• The korean journal of orthodontics
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• v.14 no.1
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• pp.15-24
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• 1984

The purpose of this study was to evaluate the effect of O.M.A on Angle's class III malocclusion. The author analysed the data obtained from pre- and post-treatment lateral cephalograms. The results obtained were as follows : 1. Forward growth of maxillary complex was accomplished. 2. The mandible showed few morphological changes in the presence of downward and backward swing. 3. It was assumed that the hooks attached to the intraoral appliance should be placed as far frontally as possibie. 4. Relations of the upper and lower jaws were improved resulting in better facial profiles.

• The korean journal of orthodontics
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• v.28 no.3 s.68
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• pp.479-486
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• 1998

Bimaxillary Protrusion can be treated effectively in growing patients and in adults with conventional orthodontic therapy. However, In the adult patient, combined surgical and orthodontic treatment modalities may offer distinct advantages over such conventional therapy. In those cases complicate by vertical jaw dysplasia, sagittal dysplasia, or transverse skeletal discrepancy in addition to bimaxillary protrusion, the possibilities of obtaining successful results through orthodontic treatment alone greatly diminish. Surgical retraction of both maxillary and mandibular anterior segments with subapical osteotomies and ostectomies in the extraction site may be a good treatment alternative. Treatment time and possible adverse effects of lengthy orthodontic therapy may be reduced and optimum esthetic improvement may be facilitated. On the following cases, patient who had bimaxillary protrusion with Angle class III malocclusion was treated with combined orthodontic - surgical therapy by anterior subapical segmental osteotomies.

• The korean journal of orthodontics
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• v.5 no.1
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• pp.57-63
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• 1975

For the purposes of augmentation of the aid for case analysis and diagnosis of malocclusion, a roentgenocephalometric study was made from 84 Korean adolescences. The Subjects consist of 42 males and 42 females aged from 17 to 20 years with normal occlusion and acceptable facial appearance. The author measured 18 angles and 14 linear distances as suggested by Jarabak. The following results were obtained. 1) Each linear measurement of the males' skull was greaten than that of the females. 2) The posterior to anterior facial height was $69.2\%$ in the males and $67.1\%$ in the females. 3) In the relationship of upper lip to esthetic line, the lip of females was more behind than that of males. 4) Saddle angle was $124.7^{\circ}$, articular angle was $148.7^{\circ}$, genial angle was $119.4^{\circ}$ and upper and lower genial angles were $45.1^{\circ}\;(N-Go-a^{\circ})$ and $74.2^{\circ}\;(N-Go-Me^{\circ})$. 5) The ratio of mandibular body to anterior cranial base was about 1:1. 1. 6) The angulations of $SNA^{\circ},\;SNB^{\circ}\;and\;SNP^{\circ}$ were as follows; $SNA^{\circ},\;80.3^{\circ},\;SNB^{\circ},\;79.8^{\circ},\;SNP^{\circ},\;81.1^{\circ}$. 7) The angle of the sella-nasion plane to the mandibular plane $(SNG^{\circ}Me^{\circ})$ was $32.0^{\circ}$ and that of the occlusal plane to the mandibular plane was $18.2^{\circ}$. 8) The angle of the maxillary central incisor to the sellanasion plane $(1-SN^{\circ})$ was $105.6^{\circ}$. That of the mandibular central incisor to the mandibular plane $(1-GoMe^{\circ})$ was $94.0^{\circ}$, and the interincisal angle $(1\;to\;1^{\circ})$ was $127.6^{\circ}$. 9) The linear distance from incisal edge of upper central incisor to facial plane was 8.0mm and that of lower central incisor was 4.6mm. 10) In the relationship of the lower lip to the esthetic line, the lower lip was 0.2mm front of the esthetic line.

