined with laboratory tests confirming injury to peripheral nerve establishes the diagnosis of neuropathic pain. Although treatment of neuropathic pain may be difficult, optimum treatment can be achieved if dentist has a complete understanding of the therapeutic options. Pharmacologic therapy has been the mainstay of treatment. Selection of an appropriate pharmacologic agent is by trial and error since individual response to different agents, doses, and serum level are highly variable. An adequate trial for each agent tried is key to pharmacologic treatment of neuripathic pain. If pharmacologic treatment is not effective, nerve block using lidocaine, steroid and alcohol and neurectomy must be considered for treatment option.

• 한국치위생학회지
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• 제13권5호
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• pp.819-826
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• 2013

Objectives : The purpose of this study was to analyze the types of dental emergencies. This study was carried out for dental trauma patients visiting the emergency room in H hospital from 2005 to 2006. Methods : Subjects were 252 patients. Demographic characteristics consisted of age, gender, dentition, and dental related injury. Results : Male patients had 1.65 times higher tooth injury than female. Teenagers had higher prevalence of tooth injury. Main cause of dental injury was falling down. Young children accounted for 41.7% of the injuries. Late evening was the highest outbreak time of injury. The most commonly affected teeth were central incisor and lateral incisor. The damage of oral soft tissue was more common than the that of alveolar bone. Main area of primary tooth loss was gingiva(10.7%), tongue or soft palate(7.5%), and frenulum(6.0%). Subluxation(28.6%) and luxation(28.6%) were main cause for the primary teeth. Tooth fracture(50.0%) were the most common injury. Conclusions : Thus, to understand the incidence, causes and patterns of dental trauma is to help preserving natural teeth. The results of this study could provide the clinical guidelines on the treatment of dental emergency patients.

• 구강회복응용과학지
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• 제28권2호
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• pp.171-178
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• 2012

보툴리눔 독소 주사는 이마, 눈가 주름치료 등 미용성형분야 뿐만 아니라 구강 악안면 분야에서는 만성 편두통(chronic migraine), 근육긴장이상(dystonia), 경직(spasticity), 측두하악장애(temporomandibular disorders, TMD)의 치료 등에 사용되어 왔다. 최근 보툴리눔 독소 주사가 운동신경에서 마비효과 뿐만 아니라 감각신경에서 말초감작과 신경원성염증과 관련되는 substance P, CGRP, glutamate 등 비콜린성 신경전달물질의 유리를 차단하여 통증신호를 차단하는 역할을 한다는 가설이 제기되고 있다. 따라서 본 연구는 쥐, 토끼 등 동물 신경 손상 모델에 대한 실험과 치과 치료 후 발생한 신경 손상 환자에서 보툴리눔 독소의 진통 효과 및 작용 기전을 살펴보고자 한다.

• Journal of Microbiology and Biotechnology
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• 제34권6호
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• pp.1328-1339
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• 2024

Cadmium (Cd) is a prevalent environmental contaminant that poses a potential hazard to the health of both humans and animals. In this study, biosynthesized selenium-enriched Lactobacillus plantarum and selenium nanoparticles (SeNPs) were developed and evaluated for their protective effects against Cd-induced hepatic injury in mice through oral administration for 4 weeks. Cadmium exposure resulted in severe impairment of liver function, as evidenced by increased levels of serum markers of liver injury and, oxidative stress and significant damage to liver tissue, and a notable decrease in the diversity of the intestinal microbiota. Oral administration of Se-enriched L. plantarum (LS) reduced cadmium accumulation in the liver by 49.5% and, restored other cadmium-induced damage markers to normal levels. A comparison of the effects with those of L. plantarum (L) and SeNPs isolated from LS revealed that LS could more effectively alleviate hepatic oxidative stress and reduce the intrahepatic inflammatory responses of the liver, further protecting against cadmium-induced liver injury. These findings suggest that the development of LS may be effective at protecting the liver and intestinal tract from cadmium-induced damage.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권5호
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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.

• The Korean Journal of Pain
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• 제35권4호
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• pp.383-390
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• 2022

Background: The treatment of trigeminal neuralgia remains a challenging issue. Stem cells from human exfoliated deciduous teeth (SHED) provide optimized therapy for chronic pain. This study aimed to investigate the mechanisms underlying the attenuation of trigeminal neuralgia by SHED. Methods: Trigeminal neuralgia was induced by chronic constriction injury of the infraorbital nerve. The mechanical threshold was assessed after model establishment and local SHED transplantation. Endoplasmic reticulum (ER) morphology and Caspase12 expression in trigeminal ganglion (TG) was evaluated as well. BiP expression was observed in PC12 cells induced by tunicamycin. Results: The local transplantation of SHED could relieve trigeminal neuralgia in rats. Further, transmission electron microscopy revealed swelling of the ER in rats with trigeminal neuralgia. Moreover, SHED inhibited the tunicamycin-induced up-regulated expression of BiP mRNA and protein in vitro. Additionally, SHED decreased the up-regulated expression of Caspase12 mRNA and protein in the TG of rats caused by trigeminal neuralgia after chronic constriction injury of the infraorbital nerve mode. Conclusions: This findings demonstrated that SHED could alleviate pain by relieving ER stress which provide potential basic evidence for clinical pain treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권4호
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• pp.679-700
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• 1996

Inferior alveolar nerve dysfunction may be the result of trauma, disease, or iatrogenic injury. Inferior alveolar nerve injury is inherent risk in endodontic therapy, orthognathic surgery of the mandible, and extraction of mandibular teeth, particularly the third molars. The sensory disturbances of inferior alveolar nerve associated with such injury have been well documented clinical problem that is commonly evaluated by several clinical sensory test including Tinels sign, Von Frey test(static light touch detection), directional discrimination, two-point discrimination, pin pressure nociceptive discrimination, and thermal test. These methods used to detect and assess inferior alveolar nerve injury have been subjective in nature, relying on the cooperation of the patients. In addition, many of these techniques are sensitive to differences in the examiners experience and skill with the particular technique. Data obtained at different times or by different examiners are therefore difficult to compare. Prior experimental studies have used electro diagnostic methods(sensory evoked potential) to objectively evaluate inferior alveolar nerve after nerve injury. This study was designed with inferior alveolar nerve of rabbit. Several types of injury including mind, moderate, severe compression and perforation with 19 gauze, 21 gauze needle and 6mm, 10mm traction were applied for taking the sesory evoked ppterntial. Latency and amplitude of injury rabbit inferior alveolar nerve were investigated with sensory evoked potential using unpaired t-test. The results were as follows : 1. Intensity of threshold (T1) was $128{\pm}16{\mu}A$ : latency, $0.87{\pm}0.07$ microsecond : amplitude, $0.4{\pm}0.1{\mu}V$ : conduction velocity, 23.3 m/s in sensory evoked potential of uninjured rabbit inferior alveolar nerve. 2. Rabbit inferior alveolar nerve consists of type II and III sensory nerve fiber. 3. Latency was increased and amplitude was decreased in compression injury. The more injured, the more changed in latency and amplitude. 4. Findings in perforation injury was similar to compression injury. Waveform for sensory evoked potential improved by increasing postinjured time. 5. Increasing latency was prominent in traction injury rabbit inferior alveolar nerve. 6. In microscopic histopathological findings, significant degeneration and disorganization of the internal architecture were seen in nerve facicle of severe compression and 10mm traction group. From the above findings, electrophysiological assessment(sensory evoked potential) of rabbit injured inferior alveolar nerve is reliable technique in diagnosis and prognosis of nerve injury.