• The Journal of Korean Academy of Prosthodontics
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• v.30 no.3
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• pp.338-360
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• 1992

This study was performed to investigate the phonetic alterations with upper anterior teeth were missing. To compare the changes of the phonations, before and after insertion of the temporary prosthesis, six subjects who lost their upper anterior teeth were selected (2-male, 4-female). Tested sounds (/ga(가), na(나), da(다), ra(라), sa(사), ja(자), cha(차), ta(타), pa(파), ha(하), gi(기), ni(니), di(디), ri(리), si(시), jl(지), chi(치), ti(티), pi(피), hi(히), seu(스), se(세), so(소), su(수)/were programmed into an IBM AT with and without temporary prosthesis. These experiments were analyzed by formants, consonants durations, and energy level changes with an LSI speech work station program. During the pronunciation of the tested sounds (with and without temporary prosthesis), mandibular movements were recorded to a Mandibular Kinesiogram and analyzed . The findings led to the following conclusions: 1. Objective differences could not be found. However, in every informant, subjective improvement could be noticed. 2. There were no persistant correlations of the formant's changes. And in every informant, phonetic changes were variable. 3. There were various changes of the consonant durations in every informant. By and large, those of /si(시), jl(지), chi(치), Pi(피), hi(히)/ were longer than other tested sounds. After insertion of the prosthesis, durations were shorter. Consonants with /i(ㅣ)/ were longer than with /a(ㅏ)/, with or without prosthesis. 4. With and without temporary prosthesis, mandibular movements were various in the frontal view. Mandibular movements showed lateral deviations, and mandibular positions with /si(시), ji(지), ti(티), seu(스), hi(히)/ were nearer to the mandibular rest position. 5. The kinds of temporary prosthesis and conditions of the missing teeth influenced every informant variously, so there were no correlation between informants. 6. Energy levels increased in all tested sounds with a fixed temporary prosthesis. And, there were no differences between before and after insertion of a removable temporary prosthesis. However, sibilant sounds, and consonants with /i(ㅣ)/ showed a little increased energy level.

• The korean journal of orthodontics
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• v.17 no.1
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• pp.73-83
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• 1987

The purpose of this longitudinal study was to examine the growth changes of mandibular symphysis and lower incisors with age. The material was 294 lateral cephalometric radiographs taken longitudinally from 6 to 13 year old children, who were not teated orthodontically. The following conclusions seem to be warranted. 1. The sex difference of the measurements of mandibular symphysis and lower incisors were not statistic ally significant. 2. There were growth increments (2.69mm in boys and 2.08mm in girls) in the total thickness of mandibular symphysis. 3. There were a great change and individual variations on the curvature of anterior border of mandibular symphysis. 4. The chin angle had a tendency to decrease progressively in both sexes. 5. There were growth increments (8.23mm in boys and 7.40mm in girls) in the anterior dental height. 6. The lower anterior teeth tended to incline labially with age.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.165-181
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• 1999

Treatment mechanics should be individualized to be suitable for each patient's personal teeth and anatomic environment to get a best treatment result with the least harmful effects to teeth and surrounding tissues. Especially, the change of biomechanical reaction associated with that of the centers of resistance of teeth should be considered when crown-to-root ratio changed due to problematic root resorption and/or periodontal disease during adult orthodontic treatment. At the present study, in order to investigate patterns of initial displacements of anterior teeth under certain orthodontic force when crown-to-root ratio changed in not only normal periodontal condition but also abnormal periodontal and/or teeth condition, the changes of the centers of resistance for maxillary and mandibular 6 anterior teeth as a segment were studied using the laser reflection technique, the lever & pulley force applicator and the photodetector with these quantified variables reducing alveolar bone 2mm by 2mm for each of maxillary 6 anterior teeth until the total amount of 8mm and root 2mm by 2mm for each of mandibular 6 anterior ones until the total amount of 6mm. The results were as follows: 1. Under unreduced condition, the center of resistance during initial displacement of maxillary 6 anterior teeth was located at the point of about $42.4\%$ apically from cemento-enamel junction(CEJ) of the averaged tooth of them and kept shifting to about $76.7\%$ with alveolar bone reduction. 2. The distance from the averaged alveolar crest level of maxillary 6 anterior teeth to the center of resistance for the averaged tooth of them kept decreasing with alveolar bone reduction, but the ratio to length of the averaged root embedded in the alveolar bone was stable at around $33\%$ regardless of that. 3. Under unreduced condition, the center of resistance during initial displacement of mandibular 6 anterior teeth was located at the Point of about $43\%$ apically from CEJ of the averaged tooth of them and this ratio kept increasing to about $54\%$ with root reduction. But the distance from CEJ to the center of resistance decreased from around 5.3mm to around 3.3mm, that is to say, the center of resistance kept shifting toward CEJ with the shortening of root length. 4. A unit reduction of alveolar bone had greater effects on the change of the centers of resistance than that of root did during initial Phase of each reduction. But both of them had similar effects at the middle region of whole length of the averaged root.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.18 no.1
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• pp.203-212
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• 1988

