• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.53-63
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• 1996

In order In analyze the occlusion of TMD patient, 73 casts and post eroanterior cephalometric X-rays of patients showing TMD symptoms at first interview were measured and compared that of 30 non-patients . Horizental overjet, vertical overbite, openbite, crossbite, depth of curve of Spee, midline deviation, facial asymmetry, attrition, and TPI were measured and processed statistically The results could be summarized as follows, 1. TMD group showed the highest prevalence in twenties, teens, and before 9 years old group in order, and more prevalent in female than male. 2. There were no statistically significance between two groups of overjet and overbite measurements, but showed significance of 6 classification of anterior tooth relationship between two groups TMD groups. 3. n group had more anterior openbite than normal group but there were no statistically significance between two groups. 4. Anterior crossbite was more prevalent in normal group brit posterior crossbite was more prevalent in TMD group. 5. TMD group showed deeper curve of Spee and there were statistically significance between two groups. 6. TMD group had more attrition than normal group and there were statistically significance beween two groups. 7 TMD group showed more facial asymmetry than normal group. 8. TPI did not showed statistical significance beween two groups. According to the above results, TMD group showed severe and complex mode of malocclusion and this should be carefully regarded when treatment planning and during the treatment of malocclusion.

• The korean journal of orthodontics
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• v.28 no.6 s.71
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• pp.955-974
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• 1998

The purpose of the present study was to seek bracket-adhesive combinations which have adequate bond strength with no enamel and bracket fracture. The shear bond strengths were measured, the sites of failure and the enamel damage were investigated and the peripheral sealing and adaptation between enamel surface, bonding adhesive and bracket were evaluated. 240 noncarious human premolars were divided into twenty four groups of ten teeth. Shear bond strengths of each group were determined in an universal testing machine after two days passed and the debonded specimens were inspected to determine the predominant bond failure sites. To evaluate peripheral sealing and adaption between enamel surface, adhesive and bracket, each specimen was cut longitudinally into two halves which included the midsection of the bracket, adhesive and enamel and exmined in scanning electron microscope. Six different types of brackets were bonded to the tooth with four different type of adhesives. Six different types of brackets were Image, Plastic, Crystaline, Fascination, Transcend 2000 and metal bracket and four different adhesives were No-mix, Light-Bond, OrthoLC and Superbond C&B. From this study, it may be concluded that (1) The mean shear bond strength varied from a high of 36.58 Kg (410.07 Kg/$cm^2$) with the Fascination-Light Bond combination group to a low of 8.93 Kg (75.51 Kg/$cm^2$) with theImage-OrthoLC combination group. When using OrthoLC as adhesive, the mean shear bond strength was significantly lower than that of other combination groups, (2) Regardless of adhesives, the mean shear bond strength of Fascination brackets was relatively high whereas Plastic and Image brackets had low shear bonding strength. The shear bond strength of Crystaline bracket and Transcend 2m was relatively equal to or lower than that of metal bracket, (3) There was a correlation between bond strength, enamel damage and bracket fracture. As the shear bond strength was increased, the rate of enamel damage and bracket fracture were increased, (4) The combination groups that use OrthoLC as adhesive were debonded in shear stress without enamel fracture and bracket fracture, whereas the combination groups that use Superbond C&B as adhesive experienced a relative high enamel fracture rate and bracket fracture rate, (5) Peripheral sealing and adaptation between enamel-adhesive-bracket were relatively good when using Light-Bond or No-mix as adhesive. Regardless of adhesives, adaptation between bracket-adhesive were relatively good in Ceramic brackets, (6) The combination groups which had adequate bonding strength with no enamel and bracket fracture were Crystaline-No mix, Crystaline-Light Bond, Crystaline-OrthoLC, metal-No mix, metal-Light Bond and metal-OrthoLC combination groups.

• The korean journal of orthodontics
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• v.30 no.6 s.83
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• pp.731-738
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• 2000

