• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권6호
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• pp.464-469
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• 2011

Introduction: As dental implant surgery is becoming increasingly popular, it has become one of the causes for the hypesthesia of the inferior alveolar nerve, along with other surgical procedures, such as a third molar extraction. In addition, it tends to cause legal problems between the operator and patient. Therefore, there must be a proper method that is reliable, objective and economical to assess the nerve impairment. For this reason, an attempt was made to use an Electric Pulp Tester to assess inferior alveolar nerve block anesthesia. Materials and Methods: Thirty patients were tested. Electric pulp testing of the lower jaw skin was performed at the three different times, before anesthesia, at the onset of sensory changes and after 15 minutes waiting from the onset, and on the 10 points of the chin, which produced 10 sections on the skin area. Results: Twenty seven patients (90%) could feel the electric stimulus on the chin at all 10 points before local anesthesia and the scores represent the statistical differences between the right and left points except R4 and L4. After anesthesia, the difference between the right and left points (L3-R3, L4-R4, L5-R5) increased significantly with time but two points (L2, R2) showed no significant difference. The scores on the left chin (L3, L4, L5) increased, whereas the other points (R1-R5, L1, L2) showed no significant differences. Conclusion: This study highlights the potential clinical use of an electric pulp tester for an assessment of inferior alveolar nerve impairment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.30.1-30.7
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• 2015

Background: The inferior alveolar nerve (IAN) may be injured during extraction of the mandibular third molar, causing severe postoperative complications. Many methods have been described for evaluating the relative position between the mandibular third molar and the inferior alveolar canal (IAC) on panoramic radiography and computed tomography, but conventional radiography provides limited information on the proximity of these two structures. The present study assessed the benefits of three-dimensional computed tomography (3D-CT) prior to surgical extraction of the mandibular third molar, to prevent IAN damage. Methods: This retrospective study included 4917 extractions in 3555 patients who presented for extraction of the mandibular third molars. The cases were classified into three groups, according to anatomical relationship between the mandibular third molars and the IAC on panoramic radiography and whether 3D-CT was performed. Symptoms of IAN damage were assessed using the touch-recognition test. Data were compared using the chi-square test and Fisher's exact test. Results: Among the 32 cases of IAN damage, 6 cases were included in group I (0.35 %, n = 1735 cases), 23 cases in group II (1.1 %, n = 2063 cases), and 3 cases in group III (0.27 %, n = 1119 cases). The chi-square test showed a significant difference in the incidence of IAN damage between groups I and II. No significant difference was observed between groups I and III using Fisher's exact test. In the 6 cases of IAN damage in group I, the mandibular third molar roots were located lingual relative to the IAC in 3 cases and middle relative to the IAC in 3 cases. The overlap was ${\geq}2mm$ in 3 of 6 cases and 0-2 mm in the remaining 3 cases. The mean distance between the mandibular third molar and IAC was 2.2 mm, the maximum distance 12 mm, and the minimum distance 0.5 mm. Greater than 80 % recovery was observed in 15 of 32 (46.8 %) cases of IAN damage. Conclusions: 3D-CT may be a useful tool for assessing the three-dimensional anatomical relationship and proximity between the mandibular third molar and IAC in order to prevent IAN damage during extraction of mandibular third molars.

• Journal of Oral Medicine and Pain
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• 제32권2호
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• pp.177-185
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• 2007

