• The korean journal of orthodontics
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• v.43 no.3
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• pp.134-140
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• 2013

Objective: To evaluate lower incisor position and bony support between patients with Class II average- and high-angle malocclusions and compare with the patients presenting Class I malocclusions. Methods: CBCT records of 79 patients were divided into 2 groups according to sagittal jaw relationships: Class I and II. Each group was further divided into average- and high-angle subgroups. Six angular and 6 linear measurements were performed. Independent samples t-test, Kruskal-Wallis, and Dunn post-hoc tests were performed for statistical comparisons. Results: Labial alveolar bone thickness was significantly higher in Class I group compared to Class II group (p = 0.003). Lingual alveolar bone angle (p = 0.004), lower incisor protrusion (p = 0.007) and proclination (p = 0.046) were greatest in Class II average-angle patients. Spongious bone was thinner (p = 0.016) and root apex was closer to the labial cortex in high-angle subgroups when compared to the Class II average-angle subgroup (p = 0.004). Conclusions: Mandibular anterior bony support and lower incisor position were different between average- and high-angle Class II patients. Clinicians should be aware that the range of lower incisor movement in high-angle Class II patients is limited compared to average- angle Class II patients.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.1
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• pp.16-22
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• 2017

Objectives: Bisphosphonate is the primary cause of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Bisphosphonates are eliminated from the human body by the kidneys. It is anticipated that bisphosphonate levels in the body will increase if the kidney is in a weak state or if there is systemic disease that affects kidney function. The aim of this study was to analyze the relevance of renal function in the severity of BRONJ. Materials and Methods: Ninety-three patients diagnosed with BRONJ in Pusan National University Dental Hospital from January 2012 to December 2014 were included in this study. All patients underwent a clinical exam, radiographs, and serologic lab test, including urine analysis. The patient's medical history was also taken, including the type of bisphosphonate drug, the duration of administration and drug holiday, route of administration, and other systemic diseases. In accordance with the guidelines of the 2009 position paper of American Association of Oral and Maxillofacial Surgeons, the BRONJ stage was divided into 4 groups, from stage 0 to 3, according to the severity of disease. IBM SPSS Statistics version 21.0 (IBM Co., USA) was used to perform regression analysis with a 0.05% significance level. Results: BRONJ stage and renal factor (estimated glomerular filtration rate) showed a moderate statistically significant correlation. In the group with higher BRONJ stage, the creatinine level was higher, but the increase was not statistically significant. Other factors showed no significant correlation with BRONJ stage. There was a high statistically significant correlation between BRONJ stage and 'responder group' and 'non-responder group,' but there was no significant difference with the 'worsened group.' In addition, the age of the patients was a relative factor with BRONJ stage. Conclusion: With older age and lower renal function, BRONJ is more severe, and there may be a decrease in patient response to treatment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.1
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• pp.19-27
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• 2020

Objectives: Pentoxifylline (PTX) is a methylxanthine derivative that has been implicated in the pathogenesis of peripheral vessel disease and intermittent lameness. The purpose of this study was to investigate the effect of PTX and tocopherol in patients diagnosed with osteoradionecrosis (ORN), bisphosphonate-related osteonecrosis of the jaw (BRONJ), and chronic osteomyelitis using digital panoramic radiographs. Materials and Methods: This study was performed in 25 patients who were prescribed PTX and tocopherol for treatment of ORN, BRONJ, and chronic osteomyelitis between January 2014 and May 2018 in Seoul National University Dental Hospital. Radiographic densities of the dental panorama were compared prior to starting PTX and tocopherol, at 3 months, and at 6 months after prescription. Radiographic densities were measured using Adobe Photoshop CS6 (Adobe System Inc., USA). Blood sample tests showing the degree of inflammation at the initial visit were considered the baseline and compared with results after 3 to 6 months. Statistical analysis was performed using the Mann-Whitney test and repeated measurement ANOVA using IBM SPSS 23.0 (IBM Corp., USA). Results: Eight patients were diagnosed with ORN, nine patients with BRONJ, and the other 8 patients with chronic osteomyelitis. Ten of the 25 patients were men, average age was 66.32±14.39 years, and average duration of medication was 151.8±80.65 days (range, 56-315 days). Statistically significant increases were observed in the changes between 3 and 6 months after prescription (P<0.05). There was no significant difference between ORN, BRONJ, and chronic osteomyelitis. Only erythrocyte sedimentation rate (ESR) was statistically significantly lower than before treatment (P<0.05) among the white blood cell (WBC), ESR, and absolute neutrophil count (ANC). Conclusion: Long-term use of PTX and tocopherol can be an auxiliary method in the treatment of ORN, BRONJ, or chronic osteomyelitis in jaw.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.4
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• pp.240-249
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• 2020

