• The korean journal of orthodontics
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• v.26 no.2 s.55
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• pp.141-151
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• 1996

This study was undertaken to assess the effect of growth on the lips. Not only does lip growth influence the stability of such orthodontic treatment; it also directly influence facial profile, in which the lips have an important part. An understanding of the growth of lips is thus central to a consideration of profile change in orthodontics. By analyzing the serial lateral cephalograms of 15 male and 15 female of 8 years old to 16 yaers old who have normal occlusion. The result of this study were summerized as follows; 1. The largest growth increments in the length of the lips was mod age of 14 in both sexes. 2. The thickness of lips showed lager value for the male than that of the female in the most age group. The lagest growth increments at A point was occured age of 14, while Ls, Li, B point decreased after the age of 10-11. 3. The largest increase in the interval between crest of lower lip and edge of upper incisors was occured between ages 9 and 11 in males. The interval decreased slightly from 8 to 16 years in females. 4. The nasolabial angle decreased slightly from 8 to 16 years in both sexes. 5. The mentolabial angle showed large variation.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.4
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• pp.409-415
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• 2019

Cleidocranial dysplasia (CCD) is an autosomal-dominant disease characterized by the delayed closure of cranial sutures, defects in clavicle formation, supernumerary teeth, and delayed tooth eruption. Defects in the Runt-related transcription factor 2 (RUNX2), a master regulator of bone formation, have been identified in CCD patients. The aim of this study was to identify the molecular genetic causes in a CCD family with delayed tooth eruption. The 23-year-old female proband and her mother underwent clinical and radiographic examinations, and all coding exons of the RUNX2 were sequenced. Mutational analysis revealed a single nucleotide deletion mutation (NM_001024630.4 : c.357delC) in exon 3 in the proband and her mother. The single C deletion would result in a frameshift in translation and introduce a premature stop codon [p.(Asn120Thrfs^*24)]. This would result in the impaired function of RUNX2 protein, which may be the cause of delayed eruption of permanent teeth in the family.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.15-23
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• 2000

Streptococcus salivarius is a normal inhabitant in the human oral cavity. Streptococcus salivarius 119 in this study was isolated from the oral cavity of child and identified, and its action mechanism on the formation of denal plaque by Streptococcus matans was studied. 1. The optical density of absorbance at 550 nm was 0.327 in the culture of Streptococcus mutans in disposable cuvette, whereas being 0.119 in the combined culture of Streptococcus mutans and Streptococcus salivarius 119. 2. The mean weight of produced artificial plaque on the wires in the beaker was 84.7mg in culture of Streptococcus mutans only, whereas being reduced to 12.3mg in the combined culture of Streptococcus mutans and Streptococcus salivarius 119. 3. When Streptococcus mutans was cultured in the media containing culture supernatant of Streptococcus salivarius 119 in BHI broth, the mean weight of produced artificial plaque was 100.5mg on the wires, whereas being reduced to 20.4mg in the media containing culture supernatant of Streptococcus salivarius 119 in BHIS broth. 4. The viable cells of Streptococcus oralis and Streptococcus salivarius 119 were $4.8\times10^7\;and\;7.5\times10^8$ per ml respectively after each culture, wheras being $4.2\times10^7\;and\;5.8\times10^7$ per ml in the combined culture of Streptococcus oralis and Streptococcus salivarius 119. 5. The polymer produced by Streptococcus salivarius 119 was glucan on the thin layer chromatography. 6. The glucan produced by Streptococcus salivarius 119 was water-soluble glucan containing $1\rightarrow6$ linkages as the main linkage on the thin layer chromatography. These results suggested that isolated Streptococcus salivarius 119 inhibited the formation of artificial plaque by the production of water-soluble glucan.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.297-313
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• 1997

