• The Journal of the Korean dental association
• /
• v.11 no.4
• /
• pp.277-280
• /
• 1973

The author observed the changes of dental arch dimensions and compared spae-maintainer group with non-space-maintainer group after primary tooth extraction. The results were as follows 1) The rate of growth of dental arch of expeirmental group in intercanine width and in inter-1st molar width was more rapid than that of the control group. 2) Arch length is almost no dimensions but it was slightly decreased in lower arch. 3) Dental arch growth and tooth eruption were stimulated by space-maintainer appliance, so it is the best way to replace a new appliance at least once a year. 4) It is thought that satisfactory conclusions in this observation must be researched successively until the mixed dentition completes.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.6 no.1
• /
• pp.15-20
• /
• 1979

Sixty non-vital primary molars of forty six children who were patients at the Pedodontic Department of Seoul University Hospital, aged from 2 years 7 months to 9 years 1 month were performed for coronal pulp therapy. For the evaluation of non-vital pulp therapy, the author observed those teeth both clinically and roentgenographically. The results were as follows: 1. Coronal therapy of non-vital tooth can be accepted as one of the ordinary methods at the view of the save of tooth, time and simplicity. 2. The results were satisfactory 78.3% clinically and 68.3% roentgenographically. 3. The dissatisfactory signs were a) Clinical view There were dissatisfactory signs on 13 cases. (1) 2 teeth had fistulous opening. (2) 11 teeth reacted to purcussion and mobility. b) Roentgenographical view There were dissatisfactory signs on 19 cases. (1) 13 teeth showed roentgenolucency at bifurcation area. (2) 2 teeth showed pathological root resorption. (3) 4 teeth showed periodontal thickening.

• Korean Journal of Cleft Lip And Palate
• /
• v.5 no.1
• /
• pp.43-58
• /
• 2002

A General survey on the cleft lip and/or palate patients in Pusan National University Hospital was done. The conclusions were as follow. 1. In gender ratio, male was higher than female. 2. In the cleft type, unilateral cleft lip and palate, cleft lip and alveolus, and bilateral cleft lip and palate in higher ratio order. Left unilateral cleft lip and palate was higher than right in ratio. 3. In first hospital visiting age for dental treatment, the group from 6 years old to 12 years old was most and in that the age group for attending elementary school (about 7-8 years old) showed especially higher ratio. The large majority of patient were born in 1980's and lived in Pusan metropolitan city, KyungSangNamDo. Especially, most of them lived in the neighboring Held of Pusan National University Hospital. 4. Class III skeletal pattern and Angle's Class III molar relationship was most prevalent. Angle's Class II molar relationship showed relative higher ratio because tooth loss and malposition. 5. Primary lip closure in 3 months, secondary lip closure in 6-7 years old, palatal closure in 12-16 months and bone graft in 8-10 years old were operated mostly. Rhinoplasty and scar revision were operated in too early age so the need of infantile orthopedics must be considered. 6. Maxillary expansion and protraction were operated mostly in 8-11 years old but operating in primary dentition must be considered. 7. Tooth alignment were started mostly in mixed dentition and consideration about prosthodontic treatment and retention will be need. 8. In tooth anomaly, tooth malformation and missing were most prevalent.

• The Journal of the Korean dental association
• /
• v.55 no.5
• /
• pp.328-338
• /
• 2017

Introduction: The aim of the current study was to describe the prevalence and treatment of mandibular first molar eruption disturbances. Methods: A total of 38 mandibular first molars(M1mn) from 36 patients(17 males and 19 females; aged 9 years 2 months?35 years 10 months) were identified from the 13,391 patients that received orthodontic treatment from 1983?2012. The subjects were classified into 3 categories based on panoramic radiographic examination: impaction due to ectopic position of the tooth germ relative to the contra-side same tooth(Group 1), impaction due to obstruction of the eruption path with cyst or calcium mass (Group 2), and primary and secondary retention due to defects in the follicle or periodontal ligament(PDL; Group 3). The treatment outcomes were evaluated into four categories: no treatment(A), orthodontic traction(B), autotransplantation(C), and extraction due to orthodontic traction failure(D). Results: The prevalence rate of M1mn eruption disturbances in this sample was 0.27%. In Groups 1 and 2, most of the impacted M1mn were erupted successfully by orthodontic traction. In Group 3, most of the retained M1mn were failed to erupt and recommended for extraction. Conclusions: Treatment prognosis was favorable on Group 1 & 2 than Group 3. After removing an element of the cause in case of Group 1 & 2, orthodontic traction or periodic observation will be recommended.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.1
• /
• pp.47-61
• /
• 1998