This study was designed to observe mandibular condyle shape and position in an asymptomatic popular ion. Using Accurad-200 head holder(Denar Corp.) for transcranial radiography of the temporo-mandibular joint region, transcranial radiographs were taken at the centric occlusion and 1 inch mouth opening in 73 males and females who were asymptomatic for TMJ disturbances, had no severe carious or missing teeth, and no history of prosthodontic or orthodontic treatments. Mandibular condyles were classified morphologically at the centric occlusion and evaluated in positional relationship with mandibular fossa and articular eminence at the centric occlusion and 1 inch mouth opening. The results were as follows: 1. In the morphologic classification of mandibular condyle, the convex shape was more prevalent in an asymptomatic population(90.4%), the locally concave shape and wedge shape were 5.5%, 4.1%. 2. At the centric occlusion, the means of joint space were 3.43nm superiorly, 2.17㎜ anteriorly, and 2.61㎜ posteriorly. 3. At the centric occlusion, the mandibular condyles were placed slightly anterior to the center of their fossa. 4. At the 1 inch mouth opening, the mandibular condyles were placed anterior to the articular eminence more than posterior to or below the top of the articular eminence.

• Journal of Oral Medicine and Pain
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• v.9 no.1
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• pp.157-167
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• 1984

A human bite-mark shows special feature according to the suspect's dentition. The teeth which most frequently give useful bite-marks are six upper and lower anteriors, while the premolar teeth somtimes give marks it is often difficult to distinguish. The author tried to classify and to analize the anterior dentition which makes the bite-mark directly by means of 672 maxillary and 691 mandibular stone model taken from Korean adult aging from 17 to 40 years old. The results were as follows : 1. There was no particular correlation between the presence of six normal-shaped and correctly positioned upper and lower anteriors and the presence of rotation of teeth. 2. Inter central incisor, inter lateral incisor, inter canine width and angles of adjecent teeth were not identical eath other in studied models. 3. The results of this analysis supported the statement that any bite-mark had no same feature.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.383-399
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• 1998

Tooth development is usually described in four stages such as bud stage, cap stage, bell stage and crown stage. Exact time of appearance of tooth primordia is different among reports, and up to now there is no timetable regarding initial tooth development. To understand the congenital malformations and other disorders of the orofacial region, there is a need to establish a standard timetable on early tooth development. Till now, studies on the tooth development were mainly on later fetuses, and only few reports on early stage. Also, there were no reports on the time when bud stage turns to cap stage, and cap stage to bell stage. In this study, external morphology of face and the early development of the tooth, and transition of bud stage to cap stage, cap stage to bell stage were studied using 27 staged human embryos and 9 serially sectioned human fetuses. The results are as follows: 1. Mandibular region was formed by union of both mandibular arch at stage 15, and maxillary region by union of maxillary arch, medial nasal prominence, and intermaxillary segment at stage 19. 2. Ectodermal thickening which represents the primordia of tooth appeared in mandibular region at stage 13, and maxillary region at stage 15. 3. Bud stage began from mandibular primary central incisor at stage 17, and maxillary primary central incisor at stage 18. And the sequence of appearance was in the mandibular primary lateral incisor at stage 19, maxillary primary lateral incisor at stage 20, mandibular primary canine at stage 22, maxillary primary canine and primary first molar at stage 23, madibular primary first molar and maxillary primary second molar at 9th week, and mandibular primary second molar at 10th week of development. 4. Cap stage began from the primary anterior teeth at 9th week, and primary second molar still had the characteristics of cap stage at 12th week of development. 5. Transition to bell stage started from the primary anterior teeth at 12th week, and primary second molar started at 16th week of development. 6. Trnasition to crown stage started from primary anterior teeth at 16th week, and primary second molar at 26th week of development.