Objectives: Although the side effects of radiation therapy vary from mucositis to osteomyelitis depending on the dose of radiation therapy, to date, an experimental animal model has not yet been proposed. The aim of this study was to develop an animal model for assessing complications of irradiated bone, especially to quantify the dose of radiation needed to develop a rat model. Materials and Methods: Sixteen Sprague-Dawley rats aged seven weeks with a mean weight of 267.59 g were used. Atraumatic extraction of a right mandibular first molar was performed. At one week after the extraction, the rats were randomized into four groups and received a single dose of external radiation administered to the right lower jaw at a level of 14, 16, 18, or 20 Gy, respectively. Clinical alopecia with body weight changes were compared and bony volumetric analysis with micro-computed tomography (CT), histologic analysis with H&E were performed. Results: The progression of the skin alopecia was different depending on the irradiation dose. Micro-CT parameters including bone volume, bone volume/tissue volume, bone mineral density, and trabecular spaces, showed no significant differences. The progression of osteoradionecrosis (ORN) along with that of inflammation, fibrosis, and bone resorption, was found with increased osteoclast or fibrosis in the radiated group. As the radiation dose increases, osteoclast numbers begin to decrease and osteoclast tends to increase. Osteoclasts respond more sensitively to the radiation dose, and osteoblasts are degraded at doses above 18 Gy. Conclusion: A standardized animal model clinically comparable to ORN of the jaw is a valuable tool that can be used to examine the pathophysiology of the disease and trial any potential treatment modalities. We present a methodology for the use of an experimental rat model that incorporates a guideline regarding radiation dose.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.2
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• pp.75-85
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• 2023

Objectives: Suspending bisphosphonates (BPs) to reduce the risk and severity of medication-related osteonecrosis of the jaw (MRONJ) remains controversial. In this study, we quantitatively evaluated the clinical significance of BP suspension before surgery in osteoporosis patients with MRONJ. Materials and Methods: We analyzed 24 osteoporosis patients with MRONJ who were treated from 2012 to 2020 at Seoul National University Dental Hospital and compared the treatment outcomes of those who suspended BPs with those who did not. The number of surgical interventions, follow-up panoramic radiographs for relative bone density measurement, and laboratory blood tests including white blood cells, erythrocyte sedimentation rate, absolute neutrophil count, hemoglobin, hematocrit, and alkaline phosphatase were analyzed. ANOVA, Student's t-test, and Mann-Whitney U tests were used to compare results. Fisher's exact test was used to discover the association between treatment outcome and BP suspension, and Pearson's correlation test was used to measure the statistical relationship between the changes in serum inflammatory markers. Results: The number of interventions was significantly higher in the non-drug suspension group due to recurrence (P<0.05). The relative bone density in patients who suspended BPs was significantly different over time (P<0.05), with the highest density at one-year follow-up. Fisher's exact test shows an association between successful treatment outcomes and BP suspension. The alkaline phosphatase and erythrocyte sedimentation rate levels decreased significantly in the BP-suspended group, and a positive correlation was found between these elevated markers. Conclusion: A significant increase in bone density throughout follow-up and a lower number of interventions were found in the BP suspension group compared to the non-drug suspension group. Also, BP suspension decreased inflammatory markers in the serum after surgery, resulting in good treatment outcomes. BP suspension is a prognostic factor for MRONJ and should be implemented before surgery.

