• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.93-104
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• 2000

Orthodontic treatment in conjunction with second-molar extraction has been a controversial issue among orthodontists over many decades. The aim of this study was to investigate the treatment effects of upper second molar extraction cases. The sample included 19 upper second molar extraction orthodontic cases(ten Angle's Class I's and nine Class II's, average age=13Y 6M) cared at Kyung-Hee University Department of Orthodontics. Lateral cephalometric radiographs were taken before and immediately after treatment. Seventy-nine points were digitized on each cephalogram and 38 cephalometric parameters were computed comprising 22 angular measurements, 13 linear measurements, and 3 facial proportions. The data obtained from each malocclusion group were analyzed by paired t-test. The statistical results disclosed that there was no significant change in skeletal pattern after treatment except for that accountable by growth while there was statistically significant change in dentoalveolar and soft tissue patterns. There were no significant changes in Bjork sum, posterior facial height /anterior facial height and lower anterior facial height /anterior facial height. No significant changes in anteroposterior position of maxilla and palatal plane were manifested. Although facial axis and lower facial height was slightly increased and the mandible was rotated backward and downward, there was no remarkable change in the mandibular plane. There were statistically significant changes in distal movement of upper first molar, molar key correction and overjet reduction while there was no change in the occlusal plane. The upper lip was slightly retracted simultaneously with slight increase in nasolabial angle. These results signify that distalization of upper dentition with the second molar extraction does change occlusal relationship without gross modifications in the craniofacial skeletal configurationson. Henceforth the second molar extracted would be recommended to treat severe anterior crowding and protrusion with minor skeletal discrepancy.

• Journal of Korean society of Dental Hygiene
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• v.15 no.2
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• pp.205-216
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• 2015

Objectives: The purpose of the study is to investigate the psychological state of the patients according to skeletal class III malocclusion symptoms. Methods: The subjects were 200 skeletal class III malocclusion patients. The questionnaire consisted of general characteristics, clinical manifestation, and T score of Korean version of self-rated Symptom Checklist-90-Revision modified by Jae-hwan Kim. The data were analyzed using SAS version 9.2 and t-test, ANOVA, and ANCOVA were used. Clinical manifestation included subjective recognition and radiological analysis. The subjective recognition of the patients consisted of self-satisfaction of the appearance, phonation, mastication, and temporomandibular joint pain. T score consisted of somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism. Results: The most serious factor in 9 scales was the severe TMJ pain by ANCOVA. Male patients had a higher T score in phobic anxiety, psyochoticism, somatization and depression than female patients. Those having low appearance satisfaction had the problem in interpersonal sensitivity. Obsessive-compulsive symptoms were conspicuous in phonation difficulty and temporomandibular pain. Conclusions: The patients with skeletal class III malocclusion have more satisfaction with appearance, pronunciation, and phonation than those with skeletal class III malocclusion and overjet. Proper dental treatment will improve the communication and quality of life.

• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.393-399
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• 1995

Mandibular retrusion showing the facial problem with a marked maxillarry incisors protrusion and chin deficiency, resulting in a highly convex profile is uncommon in Korea.. The large incisor overjet and deep-bite create functional limitations and unpleasing esthetic result. The majority of theses cases are susceptible to correction by orthodontic therapeutic methods. But severe Class II retrognathic cases in which orthodontic treatment alone has not been capable of achieving good results. Orthognathic surgery offers several approaches. In this case, mandibular advancement by bilateral sagittal split ramus osteotomy and augmentation genioplasty has a special surgical problems. The suprahyoid muscle gorup are lengthened if the body of the mandible is surgically repositioned anteriorly. Instability of results and relapse return to original position shoud predicted during post-surgical muscular readjustment.. To maintain maximum correction with this technique, it is suggested that the mandibular body be well rotated forward at time of surgical intervention and overcorrected anteriory as much as possible. So, the authors report the case with review of concerned literature.

• The korean journal of orthodontics
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• v.49 no.6
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• pp.413-426
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• 2019

