• The Journal of the Korean dental association
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• v.55 no.7
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• pp.450-456
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• 2017

The purpose of this case report is to present a case of free gingival graft for treatment of mandibular incisor labial gingival recession relapsed after laterally positioned flap surgery. A 22 year-old female patient with discomfort and labial gingival recession on left mandibular central incisor was treated. The patient had been treated root coverage on same site by laterally positioned flap surgery, but treated site had relapsed in one month. Exposed root surface was covered by free gingiva from left palatal area. Although gingival color did not completely match with adjacent gingiva, more than 5mm keratinized gingiva was attained. The patient showed no further recurring pain and recession on gingiva after 5 months from the surgery. In conclusion, the root coverage with gain of keratinized gingiva could be achieved through free gingival graft from palate on relapsed gingival recession.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.345-350
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• 2016

Transferring condylar and anterior guidance on an articulator is essential to the diagnosis of a patient for full mouth reconstruction. In this clinical report, ARCUS digma I system was used to measure inherent condylar guidance of a patient requiring full mouth reconstruction in preoperate treatment, and the patients was given provisional restoration based on a functional anterior guidance. Then, ARCUS digma II system was used to mount the final casting model on an articulator, and the definitive prosthesis was placed in the patient. An esthetic and functionally proper clinical result regarding inherent condylar path of the patient was observed, and results from comparison of the two systems are given in this case.

• Journal of Oral Medicine and Pain
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• v.32 no.3
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• pp.293-303
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• 2007

The purpose of this paper is to evaluate if there is a relationship between anterior disc displacement without reduction and development of anterior open bite, and a relation between occurrence of open bite and occlusal appliance therapy. In general, the statistically significant differences were found between the Group 1 and 2 and normal mean group. The variables that represent mandibular size and form, showed a statistical significance in all 3 groups. Also 3 groups patients had a smaller ANB, a larger FMA than normal mean group. When we compared the 3 groups with respect to all cephalometric measurements by One-way analysis of variance (ANOVA), group 1 and 2 patients had a larger FMA, a larger SN to mandibular plane angle, a larger maxillomandibular plane angle, a larger occlusal plane to mandibular plane angle, a smaller total posterior facial height/total anterior facial height(%), and a larger gonial angle than group 3. The statistically significant differences were not found between the Group 1 and 2, and skeletal patterns were similar. Thus, morphologic features of patients with vertical discrepancies may represent a risk factor for the development of anterior open bite with or without occlusal appliance treatment. In case of patients with vertical discrepancy, we may have to be more careful when inducing a change of the vertical dimension.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.185-192
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• 2008

Purpose: This study was designed to investigate the fitness of adjustable dental impression trays on the Caucasian and African American. Material and methods: The size and shape of these trays were designed from the results of the dental arch size of Korean adults. Tray samples were made by CAD-CAM working. Sixty Caucasian (male:30, female:30) and sixty African American (male:30, female:30) were selected for taking irreversible hydrocolloid impression using these trays. The author measured the width and length of impression material on the several measuring points. Results: 1. Uniform impression material width was achieved by controling the width of the tray using stops and beveled guides. 2. In the maxillary tray on the Caucasian, the impression material thickness was measured to be rather great showing thickness of the midpalatal part 13.0 mm. 3. In the maxillary tray on the African American, the impression material thickness was measured to be rather great showing thickness of the midpalatal part 12.0 mm, posterior palatal part 11.0 mm and the labial frenum width was 11.0 mm. 4. In the maxillary tray on the African American, the impression material width of posterior border (0.8 mm) was measured to be small. 5. In the mandibular tray on the Caucasian, the impression material width was measured (2.7-6.7 mm) and posterior border width (2.1 mm) was measured small. The impression material length was measured (2.8-6.7 mm). 6. In the mandibular tray on the African American, the impression material width was measured to be rather great showing width of the labial frenum 9.2 mm and the width of posterior border was measured too small (0.3 mm). Conclusion: This adjustable dental tray shows good accuracy to Korean because it was designed by the analysis of the dental arch size of Korean adult model. With this result, it can be applied to Caucasian and African American, we can take more easy and accurate dental impressions.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.175-184
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• 2008

