• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.3
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• pp.139-144
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• 2012

This study was performed in order to evaluate the occurrence of temporomandibular joint disorder after surgical correction of skeletal class II malocclusion. Materials and Methods: This study included 21 patients who underwent orthognathic surgery for the correction of dentofacial deformities by a single surgeon at Mokdong Hospital, Ewha Womans University from 2000 to 2010. They underwent bilateral sagittal split ramus osteotomy for the treatment of undesirable mandibular advancement. The temporomandibular disorder (TMD) symptoms prior to surgery were recorded and the radiographic evaluation (panorama, bone scan, and magnetic resonance imaging [MRI]) of the post-surgery temporomandibular joint (TMJ) were assessed in order to evaluate condylar resorption, remodeling and disc displacement. The minimum follow-up period, including orthodontic treatment, was 12 months. Orthognathic procedures included 1-jaw surgery (n=8 patients) and 2-jaw surgery (n=13 patients). The monocortical plate was used for bilateral sagittal split ramus osteotomy fixation. Results: Among class II malocclusion patients with TMD symptom, clicking improved in 29.1%, and maximum mouth opening increased from $34.5{\pm}2.1$ mm to $37.2{\pm}3.5$ mm. The differences were not statistically significant, however. Radiographic changes in bone scan improved slightly based on the report by radiologist but not in TMJ dynamic MRI. Conclusion: No particular improvements were found in patients with joint sound only. Patients with limitation of mouth opening showed an increase in the degree of opening, but the difference was not statistically significant (P>0.05).

• The korean journal of orthodontics
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• v.54 no.3
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• pp.171-184
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• 2024

Objective: This study aimed to determine the maxillary and mandibular basal bone regions and explore the three-dimensional positional relationship between the dentition and basal bone regions in patients with skeletal Class I and Class II malocclusions with mandibular retrusion. Methods: Eighty patients (40 each with Class I and Class II malocclusion) were enrolled. Maxillary and mandibular basal bone regions were determined using cone-beam computed tomography images. To measure the relationship between the dentition and basal bone region, the root position and root inclination were calculated using the coordinates of specific fixed points by a computer program written in Python. Results: In the Class II group, the mandibular anterior teeth inclined more labially (P < 0.05), with their apices positioned closer to the external boundary. The apex of the maxillary anterior root was positioned closer to the external boundary in both groups. Considering the molar region, the maxillary first molars tended to be more lingually inclined in females (P = 0.037), whereas the mandibular first molars were significantly more labially inclined in the Class II group (P < 0.05). Conclusions: Mandibular anterior teeth in Class II malocclusion exhibit a compensatory labial inclination trend with the crown and apex relative to the basal bone region when mandibular retrusion occurs. Moreover, as the root apices of the maxillary anterior teeth are much closer to the labial side in Class I and Class II malocclusion, the range of movement at the root apex should be limited to avoid extensive labial movement.

• Korean Journal of Cleft Lip And Palate
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• v.20 no.1
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• pp.49-58
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• 2017

We report the rehabilitation of Class II malocclusion with multiple teeth fracture due to trauma. A multidisciplinary team approach was necessary to treat patient's problems such as bone fracture, malocclusion, and multiple teeth fracture. Emergency conservative treatment, orthodontic treatment and prosthetic restoration successfully restored the occlusion. However, special considerations were needed along the orthodontic treatment process due to the unexpected complications such as ankylosis, root resorption and detection of additional teeth fractures.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.3
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• pp.496-503
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• 2001

Maxilla overgrowth who diagnosis with skeletal Class II division 1 have transverse and also sagittal problem. If maxillary growth vector is direction to anterior inferior, mandible is rotation to clockwise pattern and it disturbance it's anterior growth. At this time, treatment goal is restrict of maxillary growth to accomplish ideal intermaxillary relation and one of treatment choice is the application of extraoral force. This report is 3 case treated by activator and headgear combination therapy, who diagnosed with skeletal Class II div. 1 malocclusion.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.17.1-17.5
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• 2019

