• The korean journal of orthodontics
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• v.36 no.4
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• pp.263-274
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• 2006

Objective: The purpose of this study was to evaluate clinical and microbiological changes in periodontal tissue around the banded molars after debanding. Methods: This study included 17 young adult patients treated with fixed orthodontic appliances including bands on the last molars more than 1 years. Probing depth and bleeding frequency were measured and plaque samples were collected from the last banded molars in all quadrants of each patient. All the data were collected immediately after debanding and 4 weeks after debanding. Results: Using polymerase chain reaction based on 16S rDNA, the presence of Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola was detected. After debanding, probing depth, bleeding frequency, and prevalance of periodontopathogens were reduced. Probing depth and bleeding frequency were most decreased in the buccal site of the mandibular left molar and were least decreased in the lingual site of the maxillary right molar. Conclusion: The results of this study indicated that proper management of oral hygiene after debanding can recuperate unfavorable periodontal condition caused by orthodontic treatment.

• The korean journal of orthodontics
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• v.37 no.2 s.121
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• pp.125-136
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• 2007

Objective: Soft tissue changes due to orthodontic treatment has large individual variation. Therefore continuous evaluation during treatment is required. Patients with fixed orthodontic appliances often wonder if their lip positions will change after the removal of brackets, but only a few studies exist on this topic. The objective of this study was to evaluate the changes of the lips and perioral soft tissue after bracket removal. Methods: The sample used in this study was 19 males and 33 females. Cephalometric X-rays were taken at 3 stages - T1 (before debonding), T2 (just after debonding), T3 (1.5 months after debonding). Results: The lower lip was retruded immediately after debonding (T2-T1), and 1.5 months after debonding (T3-T2). The mean amounts of retrusion from the vertical reference plane (sG perpendicular line) were about 0.38 mm for the upper lip and 0.88 mm for the lower lip. Immediately after debonding, lip retrusion of females was greater than that of males. During the post-debonding period, lower lip of males was retruded more than that of females. Conclusion: Lips are retruded after bracket removal, and there is no gender difference 1.5 months after debonding.

• Journal of Periodontal and Implant Science
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• v.37 no.1
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• pp.45-51
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• 2007

This study evaluated the possibility of the 3-dimensional attachment of human periodontal ligament fibroblasts to a periodntally involved root surface after an EDTA treatment in vitro. The human PDL fibroblasts were isolated from the middle third of the root of periodontally healthy teeth extracted for orthodontic reasons. The cells were cultured in a medium containing Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at $37^{\circ}C$ in humidified air containing 5% $CO_2$. Eight single-rooted teeth were obtained from patients diagnosed with periodotitis. After scaling and root planing, four teeth were etched with 24% ethylenediaminetetracetic acid (EDTA) for two minutes (Experimental group). The other four teeth were not treated with EDTA and were used as the control group. The human PDL fibroblasts were placed in the total root surface and cultured for 4 weeks. The teeth were fixed in 2.5% glutaraldehyde in PBS before preparation for the scanning electron microscopy (SEM) examination. The human PDL fibroblasts showed a healthy morphology on the root surfaces treated with EDTA (Experimental group) and a relatively unhealthy appearance on the treated root surfaces (Control group). This suggests that EDTA favorably affects the 3-dimensional attachment of human PDL fibroblasts cultured on the root surfaces. which may play an important role in periodontal healing and regeneration.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.376-381
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• 2008

In mixed dentition there exists many empty spaces in the arch due to eruption of permanent teeth and exfoliation of primary teeth. The empty spaces makes it difficult to apply fixed orthodontic appliances. Horseshoe Appliance can be used effectively at this stage, holding the whole dentition in one piece. It covers every surface of erupted teeth and prevents extrusion and rotation of single tooth. By using intermaxillary elastic force, remodeling of the alveolar bone is opposite in each arch. In patients who were treated with horseshoe appliance, forward growth of maxilla, labioversion of maxillary incisors and linguoversion of mandibular incisors were obtained. Minimum downward and clockwise rotation of mandible was shown, so increasing anterior facial height was minimized.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.479-484
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• 2000

The conventional treatment of skeletal class III malocclusion has been focused on the application of orthopedic forrce primarily to the mandible. Thus moderate Class III malocclusions can be corrected by the anterior displacement of the maxilla and maxillary dentition, possibly by restricting the growth of the mandible or by changing its direction. The patients having skeletal Class III malocclusion were treated with removable appliance & fixed appliance for detailed tooth movement and the following results were observed: 1. The anterior crossbite was corrected. 2. The forward and downward growth of the maxillary complex was obtained. 3. The lingual tipping of the mandiblar incisors was performed and the mandible was rotated in the clockwise direction.

