• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.4
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• pp.279-288
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• 2007

In the present study, we focused on stem cells in the dental papilla of the tooth germ. The tooth germ, sometimes called the tooth bud, is the primordial structure from which a tooth is formed. The tooth germ consists of the enamel organ, the dental papilla, and the dental follicle. The dental papilla lies below a cellular aggregation of the enamel organ. Mesenchymal cells within the dental papilla are responsible for formation of dentin and pulp of a tooth. Tooth germ disappears as a tooth is formed, but that of a third molar stays in the jawbone of a human until the age of 10 to 16, because third molars grow slowly. Impacted third molar tooth germs from young adults are sometimes extracted for orthodontic treatment. In the present study, we evaluated the osteogenic activity and mineralization of cultured human dental papilla-derived cells. Dental papillas were harvested from mandible during surgical extraction of lower impacted third molar from 3 patients aged 13-15 years. After passage 3, the dental papilla-derived cells were trypsinized and subsequently suspended in the osteogenic induction DMEM medium supplemented with 10% fetal bovine serum, 50 g/ml L-ascorbic acid 2-phosphate, 10 nM dexamethasone and 10 mM -glycerophosphate at a density of $1\;{\times}10^6\;cells/dish$ in a 100-mm culture dish. The dental papilla-derived cells were then cultured for 6 weeks and the medium was changes every 3 days during the incubation period. Dental papilla-derived cells showed positive alkaline phosphatase (ALP) staining during 42 days of culture period. The formation of ALP stain showed its maximal manifestation at day 7 of culture period, then decreased in intensity during the culture period. ALP mRNA level was largely elevated at 1 weeks and gradually decreased with culture time. Osteocalcin mRNA expression appeared at day 14 in culture, after that its expression continuously increased in a time-dependent manner up to day 28. The expression remained constant thereafter. Runx2 expression appeared at day 7 with no detection thereafter. Von Kossa-positive mineralization nodules were first present at day 14 in culture followed by an increased number of positive nodules during the entire duration of the culture period. Osteocalcin secretion was detectable in the culture medium from 1 week. The secretion of osteocalcin from dental papilla-derived cells into the medium greatly increased after 3 weeks although it showed a shallow increase by then. In conclusion, our study showed that cultured human dental papilla-derived cells differentiated into active osteoblastic cells that were involved in synthesis of bone matrix and the subsequent mineralization of the matrix.

• Journal of The Korean Dental Society of Anesthesiology
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• v.3 no.1 s.4
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• pp.10-18
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• 2003

Background: Studies on the pain have been dealing with many different ways for last several centuries. Especially, preemptive analgesia is being used as a method to control the postoperative pain. Many studies on its efficacy have been processed in different ways about various drugs, administration methods and times for various operations. And the value of preemptive analgesia are still controversial regarding the results of other clinical studies. The authors performed a clinical study on efficacy of preemptive analgesia using an non-steroidal anti-inflammatory drug (NSAID) for the surgical extraction of impacted third molar teeth and present the more effective pain treatment after oral surgery with literature review. Methods: Using a randomized double blind test design, this study compared the analgesic efficacies of an NSAID, Talniflumate 370 mg. This drug administrated first either 1 hour preoperatively (experimental group) or when the pain developed moderately to severely over 5 scale of verbal rating scales (0-10) to respective 30 patients undergoing the removal of impacted third molars. Pain intensity and the time from the end of surgery were assessed postoperatively whenever the patients demanded additional drug over 5 scale for forty eight hours using same verbal rating scales. Results: The sex distribution, the age of the patients. and the time required for surgery in two groups were similar. The average first time for demanding additional drug after surgery was 163.9 minutes in experimental group and 191.5 minutes in control group. At this time, the average pain intensity was 5.8 in experimental group and 6.1 in control group. And the average second time for demanding additional drug was 365.5 minutes in experimental group and 351.8 minutes in control group. At this time. the average pain intensities were 6.6 in experimental group and 6.2 in control group. No statistically significant difference was found between the average first times and second times, and the average pain intensities at first and second times in two groups. Conclusions: From these results the efficacy of preemptive analgesia used in this study was not appeared. This clinical study indicates that many NSAIDs administrated preoperatively in present practices have weak efficacy of preemptive analgesia for postoperative pain, thus the authors recommend that only postoperative analgesics are adequate without preoperative use of analgesics.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.2
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• pp.145-153
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• 2022

