• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.268-277
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• 2008

Authors evaluated 1171 patients at the department of Pediatric Dentistry in Kyoungpook National University Hospital through clinical records and radiographs. And the following features were studied ; age, sex distribution, number of mesiodens per patients, cause of discovery of mesiodens, location, status of eruption, shape and orientation of crown, complication, dental age of adjacent upper incisor tooth at the time of surgical extraction of mesiodens and the relationship between the resolution rate of complication after extraction of mesiodens and the dental age of adjacent upper incisor tooth, length of diastema, the eruption status of lateral incisor and the crowding status of premaxilla. The followings are the results : 1. The cause of discovery of mesiodens were as follows ; delayed eruption of the permanent incisors in 13.8%, midline diastema in 11.6%, radiographs taken for other reasons in 23.4% and for caries treatment in 15.1%. 2. Complication due to the presence of mesiodens did not occur in 36.8%, delayed eruption of adjacent teeth was observed in 16.1%, midline diastema in 34.4%, rotation in 8.8%, displacement in 2.4%, and crowding in 1.0% of all evaluated patients. 3. As for the dental age of adjacent upper incisor tooth at the time of surgical extraction of mesiodens, below 1/3 of total root length were observed in 3.5%, $1/3{\sim}1/2$ of total root length in 19.9%, $1/2{\sim}2/3$ of total root length in 54.7% and over 2/3 in 21.9% of all evaluated patients. 4. Resolution rate of delayed eruption after the extraction of mesiodens was significant higher in the group with the root length below 1/2. Resolution rate of midline diastema was significant higher in the group with diastema width below 3mm and with non-crowding of adjacent upper incisor teeth.

• The korean journal of orthodontics
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• v.34 no.1 s.102
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• pp.63-70
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• 2004

The midpalatal suture area has some advantages for supporting miniscrews : it has no specific anatomical structure, it is composed of thick cortical bone, and covered with attached gingiva. So it is suitable area for inserting miniscrews. However, the midpalatal suture area appears thinner when seen in ceph. As a result, Clinicians can misunderstand that inserting miniscrews cause the problem, both the risk of perforation and the decrease of stability. The purpose of this article is measuring the vertical bone thickness of the midpalatal suture area for inserting miniscrews. The total of 25patient (male : 13, female : 12), who are in their twenties, were taken CT. The vertical bone thickness of the midpalatal suture area was measures from the transverse section of CT. As a result, We reached a conclusion from the differences of each area. It is as follows: 1. There is no significant difference between the thickness of male group and that of female group. 2. In coronal section, Bone thickness becomes thinner from the midpalatal suture to Left & Right side, in sagittal section, Bone thickness becomes thinner from incisive foramen to PNS. 3. The area that is within 3mm of left and right from the midpalatal suture area transversely and within 25mm backward from the incisive foramen sagittaly is enough for inserting miniscrews.

• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.35-42
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• 2005

There is lack of data for the amount of vertical bone in the midpalatal region for miniscrew implantation. The purpose of this study was to measure the structure of the midpalatal suture area using CT image and V-works 4.0 program (Cybermed Inc, Seoul, Korea). CT images of 14 male and 14 female adults were reconstructed. In detail, it was 1) to measure the length of maxilla on the midsagittal plane 2) to measure vertical bone height in the midpalatal area 3) to establish the zone of safety for miniscrew implantation. The following results were obtained. The mean length of ANS-PNS was 51.08mm in males and 47.34mm in females. There was a statistically significant difference between males and females (p<0.05). The vertical bone height of the midpalatal suture area was above 0mm except for 6mm posterior from the central Point of ANS-PNS in males The zone of safety was located 19.43mm posterior from the ANS in males while it was 17.62mm in females along the palatal plane. These results support that the safety zone of the midpalatal area is suitable for screw implantation. Midpalatal miniscrew implantation is a powerful tool in modern orthodontics Through many applications. it can expand the modern orthodontic field.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.275-283
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• 1999

Authors evaluated 152 patients at the department of Pediatric Dentistry in Seoul National University Hospital through clinical records and radiographs. And the following features were studied ; age, sex distribution, number of mesiodens per patients, location, status of eruption, shape and orientation of crown, and complication. From the above results, the relationship between features of mesiodens and complications were evaluated using chi-square analysis. 1. Complications due to the presence of mesiodens did not occur in 31.6%, delayed eruption of adjacent teeth was observed in 33.6%, midline diastema in 22.4%, rotation in 8.6%, displacement in 3.3%, and crowding in 0.7% of all evaluated patients. 2. As compared with the above 8.5 year group, in the under 8.5 year group, the frequency of complications was significantly higher(P<0.05). As compared with those positioned lingually, in mesiodens labially or within the arch the frequency of complications was significantly higher(P<0.01). Also, the frequency of complications was significantly higher when the mesiodens was tuberculate in form(P<0.05). 3. Of the 104 patients with complications, the frequency of delayed eruption was significant higher in the under 8.5 year group, and in above 8.5 year group, the frequency of malocclusion was significantly higher(P<0.05). When mesiodens were located in the midline region, the frequency of malocclusion was significant higher, while in case with laterally positioned mesiodens the frequency of delayed eruption was significantly higher(P<0.01).