The purposes of this study were to compare the soft tissue changes following hard tissue change after surgery between the one jaw and two-jaw surgery in skeletal class III patients and to get the reference of the incisal inclination at presurgical orthodontics. For this study 24 patients for the two-jaw surgery group and 18 patients for one jaw surgery group were selected. Lateral cephalograms were taken at pretreatment, after presurgical orthodontic treatment, immediately after surgical treatment and at least 6 months after surgery. They were traced and analyzed on skeletodental structure and soft tissue. The results were as follows: 1. After surgery, maxilla, maxillary incisors and upper lip were moved anteriorly and superiorly in two-jaw surgery group. Mandible and mandibular incisors were moved posteriorly and superiorly, and thickness of lower lip was increased in both group but there were no statistically significant difference. Anterior facial height was more decreased in two-jaw surgery group (p<0.05). At least 6 months after surgery, by the postorthodontic treatment, maxillary incisors were moved labially 1.44mm, mandible and mandiibular incisors were moved lingually 1.43mrn, 1.26mm respectively in one jaw surgery group. But there was no statistically significant changes of hard tissue in two :jaw surgery group. 2. The correlation coefficients of maxillary hard and soft tissue horizontal changes were high in two jaw surgery group and the ratios for soft tissue to A point were 19% at Sri, 80% at SLS, 82% at LS. The ratios for soft tissue to B point were 92% at LI, 104% at ILS in one jaw surgery group, 89% at LI, 101% at ILS in two-jaw surgery group. 3. The correlation coefficients and change ratios of mandibular incisors and LL HS on lower lip horizontal changes were 0 0.89 and 75%, 85% in one jaw surgery group, 0.93, 0.90 and 76%, 87% in two-jaw surgery group. The correlation coefficients of maxillary incisors and Sn, SLS and LS on upper lip horizontal changes were 072, 0.76 and 0.75 in two jaw surgery group and ratios of changes were 57%, 58% and 59%. 4. The regression equations between skeletal horizontal discrepancy and incisal inclinaton were taken in one jaw surgery group. Those were FMIA=57.48-2.17ANB, U1-SN=-75.02+2.17SNB and $R^2$ were 0.63, 063 respectively. So if there is skeletal horizontal discrepancy by mandibular prognathism in one jaw surgery case, we consider attaining more labial inclination of maxillary incisors than normal and more lingual inclination of mandibular incisors than normal. But correlation coefficient of the regression equations in two jaw surgery group was low, so, that equation was not reliable.

• The korean journal of orthodontics
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• v.36 no.2 s.115
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• pp.103-113
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• 2006

Most elderly women experience a decrease in their bone density due to a deficiency of calcium intake, ovariectomy, or menopause. This study evaluated the usability of the microscrew as a skeletal anchorage system in these orthodontic treatment cases, using rats as a research group. The 4 month old sprague-dawley species rats were divided into two groups, the OS (Ovariectomy Screw), and the SS (Sham operation Screw) group. In both the OS and SS groups, microscrews were implanted into the palatal bone between the upper molar teeth and two upper incisors were retracted using NETE coil spring with 75 g of force. After 3days, the again after 7 days, 7 rats in each group were sacrificed. Three days before they were sacrificed, Alizarin red S was intraperitoneally injected, and their maxillary bone, tibia and blood from their hearts were taken. The components of the extracted blood were biochemically analyzed and non-decalcified grinding resin sections for maxillary bone and tibia were made. The sections were examined with a polarization microscope, and fluorescent microscope. Smaller concentrations of Ca and P, the inorganic substances closely related to bone density, were found in the extracted blood of the OS group. Both OS and SS groups showed a possibility of bone remodeling with a high concentration of ALP after 7 days. An increase in bone density on the tension and compression sides of the microscrew and the tension side of the tooth for both OS and SS groups was confirmed with a polarization microscope. However, the bone density of the pressure side of the tooth and apical side was decreased. More deposits of Alizarin red S in the bone after 7 days rather than 3 days seen with a fluorescent microscope suggested the existence of new bone formation.

• Journal of dental hygiene science
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• v.11 no.2
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• pp.69-76
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• 2011

The aim of this study was to compare the effects on the resistance to demineralization by the frequency and method of fluoride application in vitro. ninety-one human enamel specimens were embedded in acrylic resin with the labial surfaces exposes. The specimens were divided into 7 groups; (1) non-treated; (2) 1.23% APF gel 1 time; (3) 2% NaF sol 1 time; (4) 2% NaF sol iontophoresis 1 time; (5) 1.23% APF gel 4 time; (6) 2% NaF sol 4 time; (7) 2% NaF sol iontophoresis 4 time. All the groups were immersed in the remineralizing solution (RS) before baseline and divided into 7 test groups of 13 specimens each. All the specimens were exposed to a pH-cycling model which consisted of demineralization (6 hours) and remineralization (18 hours) for 5 days. The Vickers surface micro-hardness number of all the specimens was measured using microhardness tester and the specimen surfaces were observed by scanning electron microscope (SEM). The results were analyzed using one-way ANOVA followed a Tukey's multiple comparison at a significance level of 0.05. The group 7 showed higher level of microhardness after Fluoride application. The group 1 showed lowest level of microhardness but group 7 showed higher level of microhardness after pH-cycling model, there were significant differences between groups. After the modified pH-cycling, the 2% NaF solution with the iontophoresis group showed the best resistance to demineralization(p<0.05). These results were also confirmed by SEM. The fluoride iontophoresis method was the most effective of the regimens in increasing the acid resistance of the enamel.

