• 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.

• Imaging Science in Dentistry
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• v.51 no.1
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• pp.9-16
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• 2021

Purpose: The purpose of this study was to analyze the reliability of 7 panoramic radiographic signs for predicting proximity of the root apices of mandibular third molars to the mandibular canal using cone-beam computed tomography and to correlate these findings with the Pell and Gregory and the Winter classification systems. Materials and Methods: An observational, cross-sectional, descriptive study was conducted on 74 patients with bilateral impacted mandibular third molars. Four panoramic radiographic signs were observed in the tooth root (darkening, deflection, and narrowing of the root apices, and bifid apices), and another 3 in the mandibular canal (diversion, narrowing, and interruption of the mandibular canal). Cone-beam computed tomography images were analyzed to identify disruption and diversion of the mandibular canal and root deflection. Results: Binary logistic regression showed that only 4 of the 7 panoramic radiographic signs were able to predict proximity of the root apices of the mandibular third molars to the mandibular canal: darkening of the root, deflection of the root, narrowing of the root, and interruption of the mandibular canal(P<0.05). Conclusion: Darkening, deflection, and narrowing of the root, in tandem with the interruption of the mandibular canal on panoramic radiographs, indicate that cone-beam computed tomography should be performed when planning the extraction of impacted mandibular third molars. Proximity between mandibular third molars and the mandibular canal is correlated with the Winter classification.

• Imaging Science in Dentistry
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• v.53 no.4
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• pp.303-312
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• 2023

Purpose: This study investigated the prevalence of developmental and acquired pathologic conditions associated with impacted third molars (3Ms) in a Southern Brazilian population and evaluated whether demographic and tooth characteristics were correlated with the presence of bone or tooth lesions. Materials and Methods: Panoramic radiographs were assessed for developmental (bone-related) or acquired (tooth-related) pathoses associated with impacted upper or lower 3Ms. Data on tooth positioning, tooth development, and patient demographics were collected. A trained, calibrated postgraduate student evaluated all images. Binary and multivariate logistic regression models were used to assess associations between outcomes and the demographic and radiographic variables. The threshold for statistical significance was set at 5% (P<0.05). Results: The sample comprised panoramic radiographs from 2054 patients, predominantly female (59.2%), with a mean age of 27.2±11.5 years. Overall, 4066 impacted 3Ms were evaluated, revealing 471 (11.6%) developmental and 710 (17.5%) acquired pathoses. Among the developmental pathoses, 460 (95.2%) were indicative of dentigerous cysts. Male sex, lower 3M location, vertical or distoangular positioning, and incomplete root formation were associated with an elevated likelihood of developmental pathology. Lower tooth position, complete root formation, and partial eruption were linked to an increased probability of an acquired pathology in the third or second molar. Conclusion: The prevalence of pathologic conditions associated with impacted 3Ms was low. Male sex, lower 3M placement, horizontal or distoangular positioning, and incomplete root formation were associated with developmental pathoses, while lower tooth position, complete root formation, and partial eruption were related to acquired pathoses.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.1
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• pp.32-35
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• 2011

Purpose: Mandibular angle fractures constitute approximately 30% of mandibular fractures, and the mandibular third molar is usually in line with the fracture. This study evaluated the relationship between the extraction of a tooth in line with a mandibular angle fracture and the infection rate. Methods: One hundred and forty seven patients with mandibular angle fractures containing a tooth in line with the fracture from 2005 to 2008 were enrolled in this study. The patients were divided into two groups based on an extraction, and the infection rates were evaluated in both groups. Results: An extraction was performed in 70 patients (47.6%) and postoperative infections occurred in 14 patients (9.5%). Six (8.6%) of the 70 patients in the extraction group and 8 (10.4%) of the 77 patients in the non-extraction group had an infection. There was no significant difference between the two groups (P=0.708). Conclusion: These results show that there is no increased risk of postoperative complications when a tooth is present

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.3
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• pp.293-296
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• 2000

The purpose of this study is to find the histopathological pattern of cysts. We reviewed the hospital chart, out-patient chart, roentgenogram, histopathologic report and operation report of 152 patients who had been diagnosed as cyst and treated at the department of Oral and Maxillofacial Surgery of Korea university hospital between Jan. 1, 1995 and Dec. 31, 1998. And then we studied clinically with regard to pathological classification, age and sex distribution, anatomical distribution and so on. The results were as follows : 1. In pathologic classification, radicular cyst (97cases, 64%), dentigerous cyst (35cases, 23%), odontogenic keratocyst (8cases, 5.3%) were dominant among cases of cyst. 2. The pattern of age distribution in cases of radicular cyst, dentigerous cyst and odontogenic keratocyst was similar to that found in previous studies. The peak incidence was in the second decade (27%) and third decade (29%) in overall cases. 3. The male-to-female ratio was 1.9 : 1. 4. Radicular cyst occured most frequently in the maxillary incisor teeth area, dentigerous cyst in mandibular wisdom teeth area, and odontogenic keratocyst in mandibular molar area.

