• The korean journal of orthodontics
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• v.35 no.6 s.113
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• pp.485-494
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• 2005

Maxillary anterior teeth were intruded and lingually root torqued with two maxillary anterior microimplants between the lateral incisors and canines. Overerupted maxillary canines were intruded with two other microimplants between the maxillary canines and first premolars. Maxillary posterior teeth and canines were distalized, then the maxillary incisors were retracted with two maxillary posterior microimplants between the first and second molars. The mandibular anterior teeth were intruded and the mandibular posterior teeth were extruded with conventional method such as anterior bite plane, intrusion arch and Class II elastics. The mandible moved slightly forward after the correction of deep bite and retroclination of the upper incisors. Consequently, microimplant anchorage (MIA) provided absolute anchorage for simultaneous correction of Class II canine and molar relationships and deep overbite.

• The korean journal of orthodontics
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• v.36 no.1 s.114
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• pp.30-44
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• 2006

This study was performed to investigate the location of the ideal bracket positioning plane in lingual orthodontics using the three-dimensional finite element method. Displacement of the anterior teeth were evaluated according to the vertical and the angular movements of the bracket positioning plane. To achieve the ideal movement of anterior teeth in the lingual central plane, the location of the force application point and the amount of the moment applied to the four incisors were evaluated. As the bracket positioning plane was moved parallel toward the incisal edge, uncontrolled tipping and extrusion of the maxillary and the mandibular incisors were increased. But lingual tipping of the crown was decreased in the maxillary and the mandibular canines. As the bracket positioning plane was inclined toward the incisal edge, lingual tipping was increased in the 6 anterior teeth and extrusion of incisors and intrusion of the canine was also increased. As the retraction hook of the canine bracket was elongated, lingual tipping and extrusion of the central incisor and mesial movement and extrusion of the lateral incisor were increased. In the canine, mesial and labial movements of the crown were increased. When the moment was applied to the 4 incisors of the maxillary and the mandibular arch in the lingual central plane, 280 gf-mm in the maxillary central incisor, 500 gf-mm in the maxillary lateral incisor, 170 gf-mm in the mandibular central incisor and 370 gf-mm in the mandibular lateral incisor produced bodily movement of the individual tooth.

• Journal of the Korean Orthopaedic Association
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• v.56 no.5
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• pp.391-397
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• 2021

Purpose: Tranexamic acid (TXA) can reduce perioperative blood loss and the frequency of blood transfusions in lower extremity surgery. On the other hand, the effects of TXA on reverse total shoulder arthroplasty (rTSA) remain undetermined. This study evaluated the efficacy of TXA on perioperative blood loss, transfusion requirements, and the change in the hemotologic index. Materials and Methods: This study evaluated patients who underwent rTSA from September 2009 to July 2020. The patients were classified into two groups. The TXA group were administered TXA intravenously and topical TXA during surgery. The non-TXA group was not administered TXA. The quantity of hemovac drainage, which represented the postoperative blood loss, transfusion requirements, and postoperative change in hemoglobin and hematocrit level, were recorded. Results: The TXA and non-TXA groups consisted of 93 and 84 patients, respectively. The preoperative demographics showed no significant differences in age (72.0±7.0 vs. 71.5±5.8, p=0.656), sex (male:female, 28:65 vs. 23:61, p=0.689) and the prevalence of hypertension and diabetes (hypertension:diabetes:both, 36:3:13 vs. 32:3:8, p=0.806) between the two groups. There were significant differences in the requirements of transfusion (0 vs. 9, p=0.001), hemovac drainage at the 1^st (98.8±61.2 ml vs. 162.7±98.8 ml, p<0.001), the 2^nd postoperative day (73.8±48.4 ml vs. 91.5±54.5 ml, p=0.024), hemoglobin level at the 1^st (11.7±1.2 g/dl vs. 11.2±1.4 g/dl, p=0.048), 3^rd (10.9±1.2 g/dl vs. 10.2±1.2 g/dl, p<0.001), and 6^th (11.2±1.3 g/dl vs. 10.7±1.3 g/dl, p=0.020) postoperative day, and the hematocrit level at the 1^st (35.0%±3.6% vs. 32.5%±3.8%, p=0.001), 3^rd (32.3%±5.0% vs. 29.8%±3.6%, p<0.001), and 6^th (33.5%±3.8% vs. 31.5%±3.7%, p<0.001) postoperative day between the two groups. Conclusion: Intravenous and topical intra-articular TXA can reduce the transfusion requirement and blood loss in rTSA.