Background: Class II malocclusion patients with hyperdivergent facial types are characterized by short mandibular body lengths and anterior open bite. Accordingly, the treatment for hyperdivergent skeletal class II malocclusion is a lengthening of the mandibular body length and a counterclockwise rotation of the mandible. To prevent post-operative relapse, botulinum toxin-A (BTX-A) injection can be a retention modality. Case presentation: A class II open-bite patient received BTX-A injection to the anterior belly of her digastric muscle for the prevention of post-operative relapse. The relapse was evaluated via a clinical examination and a lateral cephalometric radiograph after the completion of post-surgical orthodontic treatment. The patient showed stable occlusion without any signs of relapse at 15 months post-operatively. Conclusion: In this case presentation, a single injection into the anterior belly of the digastric muscle was sufficient for the prevention of post-operative open bite.

• The korean journal of orthodontics
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• v.50 no.3
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• pp.170-180
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• 2020

Objective: To compare short- and long-term dentoalveolar, skeletal, and rotational changes evaluated by Björk's structural method of superimposition between children with Class II malocclusion treated by functional appliances and untreated matched controls. Methods: Seventy-nine prepubertal or pubertal children (mean age, 11.57 ± 1.40 years) with Class II malocclusion were included. Thirty-four children were treated using an activator with a high-pull headgear (Z-activator), while 28 were treated using an activator without a headgear (E-activator). Seventeen untreated children were included as controls. Lateral cephalograms were obtained before treatment (T1), after functional appliance treatment (T2), and after retention in the postpubertal phase (T3). Changes from T1 to T2 and T1 to T3 were compared between the treated groups and control group using multiple linear regression analysis. Results: Relative to the findings in the control group at T2, the sagittal jaw relationship (subspinale-nasion-pogonion, p < 0.001), maxillary prognathism (sella-nasion-subspinale, p < 0.05), and condylar growth (p < 0.001) exhibited significant improvements in the Z- and E-activator groups, which also showed a significantly increased maxillary incisor retraction (p < 0.001) and decreased overjet (p < 0.001). Only the E-activator group exhibited significant backward rotation of the maxilla at T2 (p < 0.01). The improvements in the sagittal jaw relationship (p < 0.01) and dental relationship (p < 0.001) remained significant at T3. Condylar growth and jaw rotations were not significant at T3. Conclusions: Functional appliance treatment in children with Class II malocclusion can significantly improve the sagittal jaw relationship and dental relationships in the long term.

• The korean journal of orthodontics
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• v.34 no.3 s.104
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• pp.229-240
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• 2004

The purpose of this study was to evaluate the compensatory changes of occlusal plane angle in relation to skeletal factors. Lateral cephalograms of 61 adults with normal occlusion and 92 adults with skeletal malocclusions were traced and measured to analyze skeletal factors and occlusal plane angles. In terms of horizontal relationships, the normal occlusion group and malocclusion group were classified Into subgroups of skeletal Classes I, II, and III, while in terms of vertical relationships, each group was also classified into horizontal , average, and vertical subgroups. Some measurements were evaluated statistically by ANOVA and Post Hoc, and the others were reviewed by Paired t-tests. In this study, only the occlusal plane angle to AB plane did not show a significant difference between the normal occlusion group and malocclusion group. After treatment, the occlusal plane angle to the AB plane of the malocclusion group was approximated to that of normal occlusion group. The LOP to AB plane angle of the normal occlusion group was 91.7 in skeletal Class I, 88.8 in skeletal Class II, and 93.5 in skeletal Class III. This study was done to assess the treatment changes of the occlusal plane in the malocclusion group, and to draw a comparison with the normal occlusion group in order to present a reference to establish a new occlusal plane inclination.