The purpose of this study was to compare the microleakage pattern of glass ionomer with resin restoration in microleakage pattern of primary and permanent teeth. Microscopical observation of interface between tooth structure and restoration was also performed. 80 and 8 sound molar teeth were used for the microleakage test and SEM study respectively. Data were analyzed statistically using ANOVA test and/or t-Test. The results of the present study were as follows: 1. According to the result of microleakage pattern between primary and permanent tooth, primary tooth generally showed more micro leakage than permanent tooth in all groups (p<.05). 2. In the resin-filled groups, occlusal margin was shown to have more microleakage than gingival margin(p<.05). Whereas the glass ionomer-filled groups showed no statistically significant differences between them(p>.05). 3. No statistically significant differences in microleakage could be found between two different resin groups(p>.05), while Fuji II LC group showed less microleakage than Ketac-Fil group(p>.05). 4. The various type hybrid layer was evident under SEM in resin-filled groups both in primary and permanent teeth with generally thicker layer in primary group. Among glass-ionomer group, Fuji II LC group showed more intact adhesion to tooth surface than Ketac-Fil group

• Restorative Dentistry and Endodontics
• /
• v.40 no.4
• /
• pp.276-285
• /
• 2015

Objectives: The purpose of this study was to evaluate the efficacy of mineral trioxide aggregate (MTA), Biodentine and Propolis as pulpotomy medicaments in primary dentition, both clinically and radiographically. Materials and Methods: A total of 75 healthy 3 to 10 yr old children each having at least one carious primary molar tooth were selected. Random assignment of the pulpotomy medicaments was done as follows: Group I, MTA; Group II, Biodentine; Group III, Propolis. All the pulpotomized teeth were evaluated at 3, 6, and 9 mon clinically and radiographically, based on the scoring criteria system. Results: The clinical success rates were found to be similar among the three groups at 3 and 6 mon where as a significant decrease in success rate was observed in Group III (84%) compared to both Group I (100%) and Group II (100%) at 9 mon. Radiographic success rates over a period of 9 mon in Groups I, II, and III were 92, 80, and 72%, respectively. Conclusions: Teeth treated with MTA and Biodentine showed more favorable clinical and radiographic success as compared to Propolis at 9 mon follow-up.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.36 no.5
• /
• pp.417-422
• /
• 2010

Introduction: Bone density is one of the important factors for the long term success of endosseous implants. The bone density varies from site to site and from patient to patient. A preoperative evaluation of the bone density is quite useful to oral surgeons for planning dental implantation. More accurate information on the bone density will help surgeons identify suitable implant sites, thereby increase the success rate of dental implantation. This study examined the correlation between the bone density measured preoperatively by computed tomography (CT) and the implant primary stability measured by resonance frequency analysis. Furthermore, the effects of the implant sites, gender, age and generalized systemic disorder patients on the bone density and primary implant stability were examined. Materials and Methods: One hundred and fourteen patients were selected. None of the patients had undergone a tooth extraction or bone graft history in the previous year. Preoperatively, the patients underwent CT scanning to evaluate the Hounsfield unit (HU), and resonance frequency analysis (RFA) was used to evaluate the implant primary stability at the time of implant installation. All implants were 4.0 mm diameter and 11.5 mm length US II. All patients were recorded and the HU and implant stability quotient (ISQ) value were evaluated according to the sites, gender and age. Results: The highest HU values were found in the mandibular anterior site ($827.6{\pm}151.4$), followed by the mandibular molar site ($797{\pm}135.1$), mandibular premolar site ($753.8{\pm}171.2$), maxillary anterior site ($726.3{\pm}154.4$), maxillary premolar site ($656.7{\pm}173.8$) and maxillary molar site ($621.5{\pm}164.9$). The ISQ value was the highest in the mandibular premolar site ($81.5{\pm}2.4$) followed by the mandibular molar site ($80.0{\pm}5.7$), maxillary anterior site ($77.4{\pm}4.1$), mandibular anterior site ($76.4{\pm}11.9$), maxillary premolar site ($74.2{\pm}14.3$) and maxillary molar site ($73.7{\pm}7.4$). The mean HU and ISQ value were similar in females and males. (HU: P=0.331, ISQ: P=0.595) No significant difference was also found in the age group respectively. However, the correlation coefficients between the variables showed a closed correlation between the HU and ISQ value. Conclusion: These results showed close correlation between the bone density (HU) and primary stability value (ISQ) at the time of implant installation (Correlation coefficients=0.497, P<0.01). These results strengthen the hypothesis that it might be possible to predict and quantify the initial implant stability and bone density from a presurgical CT diagnosis.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.34 no.1
• /
• pp.62-72
• /
• 2007