• Clinics in Shoulder and Elbow
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• v.16 no.2
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• pp.73-83
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• 2013

Purpose: The goal of this study is to evaluate the minimum three-year follow-up results of reverse total shoulder arthroplasty (RTSA) for glenohumeral (GH) arthritic and pseudoparalytic patients with severe rotator cuff deficiency. Materials and Methods: We evaluated 13 patients (three males and 10 females) who underwent RTSA from July 2007 to July 2010. The average follow-up duration was 54.2 months (range, 37~74 months). Clinical results were evaluated using the Visual Analog Scale (VAS) for pain, active Range of Motion (ROM): active forward flexion (aFF); active external rotation at the side (aERs); active internal rotation to the back (aIRb), American Shoulder and Elbow Surgeons (ASES) score, Korean Shoulder Score (KSS), and intraoperative and postoperative complications. Results: VAS score improved from 7.5(6~10) points to 1.5(0~4), and ROM of active forward elevation improved from $42.7(10{\sim}100)^{\circ}$ to $129.1(110{\sim}180)^{\circ}$. In addition, ASES score improved from preoperative 32.9 (11.7~46.7) points to 80.2(58.3~95.0) postoperatively, and KSS score improved from 36.8(24~47) points to 78.4 (61~92). Twelve out of 13 cases showed various degrees of scapular notching at the last follow-up. There was one case of intraoperative anterior glenoid fracture and two cases of temporary nerve injury. Revision surgery was performed in two cases for treatment of delayed postoperative deep infection. Conclusion: According to minimum three-year follow-up results, RTSA may be an effective treatment option for glenohumeral (GH) arthritic and pseudoparalytic patients. However, considering the possibility of complications related to delayed deep infection or surgeon's technique, RTSA should be judiciously and carefully indicated by expert surgeons.

• The korean journal of orthodontics
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• v.32 no.1 s.90
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• pp.9-18
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• 2002

The present study hypothesized that the double keyhole looped archwire plays a positive role for the sake of translatory movement and/or controlled tipping of upper 6 anteriors, and secures anchorage control as well. The purposes of the study were to evaluate the changes in lateral cephalograms during orthodontic treatment with DKHLs and to compare the skeletal & dental changes before- & after-treatment. The materials of this study were lateral cephalograms of 20 adult patients with upper dentoalveolar protrusion both in class I and in class II Division1 malocclusion. Lateral cephalograms were taken before and after orthodontic treatment with upper 1st bicuspid extraction and DKHLs. The results were obtained as follows : 1. There were no statistically significant differences in skeletal measurement except SNB and PTFH between before- & after-treatment. The major changes were in dentoalveolar region. 2. After treatment, there were statistically significant decrease in dental measurement except interincisal angle. 3. Both upper & lower lip protrusion was decreased. 4. There were statistically differences in upper anterior crown horizontal & root vertical dimension(7.08 ${\pm}$ 2.14 mm, 2.38 ${\pm}$ 1.15 mm, p<0.01). 5. There were statistically differences in upper posterior dental(both crown & root) horizontal dimension(2.48 ${\pm}$ 0.99 mm, 2.05 ${\pm}$ 0.91 mm, p<0.01).

