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The effects of plaque control instruction in orthodontic patients.

Young Ji JAE ; Jin Beom KIM ; Woo Sung SON

Korean Journal of Orthodontics.1995;25(1):221-231.

The purpose of this study w-s to predict the respose to the chincap therapy from the initial cephalometric measurements and to obtain the indication of chincap therapy. 40 patients selected for this study were classified into two groups by the occlusal stability after completion of permanent dentition and the iiu4n ovement of facial profile, after chincap therapy. One was g response group which consisted of 25 children and the other was poor response group with 15 patients. Various measurements of the craniofacial structure in the initial lateral cephalogram were calculated and analyzed by t-test and discriminant analysis. The results were, as follows 1. Good response group had more horizontal growth pattern in initial stage of treatment, and the contributing measurements were Bjork sum, anterior-posterior facial height ratio, gonial angle, lower gonial angle and occlusal plane to AB plane angle. 2. The critical points and predictive values of the influential skeletal measurements were calculated. 3. The discriminant function was obtained from three. major influential measurements; Bjork sum, gonial angle and occliml plane to AB plane angle, and this function could discreminate correctly in 85% of this samples.
Child ; Dental Occlusion ; Dentition, Permanent ; Humans

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An experimental study on the fatigue characteristics of orthodontic brackets bonded to enamel.

Hae Woon CHOI ; Jeong Gee KIM

Korean Journal of Orthodontics.1995;25(1):55-72.

The purpose of this study is to evaluate the effects of mechanical and thermal fatigue on the shear bond strength(SBS) in orthodontic brackets bonded to human premolars with chemically cured adhesive(Mono-Lok(2), Rocky Mountain Orthodontics). Two types of metal brackets (Ormesh, Microloc) and three types of ceramic brackets (Fascination, Starfire, Transcend 2000) were used in this study. The 10(6) loadcycles of l7.4 x 10(2)sin2piftl g,cm and the 1,000 thermocycles of 15 second dwell time each In 5degrees C and 55degrees C baths were acturated as mechanical and thermal fatigue stress, and SBS were measured after each fatigue test. The fracture sites were examined by stereoscope and scanning electron microscope. The results obtained were summarized as follows ; 1. In static shear bond test, Fascination brackets showed the maximum SBS(20.78+/-3.45 MPa) and Microloc brackets showed the minimum SBS(14.88+/-3.10 MPa). Fascination and Starfire brackets showed significantly greater SBS than Microloc brackets(P<0.05). 2. In mechanical fatigue test, Fascination brackets showed the maximum SBS (20.19+/-3.45 MPa) and Starfire brackets showed the minimum SBS(9.10+/-8.33 MPa). The SBS of Transcend 2000 brackets(P<0.01) and Starfire brackets(P<0.05) significantly decreased after 106 loadcycles. 3. In thermocycling test, Ormesh brackets showed the maximum SBS (19.36+/-2.76 MPa) and Starfire brackets showed the minimum SBS(l1.94+/-6.86 MPa). The SBS of Transcend 2000(P<0.01), Microloc and Starfire brackets(P<0.05) significantly decreased after 10(3) thermocycles. 4. Failure sites of thermocycling groups were similar to those of static groups but after mechanical fatigue test, Ormesh and Transcend 2000 brackets failed at the bracket/resin interface and Microloc brackets failed within adhesive. Facination brackets failed at the enamel/resin interface irrespective of experimental condition.
Adhesives ; Baths ; Bicuspid ; Ceramics ; Dental Enamel* ; Fatigue* ; Humans ; Orthodontic Brackets*

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A study on metal release of tin ion-plated stainless steel orthodontic appliances.

Myung Sook KIM ; Jae Hyun SUNG ; Oh Won KWON

Korean Journal of Orthodontics.1995;25(1):43-54.