• The korean journal of orthodontics
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• v.18 no.1 s.25
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• pp.235-252
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• 1988

The quadrilateral analysis is a proportional analysis which evaluates the skeletal configuration of lower face on the relations between both jaws in the horizontal as we]1 as vortical dimensions. This study was undertaken to analyse the harmony and disharmony of quadrilateral patterns in normal occlusion and malocclusion. The present study was carried out on lateral cephalograms of 530 Korean children; the subjects consisted of 135 normal occlusions (63 male and 72 female), 105 Class II division 1 malocclusions (52 male and 53 female), 109 Class III malocclusions (50 male and 59 female), 91 hypodivergent facial types (44 male and 47 female) and 90 hyperdivergent facial types (45 male and 45 female). The following conclusions were reached: 1. Means and standard deviation in each group and sex were obtained from normal occlusion and malocclusion. 2. Quadrilateral mean diagram in normal occlusion was constructed for male and female, respectively. 3. In normal occlusion, 1:1 ratio exists between the maxillary base length (A' to Ptm') and mandibular base length (B' to J'), but lower facial height is targer than above. 4. Difference is effective to estimate the degrees of Class II and Class III malocclusion, and lower facial height (LFH) and sagittal angle is effective to recognize the hypodivergent and hyperdivergent facial type. 5. Quadrilateral analysis is able to visualize the anteroposterior and vertical dysplasia of lower face, and it is helpful to recognize certain problems in malocclusion.

• The korean journal of orthodontics
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• v.50 no.2
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• pp.98-107
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• 2020

Objective: The aim of this study was to compare posterior tooth inclinations, occlusal force, and contact area of adults with different sagittal malocclusions. Methods: Transverse skeletal parameters and posterior tooth inclinations were evaluated using cone beam computed tomography images, and occlusal force as well as contact area were assessed using pressure-sensitive films in 124 normodivergent adults. A linear mixed model was used to cluster posterior teeth into maxillary premolar, maxillary molar, mandibular premolar, and mandibular molar groups. Differences among Class I, II, and III groups were compared using an analysis of variance test and least significant difference post-hoc test. Correlations of posterior dental inclinations to occlusal function were analyzed using Pearson's correlation analysis. Results: In male subjects, maxillary premolars and molars had the smallest inclinations in the Class II group while maxillary molars had the greatest inclinations in the Class III group. In female subjects, maxillary molars had the smallest inclinations in the Class II group, while maxillary premolars and molars had the greatest inclinations in the Class III group. Occlusal force and contact area were not significantly different among Class I, II, and III groups. Conclusions: Premolar and molar inclinations showed compensatory inclinations to overcome anteroposterior skeletal discrepancy in the Class II and III groups; however, their occlusal force and contact area were similar to those of Class I group. In subjects with normodivergent facial patterns, although posterior tooth inclinations may vary, difference in occlusal function may be clinically insignificant in adults with Class I, II, and III malocclusions.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.3
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• pp.637-649
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• 1997

Early orthodontic treatment in growing children requires the removable orthodontic appliances. The removable orthodontic appliance can be used in the primary dentition and mixed dentition. The purposes of use of removable orthodontic appliance in prmary dentition or mixed dentition are the interception of skeletal or dental malocclusion, guiding the normal dentition, and retention after comprehensive orthodontic treatment. Therefore, it is needed to use the removable orthodontic appliance in children with malocclusion. This report presents cases of growing children with skeletal class II and III malocclusion treated with removable orthodontic appliance during mixed dentition and Multiloop Edgewise Arch Wire(MEAW) during permanent dentition. The results obtained through these cases were summarized as follows : 1. Removable orthodontic appliances guide normal dentition and skeletal growth in growing children. 2. Removable orthodontic appliances play an important role in intercepting malocclusion in mixed dentition before use of fixed orthodontic appliance. 3. MEAW can be applied to finishing stage of all cases and is effective in correction of occlusal plane, achievement of interdigitation, and control of dental inclination. 4. It is needed that removable appliances are used during mixed dentition through correct diagnosis and fixed appliance are used in permanent dentition.