Purpose: This study was designed to investigate the fitness of adjustable dental impression trays on the Chinese and the Japanese. Material and methods: Initial design of the adjustable dental trays was developed from the results of the dental arch size of Korean adults. This design was applied to the CAD-CAM process in order to create tray model samples. Simple silicon-base molds were then replicated based on these sample models. Polyurethane injection into the silicon- base molds completed the process of creating a large number of test products. 60 Chinese dental students (male:30, female:30) from the Shanghai Second Medical University and 60 Japanese alumni from the Kumamoto high school (male:30, female:30) were selected for taking irreversible hydrocolloid impression with these trays. The width and length of the impression body were measured on several measuring points by Vernier caliper. The results were analyzed statistically to evaluate the fitness of the trays. Results: 1. Uniform impression material thickness was achieved on the Chinese and Japanese by controlling the width of the tray using stops and beveled guides. The material thickness was generally within the range of 3 mm to 6 mm. 2. In the maxillary tray of the Chinese, average thickness of the impression material of the labial vestibule of the incisal teeth was 6.2 mm, the canine was 5.9 mm and the midpalatal part 10.5 mm and the posterior palatal part 9.7 mm. These were relatively large values. 3. In the mandibular tray of the Chinese, average length of the impression material of the lingual vestibule of first, second premolar contact point was 8.9 mm, the incisal teeth was 7.8 mm and thickness of the labial part of canine was 6.8 mm and premolars 7.0 mm. These were relatively large values. 4. In the maxillary tray of the Japanese, average thickness of the impression material of the labial vestibule of the incisal teeth was 7.4 mm, the canine was 7.7 mm and the midpalatal part 9.1 mm. These were relatively large values. 5. In the mandibular tray of the Japanese, average thickness of the impression material of the labial vestibule of first, second premolar contact point was 8.4 mm, and thickness of the labial part of canine was 7.4 mm. These were relatively large values. Conclusion: This adjustable dental tray shows good accuracy to Korean because it was designed by the analysis of the dental arch size of Korean adult model. With this result, it can be applied to Chinese and Japanese, we can take more easy and accurate dental impressions.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.169-179
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• 2004

The purpose of this study was to discriminate clinically and radiographically among the three groups of dentigerous cysts studied. First, Group I, involved area of dentigerous cyst was successive permanent tooth area beneath deciduous tooth. Second, Group II, involved permanent molar area, and the last, Group III involved maxillary anterior supernumerary tooth area. The author observed and compared the clinico-radiographic features of 49 cases of Group I, 36 cases of Group II, and 15 cases of Group III of dentigerous cyst and this observation and comparison had been done by based on the charts and panoramic films. The obtained results were as follows: 1. The cases of Group I were 29 cases and, those of Group II were 36 and those of Group III were 15. 2. The incidence of dentigerous cyst is high in first decade. In Group I, before first decade and early first decade was 87.8%, in Group II and Group III, was discovered more lately. 3. The frequency of dentigerous cyst is 2.5 times higher in male than in female. 4. The sequence of chief complaint was swelling(50%), routine examination(32%), and pain(9%). 5. When considering the type of the cyst, lateral type is many most in Group I (71.4%) and central type is many most in Group II (94.4%) and Group III (100%). 6. The most size of dentigerous cyst was 2 crown size in Group I, 1 crown size in Group II, above of 4 crown size in Group III. 7. Almost involved teeth showed displacement and some tooth of displaced teeth showed delayed root development and dilaceration of root. 8. The most many response of alveolar bone was buccal bone expansion in Group I (67.3%), no bone expansion in Group II(66.7%) and palatal bone expansion in Group III (60.0%). 9. The percentage of involved teeth were as follows : The mandibular third molar was 31% and many most. The mandibular second premolar was 30%. Mesiodens of maxillary anterior area was 15%. The maxillary canine was 8%. The mandibular first premolar was 5%. 10. In the Group I, causes suggesting of dentigeous cyst are pulpotomized deciduous tooth(59.2%), severe dental caries of deciduous tooth, untreated traumatic history on the deciduous tooth etc. 11. The treatment method of dentigerous was marsupialization in 61.2% of cases of Group I and that was enucleation in 61.1% of cases of Group II and in 80.0% of cases of Group III.