This study was conducted to examine the metal release of TiN-plated stainless steel orthodontic appliances by constructing the simulated orthodontic appliances equivalent to maxillary half arch, by dividing into TiN-plated and TiN-nonplated groups and by dividing again these groups into welded and nonwelded groups. And then, the total quantity of metal release was obtained by measuring the amounts of both soluble and precipitated nickel and chromium after immersing in artificial saliva for 15 days. And then, the corrosion appearance of surface structure was observed by using SEM. The results of this study were summarized as follows. 1. The total amounts of released nickel and chromium showed that the TiN-plated group after welding (Group I) was 25.46microgram, respectively, and 17.4microgram, while the TiN-nonplated group after welding(Group III) was 54.69microgram, respectively, and 85.27microgram. Then, the TiN-plated group indicated less amounts of metal release(p<0.05). 2. The total amounts of the TiN-plated group without welding (Group II) was 0.05microgram and 0.34microgram, respectively. Then, it was shown that the TiN-plated group without welding(Group II) indicated less metal release than that of the TiN-plated group after welding(Group I)(p<0.01, p<0.05). 3. When observing their surface structure, there were a lot of precipitate and pitting corrosion in the groups with welding(Group I & III), when the TiN-plated group(Group I) showed lower level than the TiN-nonplated group(Group III). On the other hand, the groups without welding(Group II & IV) indicated a little of pitting corrosion. 4. In case of observation with the naked eyes, it was shown that there were significant discoloration and corrosion in the groups with welding(Group I & III), while there was no any remarkable change in the groups without welding(Group II & IV).
Chromium ; Corrosion ; Hand ; Nickel ; Orthodontic Appliances* ; Saliva, Artificial ; Stainless Steel* ; Tin* ; Welding

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A study of bracket position in Korean.

Sun Bok LEE ; Dong Joo LEE

Korean Journal of Orthodontics.1986;16(2):107-114.

This study was undertaken to determine the adequate bracket positron m Korean. The subjects were consisted of casts and photographs of 30 males & 30 females. They had acceptable profile, normal occlusion, no loss of teeth and no experience of dental treatment. The following conclusions were obtained. 1. In case of no necessity of the posterior teeth movement, bracket angulation was made automatically by paralleling the bracket slot with occlusal plane. 2. Axial inclination of all teeth were measured, and those of canine & premolar were much variable. 3. Adequate bracket position of Korean occlusion were obtained.
Bicuspid ; Dental Occlusion ; Electrons ; Female ; Humans ; Male ; Tooth

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A comparative study of the tongue, mandible and hyoid bone position between the adenoid hypertrophied children and the normal children.

Gong Geun LEE ; Young Kyu RYU

Korean Journal of Orthodontics.1986;16(2):99-106.

The author studied 21 adenoid hypertrophied children and 50 normal children by the horizontal, vertical and angular measurements to analyze, the effects of the lymphadenoid hypertrophy to the tongue, mandible, and hyoid bone position. The results were as follows; 1. The tongue of the Adenoid hypertrophy children was positioned more anterior and lower than that of the normal children. 2. The horizontal, vertical, and angular measurements of the mandible position were larger in the experimental group and especially ANS to ME, PNS to MP, PTM to MP, PP to MP, FOP to MP showed statistically significant difference. 3. The measurements of the hyoid bone position were also larger in the experimental group.
Adenoids* ; Child* ; Humans ; Hyoid Bone* ; Hypertrophy ; Mandible* ; Tongue*

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The effect of lip thickness on lip profile change after orthodontically treated patients with 4 first bicuspid extraction.

Sun Hyung PARK ; Sung Hun PARK ; Young Moon CHO ; Jung Hoon KIM

Korean Journal of Orthodontics.2002;32(5):355-360.

After orthodontic treatment, there are several changes in soft tissue profile. Changes appear at lower anterior facial profile area, especially upper and lower lip. But there are many individual variations in the pattern of changes. So, this study was conducted to find out that the basic upper lip thickness could be one of the factors that could influence the treatment results. The samples were composed of 43 adult patients who had their 4 first premolars extracted. Groups were classified by their basic lip thickness. In group 1(thin upper lip group), there was negative relationship between mentolabial angle and lower lip change. In group 2(average lip thickness group), upper lip change was related to upper incisor change, lower incisor change, lower lip change and nasolabial angle change. And lower lip change was related to upper lip change, upper incisor change, lower incisor change. In group 3(thick upper lip group), there was no relation between both lip change and other variables.
Adult ; Bicuspid* ; Humans ; Incisor ; Lip*

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A proposal of landmarks for craniofacial analysis using three-dimensional CT imaging.

Hye Sook CHANG ; Hyoung Seon BAIK

Korean Journal of Orthodontics.2002;32(5):313-325.

