• The Journal of the Korean dental association
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• v.57 no.6
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• pp.333-343
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• 2019

Many orthodontists face difficulties in aligning incisors in an esthetically critical position, because the individual perception of beauty fluctuates with time and trend. Temporary anchorage device (TAD) can aid in attaining this critical incisor position, which determines an attractive smile, the amount of incisor display, and lip contour. Borderline cases can be treated without extraction and the capricious minds of patients can be satisfied with regard to the incisor position through whole dentition distalization using TAD. Mild to moderate bimaxillary protrusion cases can be treated with TAD-driven en masse retraction without premolar extraction. Patients with Angle's Class III malocclusion can be the biggest beneficiaries because both sufficient maxillary incisal display, through intrusion of mandibular incisors, and distalization of the mandibular dentition are successfully achieved. In addition, TAD can be used to correct various other malocclusions, such as canting of the occlusal plane and dental/alveolus asymmetry.

• Journal of Korean Dental Science
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• v.16 no.2
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• pp.204-210
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• 2023

Lesch-Nyhan syndrome is a rare X-linked recessive disorder characterized by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyl transferase, which is important in the metabolism of purines. Prevalence of Lesch-Nyhan syndrome is 1:100,000 to 1:380,000 live births, and Lesch-Nyhan syndrome mainly affects males. It is characterized by neurologic dysfunction, uric acid overproduction, and cognitive and behavioral disturbances. The self-mutilation is the most distinctive symptom in Lesch-Nyhan syndrome, appearing about 1 year of age. It is expressed as persistent bites in the oral mucosa, tongue, lips, and fingers, which leads to the total or partial destruction of the affected tissues. Several medical and dental management methods might be performed in Lesch-Nyhan syndrome patients. Dental approaches to prevent injuries caused by self-mutilation include treatments with oral appliances such as mouth guards or lip bumpers, extraction, and orthognathic surgery. This report described two brothers with Lesch-Nyhan syndrome, who injured themselves on oral tissues. The methods of tooth reduction and extraction were performed to prevent injuries caused by self-mutilation.

• Journal of Digital Contents Society
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• v.18 no.2
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• pp.267-274
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• 2017

Recently, there is a new trend about internet of things (IoT) such as shops with smart mirror around the fashion and beauty industry. Since smart mirror can display a content through a monitor which is attached to back of mirror system while looking through a mirror, it can be applied to various industries such as fashion, beauty and health care. This paper proposes an efficient learning system requiring no assistance from others for the hearing deaf who atrophy verbal skill and are inaccurate in pronunciation by using features of smart mirror. Also, this system proposes an efficient and simple lip reading method which can be applied to an embedded system and improves a learning efficiency by employing previously verified pronunciation training data.

• Korean Journal of Cleft Lip And Palate
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• v.4 no.1
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• pp.1-11
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• 2001

Disposable blade is widely used for palatal and oral mucosal incision in oral and maxillofadal surgery nowadays, But its design and durability need for improvement, Especially, there are so many hard tissues intraoral area, such as bone and tooth, therefor the sharpness of the surgical blade was easily destroyed, The purpose of this study was to make basic data for developing new design of surgical blade using in oral and maxillofacial area including for the patients who have cleft lip and palate deformities, Some questionnaires about the usefulness of currently used surgical blades were sent to 150 dentists, the 54 of them made a reply, Secondly, The used-once blade and fresh new blade were examined under the scanning electron microscope with the 4000-times magnification, Lastly, the tissue reaction following the surgical incision with a fresh-new and a used blade on rat buccal cheek mucosa and hard palate was evaluated with light microscope with hematoxilin-eosin staining, The time interval from the surgical trauma to taking a sample were 1 day, 3 days, 7 days, and 14 days, At each time schedule, 2 Sprague-Dawley rats were sacrificed, Many dentists were agreed to need for changing the design of the surgical blades and also demand to improve the durability of the blades, They were also eager to adopt the new design of blade if it was available, The blade used in surgical extraction procedure was heavily damaged in its sharpe edge of number 15 blade, The histological differences were not prominent, but the delayed healing was detected in buccal mucosal defects especially in the surgical group with used blade, There are slight different changes in hard palatal defects between a used and a new blade group, In this study, we could find that there are imperative demanding on improvement of surgical blade design and durability for oral and maxillofadal area, The blade currently using in surgical extraction was easily damaged, The animal model of this study was not perfect for the purpose of this study.