치과치료와 관련한 의원성 손상이나 국소마취의 후유증은 미각장애를 유발하기도 한다. 본 연구는 편측 하치조신경 전달마취를 시행하여 마취 전후의 미각기능의 변화를 정량 및 정성적으로 비교하여, 치과치료와 관련하여 발생할 수 있는 하치조신경의 무감각증이나 감각저하로 인한 미각기능의 변화 가능성을 평가하고자 하였다. 20대의 건강한 지원자 30명(남:녀=1:1, 평균연령 $24.0{\pm}1.8$세)을 대상으로 하여 피검자의 우측에 2% 염산리도카인을 사용하여 통법에 따라 하치조신경 전달마취를 시행하였다. 마취 전후 미각기능의 변화를 조사하기 위하여 전기미각측정기를 이용하여 전기미각역치를 측정하였으며 국소적용법을 이용한 화학용액법으로 미각강도를 평가하였다. 검사를 위해 1M/l의 NaCl 및 sucrose 용액, 0.032 M/l의 구연산용액, 0.001 M/l의 염산키니네용액을 사용하였으며 미각강도는 9점 척도를 이용하여 평가하도록 하였다. 검사는 구강내 8 부위, 즉 좌우측 혀 전방과 외측방, 유곽유두, 연구개에 대해 시행되었다. 편측 하치조신경 전달마취를 시행한 결과, 마취된 측의 혀 전방과 외측, 유곽유두에서 전기미각역치가 상승하고 짠맛, 단맛, 신맛, 쓴맛에 대한 미각강도 감소가 감소하였다.(p<0.05) 마취되지 않은 반대측의 혀 전방과 외측방에서도 짠맛과 단맛의 경우에 대한 미각강도가 감소되었으나(p<0.05), 전기미각역치의 변화는 없었다. 본 연구의 결과는 편측의 하치조신경 전달마취는 마취가 된 혀의 1/2 부위에서 고삭신경과 설인신경에 영향을 주어 미각장애를 유발할 수 있음을 보여주며, 반대측에서도 미각강도의 변화를 일부 초래할 수 있는 것으로 추측해 볼 수 있다.

• Journal of Periodontal and Implant Science
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• 제50권1호
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• pp.28-37
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• 2020

Purpose: The aim of our study was to determine the prevalence and degree of lingual concavities in the first molar region of the mandible to reduce the risk of perforating the lingual cortical bone during dental implant insertion. Methods: A total of 163 suitable cross-sectional cone-beam computed tomography images of edentulous mandibular first molar regions were evaluated. The mandibular morphology was classified as a U-configuration (undercut), a P-configuration (parallel), or a C-configuration (convex), depending on the shape of the alveolar ridge. The characteristics of lingual concavities, including their depth, angle, vertical location, and additional parameters, were measured. Results: Lingual undercuts had a prevalence of 32.5% in the first molar region. The mean concavity angle was 63.34°±8.26°, and the mean linear concavity depth (LCD) was 3.03±0.99 mm. The mean vertical distances of point P from the alveolar crest (Vc) and from the inferior mandibular border were 9.39±3.39 and 16.25±2.44, respectively. Men displayed a larger vertical height from the alveolar crest to 2 mm coronal to the inferior alveolar nerve (Vcb) and a wider LCD than women (P<0.05). Negative correlations were found between age and buccolingual width at 2 mm apical to the alveolar crest, between age and Vcb, between age and Vc, and between age and LCD (P<0.05). Conclusions: The prevalence of lingual concavities was 32.5% in this study. Age and gender had statistically significant effects on the lingual morphology. The risk of lingual perforation was higher in young men than in the other groups analyzed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권6호
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• pp.384-393
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• 2012

The trigeminal nerve, one of the cranial nerves, innervates the maxillofacial area and has three branches: the ophthalmic, maxillary, and mandibular nerves. Paresthesia, due to damages to the inferior alveolar nerve and mental nerve (branches of the mandibular nerve), is quite frequent in dental implants and third molar extractions. As medical disputes are increasing, it is necessary to formulate an objective and reasonable disability evaluation. When evaluating the frequent rate of impairment for inferior alveolar nerve damage, it may be reasonable to follow the criteria for the rate of maxillofacial impairment of the American Association of Oral and Maxillofacial Surgeons (AAOMS) - the most scientific and reputable criteria based on the American Medical Association (AMA). Therefore, the Committee of Guides for Maxillofacial Impairment Ratings, in the Korean Association of Oral and Maxillofacial Surgeons (KAOMS), is trying to suggest more reasonable and realistic guidelines for evaluating impairments by reviewing the current evaluation criteria and those of AMA and AAOMS.

