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KJO Korean Journal of Orthodontics

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pISSN 2234-7518
eISSN 2005-372X
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    • Original Article l 2019-09-25

      Effectiveness of anchorage with temporary anchorage devices during anterior maxillary tooth retraction: A randomized clinical trial

      Stéphane Barthélemi , Alban Desoutter, Fatoumata Souaré and Frédéric Cuisinier

      Abstract : ObjectiveThis study evaluated the efficiency of anchorage provided by temporary anchorage devices (TADs) in maxillary bicuspid extraction cases during retraction of the anterior teeth using a fixed appliance.MethodsPatients aged 12 to 50 years with malocclusion for which bilateral first or second maxillary bicuspid extractions were indicated were included in the study and randomly allocated to the TAD or control groups. Retraction of the anterior teeth was achieved using skeletal anchorage in the TAD group and conventional dental anchorage in the control group. A computed tomography (CT) scan was performed after alignment of teeth, and a second CT scan was performed at the end of extraction space closure in both groups. A three-dimensional superimposition was performed to visualize and quantify the maxillary first molar movement during the retraction phase, which was the primary outcome, and the stability of TAD movement, which served as the secondary outcome.ResultsThirty-four patients (17 in each group) underwent the final analysis. The two groups showed a significant difference in the movement of the first maxillary molars, with less significant anchorage loss in the TAD group than that in the control group. In addition, TAD movement showed only a slight mesial movement on the labial side. On the palatal side, the mesial TAD movement was greater.ConclusionsIn comparison with conventional dental anchorage, TADs can be considered an efficient source of anchorage during retraction of maxillary anterior teeth. TADs remain stable when correctly placed in the bone during the anterior tooth retraction phase.

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    • Original Article l 2019-05-25

      Influence of changing various parameters in miniscrew-assisted rapid palatal expansion: A three-dimensional finite element analysis

      Soungjun Yoon , Dong-Yul Lee, and Seok-Ki Jung

      Abstract : ObjectiveThis study aimed to analyze the effect of changing various parameters of the bone-borne rapid palatal expander (RPE) using the finite element method (FEM).MethodsIn eight experimental groups, we investigated the effect of the number, position, and length of miniscrews; positional changes of the expander; and changes in the hook length on maxillary expansion. In finite element analysis, we compared the magnitude and distribution of stress, and the displacement changes following expansion of the bone-borne RPE.ResultsWhen we compared the number and position of miniscrews, placing miniscrews in the anterior and posterior sides was advantageous for maxillary expansion in terms of stress distribution and displacement changes. Miniscrew length did not significantly affect stress distribution and displacement changes. Furthermore, anteroposterior displacement of the expander did not significantly affect transverse maxillary expansion but had various effects on vertical changes of the maxilla. The maxilla rotated clockwise when the miniscrews were placed in the anterior region. The hook length of the expander did not show consistent results in terms of changes in stress distribution and magnitude or in displacement changes.ConclusionsThe findings of this study suggest that changes in the location and length of the miniscrews and displacement of the bone-borne RPE could affect the pattern of the maxillary expansion, depending on the combination of these factors.

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    • Original Article l 2019-05-25

      Palatal en-masse retraction of segmented maxillary anterior teeth: A finite element study

      Jae Hyun Park , Yoon-Ah Kook, Yukio Kojima, Sunock Yun, and Jong-Moon Chae

      Abstract : ObjectiveThe aim of this finite element study was to clarify the mechanics of tooth movement in palatal en-masse retraction of segmented maxillary anterior teeth by using anchor screws and lever arms.MethodsA three-dimensional finite element method was used to simulate overall orthodontic tooth movements. The line of action of the force was varied by changing both the lever arm height and anchor screw position.ResultsWhen the line of action of the force passed through the center of resistance (CR), the anterior teeth showed translation. However, when the line of action was not perpendicular to the long axis of the anterior teeth, the anterior teeth moved bodily with an unexpected intrusion even though the force was transmitted horizontally. To move the anterior teeth bodily without intrusion and extrusion, a downward force passing through the CR was necessary. When the line of action of the force passed apical to the CR, the anterior teeth tipped counterclockwise during retraction, and when the line of action of the force passed coronal to the CR, the anterior teeth tipped clockwise during retraction.ConclusionsThe movement pattern of the anterior teeth changed depending on the combination of lever arm height and anchor screw position. However, this pattern may be unpredictable in clinical settings because the movement direction is not always equal to the force direction.

