• The korean journal of orthodontics
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• v.47 no.2
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• pp.142-147
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• 2017

The purpose of this study was to investigate immediate changes in the mandibular dentition after maxillary molar distalization using headgear in non-growing patients. Sixteen patients (mean age, $18.9{\pm}2.0$ years) with Class II molar relationship and crowding were included in the present study. To correct the molar relationship, headgear was used for maxillary molar distalization. Cone-beam computed tomography-generated half-cephalograms (CG Cephs) and dental casts were used to evaluate dental changes for each subject before and immediately after molar distalization using headgear. The mean duration that subjects wore the headgear was 6.3 months. CG Cephs showed that the first maxillary molars were distalized $4.2{\pm}1.6\;mm$ with $9.7^{\circ}{\pm}6.1^{\circ}$ of distal angulation. The intercanine, interpremolar, and intermolar widths of the mandible increased after maxillary molar distalization. The present study's results suggest that maxillary molar distalization using headgear induces a spontaneous response in the untreated mandibular dentition of non-growing patients.

• 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.486-490
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• 1994

Maxillary first molar is the key in normal occlusion. Mesial drifting of maxillary first molar result form early loss of second deciduous molar. Mesial drifted maxillary first molar was treated by headgear, Hawley appliance with screw, brasswire, etc. But, these appliance should be necessary for patients cooperation. Recently, several appliance for molar distalizing without patients cooperation has been introduced. We are reporting in this paper about distalizing of mesial drifted maxillary first molar because of early loss of deciduous second molar by open coil jig. Distalization of molar by open coil jig is predictable, rapid, painless method without mecesscity of patient cooperation.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.3
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• pp.523-531
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• 2008

Maxillary molar distalization is a treatment approach for patients with Class II malocclusions who do not require extractions and mesial movements of mandibular molars. The pendulum appliance is effective for distalization of the maxillary molars and independent of patient cooperation. This appliance can stabilize the maxillary premolars and use the palatal rugae area as an additional anchorage. However, caution is needed to control collateral effects, including increase of lower facial height, incisor protrusion and damage to the rugae area. This article reports the cases in which maxillary molar distalization achieved by pendulum appliance resolves the space problems and corrects the molar relationships.

• The korean journal of orthodontics
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• v.45 no.2
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• pp.82-88
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• 2015

Objective: The aim of this study was to evaluate the reliability of measurements obtained after the superimposition of three-dimensional (3D) digital models by comparing them with those obtained from lateral cephalometric radiographs and photocopies of plaster models for the evaluation of upper molar distalization. Methods: Data were collected from plaster models and lateral cephalometric radiographs of 20 Class II patients whose maxillary first molars were distalized with an intraoral distalizer. The posterior movements of the maxillary first molars were evaluated using lateral cephalometric radiographs (group CP), photocopies of plaster models (group PH), and digitized 3D models (group TD). Additionally, distalization and expansion of the other teeth and the degrees of molar rotation were measured in group PH and group TD and compared between the two groups. Results: No significant difference was observed regarding the amount of molar distalization among the three groups. A comparison of the aforementioned parameters between group PH and group TD did not reveal any significant difference. Conclusions: 3D digital models are reliable to assess the results of upper molar distalization and can be considered a valid alternative to conventional measurement methods.

• The korean journal of orthodontics
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• v.46 no.1
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• pp.55-61
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• 2016

Skeletal anchorage-assisted upper molar distalization has become one of the standard treatment modalities for the correction of Class II malocclusion. The purpose of this study was to analyze maxillary molar movement patterns according to appliance design, with the simultaneous use of buccal fixed orthodontic appliances. The authors devised two distinct types of midpalatal miniscrew-assisted maxillary molar distalizers, a lingual arch type and a pendulum type. Fourteen patients treated with one of the two types of distalizers were enrolled in the study, and the patterns of tooth movement associated with each type were compared. Pre- and post-treatment lateral cephalograms were analyzed. The lingual arch type was associated with relatively bodily upper molar distalization, while the pendulum type was associated with distal tipping with intrusion of the upper molar. Clinicians should be aware of the expected tooth movement associated with each appliance design. Further well designed studies with larger sample sizes are required.