• Imaging Science in Dentistry
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• 제44권2호
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• pp.171-175
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• 2014

One of the most common oral surgical procedures is the extraction of the lower third molar (LTM). Postoperative complications such as paresthesia due to inferior alveolar nerve (IAN) injury are commonly observed in cases of horizontal and vertical impaction. The present report discusses a case of a vertically impacted LTM associated with a dentigerous cyst. An intimate contact between the LTM roots and the mandibular canal was observed on a panoramic radiograph and confirmed with cone-beam computed tomographic (CBCT) cross-sectional cuts. An orthodontic miniscrew was then used to extrude the LTM prior to its surgical removal in order to avoid the risk of inferior alveolar nerve injury. CBCT imaging follow-up confirmed the success of the LTM orthodontic extrusion.

• Imaging Science in Dentistry
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• 제34권3호
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• pp.171-174
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• 2004

The present study reports a case of developmental salivary gland defect. On panoramic examination, large radiolucent lesion surrounded by a sclerotic wall was noted in the right posterior mandible. On CT examination, large lingual bone concavity with extra-osseous course of the inferior alveolar nerve bundle was detected. In atypical cases, it is suggested that confirmatory imaging using CT or MRI should be taken.

• Imaging Science in Dentistry
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• 제31권2호
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• pp.67-71
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• 2001

Purpose: To assess the possibility of using panoramic indices as an indicator of jaw osteoporosis. Methods: Mandibular cortical width (MCW), degree of mandibular alveolar bone resorption (ABR) and morphology of mandibular inferior cortex (MIC) on panoramic radiograph were used as panoramic indices. These panoramic indices were compared with bone mineral density (BMD) of lumbar (L1-L4) and femoral neck measured by dual energy X-ray absorptiometry. We also compared MCW and ABR of young men with those of postmenopausal women. Results : There was a significant correlation between ABR and BMD of lumbar and femoral neck. And also significant correlation between MIC and BMD of lumbar and femoral neck. ANOVA test of BMD of lumbar and femoral neck showed significant differences according to morphologic classification of inferior cortex. There was significant difference in MCW and ABR between young men and postmenopausal women. Conclusion: Our results suggested that ABR and MIC on panoramic radiograph could be reliable in screening of osteoporosis.

• 대한치과의사협회지
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• 제37권4호통권359호
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• pp.279-286
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• 1999

In patients with severely atrophic mandibular posterior area, implant placement is a problematic surgical procedure. Inferior alveolar nerve transpositioning technique offers better initial stability of implant and reduce the risk of permanent nerve damages. In this case report, the patient has bilateral atrophic mandibular posterior edentulous area. We placed 3 implants on each mandibular posterior area in conjunction with bilateral inferior alveolar nerve transpositioning to achieve sufficient bone height. The patient complained of paresthesia in lower lip and chin area and ptosis of lower lip after surgery. Neurosensory function was normal in 10 weeks after surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권5호
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• pp.233-240
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• 2019

Trigeminal nerve injury as a consequence of lower third molar surgery is a notorious complication and may affect the patient in long term. Inferior alveolar nerve (IAN) and lingual nerve (LN) injury result in different degree of neurosensory deficit and also other neurological symptoms. The long term effects may include persistent sensory loss, chronic pain and depression. It is crucial to understand the pathophysiology of the nerve injury from lower third molar surgery. Surgery remains the most promising treatment in moderate-to-severe nerve injuries. There are limitations in the current treatment methods and full recovery is not commonly achievable. It is better to prevent nerve injury than to treat with unpredictable results. Coronectomy has been proved to be effective in reducing IAN injury and carries minimal long-term morbidity. New technologies, like the roles of erythropoietin and stem cell therapy, are being investigated for neuroprotection and neural regeneration. Breakthroughs in basic and translational research are required to improve the clinical outcomes of the current treatment modalities of third molar surgery-related nerve injury.