This study was performed to describe the longitudinal management of recurrent temporomandibular joint (TMJ) ankylosis from infancy to adulthood in perspective of surgical and orthodontic treatment. A 2-year-old girl was referred with chief complaints of restricted mouth opening and micrognathia due to bilateral TMJ ankylosis. For stage I treatment during early childhood (6 years old), high condylectomy and interpositional arthroplasty were performed. However, TMJ ankylosis recurred and symptoms of obstructive sleep apnea (OSA) developed. For stage II treatment during early adolescence (12 years old), gap arthroplasty, coronoidectomy, bilateral mandibular distraction osteogenesis, and orthodontic treatment with extraction of the four first premolars were performed. However, TMJ ankylosis recurred. Because the OSA symptoms reappeared, she began to use a continuous positive airway pressure device. For stage III treatment after completion of growth (20 years old), low condylectomy, coronoidectomy, reconstruction of the bilateral TMJs with artificial prostheses along with counterclockwise rotational advancement of the mandible, genioglossus advancement, and orthodontic treatment were performed. After stage III treatment, the amount of mouth opening exhibited a significant increase. Mandibular advancement and ramus lengthening resulted in significant improvement in the facial profile, Class I relationships, and normal overbite/overjet. The OSA symptoms were also relieved. These outcomes were stable at the one-year follow-up visit. Since the treatment modalities for TMJ ankylosis differ according to the duration of ankylosis, patient age, and degree of deformity, the treatment flowchart suggested in this report could be used as an effective guideline for determining the appropriate timing and methods for the treatment of TMJ ankylosis.

• The korean journal of orthodontics
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• v.51 no.1
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• pp.43-54
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• 2021

Objective: To investigate the cephalometric predictors of the future need for orthognathic surgery in Korean patients with unilateral cleft lip and palate (UCLP) despite long-term use of facemask with miniplate (FMMP). Methods: The sample consisted of 53 UCLP patients treated by a single orthodontist using an identical protocol. Lateral cephalograms were taken before commencement of FMMP therapy (T0; mean age, 10.45 years), after FMMP therapy (T1; mean age, 14.72 years), and at follow-up (T2; mean age, 18.68 years). Twenty-eight cephalometric variables were measured. At T2 stage, the subjects were divided into FMMP-Nonsurgery (n = 33, 62.3%) and FMMP-Surgery (n = 20, 37.7%) groups according to cephalometric criteria (point A-nasion-point B [ANB] < -3°; Wits-appraisal < -5 mm; and Harvold unit difference [HUD] > 34 mm for FMMP-Surgery group). Statistical analyses including discrimination analysis were performed. Results: In FMMP-Surgery group, the forward position of the mandible at T0 stage was maintained throughout the whole stages and Class III relationship worsened with significant growth of the mandibular body and ramus and counterclockwise rotation of the maxilla and mandible at the T1 and T2 stages. Six cephalometric variables at T0 stage including ANB, anteroposterior dysplasia indicator, Wits-appraisal, mandibular body length, HUD, and overjet were selected as effective predictors of the future need for surgical intervention to correct sagittal skeletal discrepancies. Conclusions: Despite long-term use of FMMP therapy, 37.7% of UCLP patients became candidates for orthognathic surgery. Therefore, differential diagnosis is necessary to predict the future need for orthognathic surgery at early age.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.2
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• pp.155-159
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• 2022

Cohen syndrome is a rare genetic disorder associated with mutations in the VPS13B gene. Individuals with this disorder present with diverse clinical manifestations, including muscle hypotonia, intellectual disabilities, and typical facial characteristics, such as prominent upper central incisors and micrognathia. General anesthesia was administered to a 23-year-old man with Cohen syndrome. Although we observed prominent upper central incisors, an overjet of 10 mm, micrognathia, and thyromental distance of 4 cm, hypotonia was not observed in the patient. Intubation was rendered difficult when performing a direct laryngoscopy. However, smooth intubation was achieved using a video laryngoscope. The patient's train of four (TOF) count remained zero close to 60 min after rocuronium administration, suggesting that the drug's muscle-relaxant effect may have been prolonged. A TOF ratio of 0.79 was confirmed 130 min after rocuronium administration, and a TOF ratio of 1.0 was confirmed after administration of 150 mg of sugammadex. The patient's respiration remained stable after extubation, and no recurarization of muscle relaxation was observed. As demonstrated in this case report, it is important to closely monitor recovery from muscle relaxation and prepare multiple techniques for airway management in general anesthesia management of patients with Cohen syndrome.

• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.44-55
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• 2007

Objective: Previous studies have reported that morphological features of the first cervical vertebra (atlas) have been associated with mandibular growth direction. The purpose of this study was to show the possible positional and morphological changes of the Atlas from activator treatment in Class II malocclusion patients. Methods: Lateral cephalometric radiograph tracings were made at initial, middle and final stages of treatment. Angular and linear measurements of skeletal and morphological features were measured on the anatomical landmarks and reference planes. Results: The skeletal effects of activator treatment on Class II malocclusion patients were evident on ramal height, body length, effective body length, ANB, and overjet. Clockwise rotation of the long axis of the Atlas was found in Group 1, but there was no inclination change of the Atlas in groups 2 and 3. There was no significant correlation between anterior and posterior positions of the atlas or morphological change in all groups. - except for posterior movements of the Atlas found in group 1. Conclusion: Clockwise rotation of the atlas axis resulted from activator treatment in Cl II malocclusion patients. Change in atlas axis can be thought of as an indicator for success of activator treatment.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.219-237
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• 1999

