• The korean journal of orthodontics
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• v.52 no.2
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• pp.142-149
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• 2022

Objective: To evaluate clinical parameters and gingival crevicular fluid (GCF) cytokines in children with anterior open bite receiving passive orthodontic treatment with spurs. Methods: Twenty children with indications for interceptive orthodontic treatment, an anterior open bite, and good oral hygiene and periodontal health were included in this study. GCF samples were collected from the mandibular and maxillary central incisors before (baseline) and 24 hours and 7 days after spur bonding. Clinical and periodontal examinations and cytokine analyses were performed. Results: At 7 days after spur attachment, gingival bleeding in the mandibular group was increased relative to that in the maxillary group. Visible plaque was correlated with gingival bleeding at 7 days and the GCF volume at 24 hours after spur attachment. Compared with those at baseline, interleukin (IL)-8 levels in the maxillary group and IL-1β levels in both tooth groups increased at both 24 hours and 7 days and at 7 days, respectively. At 24 hours, IL-8, IL-1β, and IL-6 levels were higher in the maxillary group than in the mandibular group. Cytokine production was positively correlated with increased GCF volume, but not with gingival bleeding, visible plaque, or probing depth. Conclusions: Although orthodontic treatment with spurs in children resulted in increased gingival bleeding around the mandibular incisors, IL levels were higher around the maxillary incisors and not correlated with periodontal parameters. Increased cytokine levels in GCF may be associated with the initial tooth movement during open bite correction with a passive orthodontic appliance in children.

• The korean journal of orthodontics
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• v.42 no.3
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• pp.138-143
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• 2012

Objective: To evaluate the short-term effect of fangchinoline, an anti-inflammatory drug widely used in Asia, on root resorption that is associated with orthodontic tooth movement. Methods: Twenty-four Wistar rats were randomly divided into 6 groups. Mesial forces of 0, 50, or 100 g were applied to the maxillary first molar of the rats in each group for 14 days by activating nickel-titanium closed-coil springs. One-half of the rats receiving each of these treatments also received injections of 200 ${\mu}L$ fangchinoline every 2 days. Finally, movement of the maxillary first molars was measured using digitized radiographs. The molars were extracted and the surfaces of the root resorption craters were recorded using a scanning electron microscope. The distance the molars moved and resorption-area ratio was measured, and results were analyzed using 2-way ANOVA tests. Results: There were no statistical differences in the distances the first molars moved under 50 or 100 g force, regardless of treatment with fangchinoline. However, the resorption area ratios were significantly smaller in those rats that were treated with both tension and fangchinoline than in those rats treated by tension alone. Conclusions: Fangchinoline reduced the resorption area ratio in rats and is therefore an important means of alleviating root resorption.

• The korean journal of orthodontics
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• v.46 no.5
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• pp.280-289
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• 2016

Objective: The aim of this study was to analyze tooth movement and arch width changes in maxillary dentition following nonextraction treatment with orthodontic mini-implant (OMI) anchorage in Class II division 1 malocclusions. Methods: Seventeen adult patients diagnosed with Angle's Class II division 1 malocclusion were treated by nonextraction with OMIs as anchorage for distalization of whole maxillary dentition. Three-dimensional virtual maxillary models were superimposed with the best-fit method at the pretreatment and post-treatment stages. Linear, angular, and arch width variables were measured using Rapidform 2006 software, and analyzed by the paired t -test. Results: All maxillary teeth showed statistically significant movement posteriorly (p < 0.05). There were no significant changes in the vertical position of the maxillary teeth, except that the second molars were extruded (0.86 mm, p < 0.01). The maxillary first and second molars were rotated distal-in ($4.5^{\circ}$, p < 0.001; $3.0^{\circ}$, p < 0.05, respectively). The intersecond molar width increased slightly (0.1 mm, p > 0.05) and the intercanine, interfirst premolar, intersecond premolar, and interfirst molar widths increased significantly (2.2 mm, p < 0.01; 2.2 mm, p < 0.05; 1.9 mm, p < 0.01; 2.0 mm, p < 0.01; respectively). Conclusions: Nonextraction treatment with OMI anchorage for Class II division 1 malocclusions could retract the whole maxillary dentition to achieve a Class I canine and molar relationship without a change in the vertical position of the teeth; however, the second molars were significantly extruded. Simultaneously, the maxillary arch was shown to be expanded with distal-in rotation of the molars.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.97-105
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• 2001