The purpose of this study was to investigate the change of 3 point bending properties of various nickel titanium wires after recycling. Four Types of nickel-titanium (Align: martensitic type, NiTi, Optimalloy, Sentalloy: austenitic type) wires were divided to three groups: as-received condition (T0: control group), treated in artificial saliva for four weeks (T1) and autoclaved after being treated in artificial saliva (T2). Detrimental changes were observed for the selected mechanical properties in three point bending test. Loading force at 3mm deflection, unloading force at 3mm deflection, stress hysteresis, loading force at 1mm deflection, unloading force at 1mm deflection and stress hysteresis at 1mm deflection were calculated. The findings suggest that : 1. Align demonstrated statistically significant increase In loading force (p<0.05) and unloading force (p<0.01) at 3mm deflection after recycling(T2), but NiTi, Optimalloy and Sentalloy showed no statistically difference after recycling. 2. Align demonstrated statistically significant decrease in hysteresis(p<0.01) after recycling(T2) but NiTi, Optimalloy and Sentalloy showed no statistically significant difference after recycling. 3. All wires showed no statistically significant difference in loading force at 1mm deflection after recycling(T2). 4. Align demonstrated statistically significant decrease in unloading force in 1mm deflection (p<0.05) after recycling(T2) but NiTi, Optimalloy and Sentalloy showed no statistically difference after recycling 5. Loading force and unloading force of T1 showed no significant change compared with those of T0, but loading force and unloading force of T2 showed significant changes compared with those of T0(p<0.05, p<0.01 respectively). 6. Align demonstrated a tendency to lose some of this pseudoelasticity in T1 and pseudoplasticity and pseudoelasticity in T2.

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.1-16
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• 1996

The purpose of this study was to evaluate the amount and interrelationship of the soft and hard tissue changes after simultaneous maxillary advancement and mandibular setback surgery in skeletal Class III malocclusion. The sample consisted of 25 adult patients(13 males and 12 females) who had severe anteroposterior skeletal discrepancy. These patients had received presurgical orthodontic treatment and surgical treatment which consisted of simultaneous Le Fort I or Le Fort II osteotomy and bilateral sagittal split ramus osteotomy. The presurgical and postsurgical lateral cephalograms were evaluated. The computerized statistical analysis was carried out with SPSS/$PC^+$ program. The results were as follows. 1. The correlation of maxillary hard and soft tissue horizontal changes were high and the ratios for soft tissue to A point were $71\%$ at Sn, $67\%$ at SLS and $37\%$ at LS. 2. The correlation of mandibular hard and soft tissue horizontal changes were very high and the ratios were $84\%$ at LI, $107\%$ at ILS, $96\%$ at Pog' and $97\%$ at Gn'. 3. The correlation of mandibular hard tissue horizontal changes and soft tissue vertical changes were moderate. 4. The upper to lower lip length were increased(P<0.001). 5. The soft tissue thickness were decreased in upper lip and increased in lower lip(P<0.001). The postsurgical changes were reversely correlated with initial thickness in upper lip.

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.65-82
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• 1996

This study was carried out to study the changing patterns in muscle activities in Angle's II and Class III malocclusion patients following activator therapy, To study the activities of anterior temporal(T.A.), masseter(M.M.), posterior temporal(T.P.), and anterior belly of digastric(D.A.) muscles, surface electrodes were placed on 15 Angle's Class II and 17 Angle's Class III malocclusion patients and following conclusions were obtained after electromyographic recordings were taken at prior to the activator therapy and at some time between 6 -12 month after the start of activator therapy. 1. Class II and Class III malocclusion groups, when compared to normal occlusiongroup, showed no significant differences during resting and swallowing. But significant differences were observed in masseter and posterior temporal muscles during clenching. 2. Most of the muscles studied showed a certain pattern, that is those groups whose pre-treatment E.M.G. were lower than the normal value showed significant increase after activator therapy, whereas those groups whose pre-treatment E.M.G. were higher than the normal value showed significant decrease after activator therapy. This pattern was observed in all of the muscle groups studied except T.A.(swallowing), T.P.(clenching) and D.A.(swallowing, clenching) in Angle's Class III malocclusion group and in Angle's Class II malocclusion group, above tendency were observed only in T.A.(swallowing), M.M.(resting, swallowing) and T.P.(clenching). This pattern was less obvious during clenching. 3. When E.M.G. activity after activator therapy between Angle's Class II and Class III malocclusion group was compared, Class III malocclusion group showed more increase during resting, and Class II malocclusion group showed more increase during swallowing and clenching excepting M.M. and D.A. respectively.

• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.185-197
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• 2003

This study was performed to identify the characteristics of the OFC1 gene (locus: chromosome 6p24.3) in Korean patients, which is assumed to be the major gene behind the nonsyndromic cleft lip and palate. The sample consisted of 80 subjects: 40 nonsyndromic cleft lip and palate patients (proband, 20 males and females, mean age 14.2 years); and 40 normal adults (20 males and 20 females, mean age 25.6 years). Using PCR-based assay, the OFC1 gene was amplified, sequenced, and then searched for similar protein structures. Results were as follows: 1. The OFC1 gene contains the microsatellite marker 'CA' repeats. The number of the reference 'CA' repeats was 21 times, and formed as TA(CA)11TA(CA)10. But, in Koreans, the number of tandem 'CA' repeats was varied from 17 to 26 except 18, and 'CA' repeats consisted of TA(CA)n. 2. Nine allelic variants were found. Distribution of the OFC1 allele was similar between the patients and control group. 3. There was a replacement of the base 'T' to 'C' after 11 tandem 'CA' repeats in Koreans compared with Weissenbach's report. However, the difference did not seem to be the ORF prediction results between Koreans and Weissenbach's report. 4. The BLAST search results showed the Telomerase reverse transcriptase (TERT) and the Nucleotide binding protein 2 (NBP2) as similar proteins. The TERT was a protein product by the hTERT gene in the locus 5p15.33 (NCBI Genome Annotation; NT023089) The NBP2 was a protein product by the ABCC3 (ATP-binding cassette, sub-family C) gene in the locus 17q22 (NCBI Genome Annotation; NT010783). 5. In the Pedant-Pro database analysis, the predictable protein structure of the OFC1 gene had at least one transmembrane region and one non-globular region.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.253-271
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• 1992

The purpose of this study was to investigate the difference of EMG activity of the Orbicularis oris and Mentalis muscle between normal occlusion and class III malocclusion group during various lip position and to find out whether any correlations exist between the muscular activity and craniofacial morphology. In this study, 50 subjects with a mean age of 22.9 Years (range 20.0-26.0) were investigated (25 subjects were normal occlusion, and 25 subjects were class III malocclusion). EMG data were recorded from the Orbicularis oris and Mentalis muscle during rest lip posture, lip position at maximum biting, lip position at maximum sealing effort, lip position at chewing, swallowing and phonation with the Medelec MS-25 electromyographic machine. Lateral cephalometric radiographs was taken with the mandible in intercuspal position on all subjects. All data were recorded and statistically processed. The findings of this study can be summerized as follows: 1. In normal occlusion, the maximal mean amplitude of upper lip during the lip position at chewing was lower than that of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not statistically different. 2. In Class III malocclusion, the maximal mean amplitude of upper lip during the lip position at chewing, swallowing and phonation was lower than that of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not statistically different. 3. Compare to normal occlusion, the Class III malocclusion was showed low maximal mean amplitude of upper lip during rest lip posture and the lip position at swallowing of saliva, and showed great maximal mean amplitude of lower lip and meantalis muscle during the lip position at chewing and phonation. 4. In normal occlusion, the maximal mean amplitude of upper lip during various lip position was not correlated with the length and thickness of upper lip, but the maximal mean amplitude of lower lip during the lip position at chewing and swallowing was positively correlated with the thickness of lower lip. 5. In Class III malocclusion, the maximal mean amplitude of upper lip during rest lip posture was negatively correlated with the thickness of upper lip, and the maximal mean amplitude of lower lip and mentalis muscle during the lip position at chewing and swallowing was positively correlated with the thickness of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not correlated with the cephalometric measurements of soft tissue. 6. The correlation between the maximal mean amplitude of orbicularis oris and mentalis muscle and cephalometric measurements of incisors was not nearly present. 7. In normal occlusion, the maximal mean amplitude of lower lip and mentalis muscle during the lip position at maximum biting was negatively correlated with the angle between palatal plane and mandibular plane. In Class III malocclusion, the maximal mean amplitude of upper lip, lower lip and mentalis muscle during function was negatively correlated with the length of maxilla, the maximal mean amplitude of upper lip and lower lip during function was negatively correlated with the SNA and SNPo, and the maximal mean amplitude of lower lip during the lip position at chewing was negatively correlated with the ANB.

• The korean journal of orthodontics
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• v.39 no.6
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• pp.362-371
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• 2009

Objective: The purpose of this study was to compare the longitudinal treatment effects of facemask with rapid maxillary expansion (FM/RME) and chincup (CC) therapy followed by fixed orthodontic treatment (FOT) in Class III malocclusion (CIII) patients. Methods: The samples consisted of twenty-one CIII patients who had similar skeletal and dental characteristics before FM/RME or CC therapy and good retention results (Class I molar/canine relationship and positive overbite/overjet) after FOT (Group 1, FM/RME, n = 11; Group 2, CC, n = 10). Lateral cephalograms were taken before (T0) and after FM/RME or CC therapy (T1), and after FOT and retention (T2). Skeletal and dental variables were measured. Mann-Whitney U-test and Wilcoxon signed-rank test were used for statistical analysis. Results: During T0-T1, FM/RME therapy induced forward movement of point A, and labioversion of the upper incisors. Both groups showed posterior repositioning of the mandible. FM/RME resulted in increase of the vertical dimension; however, CC caused an increase in articular angle and decrease in gonial angle. During T1-T2, both groups exhibited forward growth of point A. Group 1 showed forward growth and counterclockwise rotation of the mandible and increase of IMPA; however, Group 2, showed increase of ANS-Me/N-Me and decrease of overbite. Conclusions: The key factor for successful FM/RME and CC therapy and good retention results might be a harmonized forward growth of the maxilla that could keep pace with the growth and rotation of the mandible.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.63-69
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• 2001