• Journal of Oral Medicine and Pain
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• v.31 no.4
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• pp.347-354
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• 2006

Most patients suffering from TMD appear to have unsatisfactory masticatory function and compromised values of bite force. The purposes of this study were to investigate and compare bite force between affected and unaffected sides of patients with unilateral TMD and to evaluate its relation with duration of TMD. 42 patients with unilateral TMD, from Department of Oral Medicine, Dankook University Dental Hospital, were selected for this study. The ratio of men to women was 9:33 and their mean age of $27.2{\pm}10.4$ years. The bite forces were measured over both canines (for anterior bite force) and $1^{st}$ molars (for posterior bite force) using a bite force recorder while all the subjects were asked to clench successively for 3 seconds not until pain was felt. They were compared with those measured from bilateral TMD patients(N=6, M:F=1:5, mean age: $23.0{\pm}27.3$ years). The unilateral TMD patients were divided into time groups according to duration of TMD on the basis of 1 and 6 months, respectively. Paired and unpaired t-tests were used for statistical analysis. Unilateral TMD patients in this study showed that the affected sides had significantly lower bite force than the unaffected sides(force difference of about 7-8 kgf, p<0.05) while there was no significant sides difference in the bilateral patients. Nor did bite force on the affected sides reveal significant difference between unilateral and bilateral TMD patients. With regards to TMD duration, there was significant difference between the patients with TMD < 6 months and $\geq$ 6 months (p<0.05) while no significant difference existed between < 1 month and $\geq$ 1 month. The results of this study indicated that unilateral TMD patients can exhibit more reduced bite force on the affected sides compared with that on the unaffected sides and that bite force on the unaffected sides might be deteriorated more as longer did TMD last.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.4
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• pp.570-593
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• 1996

This study was intended to perform the influence of condyle positional change after surgical correction of skeletal Class III malocclusion after BSSRO in 20 patients(males 9, females 11) using computed tomogram that were taken in centric occlusion before, immediate, and long term after surgery and lateral cephalogram that were taken in centric occlusion before, 7 days within the period intermaxillary fixation, 24hour after removing intermaxillary fixation and long term after surgery. 1. Mean intercondylar distance was $84.45{\pm}4.01mm$ and horizontal long axis of condylar angle was $11.89{\pm}5.19^{\circ}$on right, $11.65{\pm}2.09^{\circ}$on left side and condylar lateral poles were located about 12mm and medial poles about 7mm from reference line(AA') on the axial tomograph. Mean intercondylar distance was $84.43{\pm}3.96mm$ and vertical axis angle of condylar angle was $78.72{\pm}3.43^{\circ}$on right, $78.09{\pm}6.12^{\circ}$on left. 2. No statistical significance was found on the condylar change(T2C-T1C) but it had definitive increasing tendency. There was significant decreasing of the distance between both condylar pole and the AA'(p<0.05) during the long term(TLC-T2C). 3. On the lateral cephalogram, no statistical significance was found between immediate after surgery and 24 hours after the removing of intermaxillary fixation but only the lower incisor tip moved forward about 0.33mm(p<0.05). Considering individual relapse rate, mean relapse rate was 1.2% on L1, 5.0% on B, 2.0% on Pog, 9.1% on Gn, 10.3% on Me(p<0.05). 4. There was statistical significance on the influence of the mandibular set-back to the total mandibular relapse(p<0.05). 5. There was no statistical significance on the influence of the mandibular set-back(T2-T1) to the condylar change(T2C-T1C), the condylar change(T2C-T1C, TLC-T2C) to the mandibular total relapse, the pre-operative condylar position to the condylar change(T2C-T1C, TLC-T2C), the pre-operative mandibular posture to the condylar change(T2C-T1C, TLC-T2C)(p>0.05). 6. The result of multiple regression analysis on the influence of the pre-operative condylar position to the total mandibular relapse revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condyalr head long axis angle, the more increasing of mandibular horizontal relapse(L1,B,Pog,Gn,Me) on the right side condyle. The same result was founded in the case of horizontal relapse(L1,Me) on the left side condyle.(p<0.05). 7. The result of multiple regression analysis on the influence of the pre-operative condylar position to the pre-operative mandibular posture revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condylar head long axis angle, the more increasing of mandibular vertical length on the right side condyle. and increasing of vertical lengh & prognathism on the left side condyle(p<0.05). 8. The result of simple regression analysis on the influence of the pre-operative mandibular posture to the mandibular total relapse revealed that the more increasing of prognathism, the more increasing of mandibular total relapse in B and the more increasing of over-jet the more increasing of mandibular total relapse(p<0.05). Consequently, surgical mandibular repositioning was not significantly influenced to the change of condylar position with condylar reposition method.