• The korean journal of orthodontics
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• v.32 no.6 s.95
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• pp.413-424
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• 2002

Preadolescent children with deficient maxillae are suitable candidates for the maxillary protraction appliance(MPA). The theoretical effect of the MPA is protraction or anterior displacement of the maxilla. However, it is known that complex effects such as anterior displacement of the maxillary teeth, downward and backward rotation of the mandible, linguoversion of the mandibular anterior incisors, are known to play a role in improving the Cl III malocclusion. There have been much studies with regard to maxillary protraction, but the different effects of MPAs depending on the vertical facial pattern are not known precisely. This study was based on 67 patients (31 males, 36 females) aged from 6 years 6 months to 13 years 3months, who visited the Dept. of Orthodontics at Yonsei Univ., Dental Hospital and diagnosed as skeletal Class III with maxillary deficiency. They were divided into 3 groups (low, average, high angle groups) depending on genial angle and the SNMP (Go-Gn) angle, respectively. Pretreatment and post-treatment lateral cephalograms were used to compare the effects of MPA and the following conclusions were obtained: 1) A significantly large amount of backward movement of the B point was observed in patients with a low SNMP angle. Those with a high SNMP angle had significant forward movement at A point. 2) The patients with low genial angle had the least forward movement at the A point, and those with a high angle had more forward movement. 3) In comparing the arcTan of the A point, the high angle group showed more horizontal movement while the low angle group showed more vertical movement. 4) There was no significance between the treatment duration of the SNMP and the Genial angle groups.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.165-181
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• 1999

Treatment mechanics should be individualized to be suitable for each patient's personal teeth and anatomic environment to get a best treatment result with the least harmful effects to teeth and surrounding tissues. Especially, the change of biomechanical reaction associated with that of the centers of resistance of teeth should be considered when crown-to-root ratio changed due to problematic root resorption and/or periodontal disease during adult orthodontic treatment. At the present study, in order to investigate patterns of initial displacements of anterior teeth under certain orthodontic force when crown-to-root ratio changed in not only normal periodontal condition but also abnormal periodontal and/or teeth condition, the changes of the centers of resistance for maxillary and mandibular 6 anterior teeth as a segment were studied using the laser reflection technique, the lever & pulley force applicator and the photodetector with these quantified variables reducing alveolar bone 2mm by 2mm for each of maxillary 6 anterior teeth until the total amount of 8mm and root 2mm by 2mm for each of mandibular 6 anterior ones until the total amount of 6mm. The results were as follows: 1. Under unreduced condition, the center of resistance during initial displacement of maxillary 6 anterior teeth was located at the point of about $42.4\%$ apically from cemento-enamel junction(CEJ) of the averaged tooth of them and kept shifting to about $76.7\%$ with alveolar bone reduction. 2. The distance from the averaged alveolar crest level of maxillary 6 anterior teeth to the center of resistance for the averaged tooth of them kept decreasing with alveolar bone reduction, but the ratio to length of the averaged root embedded in the alveolar bone was stable at around $33\%$ regardless of that. 3. Under unreduced condition, the center of resistance during initial displacement of mandibular 6 anterior teeth was located at the Point of about $43\%$ apically from CEJ of the averaged tooth of them and this ratio kept increasing to about $54\%$ with root reduction. But the distance from CEJ to the center of resistance decreased from around 5.3mm to around 3.3mm, that is to say, the center of resistance kept shifting toward CEJ with the shortening of root length. 4. A unit reduction of alveolar bone had greater effects on the change of the centers of resistance than that of root did during initial Phase of each reduction. But both of them had similar effects at the middle region of whole length of the averaged root.