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    • Original Article l 2019-07-25

      Short-term changes in muscle activity and jaw movement patterns after orthognathic surgery in skeletal Class III patients with facial asymmetry

      Kyung-A Kim , Hong-Sik Park, Soo-Yeon Lee, Su-Jung Kim, Seung-Hak Baek, and Hyo-Won Ahn

      Abstract : ObjectiveTo evaluate the short-term changes in masticatory muscle activity and mandibular movement patterns after orthognathic surgery in skeletal Class III patients with facial asymmetry.MethodsTwenty-seven skeletal Class III adult patients were divided into two groups based on the degree of facial asymmetry: the experimental group (n = 17 [11 male and 6 female]; menton deviation ≥ 4 mm) and control group (n = 10 [4 male and 6 female]; menton deviation < 1.6 mm). Cephalography, electromyography (EMG) for the anterior temporalis (TA) and masseter muscles (MM), and mandibular movement (range of motion [ROM] and average chewing pattern [ACP]) were evaluated before (T0) and 7 to 8 months (T1) after the surgery.ResultsThere were no significant postoperative changes in the EMG potentials of the TA and MM in both groups, except in the anterior cotton roll biting test, in which the masticatory muscle activity had changed into an MM-dominant pattern postoperatively in both groups. In the experimental group, the amount of maximum opening, protrusion, and lateral excursion to the non-deviated side were significantly decreased. The turning point tended to be shorter and significantly moved medially during chewing in the non-deviated side in the experimental group.ConclusionsIn skeletal Class III patients with facial asymmetry, the EMG activity characteristics recovered to presurgical levels within 7 to 8 months after the surgery. Correction of the asymmetry caused limitation in jaw movement in terms of both ROM and ACP on the non-deviated side.

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    • Original Article l 2020-01-25

      Accuracy and reliability of measurements performed using two different software programs on digital models generated using laser and computed tomography plaster model scanners

      Leonardo T. Camardella, Edwin M. Ongkosuwito, E. Willemijn Penning, Anne Marie Kuijpers-Jagtman, Oswaldo V. Vilella, and K. Hero Breuning

      Abstract : ObjectiveThe aim of this study was to compare the accuracy and reliability of measurements performed using two different software programs on digital models generated using two types of plaster model scanners (a laser scanner and a computed tomography [CT] scanner).MethodsThirty plaster models were scanned with a 3Shape laser scanner and with a Flash CT scanner. Two examiners performed measurements on plaster models by using digital calipers and on digital models by using Ortho Analyzer (3Shape) and Digimodel® (OrthoProof) software programs. Forty-two measurements, including tooth diameter, crown height, overjet, overbite, intercanine and intermolar distances, and sagittal relationship, were obtained.ResultsStatistically significant differences were not found between the plaster and digital model measurements (ANOVA); however, some discrepancies were clinically relevant. Plaster and digital model measurements made using the two scanning methods showed high intraclass coefficient correlation values and acceptable 95% limits of agreement in the Bland-Altman analysis. The software used did not influence the accuracy of measurements.ConclusionsDigital models generated from plaster casts by using laser and CT scanning and measured using two different software programs are accurate, and the measurements are reliable. Therefore, both fabrication methods and software could be used interchangeably.