• Korean Journal of Ichthyology
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• v.22 no.2
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• pp.132-135
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• 2010

A specimen of Arnoglossus polyspilus (G$\ddot{u}$nther) (229.0 mm standard length) belonging to the family Bothidae, collect from the coastal waters of Jeju Island, represents the first record of the species from Korea. This species is characterized by having caudal fin with two simple rays on both upper and lower margins, several anterior dorsal fin rays somewhat elongated, upper jaw extending to below anterior 1/3 of lower eye, and one gill raker on the upper limb of the first gill arch. We add this species to the Korean fish fauna and propose its new Korean name, "No-rang-ban-jeom-ga-ja-mi".

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.1
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• pp.89-93
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• 2005

Intraosseous neurilemmoma(Schwannoma) is an extremely rare benign neoplasm. The site most commonly involved is the mandible. This occurrence is understandable because of the length of the inferior alveolar canal through the mandible. No other bone contains a canal that transmits a neurovascular bundle of such size and length. We report on a peripheral and central neurilemmoma along pathway of inferior alveolar nerve of the lower lip and mandible in a 28-year old man. A panoramic radiograph of the mandible showed a well-defined bilocular lesion with a thin uniform sclerotic margin located in the ramus and body of the mandible. The CT scan confirmed a well-defined lesion with thinning of the cortex of the body of the left side of the mandible. Histologically, the lesion was a cellular neoplasm with distinct palisading and numerous Verocay bodies. Complete excision was achieved by removing the tumor with the inferior alveolar nerve.

• Journal of the korean academy of Pediatric Dentistry
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• v.6 no.1
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• pp.27-33
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• 1979

The author studied the response to the stimulation of an electric pulp stimulator of healthy 854 permanent anterior teeth in 122 children aged from six to eleven years old, during different stages of tooth development. The results were as followings: 1) In completely open apices, 13.1% (18 teeth) showed positive responses, and 86.9% (120 teeth) showed negative responses. In two-thirds open apices 33.1% (75 teeth) showed positive responses, and 66.9% (152 teeth) showed negative responses. In one-third open apices 57.8% (118 teeth) showed positive responses, and 42.2% (86 teeth) showed negative responses. In closed apices 80.0% (228 teeth) showed positive responses, and 20.0% (57 teeth) showed negative responses. 2) The number of positive responses increased in each upper and lower central incisors during the stages of root development, but not in upper lateral incisors. 3) There were no significant differences statistically in responses between the teeth of the right and left sides and the upper and the lower jaw, in the same stages of root development.

• The Journal of the Korean dental association
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• v.11 no.8
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• pp.531-540
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• 1973

1) The authors has observed in a boy of 21 years old a supernumerary 3rd premolar tooth the crown of which emerged from the fight lingual side close to the both premolar, mandible. 2) They may have a conical form or be otherwise rudimentary or vestigial, but they do not present ancestal characters. 3) According to the reports of formaers and our experiences about it, the large number of the eruption area was in lingual or palatal side. 4) A third premolar in man could only be accounted for as atavisms by a reversion covering so long a period of time.

• Restorative Dentistry and Endodontics
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• v.44 no.4
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• pp.42.1-42.16
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• 2019

Antiresorptive drugs (ARDs), such as bisphosphonates or denosumab, that prevent bone resorption are widely used in patients with osteoporosis or with cancer that has metastasized to the bones. Although osteonecrosis of the jaw (ONJ) is a well-documented complication of ARD use, the benefits ARDs outweigh the complication. Thus, research has focused on finding ways to prevent or reduce the risk of developing ONJ. Dentists, as part of a multi-professional team, have a critical role in preventing ONJ. However, many dentists tend to hesitate to provide dental care to patients with ONJ, or tend to think that it is a problem to be dealt with by oral surgeons. This review gives an overview of ARD-related ONJ and provides the guidelines for dental care in patients taking ARDs to lower the risk of developing ONJ.