Background: Postoperative analgesia (POA) is an important determinant of successful treatment. Dexmedetomidine (DEX) has recently gained attention as a promising adjuvant to local anesthetics (LA). The present study aimed to evaluate the efficacy and safety of levobupivacaine (LB) as an adjuvant during inferior alveolar nerve block (IANB) in the extraction of lower impacted third molars (LITM). Methods: A prospective, randomized, placebo-controlled, triple-blind, parallel-arm, and clinical study was performed on 50 systemically healthy participants who required removal of an asymptomatic LITM. Using a 1:1 distribution, the participants were randomized into two groups (n = 25). Group L (control group) received 1.8 mL of 0.5% LB and 0.2 mL normal saline (placebo) and Group D (study group) received a blend of 1.8 mL of 0.5% LB and 0.2 mL (20 ㎍) DEX. The primary outcome variable was the duration of POA and hemodynamic stability, and the secondary variable was the total number of analgesics required postoperatively for up to 72 h. The participants were requested to record the time of rescue analgesic use and the total number of rescue analgesics taken. The area under the curve was plotted for the total number of analgesics administered. The pain was evaluated using the visual analog scale. Data analysis was performed using paired students and unpaired t-test, Mann-Whitney U test, Chi-square test, and receiver operating characteristic analysis. Statistical significance was set at P < 0.05. Results: The latency, profoundness of anesthesia, and duration of POA were statistically significant (P < 0.05). The differences between mean pain scores at 6, 12, 24, 48, and 72 h were found to be significant (each P = 0.0001). Fewer analgesics were required by participants in group D (2.12 ± 0.33) than in L (4.04 ± 0.67), with a significant difference (P = 0.0001). Conclusion: Perineurally administered LA with DEX is a safe, effective, and therapeutic approach for improving latency, providing profound POA, and reducing the need for postoperative analgesia.

• Journal of Korean Dental Science
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• v.6 no.2
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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.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.3
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• pp.113-119
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• 2015

Background: The inferior alveolar nerve block (IANB) is the most common anesthetic techniques in dentistry; however, its success rate is low. The purpose of this study was to determine the correlation between IANB failure and mandibular skeletal characteristics Methods: In total, 693 cases of lower third molar extraction (n = 575 patients) were examined in this study. The ratio of the condylar and coronoid distances from the mandibular foramen (condyle-coronoid ratio [CC ratio]) was calculated, and the mandibular skeleton was then classified as normal, retrognathic, or prognathic. The correlation between IANB failure and sex, treatment side, and the CC ratio was assessed. Results: The IANB failure rates for normal, retrognathic, and prognathic mandibles were 7.3%, 14.5%, and 9.5%, respectively, and the failure rate was highest among those with a CC ratio < 0.8 (severe retrognathic mandible). The failure rate was significantly higher in the retrognathic group than in normal group (P = 0.019), and there was no statistically significant difference between the other two groups. Conclusions: IANB failure could be attributable, in part, to the skeletal characteristics of the mandible. In addition, the failure rate was found to be significantly higher in the retrognathic group.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.2
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• pp.135-139
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• 2003

A dentigerous cyst is an epithelium-lined sac that surrounds the crown of an unerupted tooth or odontoma. And the most common sites of this cyst are the mandibular and maxillary third molar and maxillary cuspid a areas. Clinically, expansion of bone with subsequent facial asymmetry, extreme displacement of teeth, severe root resorption of adjacent teeth and pain are all possible sequelae of this cyst. The standard treatment for a dentigerous cyst is enucleation and extraction of the involved tooth. But in large cysts, this can lead to functional, cosmetic and psychologic consequences to the patients. So recently, more conservative methods are used. We report 5 cases of dentigerous cysts in pediatric patient which were treated by a conservative approach, By this methods, we can preserve teeth and guide eruption of the teeth which are involved in cystic area.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.709-717
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• 2007

Impaction of maxillary incisor is rare than the third molar and canine, but its rate is higher than the other anterior teeth due to frequent mesiodens, trauma and variation of root formation (root dilaceration etc.). It is often observed in the dental age of about eight years and over. It will be occurred that the space loss, midline deviation and cyst formation due to the impaction of maxillary incisor. So it is important to evaluate the precise location of impacted tooth and to make appropriate treatment plan. Treatment would be surgical extraction or expectation for spontaneous eruption. If the impacted tooth has no pathologic change and development of the root is favorable, orthodontic traction is recommended for recovery of function and esthetics. In these cases, we performed orthodontic traction for the eruption of impacted maxillary incisors, and obtained satisfactory results.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.565-606
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• 1993

