• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.33-41
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• 1996

Retrostpective study of two groups of patients was conducted to evaluate the physiologic drift of the mandibular teeth following the extraction of four first premolars. The concept of physiologic drift, commonly referred to as 'driftodontics', following first premolar extractions has been gaining acceptance in the orthodontic community, the exact nature and amount of drift has not been adequately documented. There were also no guide lines as to when drift should be allowed to now. The purpose of this study was to quantify physiologic drift of the untreated mandibular dentition following extraction of the four first premolars during the early permanent and late permanent dentition stages. The early permanent dentition extraction sample(Group 1) included 26 Patients and the mean age at pretreatment was approximately 13.5 years. The observation period following extraction was approximately 6.96 months. The late permanent dentition extraction sample(Group 2) included 31 patients. The mean age at pretreatment was 21.3 years, followed by a observation period of 7.26 months. During the observation period, except for the extractions, no other mandibular therapy was rendered. Pre-and post-treatment lateral cephalograms and dental casts were analyzed. The obtained results were as follows 1. Group 2 showed marked changes in movements of the mandibular incisors and canines but minimal changes in molars. 2. The amount of changes in movements of the mandibular incisors and canines were significantly greater in Group 1 than in Group 2. The results showed no differences in rates of molar movements between groups. 3. Physiologic drift of the dentition produced desirable changes such as decreased Incisor Irregularity.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.404-411
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• 2022

The patient in this case was an 80-year-old female who had lost #16, 13, 26, 37, 36, 35, 44, 45, 46, 47 teeth. The patient showed loss of posterior support, loss of vertical dimension of occlusion, and deep anterior overbite. Her chief complaint was esthetic and functional discomfort. She wanted to restore normal facial aesthetic shape and masticatory function through prosthetic treatment. Clinical evaluation, radiographic examinations, and facial and oral analysis were performed. Interocclusal rest space was excessive than the average. Distance between labial vestibules and zenith of central incisors, and lower facial ratio were below the average. Taken together, occlusal rehabilitation was determined through increasing 4 mm of vertical dimension on premolars. In this case, a patient who lacked restoration space with deep bite in the anterior region due to loss of the posterior teeth support restored a stable occlusal relationship and harmonious anterior and lateral guidance through fixed and removable prosthesis with increased vertical dimension.

• The korean journal of orthodontics
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• v.30 no.4 s.81
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• pp.387-398
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• 2000

This study was aimed to observe the effect of Anterior J hook headgear on the craniofacial structures in mixed dentition with Class II malocclusion. The laterial cephalograms of 20 children treated by Anterior J hook headgear were traced, digitized and statistically analyzed. The results were as follows : 1. Forward growth of maxilla was inhibited. 2. Rotational effect of maxilla was not observed. 3. There was distal movement of maxillary dentition. 4. Maxillarly_dentoalveolar growth changes were more effective in anterior portion than posterior portion. 5. Mandible maintained a normal growth and mandibular plane angle was maintained during treatment period. 6. The ratio of anterior facial height to posterior facial height was almostly not changed.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.855-864
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• 1998

The purposes of this study were to evaluate the cephalometric characteristics of Korean female patients with Class II division 2 malocclusion and to compare Korean females with Caucasian females who had same type of malocclusion. All of the samples had Class II division 2 malocclusion with deep overbite (more than 4mm) and full permanent dentition. These samples were divided into two groups according to the races: Group 1(N=16; Korean females; average age=18Y 2M) and Group 2 (N:20; Caucasian females; average age=14Y 2M). The pretreatment lateral cephalograms were measured, analyzed and compared by using 38 variables and independent t-test. And the results were as follows: 1. Although there were no differences in Overbite, SN to mandibular plane angle, Palatomandibular plane angle, and FMA between Group 1 and 2, the other vertical relation variables of maxilla and mandible (SN to palatal plane angle, SN to occlusal plane angle, ODI) of Group 1 showed more clockwise rotation tendency of occlusal plane and less hypodivergency tendency than those of Group 2. 2. There were no differences in mandibular body length and ramus height between Group 1 and 2 except small upper genial angle of Group 1. There was less counterclockwise rotation tendency of mandible in Group 1. 3. There were no statistical significant differences in UAFH/LAFH and PFH/AFH between Group 1 and 2. 4. Although there were no differences of overjet and anteroposterior position of mandible between Group 1 and 2, the position of maxilla of Group 1 was more retropositioned than that of Group 2. 5. Except the more protrusion of lower incisor to A-Pog of Group 1, there were no differences of inclination and distance of upper and lower incisors to basal plane between Group 1 and 2. 6. The distance from upper- first molar to palatal plane showed no difference between Group 1 and 2. But the distance from lower first molar to mandibular plane of Group 1 was greater than that of Group 2. So it may be partially related to the clockwise rotation of occlusal plane and the less counterclockwise rotation tendency of mandible of Group 1. 7. Group 1 had more protrusive upper and lower lips than Group 2.