In many cases of orthodontic treatment the upper anterior teeth are retracted. Periodontal problems may arise during incisor retraction, if the amount of tooth movement and the amount of remodeling in the anterior cortical bone are not the same. Therefore in this study, to find out the relationship between the amount of tooth movement and the amount of bone remodeling during retraction of the upper anterior teeth, lateral cephalograms of 56 female patients over 18-year-old were taken before and after treatment. Among the 56 patients, two groups were divided according to the type of root movement during retraction. 26 patients mainly moved by tipping and 30 by bodily movement. The cephalograms taken before and after treatment were superimposed upon the true horizontal plane. In the Tip-Group, the horizontal bone remodeling/tooth movement ratio was 1:1.63, and in the Torque-Group it was 1:1.66. Because the amount of tooth movement and the amount of bone remodeling were not the same in both groups, in the Tip-Group the root apex moved away from the palatal cortical plate and closer to the labial cortical plate, whereas in the Torque-Group the root moved away from the labial cortical plate and closet to the palatal cortical plate. Therefore, there are limitations in the amount of incisor retraction in patients with a very thin anterior cortical plate in the maxilla, and in patients with severe skeletal discrepancies orthognathic surgery should be considered and when orthodontic camouflage treatment is the only possible method, the orthodontist must be aware of the limitations of treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.547-552
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• 2001

Extracting mandibular incisors for orthodontic treatment may adversely affect the occlusion. However, when properly used, extraction of mandibular inciors is a selection for the correction of the malocclusion. Generally, treatment for crowding needs to select between nonextraction and four premolar extraction. Approaches for crowded mandibular incisors include distal movement of posterior teeth, lateral movement of canines, labial movement of incisors, interproximal enamel reduction, removal of premolars, removal of one or two incisors, and various combinations of the above. Extraction of incisors is used in case of crowding, anterior tooth size discrepancy, absent of maxillary lateral incisors, and ectopic eruption. But severe overjet. overbite, and space are the contraindication of it. A patient had severe crowding on upper anterior teeth, impacted upper left lateral incisor, palatal ectopic eruption of upper right incisor and severe crowding on lower anterior teeth. Lower lateral incisors are extracted for space availability and facial esthetics. We report the case of orthodontic treatment of upper and lower anterior crowding through extraction of lateral incisor.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.435-447
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• 1988

This study was performed to evaluate the effect of low-power laser irradiation on the periodontium of the orthodontically moved tooth of rat. The experimental materials were 30 male rats. Orthodontic appliances were placed bilaterally between maxillary first molar and incisor teeth and the force was 1 Oz. Experimental animals were divided into eight groups as follows: no movement, 1st, 2nd, 3rd, 5th, 7th, 14th, and 28th day groups. In all experimental animals except no movement group, low-power laser was irradiated on the unilateral maxillary first molar (experimental side), but on the contralateral side, only orthodontic force was applied (control side). The histologic effects of laser on the periodontium of the orthodontically moved tooth on the consecutive experimental days were as follows: In the experimental side, by the biostimulating effect of laser, 1. Hyalinized tissue was formed later and eliminated earlier than in the control side. 2. Undermining bone resorption was occurred earlier than in the control side. 3. More osteoid tissue was deposited and calcified earlier than in the control side. 4. The most prominent changes were formation of new blood vessels and dilatation of old blood vessels.