The purpose of present study was to determine whether different kinds of curing lights can alter microtensile bond strength(MTBS) of class I cavity pulpal and axial wall specimens in primary molar. Thirty clean mandibular 2nd primary molar's occlusal enamel were removed and class I cavity, size of $2{\times}4{\times}2mm$ was prepared. Dentin bonding agent was applied according to manufacturer's manual. Each group was cured with Halogen Curing Unit, Plasma Curing Unit and LED Curing Unit. Composite resin was bulk filled and photo cured with same curing unit. MTBS specimens which size is $0.7{\times}0.7{\times}4mm$ were prepared with low speed saw. Specimens were coded by their curing lights and wall positions (Halogen - Axial wall group, Halogen - Pulpal wall group, Plasma - Axial wall group, Plasma - Pulpal wall group, LED - Axial wall group, LED - Pulpal walt group). MTBS were tested at 1 mm/min cross Head speed by Universal Testing Machine. Fractured surface and bonding surface was observed with SEM. T-test between axial and pulpal specimens in each curing lights, one-way ANOVA among different curing light specimens in each wall positions were done. Weibull distribution analysis was done. The results were as follows : Mean MTBS of pulpal wall specimens were significantly greater than that of axial wall specimens at each curing units(p<.05). There was no significant difference in the MTBS among three curing units at axial wall and pulpal wall. In Weibull distribution, pulpal wall specimens were more homogeneous than axial wall specimens.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.38 no.4
• /
• pp.337-347
• /
• 2011

The basic structure of the primary crowns usually resemble their succeeding permanent teeth. However, maxillary second primary molars resemble ipsilateral first permanent molars. Accordingly in this study, odontometric data of the two teeth was obtained, then analyzed to verify the morphological relationship and sex difference between the two teeth. Dental study casts were examined for their mesiodistal and buccolingual width of the crowns, diameter of each cusps, and intercuspal distances. Photographs of the crowns were taken to measure the angles between each cusp tip. The results are as follows : 1. In boys, PrI, PaI, DBC angle, and MBC angle did not show any statistically significant difference between the two teeth(p>0.05), and moderate level of correlations were observed. 2. In girls, crown index, DBC angle, and MBC angle of the two teeth did not show any statistically significant difference(p>0.05), and moderate level of correlations were recognized. 3. Measurements that did not show statistically significant difference between the two teeth in both boys and girls were DBC angle and MBC angle(p>0.05). In DLC angle, however, statistically significant difference was observed(p<0.01). 4. Most of the measurements showed sex differences, except DBC angle, which did not show any sex difference in both teeth(p>0.05).

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.4
• /
• pp.637-642
• /
• 2003

Morphology of primary root divergency and curvature determines the pattern of root resorption and periapical lesion, and affects successful root canal treatment. With the purpose of analysing the morphology of primary mandibular second molar roots and canals, the frequency, angle, radius, and start of curvature of the canal were measured. Fifty clinical radiographs were taken from $3{\sim}6$ years old children, followed by digitizing after scanning and analyzing by Scion image Beta 4.02TM(Scion Co. USA). The angle of curvature was determined by Schneider's method and the radius of curvature was determined by Schaefer's method. The results were as follows: 1. The angle of curvatures were $17.3^{\circ}{\pm}5.0$ (mesial), and $27.9^{\circ}{\pm}6.0$ (distal). Distal curvature was significantly larger than mesial.(p<0.05) 2. The radius of curvatures were $8.7mm{\pm}2.5$ (mesial), and $5.8\;mm{\pm}1.5$ (distal). Mesial curvature was significantly larger than distal.(p<0.05) 3. The start of curvatures were $4.1mm{\pm}0.6$ (mesial), and $4.2mm{\pm}0.6$ (distal). There were no difference between two groups. (P<0.05)