• The korean journal of orthodontics
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• v.48 no.1
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• pp.11-22
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• 2018

Objective: The aim of this study was to determine cephalometric factors that help predict favorable soft-tissue profile outcomes following treatment with the Class II Twin-block appliance. Methods: Pre- and post-treatment lateral cephalograms of 45 patients treated with the Class II Twin-block appliance were retrospectively analyzed. Profile silhouettes were drawn from the cephalograms and evaluated by three orthodontists in order to determine the extent of improvement. Samples were divided into a favorable group (upper 30% of visual analogue scale [VAS] scores, n = 14) and an unfavorable group (lower 30% of VAS scores, n = 14). Skeletal and soft-tissue measurements were performed on the cephalograms and an intergroup comparison was conducted. Results: An independent t-test revealed that the following pre-treatment values were lower in the favorable group compared to the unfavorable group: lower incisor to mandibular plane angle, lower incisor to pogonion distance, point A-nasion-point B angle, sella-nasion line (SN) to maxillary plane angle, SN to mandibular plane angle, gonial angle, and symphysis inclination. The favorable group had a larger incisor inclination to occlusal plane. Moreover, the favorable group showed larger post-treatment changes in gonial angle, B point projection, and pogonion projection than did the unfavorable group. Conclusions: Class II malocclusion patients with a low divergent skeletal pattern and reduced lower incisor protrusions are likely to show more improvement in soft-tissue profile outcomes following Class II Twin-block treatment.

• The korean journal of orthodontics
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• v.48 no.1
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• pp.30-38
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• 2018

Objective: The purpose of this study was to investigate factors influencing the success rate of orthodontic microimplants (OMIs) using panoramic radiographs (PRs). Methods: We examined 160 OMIs inserted bilaterally in the maxillary buccal alveolar bone between the second premolars and first molars of 80 patients (51 women, 29 men; mean age, $18.0{\pm}6.1years$) undergoing treatment for malocclusion. The angulation and position of OMIs, as well as other parameters, were measured on PRs. The correlation between each measurement and the OMI success rate was then evaluated. Results: The overall success rate was 85.0% (136/160). Age was found to be a significant predictor of implant success (p < 0.05), while sex, side of placement, extraction, and position of the OMI tip were not significant predictors (p > 0.05). The highest success rate was observed for OMIs with tips positioned on the interradicular midline (IRML; central position). Univariate analyses revealed that the OMI success rate significantly increased with an increase in the OMI length and placement height of OMI (p = 0.001). However, in simultaneous analyses, only length remained significant (p = 0.027). Root proximity, distance between the OMI tip and IRML, interradicular distance, alveolar crest width, distance between the OMI head and IRML, and placement angle were not factors for success. Correlations between the placement angle and all other measurements except root proximity were statistically significant (p < 0.05). Conclusions: Our findings suggest that OMIs positioned more apically with a lesser angulation, as observed on PRs, exhibit high success rates.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.6 no.1
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• pp.19-22
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• 2010

Cerebral palsy is an umbrella term encompassing a group of non-progressive non-contagious motor conditions that cause physical disability in human development. Motor disorder of cerebral palsy is often accompanied by disturbances of sensation, perception, cognition, communication, behavior and seizure disorder. Disharmony of motor function leads to frequent falling down. Moreover patients have high prevalence of class II malocclusion. Compared to normal patients, the patients with cerebral palsy tends to have high prevalence of recurrent trauma and bruxism which make restoration of the anterior tooth more difficult. This case report is consisted of three cases of cerebral palsy patients who have challenging problems with restoration of anterior teeth.

• Journal of Oral Medicine and Pain
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• v.38 no.3
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• pp.255-260
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• 2013

Bilateral sagittal split ramus osteotomy(BSSRO) of the mandible is an essential and commonly used procedure to correct dentofacial deformities and malocclusion. The possible complications associated with BSSRO include inferior alveolar nerve injury, bleeding, temporomandibular disorder, unfavorable fractures, and clinical relapse. The incidence of facial nerve palsy after orthognathic surgery recently reported is 0.1%. The probable etiologies have included facial nerve compression, complete or incomplete nerve transection, nerve traction, and nerve ischemia from anesthetic injection. Postoperative facial palsy is one of the most serious complications because it reduces the quality of life and significantly reduces social interaction. The case of a 24-year-old patient who underwent bilateral sagittal split ramus osteotomy is described. The medical records and postoperative photographs were reviewed in detail to collect information on the clinical course, treatment, and outcomes.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.5
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• pp.224-231
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• 2015