• The korean journal of orthodontics
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• v.39 no.6
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• pp.362-371
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• 2009

Objective: The purpose of this study was to compare the longitudinal treatment effects of facemask with rapid maxillary expansion (FM/RME) and chincup (CC) therapy followed by fixed orthodontic treatment (FOT) in Class III malocclusion (CIII) patients. Methods: The samples consisted of twenty-one CIII patients who had similar skeletal and dental characteristics before FM/RME or CC therapy and good retention results (Class I molar/canine relationship and positive overbite/overjet) after FOT (Group 1, FM/RME, n = 11; Group 2, CC, n = 10). Lateral cephalograms were taken before (T0) and after FM/RME or CC therapy (T1), and after FOT and retention (T2). Skeletal and dental variables were measured. Mann-Whitney U-test and Wilcoxon signed-rank test were used for statistical analysis. Results: During T0-T1, FM/RME therapy induced forward movement of point A, and labioversion of the upper incisors. Both groups showed posterior repositioning of the mandible. FM/RME resulted in increase of the vertical dimension; however, CC caused an increase in articular angle and decrease in gonial angle. During T1-T2, both groups exhibited forward growth of point A. Group 1 showed forward growth and counterclockwise rotation of the mandible and increase of IMPA; however, Group 2, showed increase of ANS-Me/N-Me and decrease of overbite. Conclusions: The key factor for successful FM/RME and CC therapy and good retention results might be a harmonized forward growth of the maxilla that could keep pace with the growth and rotation of the mandible.

• The korean journal of orthodontics
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• v.41 no.3
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• pp.174-183
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• 2011

Objective: Orthodontically induced root resorption (OIRR) involves partial loss of cementum and dentin of teeth caused by routine orthodontic treatment. It decreases root length and influences the function of affected teeth. In this study, the treatment and patient factors causing apical root resorption in Koreans were determined. The observed factors were extraction, gender, age, displacement of root apex, total treatment period, total teeth length, and shape of the root. Methods: The records of 137 patients treated with full, fixed edgewise appliances were obtained from the Department of Orthodontics, Dankook University Dental Hospital, from November 2007 to December 2008. Periapical radiographs of the maxillary central incisors and cephalometric radiographs of each patient were used to assess apical root resorption and type of tooth movement. Results: The mean amount of resorption was $1.62{\pm}1.58mm$. The amount of resorption in the extraction and non-extraction groups was $2.10{\pm}1.64mm$ and $1.18{\pm}1.39mm$, respectively. The amount of root resorption increased with the total tooth length. Severe root resorption (> 4 mm) was related to abnormal root shape (blunt, pointed, or eroded). Conclusions: The variables significantly related to OIRR were extraction, initial tooth length, and root shape.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.4
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• pp.272-281
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• 2020

Agenesis of permanent tooth in adolescent patients can be treated either by orthodontic treatment for space closure or by maintaining the space until implant restoration can be carried out in adult. However, gradual atrophy of alveolar bone width makes it difficult to restore the prosthesis in the future or may cause unaesthetic results. Therefore, maintaining of not only the missing space but also the alveolar bone width should be considered. This case is a treatment whereby a temporary replacement of missing 2 mandibular incisors in adolescent patient was carried out using 2 temporary anchorage devices (TADs). Two TADs were placed horizontally 2 - 3 mm below the top of alveolar ridge, and fixed with artificial teeth by stainless steel wires extended. During the 2 year follow-up, neither gingival inflammation nor loss of the TADs have occurred. In the radiographic evaluation, the growth of the adjacent alveolar bone was not inhibited, and the width of the alveolar bone was maintained.