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    • Original Article l 2019-09-25

      Predisposing factors for external apical root resorption associated with orthodontic treatment

      Luciana Quintanilha Pires Fernandes , Natália Couto Figueiredo, Carina Cristina Montalvany Antonucci, Elizabeth Maria Bastos Lages, Ildeu Andrade, Jr, and Jonas Capelli Junior

      Abstract : ObjectiveThis study aimed to identify possible risk factors for external apical root resorption (EARR) in the maxillary incisors after orthodontic treatment.MethodsThe root length of 2,173 maxillary incisors was measured on periapical radiographs of 564 patients who received orthodontic treatment. The Kappa test was performed to evaluate intraexaminer and interexaminer reproducibility. Multiple binary logistic regression was used to determine the association between EARR and various factors. Odds ratios and 95% confidence intervals were reported.ResultsThe risk of developing EARR was 70% higher in orthodontic treatment with maxillary premolar extraction (p = 0.004), 58% higher in patients with increased overjet (p = 0.012), 41% lower in two-phase orthodontic treatment (p = 0.037), and 33% lower in patients with deep bite (p = 0.039). The lateral incisors were 54% more likely to develop EARR (p < 0.001), dilacerated roots were 2.26 times more likely to develop EARR (p < 0.001), and for each additional millimeter of root length, the risk of EARR increased by 29% (p < 0.001).ConclusionsThe potential risk factors for EARR after orthodontic treatment included treatment with maxillary premolar extraction, increased overjet at the beginning of treatment, and dilacerated roots.

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    • Original Article l 2019-09-25

      Evaluation of skeletal maturity in the cervical vertebrae and hand-wrist in relation to vertical facial types

      Ye-Seul Lee , Sung-Hwan Choi, Kyung-Ho Kim, and Chung-Ju Hwang

      Abstract : ObjectiveTo evaluate differences in skeletal maturity in relation to vertical facial types and to compare differences in the skeletal maturity of the cervical vertebrae and hand-wrist in females.MethodsThis study included 59 females aged 7 to 9 years with skeletal Class I malocclusion. The participants were categorized into three groups (low, normal, and high) according to the mandibular plane angle. Skeletal maturity was measured using skeletal maturity indicators (SMIs) and the Tanner–Whitehouse III (TW3) method on hand-wrist radiographs and by using cervical vertebrae maturation indicators (CVMIs) on lateral cephalometric radiographs.ResultsThe SMI was higher in the high-angle group than in the low-angle group (p = 0.014). The median TW3 bone age was 11.4 months higher in the high-angle group than in the low-angle group (p = 0.032). There was no significant difference in CVMI among the three groups. Skeletal maturity showed a weakly positive correlation with the mandibular plane angle (SMI, r = 0.391; TW3, r = 0.333; CVMI, r = 0.259).ConclusionsThe skeletal maturity of the hand-wrist in females with a high mandibular plane angle was higher than that in females with a low mandibular plane angle. Obtaining additional hand-wrist radiographs may facilitate evaluation of skeletal maturity of females. In females with a high mandibular angle, the time to commence orthodontic treatment may be earlier than that in females with a low mandibular angle.

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    • Original Article l 2020-03-25

      Sex-, growth pattern-, and growth status-related variability in maxillary and mandibular buccal cortical thickness and density

      Sydney Schneider, Vaibhav Gandhi, Madhur Upadhyay, Veerasathpurush Allareddy, Aditya Tadinada, and Sumit Yadav