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.761-770
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• 1997

71 Class I malocclusion samples were selected and they were divided into premolar-extraction and non-extraction groups. Vertical and horizontal cephalometric evaluations on dental and soft tissue measurements were done before and after treatment. Also, treatment results in adolescent patients and adult patients were compared. The following conclusions were obtained: 1. In comparison of extraction and non-extraction groups, all the dental and soft tissue measurements, with exception of SN-MP angle, upper lip to E-line, vertical movement of upper first molar, md horizontal movement of lower first molar, showed statistically significant differences. 2. In comparison of extraction and non-extraction groups of adolescent samples, there were statistically significant differences in upper and lower incisor inclinations, horizontal dental movements from vertical reference line, positional changes in upper and lower lips, and mesial movements of upper first molar. 3. In comparison of extraction and non-extraction groups of adult samples, there were statistically significant differences in upper and lower incisor inclinations, horizontal dental movements from vertical reference line, positional changes in upper and lower lips from I-line and vertical reference line, vertical height of upper first molar, and mesial movement of lower first molar. 4. There was no statistically significant difference in SN-MP angle between extraction and non-extraction groups of both adolescent and adult samples.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.93-104
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• 2000

Orthodontic treatment in conjunction with second-molar extraction has been a controversial issue among orthodontists over many decades. The aim of this study was to investigate the treatment effects of upper second molar extraction cases. The sample included 19 upper second molar extraction orthodontic cases(ten Angle's Class I's and nine Class II's, average age=13Y 6M) cared at Kyung-Hee University Department of Orthodontics. Lateral cephalometric radiographs were taken before and immediately after treatment. Seventy-nine points were digitized on each cephalogram and 38 cephalometric parameters were computed comprising 22 angular measurements, 13 linear measurements, and 3 facial proportions. The data obtained from each malocclusion group were analyzed by paired t-test. The statistical results disclosed that there was no significant change in skeletal pattern after treatment except for that accountable by growth while there was statistically significant change in dentoalveolar and soft tissue patterns. There were no significant changes in Bjork sum, posterior facial height /anterior facial height and lower anterior facial height /anterior facial height. No significant changes in anteroposterior position of maxilla and palatal plane were manifested. Although facial axis and lower facial height was slightly increased and the mandible was rotated backward and downward, there was no remarkable change in the mandibular plane. There were statistically significant changes in distal movement of upper first molar, molar key correction and overjet reduction while there was no change in the occlusal plane. The upper lip was slightly retracted simultaneously with slight increase in nasolabial angle. These results signify that distalization of upper dentition with the second molar extraction does change occlusal relationship without gross modifications in the craniofacial skeletal configurationson. Henceforth the second molar extracted would be recommended to treat severe anterior crowding and protrusion with minor skeletal discrepancy.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.79-86
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• 2012

In most patients with severe crowding or lip protrusion, orthodontic treatment with tooth extraction is done. In these patients, even though space is closed after orthodontic treatment, gingival invagination is observed on the extracted site. Since there are possibilities of space recurrence and regional periodontic problems occurrence, periodontic treatment is necessary on the gingival invagination region. This case was a 16 year old female with a chief complaint of crooked teeth. Since her maxillary premolars were already extracted a few years ago at a local dental clinic, orthodontic treatment was done by extracting mandibular premolars. Unlike maxillary premolar regions, gingival invagination occurred in mandibular premolar regions and gingival flattening was done by excising the gingival invaginated region. Gingival flattening was done once on the left side, twice on the right side and showed stable results. This is a case report of a patient that was prone to gingival invagination after orthodontic treatment with extraction and was treated with gingival flattening.