This study was designed to evaluate the frequency and the severity of root resorption of the permanent teeth before orthodontic treatment by means of radiograph in the malocclusion patients. In this study the author analysed the frequency and the severity of root resorption in individual teeth, the relationships of the frequency and the severity of root resorption and age, sex, Angle's classification, overjet, overbite, and maxillary and mandibular incisor inclination, and the relationships of the frequency of root resorption and the characteristics of malocclusion and marked occlusal attrition showed in individual teeth. The results were as follows. 1. All of the persons examined showed some evidence of root resorption in one or more of the permanent teeth, $35.84\%$ of the teeth examined and more frequent in female group than male group(p<0.01). 2. On the susceptibility of the root resorption in individual teeth in this study, the author found the mandibular incisors and the maxillary incisors, in the order named, to be most susceptible in all affected teeth, but maxillary central incisors, maxillary first bicuspids, and maxillary lateral incisors, in the order named, were more susceptible to marked root resolution. 3. The more proclined maxillary Incisors the more affected root resorption in four maxillary incisors and the more proclined mandibular incisors the more affected root resorption in four mandibular incisors. 4. Overbite more affected root resorption than overjet, and the higher tender to openbite the more frequent was root resorption. 5. On the characteristics of malocclusion showed in individual teeth, the openbite teeth combined with crossbite, were most frequent in root resolution.

• The korean journal of orthodontics
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• v.31 no.5 s.88
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• pp.505-515
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• 2001

The purpose of this study was to measure the average tooth size of Korean with normal occlusion. According to the study, the average tooth ratios between the upper and lower teeth which could assure the proper ovebite, overjet and good interdigitation were calculated. The normal occluson sample of this study consisted of 43 Korean male adults and 51 Korean female adults. Among them, 22 Korean male adults and 51 Korean female adults were from KAO(Korean Association of Orthodontists), 21 Korean male adults were from Department of Orthodontics, College of Dentistry, Yonsei University. The results from this study were as follows : 1 The average tooth size of Korean Norm classified by male and female was measured. 2. The average tooth size of Korean male adults with normal occlusion was significantly larger than that of Korean female adults except upper and lower first molars. (p<0.05) 3. The tooth ratio which could Predict the proper overbite and overjet in anterior teeth and proper occlusion in posterior teeth was calculated. 1) Sum of inciosrs = 4:2.97 2) Neff's anterior coefficient = 1.22 3) Bolton's anterior ratio = 78.29%, overall ratio = 91.14% 4. A positive correlation was observed between the sum of lower anterior incisors and the sum of unilateral canine and premolars In each jaw. Based this correlation, the regression equation was made which could Predict the sum of unerupted unilateral canine and premolars in mired dentition. 1) Sum of unilateral unerupted upper canine and premolars' width = 10.435018 + 0.513346 ${\times}$ (sum or lower 4 incisors' width) 2) Sum of unilateral unerupted lower canine and premolars' width = 9.654002 + 0.502565 ${\times}$ (sum of lower 4 incisors' width)

• Journal of Oral Medicine and Pain
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• v.35 no.1
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• pp.61-73
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• 2010

The aim of this study was to investigate clinical assessment and cephalometric characteristics in 10s patients with condylar resorption, who visited in the Department of Oral Medicine Kyungpook National University Hospital at 2006, by use of panorama, transcranial view and lateral cephalometric radiograph. The results were as follows; 1. Clinical assessment 1) Total number of patients were 59. Female was 47 and male was 12, Females were predominant and patient's age ranged from 12 to 19. 2) Most of the patients had Grade II condyle resorption. 3) The number of who had Class I occlusion was 27, which was the largest group. The number of patients with openbite was 20. Average overjet was 3.58mm and average overbite was 0.97mm. 4) Most of the patients had parafunctional habit. 5) The patients of showing the pain in condylar resortion was 41 and the case of not showing the pain was 18. 6) Treatment duration of 23 patients were less than 1 month, 28 patients were treated with supported therapy. 2. Cephalometric Characteristics 1) A 16-year-old female patients showed smaller SNA, SNB and larger articular angle significantly as compared with those of normal group. 2) A 17-year-old female patients showed smaller SN, SAr, TPFH, ramus height and larger SN-GoMe, FMA, articular angle significantly as compared with those of normal group. 3) Over 18 years old female patients showed smaller SN, SNB, TPFH, ramus height and larger ANB, FMA, SN-GoMe, LAFH, articular angle, gonial angle significantly as compared with those of normal group. 4) Over 18 years old male patients showed smaller SN, TPFH, ramus height and larger FMA, SN-GoMe, LAFH, articular angle, gonial angle significantly as compared with those of normal group. 5) There was no significant difference between 10s and normal group in mandibular body length.