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.5 no.2
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• pp.99-101
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• 2012

Median artery of the forearm and wrist is not very frequently observed because it normally involutes before birth. Persistent median artery of the carpal tunnel is not frequently observed in adult life. We report a case of persistent median artery in the carpal tunnel that was examed by ultrasonography.

• The korean journal of orthodontics
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• v.30 no.4 s.81
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• pp.377-386
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• 2000

At the finishing stage, the use of asymmetric elastics to treat mild skeletal and dental midline discrepancies often creates several side effects such as canted occlusal plane, tipped incisors and unesthetic results. This report presents the clinical cases with midline discrepancies, following a differential diagnosis, optimal mechanics, and considerations in treatment. Differential diagnosis and treatment mechanics with three-piece basal archwire can obtain predictable midline correction with minimal side effects.

• The korean journal of orthodontics
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• v.26 no.2 s.55
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• pp.153-162
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• 1996

Rapid maxillary expansion is widely used for the correction of anteroposterior discrepancies, constriction of the maxillary arch, etc. This experiment was undertaken to examine the serial changes in the osteogenesis as well as the collagen fiber bundles in the intermaxillary suture during the rapid maxillary expansion treatment. Four young female dogs aged 6 to 8 months old and not showing menarche yet were used for the experiment. The maxillary impression of dogs were taken, expansion device cast and Hyrax screw soldered at the midline in the 1st premolar area. RME device was delivered to the dogs and the activation of 0.25 mm per quarter-turn was done 2 times per day for 10 days until 5 mm separation was made. Separation of the maxilla was confirmed by X-ray. The animals were sacrificed on 0, 15, 30, 60 days from the finish of maxillary separation and preparations for light microscopy and surface electron microscopy were made. The sutures were cut into frontal serial sections for examination of the histological reactions. The following results were obtained and the conclusions made. 1. The edges of the two palatal plates bordering the midpalatal suture which at the beginning of the retention period were mainly composed of compact bone, underwent extensive resorption followed by new bone formation and gradually became spongy bone rich in bone marrow which in the 60 day retention animal became the compact bone with short intermaxillary suture space. During this transformation, newly formed trabecular bone tissues were added to the original margin. 2. Throughout the expansion period, the collagen fibers underwent successive changes such as stretching, loss of polarity, and finally fibrillogenesis. Towards the end of the expansion procedure, sharpey's fiber formation in newly formed bones were observed. 3. Bony spicules were found in the initial stage of retention on occlusal topographic X-rays, which later were confirmed to have ossified. 4. Judging from the histological changes occuring during the experimental expansion, excessive expansion will cause an excessive bleeding, and retard the remodeling of intermaxillary suture. According to the above results, the bone remodeling after rapid maxillary expansion was preceded by the migration of migratory cells into the intermaxillary suture area. The bone remodeling phenomena were on-going during the 2 months retention sample.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.1
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• pp.77-94
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• 2021

The purpose of this study was to investigate the three-dimensional characteristics of mesiodens using Cone-beam Computed Tomography(CBCT) and analyze the factors affecting complications and anesthetic methods of extraction. This study evaluated 602 mesiodens of 452 patients who underwent extraction of mesiodens at the department of Pediatric Dentistry in Seoul National University Dental Hospital between 2017 and 2019. The ratio of mesiodens patients over total patient per year was gradually increased over the past 20 years. Mesiodens with labio-palatally horizontal direction while root directing labial were the most common among the mesiodens with horizontal direction. Mesiodens were the most common at the cervical side of the adjacent teeth(37.0%) and mesiodens located in the near-palatal side were observed about 3.83 times higher than the far-palatal side. Most of the mesiodens(82.1%) were in contact with adjacent permanent teeth on all three sides of the CBCT and 46.2% of mesiodens had curved roots. The patient's age, vertical position, presence of complications, and proximity showed a significant difference in the selection of general anesthesia among anesthetic methods. The direction and vertical position of mesiodens had a significant effect on complications. These results provide a better understanding of mesiodens for establishing an accurate diagnosis and treatment plan.

• Journal of Chest Surgery
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• v.35 no.9
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• pp.675-679
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• 2002

In patient with severe adhesion between lung and aorta, there is some limitation in approaching the distal arch or descending thoracic aorta through the usual left thoracotomy. We report a case of a successfully managed distal arch and descending thoracic aortic aneurysm through the median sternotomy without any manipulations of the lung in a 66 year old man who presented hemoptysis.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.375-381
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• 1999

The purpose of this study was to evaluate whether the basal bone of maxilla was expanded transversely by rapid palatal expansion through the posteroanterior cephalome- tric analysis. Thirty patients with the maxillary deficiency were utilized in this study. The posteroanterior cephalometric X-ray film were taken twice, before and after rapid palatal expansion. logram The obtained results were as follows; 1. There was a significant increase of the maxillary width by rapid palatal expansion in male and female. (P<0.001) 2. There was no significant difference between the male and female in the expansion of the maxillary width by rapid palatal expansion. 3. There was a significant increase of the maxillary width by rapid palatal expansion in the both of before and after the puberty. 4. There was no significant difference between before and after the puberty in the expansion of the maxillary width by rapid palatal expansion.