• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.125-136
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• 2008

Statement of problem: Since the concept of osseointegration in dental implants was introduced by $Br{{\aa}}nemark$ et al, high long-term success rates have been achieved. Though the use of dental implants have increased dramatically, there are few studies on domestic implants with clinical and objective long-term data. Purpose: The aim of this retrospective study was to provide long-term data on the $Neoplan^{(R)}$ implant, which features a sandblasted and acid-etched surface and external connection. Material and methods: 96 $Neoplan^{(R)}$ implants placed in 25 patients in Yonsei University Hospital were examined to determine the effect of the factors on marginal bone loss, through clinical and radiographic results during 18 to 57 month period. Results: 1. Out of a total of 96 implants placed in 25 patients, two fixtures were lost, resulting in 97.9% of cumulative survival rate. 2. Throughout the study period, the survival rates were 96.8% in the maxilla and 98.5% in the mandible. The survival rates were 97.6% in the posterior regions and 100% in the anterior regions. 3. The mean bone loss for the first year after prosthesis placement and the mean annual bone loss after the first year for men were significantly higher than that of women (P<0.05). 4. The group of partial edentulism with no posterior teeth distal to the implant prosthesis showed significantly more bone loss compared to the group of partial edentulism with presence of posterior teeth distal to the implant prosthesis in terms of mean bone loss for the first year and after the first year (P<0.05). 5. The mean annual bone loss after the first year was more pronounced in posterior regions compared to anterior regions (P<0.05). 6. No significant difference in marginal bone loss was found in the following factors: jaws, type of prostheses, type of opposing dentition, and submerged /non-submerged implants (P<0.05). Conclusion: On the basis of these results, the factors influencing marginal bone loss were gender, type of edentulism, and location in the arch, while the factors such as arch, type of prostheses, type of opposing dentition, submerged / non- submerged implants had no significant effect on bone loss. In the present study, the cumulative survival rate of the $Neoplan^{(R)}$ implant with a sandblasted and acid-etched surface was 97.9% up to a maximum 57-month period. Further long-term investigations for this type of implant system and evaluation of other various domestic implant systems are needed in future studies.

• Journal of Microbiology
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• v.45 no.3
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• pp.246-255
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• 2007

Mutans streptococci have been implicated as cariogenic bacteria in dental caries because they can produce high levels of dental caries-causing lactic acid and extracellular polysaccharide. The aim of this study was to isolate and characterize the mutans streptococci from the dental plaque obtained from Koreans. The dental plaque samples were collected from the anterior and molar teeth of both jaws in 155 subjects (aged 2 to 33.2 years, average age $13.7{\pm}4.7\;years$). The samples were diluted by 100-fold in $1{\times}\;PBS$ and plated on mitis-salivarius bacitracin (MSB) agar plates. The mutans streptococci grown on MSB plates were screened by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting dextranase gene (dex). The mutans streptococci were identified at the species level using a 16S rDNA sequencing comparison method. The biochemical tests were carried out to biotype the mutans streptococci. Ninety-five strains of the mutans streptococci out of 358 colonies, which were derived from 141 subjects, were isolated. Of them, 77 strains and 18 strains were Streptococcus mutans and Streptococcus sobrinus, respectively. The biotyping data showed that 62, 1, 20, 10, and 2 strains were biotypes I, II, IV, V and variant, respectively. Of the two strains of variant biotype, one strains was similar to biotype IV except that it was positive to the arginine hydrolysis test. We considered this one strain a new biotype, and classified it as biotype VII. In conclusion, S. mutans and its biotype I was most frequently isolated in Korean dental plaque. The mutans streptococci strains isolated in this study might be useful for the study of the pathogenesis and the prevention of dental caries.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.115-122
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• 2018

Noonan syndrome is characterized by distinctive facial features, short stature, and congenital heart disease. It is a congenital genetic disorder with a prevalence of between 1/1,000 and 1/2,500 in both genders. An 11-year-old boy with Noonan syndrome visited the hospital with an ectopically positioned tooth. A pulmonary stenosis was diagnosed and his growth and development were delayed. In many cases of this diseases there is obvious hemostasis, which he was not experiencing. His facial appearance showed characteristic features of Noonan syndrome. The patient showed a dental class II relationship, labioversion of the upper anterior teeth, and a shallow overbite. Radiographic examination revealed that the upper right canine was ectopically positioned, which led to root resorption of the upper right lateral incisor. A lateral cephalometric radiograph revealed a craniofacial pattern that was within normal limits. Surgical opening and button attachment on the impacted upper right canine were performed and traction was applied on the impacted tooth using a removable appliance. This patient was mildly affected by Noonan syndrome and showed some dental problems. However, few studies have reported the oral characteristics of Noonan syndrome despite its high incidence. Thus, this case report describes the oral features and management of Noonan syndrome.