Objectives: The purpose of this study was to evaluate changes in the pharyngeal airway space and hyoid bone position after mandibular setback surgery with bilateral sagittal split ramus osteotomy (BSSRO) and to analyze the correlation between the amount of mandibular setback and the amount of change in pharyngeal airway space or hyoid bone position. Materials and Methods: From January 2010 to February 2013, a total of 30 patients who were diagnosed with skeletal class III malocclusion and underwent the same surgery (BSSRO) and fixation method in the Division of Oral and Maxillofacial Surgery, Department of Dentistry at the Ajou University School of Medicine (Suwon, Korea) were included in this study. Lateral cephalograms of the 30 patients were assessed preoperatively (T1), immediately postoperatively (T2), and 6 months postoperatively (T3) to investigate the significance of changes by time and the correlation between the amount of mandibular setback and the amount of change in the airway space and hyoid bone position. Results: Three regions of the nasopharynx, oropharynx, and hypopharynx were measured and only the oropharynx showed a statistically significant decrease (P<0.01). A significant posterior and inferior displacement of the hyoid bone was found 6 months after surgery (P<0.01). Analysis of the correlation between the amount of mandibular setback and the amount of final change in the airway space and hyoid bone position with Pearson's correlation showed no significant correlation. Conclusion: In this study, the oropharynx significantly decreased after mandibular setback surgery, and changes in the surrounding structures were identified through posteroinferior movement of the hyoid bone during long-term follow-up. Therefore, postoperative obstructive sleep apnea should be considered in patients who plan to undergo mandibular setback surgery, and necessary modifications to the treatment plan should also be considered.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.5
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• pp.284-294
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• 2012

Objectives: The anterior open bite with temporomandibular disorders (TMD) is one of the most challenging cases both orthodontically and surgically. We introduce an intermaxillary traction treatment for patients with anterior open bite and TMD using a skeletal anchorage system (SAS). Materials and Methods: This study was comprised of 52 patients with anterior open bite and TMD. A total of four mini-screws were inserted, two screws each into the maxilla and mandible, to obtain a class II pattern of elastic application with 120-200 g force. Adjunctive muscle relaxation treatments, such as splint therapy, medication, and botulinum toxin injection were applied during or before intermaxillary traction. At least one treatment among adjunctive muscle relaxation treatment, mentioned above, was applied to 96.2% of patients. We evaluated the clinical characteristics of patients, TMD symptom changes, amount of open bite improved. The degree of open bite improvement was compared between the open bite-reduced group (21 patients) and not-reduced group (5 patients). Results: TMD symptoms (muscle/joint pain, joint sound, mouth opening) remained or improved in most patients, and worsened in about 10% of patients for each items. Anterior open bite was improved by a mean of 1.75 mm (P<0.01) during treatment. The open bite-reduced group exhibited a significant open bite improvement compared to the not-reduced group (P<0.05), with 37% of open bite improvement occurring during the first 3 months of treatment. Conclusion: The intermaxillary traction technique using SAS is a valid modality for correction of anterior open bite and improvement of TMD symptoms.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.6
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• pp.631-635
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• 2007

Purpose: The classic technique for open reduction of subcondylar fractures is the submandibular approach. The aim of this study was to evaluate clinical result of retromandibular approach to displaced subcondylar fractures. Material and methods: During a period of 24months we perfomed a prospective study with a retromandibular approach in 23 patients with displaced subcondylar fractures. In this article we describe clinical result in 23 patients with follow ups for 3 months after surgery. Preoperatively all patients had malocclusion and radiology demonstrated displacement. Result: The retromandibularl approach for ORIF was good in all case. Mouth opening(M/O) was 49mm. Occlusion was good too. Permanent facial nerve palsy was not detected. Conclusion: Our findings indicate that the retromandibular approach is a safe technique for subcondylar fractures.