• Journal of the Korean Academy of Esthetic Dentistry
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• v.31 no.1
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• pp.11-18
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• 2022

Adult patients who need implant and prosthodontic treatment often need treatment to improve the existing occlusion through orthodontic treatment for long-term stable treatment results. However, due to non-aesthetic and uncomfortable orthodontic treatment with orthodontic brackets and wires, many adult patients give up treatment even though they know the need for it. Recently, as digital dentistry has affected all areas of dentistry, clear aligner orthodontic systems have begun to be widely used, and their use is increasing in adults and old-aged people due to the esthetic advantage and convenient oral care. SERAFIN clear aligner system developed in Korea has been developed with the aim of implementing a functional occlusion harmony and is used not only for partial orthodontic treatment but also comprehensive orthodontic treatment. This patient presentation is shown the treatment using SERAFIN clear aligner system for the treatment of patient with TMD, severe extrusion of maxillary second molars, and extracted teeth.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.5
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• pp.64-69
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• 2018

Clear aligners are popular in the field of dental orthodontic treatment because they offer a discreet alternative to braces due to their use of transparent materials. They are formed from flat transparent polymer materials by hot pressed molding. It is necessary to know the mechanical properties of the polymer materials to be able to form the exact shapes of the clear aligners. However, this information is not publicly available. In this study, we present a method to reliably measure the mechanical properties of clear aligner polymer materials and analyze the factors effecting these mechanical properties. First, we surveyed standards related to the mechanical properties of polymer materials to obtain reliable data. Consequently, ISO 527 was selected for use in this study because of the size and thickness of the flat transparent polymer material. The uniaxial tensile tester was constructed and it was verified whether displacement of a crosshead could be regarded as a displacement of gauge-length by optical analysis. Uniaxial tensile tests of three thicknesses from three different companies were performed and each engineering stress-strain curve was measured. Tensile strengths and elastic moduli were obtained by analysis of the stress-strain curves. The tensile strength and elastic modulus of ISO 527 was found to be approximately 50MPa and 2.3GPa, respectively. Both values showed material and thickness dependency.

• The korean journal of orthodontics
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• v.52 no.3
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• pp.210-219
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• 2022

Objective: The purpose of this study was to examine the effectiveness and mechanism of clear aligner therapy for the correction of anterior open bite in adult nonextraction cases. Methods: Sixty-nine adult patients with anterior open bite were enrolled and classified into Angle's Class I, II, and III groups. Fifty patients presented with skeletal open bite (mandibular plane angle [MPA] ≥ 38°), whereas 19 presented with dental open bite. Fifteen cephalometric landmarks were identified before (T1) and after (T2) treatment. The magnitudes of planned and actual movements of the incisors and molars were calculated. Results: Positive overbite was achieved in 94% patients, with a mean final overbite of 1.1 ± 0.8 mm. The mean change in overbite was 3.3 ± 1.4 mm. With clear aligners alone, 0.36 ± 0.58 mm of maxillary molar intrusion was achieved. Compared with the Class I group, the Class II group showed greater maxillary molar intrusion and MPA reduction. The Class III group showed greater mandibular incisor extrusion with no significant vertical skeletal changes. Conclusions: Clear aligners can be effective in controlling the vertical dimension and correcting mild to moderate anterior open bite in adult nonextraction cases. The treatment mechanism for Class III patients significantly differed from that for Class I and Class II patients. Maxillary incisor extrusion in patients with dental open bite and MPA reduction with mandibular incisor extrusion in patients with skeletal open bite are the most significant contributing factors for open bite closure.

• 대한치과교정학회:학술대회논문집
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• 2002.11a
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• pp.27.2-28
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• 2002

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.685-693
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• 2007

Class I malocclusion without skeletal problem results from tooth size/arch-size discrepancies, either evidenced by crowding, or spacing problems. Treatment method can be chosen according to dentition, the amount of arch discrepancy, patient compliance, or patient demands. We report of clear aligner and spring aligner that can be applicated in cases of permanent dentition with minimal arch discrepancy in anterior segment. There are some limits of application, but these are very useful appliances in the selective case. When crowding exists, definitive analysis and diagnosis should be made before starting treatment because certain amount of space must be obtained somewhere in the dentition to resolve the crowding. Therefore, appliance should be applied when lacking space is small. Also, in cases with spacing arch circumference is reduced after alignment so no problem in intermaxilla occlusal relationship must be confirmed. In case with crowding, judicious removal of interproximal enamel is indicated.