      Abstract : ObjectiveThe primary objective of this study was to quantitatively analyze the bone parameters (thickness and density) at four different interdental areas from the distal region of the canine to the mesial region of the second molar in the maxilla and the mandible. The secondary aim was to compare and contrast the bone parameters at these specific locations in terms of sex, growth status, and facial type.MethodsThis retrospective cone-beam computed tomography (CBCT) study reviewed 290 CBCT images of patients seeking orthodontic treatment. Cortical bone thickness in millimeters (mm) and density in pixel intensity value were measured for the regions (1) between the canine and first premolar, (2) between the first and second premolars, (3) between the second premolar and first molar, and (4) between the first and second molars. At each location, the bone thickness and density were measured at distances of 2, 6, and 10 mm from the alveolar crest.ResultsThe sex comparison (male vs. female) in cortical bone thickness showed no significant difference (p > 0.001). The bone density in growing subjects was significantly (p < 0.001) lower than that in non-growing subjects for most locations. There was no significant difference (p > 0.001) in bone parameters in relation to facial pattern in the maxilla and mandible for most sites.ConclusionsThere was no significant sex-related difference in cortical bone thickness. The buccal cortical bone density was higher in females than in males. Bone parameters were similar for subjects with hyperdivergent, hypodivergent, and normodivergent facial patterns.

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    • Original Article l 2020-01-25

      Comparison of three midsagittal planes for three-dimensional cone beam computed tomography head reorientation

      Eon-Hwa Lee, Hyung-Seog Yu, Kee-Joon Lee, Sang-Sun Han, Hwi-Dong Jung, and Chung-Ju Hwang

      Abstract : ObjectiveThis study compared three prominent midsagittal planes (MSPs) to identify the MSP that best approximates the true symmetrical MSP.MethodsForty-three patients (mean age, 23.0 ± 8.20 years) were grouped as follows: group 1 consisted of 10 patients with skeletal Class I and a menton (Me) deviation of < 2 mm; group 2, 11 patients with skeletal Class III and a Me deviation < 2 mm; group 3, nine patients with skeletal Class III and a Me deviation of 2 to less than 4 mm; and group 4, 13 patients with skeletal Class III and an Me deviation ≥ 4 mm. The candidate MSPs were established by three-dimensional (3D) cone beam computed tomography (CBCT) reorientation methods (RMs): (1) the MSP perpendicular to the Frankfort horizontal (FH) plane while passing through the crista galli and basion; (2) the MSP including the nasion, incisive foramen, and basion; (3) the MSP including the nasion, anterior nasal spine, and posterior nasal spine. The mean absolute distances (MADs) to the MSPs were calculated from the coordinates of 1,548 points on 129 CBCT images. The differences in the values of the 3D coordinates among RMs were compared.ResultsThe MADs of the three RMs showed significant differences (p < 0.05). Most of the differences in values of the coordinates were not significant among RMs.ConclusionsAlthough the differences in distance among the three MSPs were minor, the MSP perpendicular to the FH plane while passing through the crista galli and basion best approximated the true symmetrical MSP.

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    • Case Report l 2019-09-25

      Correction of Class III malocclusion with alternate rapid maxillary expansions and constrictions using a hybrid hyrax-mandibular miniplate combination and simultaneous orthodontic treatment: A case report

      Rosana Martínez-Smit, Juan Fernando Aristizabal, and Valfrido Antonio Pereira Filho

      Abstract : In this report, we describe the successful use of alternate rapid maxillary expansions and constrictions with a hybrid hyrax-mandibular miniplate combination and simultaneous orthodontic treatment for the management of severe Class III malocclusion due to maxillary hypoplasia in an 11-year-old girl. The devices were removed after 20 months of treatment, and the family was instructed about a careful control and retention program that should be followed in accordance with the patient's growth. The final result included the correction of Class III malocclusion with adequate function and excellent facial esthetics, which restored the patient's self-esteem and provided personal motivation. The outcomes showed good stability after 24 months of retention. The decrease in the duration of active treatment is the most important finding from the present case. Considering that facial esthetics in adolescence is a determining factor for the development of a personality and interpersonal relationships, we recommend the use of this protocol for growing patients, who will exhibit not only an improved physical appearance but also a better quality of life.

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Journal Info.

March, 2021
Vol.51 No.2

Frequency: 6 times

Journal Impact Factor

  • 1.476
    2018 IF

  • 1.523
    5-Year IF

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Clinical Journal of Korean Association of Orthodontists