Three-dimensional CT imaging is efficient in examining specific structures in the craniofacial area by reproducing actual measurements through minimization of errors from patient movement and image magnification. Due to the rapid development of digital image technology and the expansion of treatment range a need for developing three-dimensional analysis has become urgent. Therefore the purpose of this study was to evaluate the percentage of error and magnification of three-dimensional CT using a dried skull and Vworks programTM (Cybermed Inc., Seoul, Korea) and also to obtain landmarks that are easy to designate and reproduce in three-dimensional images using the Vmorph-proto programTM (Cybermed Inc., Seoul, Korea). The following conclusions were obtained; 1. In the comparison of actual measurements from the dried skull and the three-dimensional image obtained from the Vworks program, the mean error was 0.99mm and the magnification was 1.04%. 2. Clinically useful hard tissue landmarks from three-dimensional images were Supraorbitale, Lateral orbital margin, Infraorbitale, Nasion, ANS, A point, Zygomaticomaxilla, Upper incisor, Lower incisor, B point, pogonion, Menton, PNS, Condylar inner margin, Condylar outer margin, Porion, Condylion, Gonion1, Gonion2, Gonion3, Sigmoid notch and Basion. 3. Clinically useful soft tissue landmarks from three-dimensional images were Endocanthion, Exocanthion, Soft tissue Nasion, Pronasale, Alare lateralis, Upper nostril point, Lower nostril point, Subnasale, Upper lip point, Cheilion, Stomion, Lower lip center, Soft tissue B, Pogonion, Menton and Preaurale. The Vworks program can be considered a clinically efficient tool to produce and measure three-dimensional images. Most of the hard and soft tissue landmarks proposed above are anatomically important points which are also easily reproducible and designated. These landmarks can be beneficial in three-dimensional diagnosis and the prediction of changes before and after surgery.
Colon, Sigmoid ; Diagnosis ; Humans ; Imaging, Three-Dimensional ; Incisor ; Lip ; Orbit ; Seoul ; Skull

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A model and cephalometric study on the percentage of anterior overbite.

Seung Jong PARK ; Dong Joo LEE

Korean Journal of Orthodontics.1986;16(2):81-97.

The purpose of this study was to investigate the factors which cause the differences in the percentage of anterior overbite in spite of normal molar relationship in terms of skeletal, dental and dentoalveolar relations. The models and cephalograms taken from 154 subjects, 89 of shallow overbite and 65 of deep overbite ranging from 18 to 29 years of age were studied and analyzed statistically. The results were as follows 1. In determining the percentage of anterior overbite, the significant differences were higher in the dental and dentoalveolar factors than in the skeletal factors and were higher in the proportional and angular measurements than in linear measurements. 2. The factor which had the greatest influence on the percentage of anterior overbite was the proportional parts of the dental and dentoalveolar heights. 3. The most influencing factor which determined the percentage of anterior overbite was the SN-MP angle among the skeletal factors.
Molar ; Overbite*

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Orthodontic consideration of nasopharyngeal obstruction.

Young Il JANG

Korean Journal of Orthodontics.1986;16(2):19-29.

No abstract available.

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The effect of treatment timing on maxillary protraction treatment response: A comparison of prepubertal and pubertal patients.

Kyung Ho KIM ; Kwang Chul CHOY ; Hyoung Seon BAIK ; Ji Hyun LEE

Korean Journal of Orthodontics.2002;32(5):301-312.

Treatment timing is a very important factor to consider in treating skeletal Class III patients by means of maxillary protraction. According to the literature maxillary protraction should be carried out at an early age before puberty. However, no scientific data were presented to support this statement and recent studies supported by statistical data showed disagreement concerning the optimum treatment time of maxillary protraction. Therefore, there is no agreement about the optimum treatment time of maxillary protraction. In this study hand-wrist X-rays were taken from 119 patients and subjects were grouped into prepubertal and pubertal group according to their skeletal maturity. Pretreatment and posttreatment lateral cephalometric X-rays were taken and treatment effects were compared. The average treatment time was 6.5 months for the prepubertal group and 6.1 months for the pubertal group. The obtained results were as follows; 1. The amount of maxillary forward movement was the same for prepubertal and pubertal group. 2. The amount of maxillary downward movement was the same for prepubertal and pubertal group. 3. The amount of mandibular downward and backward rotational movement was the same for prepubertal and pubertal group. 4. Dental effects were the same for prepubertal and pubertal group.
Adolescent ; Humans ; Puberty

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