Cleft lip and/or palate(CLP) is the most common congenital deformity in the craniofacial region. For a practical public health system for these patients it is necessary to have an understanding on the prevalence of CLP. However, it was difficult to estimate the exact number of CLP patients due to problems in sample selection, higher miscarriage and still birth rate, difficulty in classification, and adoptions to foreign countries. Therefore this study was to estimate the prevalence of CLP and the rate of orthodontic treatment, which is usually necessary in cleft lip and/or palate patients. The samples consisted of 218,322 Korean male adults from Seoul, Kwangju, Taegu and Pusan, all born in 1979. The screening method for recognizing the CLP patients was proceeded in steps and the results are as follows. 1. The prevalence of cleft lip and/or palate in Korean male adults born in 1979 was 0.65 out of the 1000 samples. 2. In the anteroposterior aspect of the 1000 samples, the prevalence of cleft lip, cleft lip and palate, and cleft palate was 0.26, 0.36 and 0.03 respectively. 3. In the transverse aspect of the 1000 samples, the prevalence of left, right and bilateral cleft was 0.35, 0.16, 0.12 respectively. The cleft in the left showed a much higher prevalence than in the rirht, while bilateral cleft showed a lower prevalence than unilateral cleft. 4. The orthodontic treatment rate of Korean male adults among cleft lip and/or palate Patients was $35\%$, and it was in the order of cleft lip and Palate, cleft lip, and cleft Palate, being $67\%,\;29\%\;and\;29\%$ respectively. The orthodontic treatment rate in patients with the more severe cleft lip and palate was higher than in patients solely having cleft lip or cleft palate.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.107-120
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• 2001

Nitric oxide(NO) has been reported to be one of the mediators relating to bone remodelling. Nitric oxide is synthesized from L-arguinine by nitric oxide synthetase(NOS), which is largely divided Into two groups. One group which is composed of $NOS_1\;and\;NOS_3$, is dependent of calcium or calmodulin. The other consisted of $NOS_2$, which is independent of calcium or calmodulin. NOS is thought to be a possible intermediate affecting in the course of tooth movement. This study was designed to evaluate the expression of nitrous oxide synthetase(NOS) in periodontal tissue during the experimental movement of rat incisors, by LSAB(labelled streptavidine biotin) immunohistochemical staining for $NOS_2\;and\;NOS_3$. Twenty seven Sprague-Dawley rats were divided into a control group(3 rats), and 6 experimental groups(24 rats), to which 75g of force was applied, with helical springs across the maxillary incisors. Rats of experimental groups were sacrificed at 12 hours, 1, 4, 7, 14 and 28 days after force application, respectively. After that, the tissues of the control group and experimental groups were studied immunohistochemically. The results were as follows: 1. In control group, the expression of $NOS_3$ was rare in gingiva, dentin, periodontal ligament and alveolar bone, and was mild in the capillaries of pulp and intermaxillary suture. And the expression of $NOS_2$ showed similar pattern to that of $NOS_3$. 2. There were no differences in the expression of $NOS_2\;or\;NOS_3$ in dentin, gingiva, cementum, cementoblast and odontoblast, between control and experimental groups, regardless of the duration of the force application. 3. The expression of $NOS_3$ began to increase at 4 days and showed to the highest degree at 7 days after force application, in the apical region of pressure side of periodontal ligament in experimental groups. 4. The expression of $NOS_3$ in alveolar bone was rare until 7 days, after which it increased to mild degree at 14 days through 28 days in experimental group. But there was no difference between pressure and tension side of periodontal ligament. 5. The expression of $NOS_2$ in periodontal ligament was mild from 7 days after force application, regardless of the side of periodontium, which was generally more evident than that of $NOS_3$. 6. The expression of $NOS_2$ in alveolar bone increased to mild degree at 14 days after force application, and it was evident in osteoblasts, osteoclasts and osteocytes. And the expression of $NOS_2$ was little more stronger in the tension side than that of pressure side of alveolar bone.