• The korean journal of orthodontics
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• v.34 no.1 s.102
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• pp.1-11
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• 2004

Predicting the arch length discrepancy by simply comparing the available arch perimeter with tooth materials is merely a 2-dimensional analysis of the teeth movement. However, the real teeth movement takes place 3-dimensionally and is affected by various factors such as, the arch fen the curve of Spee and the axis of the incisors. The purpose of this study is to clarify the relationship between the decrease in the arch perimeter and the horizontal positional change of the incisors after extraction of the 1st bicuspids, for more analytic evaluation of the arch length discrepancy at pre-treatment model analysis stage. In addition to that to evaluate the effect of the curve of Spee, teeth axis to the basal plane, and the incisional crowding to the treatment outcome. All patients were treated at the department of orthodontics, dental hospital, Yonsei university. Inclusion criteria for patients selection were as follows. $\cdot$ Angle classification I malocclusion with bialveolar protrusion $\cdot$ Extraction of 4 1st bicuspids $\cdot$ No tooth anomaly or prosthesis $\cdot$ No abnormal attrition $\cdot$ No ectopically erupted teeth $\cdot$ Angle classification I canine and molar relationship $\cdot$ Less than 3mm of crowding Model analysis of the above patients was performed and the following conclusions were obtained. 1. When the intercanine distance was maintained, the available space for the distal movement of the mandibular incisors after the extraction of the 4 1st bicuspids was larger than the space provided by the extraction of the 4 1st bicuspids. However the difference was less than 1mm. The more tapered the anterior arch form, the larger the difference. 2. Compared to the situation in which the intercanine distance was maintained, when the intercanine distance was expanded to meet the width of the Posterior teeth, the incisors could move about 3mm more distally. 3. The positional difference of the incisal tip was insignificant whether the central incisors were moved by tipping or bodily movement. 4. When the anterior crowding was solved without changing the intercanine distance, the larger the anterior arch length was, the more the anterior movement of the incisors. 5. When the curve of Spee was levelled, the increase in the arch perimeter was less than half of the deepest curve of Spee.

• The korean journal of orthodontics
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• v.33 no.6 s.101
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• pp.437-451
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• 2003

The purpose of this study was to measure maximum bite force and to investigate its relationship with anteroposterior, vertical, and transverse facial skeletal measurements. From among the dental students at the College of Dentistry, forty subjects (26 male and 14 female) were selected. With two sets of strain gauge, maximum bite force at the right and left first molars and anterior teeth was measured in the morning and afternoon. After taking lateral and posteroanterior cephalograms, fifty and nineteen variables were evaluated, respectively Paired t-tests and an independent t-test were done and correlation coefficients were obtained. 1. The maximum bite force at the first molars was $68.0\pm13.9kg$. in males and $55.6\pm10.5kg$ in females (p<0.05) while the force at the anterior teeth was $8.4\pm4.9kg\;and\;1.1\pm3.4kg$ respectively (p<0.05). 2. Some tendency for a greater value of maximum bite force at the preferred side was observed but not statistically significant (p>0.05). 3. Significant difference was observed between the strong bite force group and the weak bite force group in some cephalometric and other measurements (p<0.05). N-S-Ar, S-Ar-Go, FH-Hl, IMPA and MMO showed a significant difference in posterior maximum bite force (P). N-S-Ar and FH-H1 also showed a significant difference in anterior maximum bite force (A). 4. Several cephalometric variables showed some correlation with maximum bite force (p<0.05). N-S-Ar, S-Ar-Go, UGA, FH-H6, FH-H1, body weight and MMO were significantly correlated with posterior maximum bite force (P). Go-Me, P-1 and IMPA were significantly correlated with anterior maximum bite force (A).