• 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 Journal of Korean Academy of Prosthodontics
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• v.53 no.1
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• pp.58-65
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• 2015

For the rehabilitation of fully edentulous patients, implant-supported removable partial dentures can be considered as one of the treatment options with complete dentures or implant-supported overdentures. If removable partial dentures are used in combination with a small number of implants placed in strategically important positions, it can offer additional stability, retention and support through implants and reduce a burden of surgical procedures compared with fixed implant-supported prostheses with extensive implant placement. Moreover, the economical benefit can be expected as well. The purpose of this case report is to present a treatment in which an implant-supported removable partial denture was fabricated considering residual alveolar bone status and demands after teeth loss in a patient who had been using a distal extension removable partial denture for a long period of time. In anterior area, fixed prostheses were fabricated with implant placement and in posterior area, short implants provide only support for the removable partial denture. In addition, denture base and clasp were made of thermoplastic acrylic resin. Finally, functionally and aesthetically satisfying treatment results can be achieved.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.348-353
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• 2003

Early detection and prudent management of mesiodens or supernumerary tooth should be considered essential in reducing disturbance in the eruption and position of the adjacent permanent incisor. While it is true that the presence of diastema may be regarded as normal at the early mixed dentition stage, the early detection and removal of the mesiodens is a prerequisite to facilitate spontaneous alignment or subsequent approximation of the permanent central incisors. In many cases, diastema due to mesiodens can be physiologically corrected spontaneously after the extraction of mesiodens. The best choice of treatment of diastema may be observation. Orthodontic intervention is required only spontaneous closing of diastema does not occur within observation period. In orthodontic intervention, careful treatment plan should be established. Clinician gives considerations to angulation of central and lateral incisor, proximity of lateral incisor, developmental stage and position of canine, pattern and extent of anterior crowding. Orthodontic movement should be done slowly with light force. In addition, periodic radiographic observation are needed to monitor the root development and root resorption. Case 1, 2 and 3 showed physiologic closures after the extraction of mesiodens. In these cases, acceptable alignment of central and lateral incisors was obtained. In case 4, orthodontic correction for diastema was performed successfully after the extraction of mesiodens. After the orthodontic closure of the diastema, it was decided that a retainer was not needed, because the dentition was under a dynamic stage in exchanging teeth and also developing arches.

• The korean journal of orthodontics
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• v.31 no.5 s.88
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• pp.535-548
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• 2001

The purpose of this study was to evaluate changes in soft tissue chin thickness and to investigate correlations between hard and soft tissues measurements after orthodontic treatment conducted by premolars extraction and incisor retraction. The sample consisted of 35 female adults with Angle classification class I or class II division 1 malocclusion. Using lateral cephalometric radiographs taken before and after treatment, hard and soft tissue structures were measured and reproducible six landmark on soft chin tissue were used to locate the various points of soft tissue contour of the chin. The res에ts were as follows : 1. There were signigicant correlations between pretreatment B-B', Pm-Pm' and pretreatment vortical skeletal measurements such as $MP{\perp}HP,\;MP{\perp}PP$, ALFH and between a-a', b-b', Me-Me' and measurements of sym-physeal morphology such as SL, SW, PL. 2. There were significant decreases at B-B', Pm-Pm' and significant increases at a-a', b-b' between pre-and posttreatment mea surements. 3. There were significant correlations among soft tissues changes and hard tissue changes except for changes at B-B' and the range of correlation coefficient was about 0.3-0.4. 4. There were significant differences at ${\Delta}UI-VP,\;LI{\perp}, and B-B' measurements between subgroups divided by posttreatment Pog-Pog' changes. 5. There were significant differences at ${\Delta}overbite,\;NPog{\perp}HP,\;and\;Me-Me'$ measurements between subgroups divided by posttreatment Me-Me' changes.

• The korean journal of orthodontics
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• v.22 no.4 s.39
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• pp.869-880
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• 1992