• The Journal of the Korean dental association
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• v.24 no.12 s.211
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• pp.1049-1060
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• 1986

The author evaluated the effect of wunderer activator for correction of functional enterior corss-bite. The Data were obtained from super-imposition of pre. and post -treatment lateral cephalo-grams. The results were as follows. 1. Correction of anterior crossbite and improvement of facial profile were occurred. 2. Axial inclination of maxillary and mandibular anterior teeth were improved. 3. Slightly down and backwakd rotation of mandible was occurred by the increment of Y-axis angle, anterior facial height and SN-MP angle.

• The Journal of the Korean dental association
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• v.55 no.12
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• pp.842-849
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• 2017

The term, 'crossed occlusion' implies clinical situation in which the residual teeth in one arch have no contact with those in the antagonistic arch, resulting in the collapse of occlusal vertical dimension. The treatment goal of this pathologic condition is restoration of the collapsed vertical dimension and stabilization of abnormal mandibular position. Previously, konus removable prostheses or tooth supported overdentures were suggested to solve crossed occlusion. Nowadays, dental implants have been used for definitive support to solve this problem. In this case report, a 65 years old female patient had a crossed occlusion, in which the maxillary posterior residual teeth and mandibular anterior residual teeth cross. Interim removable and fixed dental prostheses were used to confirm the proper vertical and horizontal jaw relation. After that, the mandibular posterior edentulous region was restored with implant-supported fixed dental prostheses. Computer tomography guided implant surgery was performed according to the concept of the restoration-driven implant placement. The maxillary anterior edentulous region was restored with Kennedy class IV removable prosthesis, considering the patient's economic status. The patient's jaw position and prostheses have been well maintained at the follow-up after 6 months of definitive restoration. The antero-posterior crossed occlusion problems appeared to be effectively solved with the combination of removable in one arch and implant-supported fixed prostheses in the other.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.3
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• pp.146-157
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• 2023

The bite collapses due to posterior teeth loss or wear results in inadequate space for restoration and esthetic concerns. Increasing the occlusal vertical dimension to improve space deficiency rotates the mandible posteriorly, creating a gap between the maxillary and mandibular anterior teeth, leading to loss of anterior guidance. To solve this problem, the prosthodontics or orthodontics treatments are the commonly used methods for proper anterior guidance. However, it is reasonable to assume that the anterior teeth can naturally relapse to their original position when the occlusal force is eliminated. Therefore, this case report aimed to test whether natural relapse could recover the lost anterior guidance to develop a less invasive and more convenient treatment method. Digital superimposition was used to evaluate the changes in anterior teeth alignment to confirm the change of the recovered anterior guidance. The appropriate indications for this new treatment method were defined and applied clinically.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.359-366
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• 2010

It was easy to find that children of a skeletal anterior crossbite in the early mixed dentition period showed a stark difference in the dental maturity between their maxillary and mandibular teeth, if they have stronger physical characteristics. If the difference of dental age between maxillary and mandibular teeth which can be identified via panoramic radiographs may serve as an early sign of class III malocclusion, this is considered valuable as a tool of early detection diagnosis. We obtained lateral cephalometric radiographs, panoramic radiographs, working model and clinical images of patients of Hellman dental age IIA and IIC who visited the department of pediatric dentistry, Pusan National University Dental Hospital and examined them to select 50 patents for normal occlusion group and skeletal anterior crossbite group, respectively. Their panoramic radiographs were used for the Demirjian's method to figure out dental ages of maxillary and mandibular teeth of each group and the eruption rate of the first molars. Their differences are as follows: 1. In both groups, the dental ages from Demirjian's method were advanced than the chronological ages. No sexual dimorphism was detected for the chronological or dental age in either group (p>0.05). 2. The difference of dental age of maxillary and mandibular teeth between the normal occlusion group and crossbite group was 0.22 and 0.69 years, respectively, with a higher difference in crossbite group(p<0.05). 3. Compared to the normal occlusion group, the crossbite group showed a higher difference in the eruption rate between maxillary and mandibular first molar(p<0.05).