• The korean journal of orthodontics
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• v.54 no.2
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• pp.117-127
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• 2024

Objective: To evaluate the effect of clear aligner treatment and differential sequence distalization of maxillary posterior teeth on anchorage loss in the upper incisors (U1s). Methods: This study used lateral cephalometries and digital models of 12 patients treated with 33% sequential distalization (group 1, mean age: 22.9 ± 0.7 years, five males, seven females) and 12 treated with 50% sequential distalization (group 2, mean age: 25.83 ± 0.5 years, three males, nine females) acquired before and after distalization of upper second premolars (U5) and upper first molars (U6) and upper second molars (U7). The amount of distalization was determined as 2.5 mm in both the groups. Independent Samples t test was used to compare normally distributed parameters. Mann-Whitney U and Wilcoxon tests were used to compare parameters that were not normally distributed. Results: In both groups, the posterior teeth significantly moved by tipping distally and the U1s were displaced anteriorly. Increase in maxillary posterior transverse width (P < 0.001) and distopalatal rotation were observed in U5, U6, and U7 after distalization. It was also observed that U1 was significantly more proclined (1.82°; P < 0.001) and protruded (0.62 mm; P < 0.001), and the overjet (0.45 mm; P < 0.001) increased more in group 1 than in group 2. Conclusions: After sequential distalization of maxillary posterior teeth, more anchorage loss was observed in the anterior region in group 1 than in group 2.

• The korean journal of orthodontics
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• v.53 no.6
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• pp.420-430
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• 2023

Objective: The purpose of this finite element method (FEM) study was to analyze the biomechanical differences and tooth displacement patterns according to the traction direction, methods, and sites for total distalization of the mandibular dentition using clear aligner treatment (CAT). Methods: A finite element analysis was performed on four FEM models using different traction methods (via a precision cut hook or button) and traction sites (mandibular canine or first premolar). A distalization force of 1.5 N was applied to the traction site by changing the direction from -30 to +30° to the occlusal plane. The initial tooth displacement and von Mises stress on the clear aligners were analyzed. Results: All CAT-based total distalization groups showed an overall trend of clockwise or counterclockwise rotation of the occlusal plane as the force direction varied. Mesiodistal tipping of individual teeth was more prominent than that of bodily movements. The initial displacement pattern of the mandibular teeth was more predominant based on the traction site than on the traction method. The elastic deformation of clear aligners is attributed to unintentional lingual tipping or extrusion of the mandibular anterior teeth. Conclusions: The initial tooth displacement can vary according to different distalization strategies for CAT-based total distalization. Discreet application and biomechanical understanding of traction sites and directions are necessary for appropriate mandibular total distalization.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.32 no.2
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• pp.36-45
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• 2023

The aesthetic appearance of the incisors is essential for a natural and healthy smile, and it is also an important factor for confidence in interpersonal relationships. If there is crowding or protrusion of the anterior teeth, root canal treatment and excessive tooth removal are often required to resolve it in a short period of time. However, it is difficult to achieve sustainable aesthetic results. In this case, orthodontic treatment will be necessary to preserve the remaining tooth structure as much as possible. Middle-aged and elderly patients are often aware of the need for orthodontic treatment, but they are hesitant to use the traditional orthodontic treatment method using brackets because of the social gaze. In this case, clear aligners can be a good option. So, in this article, a case in which aesthetic needs were resolved with clear aligners alone and another case in which satisfactory results were obtained through restorative treatment following clear aligners application are reported.

• Journal of Periodontal and Implant Science
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• v.45 no.6
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• pp.193-204
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• 2015

Purpose: With the increasing prevalence of orthodontic treatment in adults, clear aligner treatments are becoming more popular. The aim of this study was to evaluate the effect of orthodontic treatment on periodontal tissue and to compare orthodontic treatment with fixed appliances (FA) to clear aligner treatment (CAT) in periodontitis patients. Methods: A total of 35 patients who underwent orthodontic treatment in the Department of Periodontology were included in this study. After periodontal treatment with meticulous oral hygiene education, patients underwent treatment with FA or CAT, and this study analyzed patient outcomes depending on the treatment strategy. Clinical parameters were assessed at baseline and after orthodontic treatment, and the duration of treatment was compared between these two groups. Results: The overall plaque index, the gingival index, and probing depth improved after orthodontic treatment (P<0.01). The overall bone level also improved (P=0.045). However, the bone level changes in the FA and CAT groups were not significantly different. Significant differences were found between the FA and CAT groups in probing depth, change in probing depth, and duration of treatment (P<0.05). However, no significant differences were found between the FA and CAT groups regarding the plaque index, changes in the plaque index, the gingival index, changes in the gingival index, or changes in the alveolar bone level. The percentage of females in the CAT group (88%) was significantly greater than in the FA group (37%) (P<0.01). Conclusions: After orthodontic treatment, clinical parameters were improved in the FA and CAT groups with meticulous oral hygiene education and plaque control. Regarding plaque index and gingival index, no significant differences were found between these two groups. We suggest that combined periodontal and orthodontic treatment can improve patients' periodontal health irrespective of orthodontic techniques.

• The korean journal of orthodontics
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• v.52 no.5
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• pp.383-384
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• 2022