• The korean journal of orthodontics
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• v.43 no.2
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• pp.101-109
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• 2013

Objective: To evaluate the efficiency of the Frog appliance (FA) alone or in combination with headgear for distalizing the maxillary molars. Methods: Fifty patients (25 males and 25 females) aged 12.6 - 16.7 years who received treatment for Class II malocclusion at the Orthodontic Clinic of Al-Baath University were selected for this study and randomly divided into 2 equal groups. Maxillary molar distalization was achieved using the FA alone (group 1) or a combination of the FA with high-pull headgear worn at night (group 2). Lateral cephalograms were obtained before and after treatment. Results: The maxillary molars moved distally by 5.51 and 5.93 mm in groups 1 and 2, respectively. Distal movements were associated with axial tipping by $4.96^{\circ}$ and $1.25^{\circ}$, and with loss of anchorage by mesial movement of the second maxillary premolars by 2.70 and 0.90 mm in groups 1 and 2, respectively. The combined use of the FA and nighttime high-pull headgear decreased the distalization time and improved the ratio of maxillary molar distalization movement relative to the overall opening space between the first maxillary molars and second premolars. Conclusions: The FA can effectively distalize the maxillary molars, this distalization associates with some unfavorable changes. Nighttime use of high-pull headgear combined with the FA can reduce these unfavorable changes and improve treatment outcomes.

• The korean journal of orthodontics
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• v.46 no.1
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• pp.27-35
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• 2016

Objective: The aims of our study were to verify the validity of the T-Scan III system (Tekscan) as an objective occlusal evaluation tool, and to assess the differences between two occlusal indexes - the peer assessment rating (PAR) index and the American Board of Orthodontics objective grading system (OGS) - by comparing the scores derived from the T-Scan III system with the two occlusal indexes and analyzing the correlations between them. Methods: The final study sample included 48 adult volunteers (39 men and 9 women, mean age $24.14{\pm}3.16years$), after excluding 29 volunteers whose occlusion could not be evaluated by the T-Scan III system due to severe skeletal or occlusal problems. PAR index and OGS scores were assessed using dental study models, and measurements of centric occlusion, protrusive movement, and lateral excursion movement were obtained via the T-Scan III system. The results were analyzed to determine correlations. Results: Occlusal analysis by the T-Scan III system was clinically reliable (p < 0.05), and the PAR index and OGS scores were significantly correlated with several measurements obtained with the T-Scan III system (p < 0.05). Conclusions: The T-Scan III system is a quantitative and reliable method for occlusal evaluation, and represents a potential substitute for occlusal indexes. Compared to the PAR index, the OGS scores of more variables were significantly correlated with the T-Scan measurements.

• The korean journal of orthodontics
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• v.23 no.1 s.40
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• pp.123-136
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• 1993

The purpose of this report is to present the successful improvement of occlusal relationship and facial esthetics in class II division 1 malocclusion with severe labioversion of upper anterior teeth and severe overjet, and in class II malocclusion with infraversion of bilateral maxillary canines by MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, with upper second molar extraction. After treatment, there were natural contact points at canine and premolar regions, normal occlusal relation-ship and treatment results, satisfied the gnathologic concept, in this 2 cases. Compared with the routine treatment with premolar extraction, the treatment time and patients' discomfort were reduced. And the MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, resulted in reduction of the treatment time and getting the good treatment results. Consequently, the majot concerns in orthodontic treatment are appropriate diagnosis and treatment plan, so, the application of second molar extraction with appropriate case analysis and diagnosis is very helpful to orthodontic treatment.

• The korean journal of orthodontics
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• v.48 no.1
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• pp.57-62
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• 2018

Piezoelectric surgery is a novel surgical approach used in orthodontic treatment for rapid tooth movement. This paper presents a case series wherein osseous outgrowths were observed in response to piezosurgery-assisted en-masse retraction. Sixteen patients requiring upper premolar extractions were treated with miniscrew-supported en-masse retraction and received minimally invasive decortication via piezosurgery. Computed tomography (CT) of the maxillary anterior region was performed to investigate the nature of the outgrowths. In 8 of the 16 patients, hemispheric or disc-shaped osseous outgrowths were observed on the sites where piezosurgery was performed during retraction. CT images revealed that these outgrowths were alveolar bone. This case series presents a previously unreported osseous response to piezosurgery-assisted tooth movement during orthodontic treatment. The response is mostly transient and is observed in 50% of the treated patients, suggesting a bone turnover that can be assessed clinically and radiographically.