The purpose of this study was to evaluate the difference and relationship between the slope of articular eminence and the inclination of upper and lower incisor teeth, which are related to the functional stability of occlusion in mandibular protrusion, according to Ricketts' facial types, by the use of lateral cephalogram and SAM2 articulator in 68-adult normal occlusion without tooth missing, orthodontic treatment and occlusal equilibration. The results of this study were as follows : 1 . The angle of articular eminence slope to occlusal plane in brachyfacial type was steeper than that in dolichofacial type, but the angle of articular eminence slope to SN plane and FH plane was not different between facial types. 2. The upper incisor axis in dolichofacial type was steeper than that in brachyfacial type, but lingual surface slope of upper incisor was not different between facial types. 3. In all samples there was a positive correlation between the angle of articular eminence slope and the lingual surface slope of upper incisor to SN plane and FH plane, and in mesofacial type there was a positive correlation between the angle of articular eminence slope and the lingual surface slope of upper incisor to SN plane, FH plane and occlusal plane, and in brachyfacial type there was a positive correlation between the angle of articular eminence slope and the lingual surface slope of upper incisor to occlusal plane. 4. In all samples there was a positive correlation between the angle of articular eminence slope and the angle of Dc-Gn to SN plane, and in mesofacial type there was a positive correlation between the angle of articular eminence slope and the angle of Dc-Gn to occlusal plane, and in brachyfacial type there was a positive correlation between the angle of articular eminence slope and the angle of Dc-Gn to SN plane and FH plane. 5. In all samples there was a positive correlation between the angle of Dc-Gn and the lingual surface slope of upper incisor to SN plane and FH plane, and in mesofacial type there was a positive correlation between the angle of Dc-Gn and the lingual surface slope of upper incisor to SN plane. 6. In all samples and facial types there was a negative correlation between MP to 1 axis and condylar incisal angle.

• The Journal of the Korean dental association
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• v.48 no.5
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• pp.391-406
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• 2010

Orthodontic treatment for middle-aged patients has become more commonplace with various reasons including improved socioeconomic status. Understanding of oral status and treatment modalities of middle-aged patients is mandatory for accurate diagnosis and proper treatment planning. This study investigated 100 consecutive patients aged 40s and 50s and 100 aged 20s who had been examined and diagnosed at the Department of Orthodontics, Chonnam National University Dental Hospital. The results were obtained as follows; 1. Gender distribution showed female outnumbered male patients in young-aged adult patients, but middle-aged patients showed similar male and female distribution. 2. The major concern seeking orthodontic treatment was esthetics not only in young-aged but also in middle-aged adult patients, and a number of middle-aged patients were concerned about oral health as well. 3. Considerable number of middle-aged patients were referred by other dental specialties while young-aged adult patients were more self-motivated for orthodontic treatment. 4. Middle-aged adult patients had more missing teeth and periodontal disease than young-aged adults. 5. The most frequently-observed problem was dental spacing in middle-aged patients while dental crowding in young-aged adult patients. Middle-aged patients showed higher prevalence of deep overbite and overjet while most of young-aged adults presented opposite direction of problem in overbite and overjet. 6. Limited orthodontic treatment was required rather than comprehensive treatment in middle-aged patients, and the most common tooth moving area was anterior part of dentition in case of limited treatment. Need of interdisciplinary therapy with other dental specialties was more common in middle-aged patients. 7. Intervention of specific technique such as invisible TP, passive bracketing, passive wire bonding, and lingual orthodontics was more required in middle-aged patients. Considering that middle-aged patients have different characteristics than young-aged adults, the results of the present study suggest that different treatment modalities are required in middle-aged orthodontic patients in order to manage them properly and efficiently.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.167-173
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• 2001

Cystic lesion of the jaw are frequently encountered clinically. Although they rarely lead to development of tumors, they can result in resorption of the jaw bone or asymmetry of the face may occur. The purpose of this study is to find the clinical and histopathological pattern of cysts and to help better understanding for the diagnosis and treatment of jaw cysts. The hospital chart, out-patient chart, panorama X-ray, histopathological report and operation report of 246 patients were reviewed who had been diagnosed as cyst. Sex distribution, age distribution, classification, anatomic distribution, clinical sign & symptoms, treatment, post-operation complications, recurrence rate were studied. Then significant difference between the diameter of cyst with bone graft and none-bone graft was calculated with SAS program. The results were as follows. 1. Among the total patient of 246 cases, male were 163 case(67.0%), and female were 83 case(37.0%), male predominated by the ratio of 1.98. 2. By age group, the 20's accounted for the largest proportion of the cases(27.2%) and the 30' accounted for the 2nd largest proportion of the case(19.5%). 3. Radicular cyst and dentigerous cyst were most common cysts, irrespective of 166 case(67.5%) and 62 case(25.2%). 4. Clinical sign & symptoms were swelling(167case), pain(85case), pus discharge(53case), teeth discoloration(28case), indicating that most complaints were related to inflammation and facial asymmetry. 4.9% of the total cases were discovered accidentally. 5. The primary site of cysts were maxillary anterior area(43.9%), the others were, in descending order, mandibular posterior area(25.6%), maxillary posterior area(14.6%). 6. Enucleation with endodontic treatment was a main treatment method(133 case, 54.1%) and 38 cases(15.4%) were enucleation with extraction, and 37 cases(15.0%) were only enucleation, and 21 cases(8.5%) were enucleation with bone graft. 7. The average diameter of cysts with bone graft was significally greater than with non-bone graft(p<0.05). 8. Post-operation complications occurred in 10 case(4.1%), all of this were due to secondary infection.