• 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)

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.359-372
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• 1997

This study was conducted to discern differences of craniofacial, dentoalveolar structure and model measurements between sex and between class n openbite group and non-openbite group. The sample consisted of 49 adult patients with class Il malocclusion. 24 linear measurements, 22 angular measurements and 12 ratios were selected in lateral cephalometry. Also, arch width, length, anterior crowding, average molar relation were measured or calculated in diagnostic model. The data were evaluated by t-test and multiple discriminant analysis. The results were as follows, 1. Most linear measurements, with the exception of MnBL and AUDH, were significantly larger in male(p<0.05). but, intermaxillary relations and spatial position of maxilla and mandible relative to cranial base were not different for both sex. 2. With the exception of upper and lower anterior crowding, lower arch width, upper arch length, AMR, male exhibited significantly larger measurements in model analysis (p<0.05). 3. Size differences of maxilla and mandible between openbite and non-openbite group were not significant(p>0.05). but openbite group showed significantly increased genial angle(p<0.05), FH-CoGo(p<0.01), FH-NA(p<0.01) and FH-NB, FH-NPog (p<0.05). 4. ALFH and PUDH were larger(p<0.05) in openbite group. this result served as compensation for the spatial position of mandible relative to cranial base. AUPUDH (p<0.001) and ALPLDH(p<0.05) were lower in openbite group. upper anterior crowding was the only measurement which showed difference between openbite and non-openbite group(p<0.05). 5. For the purpose of classifying adult class n openbite and non-openbite group, multiple discriminant analysis was done genial angle, ALPLDH, AUPUDH, FH-NA were included in multiple discriminant equation. 39 cases($92.86\%$) were correctly classified when applied to the sample used in this study.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.314-320
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• 2017

In the treatment of esthetically important areas such as maxillary anterior teeth, they should be corresponded with surrounding tissues, and shape of the smile line, soft tissue, and hard tissue, also the anatomical shape and proportion of the teeth should be considered as well. Esthetic analysis includes facial analysis which evaluates the proper parallelism between the occlusal plane and the horizontal reference line, dentolabial analysis which assesses the position of the incisal edge and the coherence between the occlusal plane and the commissural line, tooth analysis which evaluates not only esthetics but also morphology and appearance for proper function, and gingival analysis which forms ideal outline of gingival margins. A maxillary anterior diastema can be esthetically restored through the systematic diagnostic approach and treatment planning, and orthodontic, prosthetic, and conservative treatment can be applied for the treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.4
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• pp.419-426
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• 2016

For this research 20 supernumerary teeth impacted in the maxillary anterior have been extracted and pulp cells have been collected from them. From the collected pulp cells, total of 17 (10 males, 7 females) have been selected as subjects. From this research, the run-time of successive culture of the cell from tooth number pulp tissue was $2.91{\pm}0.29$ days. From the gathering of cells from the initial pulp tissue until gaining 80% confluency took $4.53{\pm}0.94$ which was the longest. The following successive cultures took $2.73{\pm}0.32$ days. Average runtime for female was $2.81{\pm}0.27$ days whereas male had average runtime of $2.98{\pm}0.29$ days. Average run-time for inversion was $2.94{\pm}0.30$ days and for normal location, $2.80{\pm}0.20$ days. Average runtime was $2.92{\pm}0.31$ days and other forms took $2.88{\pm}0.22$ days. In the future, follow up research would be needed to evaluate the efficiency of the cells collected from the initial passage and the latter passage as stem-cells and taking into consideration the less than 3 days'time for the subculture, it could be concluded that the research efficiency and fast cultivation would be sufficiently effective.

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.53-63
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• 1996

In order In analyze the occlusion of TMD patient, 73 casts and post eroanterior cephalometric X-rays of patients showing TMD symptoms at first interview were measured and compared that of 30 non-patients . Horizental overjet, vertical overbite, openbite, crossbite, depth of curve of Spee, midline deviation, facial asymmetry, attrition, and TPI were measured and processed statistically The results could be summarized as follows, 1. TMD group showed the highest prevalence in twenties, teens, and before 9 years old group in order, and more prevalent in female than male. 2. There were no statistically significance between two groups of overjet and overbite measurements, but showed significance of 6 classification of anterior tooth relationship between two groups TMD groups. 3. n group had more anterior openbite than normal group but there were no statistically significance between two groups. 4. Anterior crossbite was more prevalent in normal group brit posterior crossbite was more prevalent in TMD group. 5. TMD group showed deeper curve of Spee and there were statistically significance between two groups. 6. TMD group had more attrition than normal group and there were statistically significance beween two groups. 7 TMD group showed more facial asymmetry than normal group. 8. TPI did not showed statistical significance beween two groups. According to the above results, TMD group showed severe and complex mode of malocclusion and this should be carefully regarded when treatment planning and during the treatment of malocclusion.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.3
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• pp.539-547
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• 2008

Apert syndrome is an autosomal dominant condition characterized by craniosynostosis, midface hypoplasia, and syndactyly of the hands and feet. It occurs in about 1 of every 65,000 to 160,000 births and is caused by a mutation in the fibroblast growth factor receptor 2(FGFR2) gene. Apert syndrome typically produces acrobrachycephaly(tower skull). The occiput is flattened, and there is a tall appearance to the fore head. Ocular proptosis is a characteristic finding, along with hypertelorism and downward slanting lateral palpebral fissures. The middle third of the face is markedly retruded and hypoplastic, resulting in a relative mandibular prognathism. The reduced size of the nasopharynx and narrowing of the posterior choana can lead to mouth breathing, contributing to an open-mouth apprance. Three fourths of all patients exhibit either a cleft of the soft palate or a bifid uvula. The maxillary hypoplasia leads to a V-shaped arch and crowding of the teeth. A 6-year-old male patient visited to the Department of Pediatric dentistry, Kangnung National University of Dental Hospital. He visited the hospital to get treatment of carious teeth. The purpose of this report is to present a specific dental manifestations about the apert syndrome.