• The korean journal of orthodontics
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• v.24 no.1 s.44
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• pp.149-159
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• 1994

The purposes of present study were to evaluate changes in models and lateral cephalometric head films during orthodontic treatment and to compare the amount of incisal retraction and anterior movement of molars with the two approaches of the retraction method of canine(sectional canine retractions vs sliding canine retractions) and the anchorage management(head gears vs no head gears, transpalatal arches vs no transpalatal arches and lingual arches vs no lingual arches) and to evaluate changes during orthodontic treatment in models with relation to lateral cephalometric head films. 67 Korean women with Angle's Class I bialveolar protrusion were selected, whose initial chronologic age was above 16 yrs. Models and lateral cephalometric head films were taken before and after orthodontic treatment with four bicuspid extraction. the results were obtained as follows. 1. Significant decreases were observed in intermolar width, arch length and arch perimeter of maxilla and mandible but significant difference was not observed in intercanine width of maxilla and mandible during treatment period. 2. The linear change of the upper incisor to upper lip was 2.84:1 and the linear change of the lower incisor to lower lip was 1.45:1 3. There were no significant differences between the two groups(sectional canine retractions vs sliding canine retractions), the !we groups(transpalatal arches vs no transpalatal arches) and the two groups(lingual arches vs no lingual arches) in the amount of incisal retraction and anterior movement of molars. There were a greater amount of maxillary incisal retraction and a lesser amount of anterior movement of maxillary molars with the use of head gears than no use of head gears. 4. Changes during orthodontic treatment in models with relation to lateral cephalometric head films were obtained as follows : 1) Maxilla Central incisors were moved 3.79mm backward, canines were moved 0.22mm laterally and 3.70mm backward, and molars were moved 0.535mm medially and 2.29mm forward. 2) Mandible Central incisors were moved 3.04mm backward, canines were moved 0.145mm laterally and 3.92mm backward, and molars were moved 0.755mm medially and 1.77mm forward.

• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.487-495
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• 1996

The purpose of this study was to evaluate the dentofacial characteristics and the fost-treatment dentofacial changes of those treated by four premolar extractions and to investigate the factors affecting extraction decision. The sample consisted of 35 patients (27 females, and 8 males) with no more than 7.0mm crowding, diagnosed as Class I protrusion. Pre-treatment and post-treatment lateral cephalograms were evaluated. Computerized statistical analysis was carried out using SPSS/PC+ program. The results were as follows. 1. There was no significant change in skeletal pattern after treatment while there was significant change in dentoalveolar and soft tissue pattern. 2. In pre-treatment skeletal pattern, a tendency toward vertical discrepancy was found. 3. In pre-treatment dental pattern, interincisal angle was $113.11^{\circ}$, U1 to FH was $117.78^{\circ}$ and L1 to A-Pog was 7.94mm. Pre-treatment upper and lower lip position was 2.88mm and 5.43mm to E line. 4. After treatment, interincisal angle increased $14.46^{\circ}$ and upper and lower lip moved back 2.45mm and 3.2mm to E line.(p<0.001) 5. The EI was 138.71 before treatment and 148.2 after treatment.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.8 no.1
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• pp.10-14
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• 2012

Self-injurious behavior (SIB) has been defined as the deliberate destruction or alteration of body tissue without conscious suicidal intent. It occurs in conjunction with a variety of psychiatric disorders as well as various developmental disabilities and some syndromes. The behavior is destructive and causes concern and distress to all involved in the care and treatment of the affected individual. A 13-year-old girl with autism, mental retardation and delayed development was reffered from her pediatrician because of severe and painful lower lip biting. An intraoral examination revealed a diffuse swelling of lower lip. It was covered with necrotic slough and the ulcer and scarring of the lower lip was observed. We chose to use an oral removable prosthesis for Conservative treatment. It was decided to use a soft silicone mouthguard in the maxillary arch. Initially, she could not tolerate the appliance inside her mouth but soon adapted with the appliance. After one month, she lost the mouth guard and started lip biting. So we made mouth guard again. There are no standard methods for preventing self-injurious behavior in a patient who is developmentally disabled. Appropriate preventive methods must be developed for each individual patient based on close observation and clinical findings. Behavior modification techniques, pharmacological treatment, extraction of teeth, orthognathic surgery and intra/extra oral appliances can be performed for adjust self-injurious behavior. A suitable oral guard could be tried initially before employing more invasive approaches.