• The korean journal of orthodontics
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• v.39 no.5
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• pp.278-288
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• 2009

Objective: The aim of this study was to investigate the changes in the center of resistance of the maxillary teeth in relation to alveolar bone loss. Methods: A finite element model, which included the upper dentition and periodontal ligament, was designed according to the amount of bone loss (0 mm, 2 mm, 4 mm). The teeth in each group were fixed with buccal and lingual arch wires and splint wires. Retraction and intrusion forces of 200 g for 4 and 6 anterior teeth groups and 400 g for the full dentition group were applied. Results: The centers of resistance were at 13.5 mm, 14.5 mm, 15 mm apical and 12 mm, 12 mm, 12.5 mm posterior in the 4 incisor group; 13.5 mm, 14.5 mm, 15 mm apical and 14 mm, 14 mm, 14.5 mm posterior in the 6 anterior teeth group; and 11 mm, 13 mm, 14.5 mm apical and 26.5 mm, 27 mm, 25.5 mm posterior in the full dentition group respectively according to 0 mm, 2 mm, 4 mm bone loss. Conclusions: The center of resistance shifted apically and posteriorly as alveolar bone loss increased in 4 and 6 anterior teeth groups. However, in the full dentition group, the center of resistance shifted apically and anteriorly in the 4 mm bone loss model.

• The korean journal of orthodontics
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• v.39 no.1
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• pp.54-65
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• 2009

This paper describes the case of a 50-year-old female with a Class II malocclusion who presented with severe bimaxillary protrusion and generalized alveolar bone loss due to adult periodontitis. The treatment plan consisted of extracting both upper and lower first premolars and periodontal treatment. Anterior segmental osteotomy(ASO) of the mandible and upper anterior segment retraction using compression osteogenesis after peri-segmental corticotomy(Speedy orthodontics) was performed. Correct overbite and overjet, facial balance, and improvement of lip protrusion were obtained. However, a slight root resorption tendency was observed on the lower anterior dentition. The active treatment period was 9 months and the results were stable for 27 months after debonding. This new type of treatment mechanics can be an effective alternative to orthognathic surgery.

• Journal of the Korean Orthopaedic Association
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• v.54 no.5
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• pp.418-426
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• 2019

Purpose: This study analyzed the features of humeral head decentralization in large to massive rotator cuff tears with a shoulder dislocation in the elderly. Moreover, shoulder instability and treatment were reviewed. Materials and Methods: From May 2005 to February 2017, Group A containing 45 cases (45 patients) over 65 years old accompanied by a large or massive rotator cuff tear with a shoulder dislocation and Group B containing 45 cases (45 patients) without a shoulder dislocation were enrolled. The mean ages in Groups A and B were 73.2 and 72.1 years old, and the mean follow-up periods were 30.7 and 31.3 months, respectively. Twenty-one cases (46.7%) in Group A underwent rotator cuff repair, and 8 cases (17.8%) underwent concomitant rotator cuff repair with Bankart repair. Sixteen cases (35.6%) underwent reverse total shoulder arthroplasty for cuff tear arthropathy. 45 cases (100%) in Group B underwent rotator cuff repair. The off-the center and head elevation were measured in the preoperative magnetic resonance imaging (MRI) of Groups A and B. The preoperative and postoperative visual analogue scale (VAS) score, American Shoulder and Elbow Surgeons (ASES) score, and University of California Los Angeles (UCLA) score in Groups A and B were compared. Results: In Groups A and B, the mean off-the centers were posterior 7.41 mm and posterior 2.02 mm (p=0.03), and the mean head elevations were superior 6.66 mm and superior 2.44 mm (p=0.02), respectively. The mean ASES scores of Groups A and B were 32.8 and 33.4 before surgery, and 77.1 (p=0.02) and 78.1 (p=0.02) after surgery (p=0.18), respectively. The mean UCLA scores of Groups A and B were 13.1 and 12.8 before surgery, and 28.9 (p=0.02) and 29.5 (p=0.01) after surgery (p=0.15), respectively. Conclusion: Patients over 65 years old with a shoulder dislocation in large to massive rotator cuff tears had higher off-the center and head elevation on the preoperative MRI than those without a shoulder dislocation. This measurement can help predict preceding shoulder instability. Early rotator cuff repairs should be performed and other treatments, such as Bankart repair and reverse total shoulder arthroplasty, should also be considered.