• The korean journal of orthodontics
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• v.46 no.5
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• pp.290-300
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• 2016

Objective: This study aimed to (1) evaluate the effects of maxillary second and third molar eruption status on the distalization of first molars with a modified palatal anchorage plate (MPAP), and (2) compare the results to the outcomes of the use of a pendulum and that of a headgear using three-dimensional finite element analysis. Methods: Three eruption stages were established: an erupting second molar at the cervical one-third of the first molar root (Stage 1), a fully erupted second molar (Stage 2), and an erupting third molar at the cervical one-third of the second molar root (Stage 3). Retraction forces were applied via three anchorage appliance models: an MPAP with bracket and archwire, a bone-anchored pendulum appliance, and cervical-pull headgear. Results: An MPAP showed greater root movement of the first molar than crown movement, and this was more noticeable in Stages 2 and 3. With the other devices, the first molar showed distal tipping. Transversely, the first molar had mesial-out rotation with headgear and mesial-in rotation with the other devices. Vertically, the first molar was intruded with an MPAP, and extruded with the other appliances. Conclusions: The second molar eruption stage had an effect on molar distalization, but the third molar follicle had no effect. The application of an MPAP may be an effective treatment option for maxillary molar distalization.

• The korean journal of orthodontics
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• v.45 no.5
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• pp.236-244
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• 2015

Objective: The aim of this study was to investigate three-dimensional molar displacement after distalization via miniscrews and a horizontal modification of the trans-palatal-arch (TPA). Methods: The subjects in this clinical trial were 26 Class II patients. After the preparation of a complete set of diagnostic records, miniscrews were inserted between the maxillary 2nd premolar and 1st molar on the palatal side. Elastic modules connected to the TPA exerting an average force of 150-200 g/side parallel to the occlusal plane were applied. Cone-beam computed tomography was utilized to evaluate the position of the miniscrews relative to the adjacent teeth and maxillary sinus, and the direction of force relative to molar furcation. The distances from the central point of the incisive papilla to the mesiopalatal cusps of the 1st maxillary molars and the distances between the mesiopalatal cusps of the left and right molars were measured to evaluate displacement of the maxillary molars on the horizontal plane. Interocclusal space was used to evaluate vertical changes. Results: Mean maxillary 1st molar distalization was $2.3{\pm}1.1mm$, at a rate of $0.4{\pm}0.2mm/month$, and rotation was not significant. Intermolar width increased by $2.9{\pm}1.8mm$. Molars were intruded relative to the neighboring teeth, from 0.1 to 0.8 mm. Conclusions: Distalization of molars was possible without extrusion, using the appliance investigated. The intrusive component of force reduced the rate of distal movement.

• The korean journal of orthodontics
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• v.45 no.4
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• pp.171-179
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• 2015

Objective: To compare dentoalveolar and skeletal changes produced by the pendulum appliance (PA) and the distal screw appliance (DS) in Class II patients. Methods: Forty-three patients (19 men, 24 women) with Class II malocclusion were retrospectively selected for the study. Twenty-four patients (mean age, $12.2{\pm}1.5years$) were treated with the PA, and 19 patients (mean age, $11.3{\pm}1.9years$) were treated with the DS. The mean distalization time was 7 months for the PA group and 9 months for the DS group. Lateral cephalograms were obtained at T1, before treatment, and at T2, the end of distalization. A Mann-Whitney U test was used for statistical comparisons of the two groups between T1 and T2. Results: PA and DS were equally effective in distalizing maxillary molars (4.7 mm and 4.2 mm, respectively) between T1 and T2; however, the maxillary first molars showed less distal tipping in the DS group than in the PA group ($3.2^{\circ}$ vs. $9.0^{\circ}$, respectively). Moreover, significant premolar anchorage loss (2.7 mm) and incisor proclination ($5.0^{\circ}$) were noted in the PA group, whereas premolar distal movement (1.9 mm) and no significant changes at the incisor ($0.1^{\circ}$) were observed in the DS group. No significant sagittal or vertical skeletal changes were detected between the two groups during the distalization phase. Conclusions: PA and DS seem to be equally effective in distalizing maxillary molars; however, greater distal molar tipping and premolar anchorage loss can be expected using PA.

• The korean journal of orthodontics
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• v.40 no.3
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• pp.195-206
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• 2010

The aim of this report is to present an intraoral upper molar distalization system supported with zygomatic anchorage plates (Zygoma-gear Appliance, ZGA). This system was used for a 16-year-old female patient with a Class II molar relationship requiring molar distalization. The system consisted of bilateral zygomatic anchorage plates, an inner-bow and heavy intraoral elastics. Distalization of the upper molars was achieved in 3 months and the treatment results were evaluated from lateral cephalometric radiographs. According to the results of the cephalometric analysis, the maxillary first molars showed a distalization of 4 mm, associated with a distal axial inclination of $4.5^{\circ}$. The results of this study show that an effective upper molar distalization without anchorage loss can be achieved in a short time using the ZGA. We suggest that this new system may be used in cases requiring molar distalization in place of extraoral appliances.