The purpose of this study was to evaluate the change of before and after treatment of anterior openbite malocclusions treated by Multiloop Edgewise Archwire technique. The openbite sample consisted of 4 male and 12 female adults, treated with nonextraction or third molar extraction. The normal sample consisted of 58 subjects, which have pleasing facial profile and normal occlusion and no experience of orthodontic or prosthodontic treatment. The 58 subjects of normal sample were subdivided by cephalemetric vertical relationship of face. The 40 subjects, cephalometric vertical relationship of face was in normal range, classified as Normal Sample group 1. The 18 subjects, increased cephalometric vertical relationship of face, classified as Normal Sample group 2. The computerized cephalometric analysis was accomplished with 50 reference points for 22 skeletal measurements, 46 dentoalveolar measurements, 8 soft tissue measurements. Statistical analysis of the data was carried out with paired t-test, Student's t-test, and DUNCAN test using SAS(PC version), The results were as follows : 1. There were no statistically significant differences in skeletal measurement between before and after treatment. The major changes were in dentoalveolar region. 2. After treatment, the long axis of maxillary and mandibular posterior teeth were distally tipped-back, and uprighted to bisected occlusal plane. The interincisal angle was increased. 3. There were no statistically significant increase in the upper posterior dental height and statistically significant decrease in the lower posterior dental height. The upper anterior dental height was increased, but there was no statistically significant increase in the absolute upper anterior dental hight. The lower anterior dental height was increased. 4. After treatment, the maxillary occlusal plane to palatal plane angle and the mandibular occlusal plane to mandibular plane angle were statistically significant increased. Then, there were no statistically significant difference between after treatment group and normal sample group 2. 5. After treatment, the percentage of upper lip length to upper anterior dental height was decreased. Then, There were no statistically significant difference between after treatment group and normal sample group 2.

• Journal of Oral Medicine and Pain
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• v.42 no.4
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• pp.89-101
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• 2017

Purpose: The purpose of this study is to investigate the prevalence of temporomandibular disorders (TMDs) in children and adolescents, their characteristic contributing factors, the characteristic features of symptoms and symptoms, and the response to treatment. Methods: We studied the researches, that were the results of the searches for words such as temporomandibular disorder, TMD, children, adolescents, and juvenile through PubMed and DBpia. Results: According to a study conducted in Busan, the ratio of adolescents increased from 18.3% to 21% in 2008 compared to 2000, and the proportion of boys increased from 38.58% to 45.38%. One of the characteristic contributing factors for adolescents is the macrotrauma such as jaw trauma, vehicle accidents, sports, physical abuse, forceful intubation, and third molar extraction. The second is a microtrauma from parafunctional habit such as bruxism, clenching, hyperextension, wind instrument, and fingernail biting that can cause joint overload, cartilage breakdown, synovial fluid alterations, and other changes within the joint. The diagnosis of TMDs in juvenile adolescents is not significantly different from that of adults. Medical history, clinical examination and radiological examinations are required. Conclusions: In the temporomandibular joint history and assessment, all comprehensive dental history examination is required, including head and neck pain, mandibular dysfunction, previous orofacial trauma, history of present illness with an account of current symptoms. For the treatment and management of temporomandibular arthritis in juvenile adolescents, understanding the characteristics of TMDs in juvenile adolescents and thoroughly analyzing appropriate diagnosis and possible contributing factors through comprehensive history taking & examination, conservative treatment, including fast and active cautions education, will be essential.

• The korean journal of orthodontics
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• v.46 no.3
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• pp.163-170
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• 2016

Objective: The aims of this study were to investigate a simple method for assessing anterior-posterior jaw relationships via cone-beam computed tomography (CBCT) images taken in the natural head position (NHP) relative to the nasion true vertical plane (NTVP), and measure normative data in Korean adults with normal profiles. Methods: Subjects were selected from patients presenting for third molar extraction and evaluated as having normal profiles by three examiners. The CBCT images of 80 subjects (39 males, 41 females) were taken in the NHP according to Solow and Tallgren's method. Linear measurements of the A-point, B-point, and Pog were calculated relative to the NTVP. Student's t -test was used to assess sexual differences in these measurements. Results: The mean linear measurements of the A-point, B-point, and Pog relative to the NTVP were 0.18 mm (standard deviation [SD], 4.77 mm), -4.00 mm (SD, 6.62 mm), and -2.49 mm (SD, 7.14 mm) respectively in Korean males, and 1.48 mm (SD, 4.21 mm), -4.07 mm (SD, 6.70 mm) and -2.91 mm (SD, 7.25 mm) in Korean females respectively. There were no statistically significant differences between Korean males and females (p < 0.05). Conclusions: Three-dimensional CBCT analysis using the NTVP is a simple and reliable method for assessing anterior-posterior skeletal relationships.