• Imaging Science in Dentistry
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• v.48 no.4
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• pp.289-293
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• 2018

Odontomas are considered a type of odontogenic hamartoma, and are generally reported not to exceed 3 cm in diameter. Some authors have referred to odontomas with a diameter exceeding 3 cm as giant odontomas. As hamartomas, giant odontomas generally show no signs or symptoms, but if they perforate the mucosa to become exposed in the oral cavity, oral and maxillofacial infections can result. Surgical removal and a histopathological examination may also be required to differentiate them from osteomas, cemento-osseous dysplasia, or mixed odontogenic tumors. This report presents the case of a 28-year-old woman with a giant odontoma in the right mandibular third molar area. Based on a review of the literature published since 2010, only 11 cases of "giant" or "large" odontomas have been reported, most of which were of the complex odontoma type. It was confirmed that they tend to occur in the right posterior mandible.

• Journal of The Korean Dental Society of Anesthesiology
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• v.3 no.2 s.5
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• pp.87-91
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• 2003

Background: The purpose of this study was to compare the availability of propofol and fentanyl (P + F) with diazepam and morphine (D + M) for intravenous conscious sedation during third molar surgery. Methods: Forty patients without systemic disease were operated under IV conscious sedation administered by either of the two techniques. Monitoring consisted of continuous observation of pulse rate, blood pressure, oxygen saturation, and the respiratory rate and were recorded every 15 minutes. Cooperation score was measured 5 and 15 minutes after induction of IV sedation. Following the operation, the surgeon and patients completed questionnaires including pain visual analog scale, amnesia, and side effects. Results: The P + F group was significantly more cooperative than the D + M group. The side effects of D + M group included pain on injection, nausea/vomiting and abdominal pain. The side effects of P + F group included talkativeness, nausea/vomiting, temporary apnea, pain on injection and vertigo. Conclusions: In this study, there were following benefits in the P + F group; more cooperative status and less pain perception. But respiratory depression developed in some patients.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.2
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• pp.131-136
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• 2016

Background: This study aimed to evaluate the patient's pain and quality of life after suture removal at either 3 or 7 days following the bilateral surgical extraction of impacted lower third molars. Methods: This study was a prospective, randomized controlled clinical trial carried out in 30 patients, who acted as their own control. Each patient required the bilaterally impacted mandibular third molars to be extracted. The impacted teeth were removed and the wound margins were approximated and sutured with black braided silk. The suture material was removed on day 3 on one side and on day 7 on the other. Each participant was asked to complete a questionnaire after the removal of the suture material on each designated day. Results: Regarding overall clinical symptoms, the mean VAS scores of male and female participants on day 3 were not significantly different from those on day 7. A significant difference was found in female participants, in that overall daily activity was better on day 7. There were significant differences in the ability to smile and laugh in both sexes and the ability to chew in the male participants was better on day 7. Conclusions: There were no significant differences in the patient's pain and quality of life between suture removal on day 3 or on day 7 following surgery to remove impacted lower third molars.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.3
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• pp.153-160
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• 2024

Objectives: This study identifies factors for differential diagnosis among lesions by retrospectively comparing panoramic and cone-beam computed tomography images and analyzing the characteristics of lesions associated with impacted mandibular third molars (IMTs). Materials and Methods: A retrospective cohort study was conducted in patients who simultaneously underwent IMT extraction surgery and related benign tumor resection or cyst enucleation at our institution from 2017 to 2021. To compare the characteristics of each group, two comparative analyses were conducted. The first comparison considered the most frequently observed lesions associated with IMTs: dentigerous cysts, odontogenic keratocysts (OKCs), and ameloblastoma. The second comparison involved placing dentigerous cysts, which have a relatively low recurrence rate, into group A and placing OKC, ameloblastoma, and odontogenic myxoma, which have high recurrence rates, into group B. Results: Significant differences in the size of the lesion were found in the order of ameloblastoma, OKC, and dentigerous cyst (P<0.05). The buccolingual width of ameloblastoma differed significantly from that of the other groups, with no significant difference observed between the OKCs and dentigerous cysts (P=0.083). Conclusion: Patient age and lesion size differed significantly among lesion types associated with IMTs, with younger age and larger lesions for OKCs and odontogenic tumors. OKCs are likely to have a larger mesiodistal width than dentigerous cysts. The buccolingual width of ameloblastomas was larger than those of dentigerous cysts and OKCs.

• Journal of The Korean Dental Society of Anesthesiology
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• v.11 no.2
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• pp.164-171
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• 2011

Altered consciousness may be the first clinical sign of a serious medical problem that requires immediate and intensive therapy to maintain life. There are many causes of the loss of consciousness in the dental office setting, such as, vasodepressor syncope, drug administration or ingestion, orthostatic hypotension, epilepsy, hypoglycemic reaction, acute adrenal insufficiency, cerebrovascular accident, hyperglycemic reaction, acute myocardial infarction, acute allergic reaction and hyperventilation. This is a case report of syncope and coma during endodontic treatment of a maxillary third molar under local infiltration anesthesia in multiple medically compromised patient. The main cause was thought to be hypoglycemic reaction. The patient was transferred to the medical emergency room and cared properly by the emergency medical physicians. The prognosis was good.