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.743-760
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• 1997

This study was done to evaluate the correlations between the size, the form of the cranial base, head posture and the horizontal and vertical position of craniofacial structures. For this purpose, 100 cephalometric radiographs were taken from the sample composed of 51 male and 49 female, 12 measurement criteria and 37 reference points were established and digitized, then calculation was performed for the values of measurement variables and the horizontal and vertical position of reference points. The correlations be4ween them were analyzed statistically and mean facial diagrams were constructed and compared with the selected groups which were composed of 10 Samples each as large and small group from the measurement value. The following results were obtained: 1. The angles n-s-ba and n-s-ar as variables for the ion of cranial base correlated highly to the horizontal and vertical position of reference points in the cervical column with statistical significance($0.1\%$ level). 2. The angles n-s-ba and n-s-ar as variables for the form of cranial base correlated to the horizontal position of the reference points in the facial structure with statistical significance($1\%$ level), but not to the vertical position of them($5\%$ level). 3. The length n-s, s-ba, and n-ar as variables for the size of cranial base were correlated th the position of craniofacial structures in various ways, but in general, highly correlated to the horizontal and vertical position of midfacial structures around the teeth and alveolar area. 4. the angle NSL/CVT and NSL/OPT as postural variables tot the inclination of cranial base and cervical column were correlated to the horizontal position of the craniofacial structures with statistical significance($1\%$ level), but not to the vortical position of them($5\%$ level). 5. The angle OPT/HOR and CVT/HOR as postural variables lot the inclination of cranial base and true horizontal line were not correlated to the horizontal and vertical position of the craniofacial structures with statistical significance($5\%$ level). 6. The correlation between the measurement variables and horizontal and vortical positions of the reference poits in soft tissue were shown as similar to the related hard tissue points.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.351-360
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• 2000

The purpose of this study was to evaluate the microleakage of class V compomers according to acid etching treatment and treatment times. Extracted 180 sound human molar teeth were selected then prepared physiologic pulpal pressure far this experiment. In this study class V cavities were prepared on buccal surface with gingival margin located in 1mm superior to CEJ under simulate physiological conditions. These specimens were randomly divided into 6 groups of 30 each and restored following methods : A: Dyract AP + Prime&Bond 2.1 Group 1 : No acid etching, according to manufacturer's instruction. Group 2 : 15 seconds acid etching and same method with Group 1. Group 3 : 30 seconds acid etching and same method with Group 1. B: F2000 groups + Single Bond adhesive Group 1 : No acid etching, according to manufacturer's instruction. Group 2 : 15 seconds acid etching and same method with Group 1 Group 3 : 30 seconds acid etching and same method with Group 1. After 500 thermocycling between $5^{\circ}C\;and\;55^{\circ}C$, the specimens were sealed with glass ionomer and nail varnish then placed in 5% methylene blue dye for 5 hours and rinsed with tab water. The specimens were embedded in orthodontic clear resin, then sectioned buccolingually through the center of restoration with a low speed diamond saw. The dye penetration on each of the specimens were then observed with a stereomicroscope at $\times20$ magnification. The results of this study were statistically analyzed using the indepedent sample t-test and analysis of variance. Results were as follows, 1. In occlusal walls, microleakage were significantly reduced in acid etched group restored with Dyract AP but no statistically significance in F2000 groups. 2. In gingival walls, microleakage were significantly reduced in group 2 restored with Dyract AP, and group 2 and group 3 in F2000 groups. 3. All groups, except group 3 in Dyract AP, showed significantly less microleakage in occlusal wall than gingival wall. 4. No statistical significance were showed between group 2 and group 3 in both materials.