• The korean journal of orthodontics
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• v.32 no.1 s.90
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• pp.1-7
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• 2002

The purposes of this study were to observe the compensation pattern of human female adults with openbite tendency and to provide the decision criteria of the diagnosis and treatment planning for those patients. Fifty patients with anterior openbite and fifty-five Patients without anterior openbite patients were selected as a control and a test group. ODI of the all patients was below 66. Mean ages of the control and the test group were 23.88 ${\pm}$ 4.53 and 24.7 ${\pm}$ 6.20 years, respectively. Lateral cephalograms were taken and forty-one variables were measured. To identify the morphological differences between the groups, statistical analyses were performed. Statistically significant differences were found in the measured variables of lower face height, N-Me, ANS-Me, ANS-Me/N-Me ratio, Mx1-SN, Mx1-FH, Mx1-NA(mm), Mx1-APo, PP to Mx6, Mn1-NB(degree), Mn1-NB(mm). The test group showed decreased lower face height, N-Me, ANS-Me, ANS-Me/N-Me ratio, more uprighted and retruded maxillo-mandibular incisors. Overeruption of the maxillary first molar was found in the control group.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.267-276
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• 1999

Distributions trends were examined in 9159 malocclusion patients who had been examined and diagnosed at Department of Orthodontics, College of Dentistry Yonsei University over a 6 year-period from 1992 to 1997. The results were as follows ; 1. The total number of orthodontic patients in 1997 increased in comparing with that of 1992(86%) and after 1995, the number of annual patients showed an increase. 2. Age distribution had shown over-19 year-old group being the largest(39.9%) but percentages of pre-adolescent patients had been decreasing while that of adult patient had gradually increased. 3. Distributions in the types of malocclusion, the Angle's Classification had shown : 33.3% for Class I, 28.6% for Class II and the largest 38.1% for Class III. 4. Among Class I patients, crowding showed the largest(32.6%) and protrusion group had gradually increased to 33.9% in 1996. Otherwise openbite and crossbite groups tend to decrease, annually. 5. Geographic distribution showed a majority of patients from Seoul(above 70%). Among the patients from Seoul, group within the distance 3-6Km from Yonsei dental hospital was the largest(32.3%) and group within 9Km showed 69% of total patients.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.246-250
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• 2000

The oral screen is a functional appliance, suitable for the treatment of developing malocclusion associated with aberrant muscular patterns. The better muscle balance between tongue and the buccinator mechanism can be established, and the reestablishment of normal growth and development can be achieved. The oral screen can be used for the correction of the following conditions : (1) thumbsucking, tongue thrusting and lip biting, (2) mouth breathing, (3) mild distocclusion with premaxillary protrusion, (4) open bites in deciduous and mixed dentition, and (5) incompetent lips. The patient should wear the oral screen every night and also during the day whenever possible. The effects of oral screen can be elevated through lip seal exercise : the lips should be kept in contact all the time to improve the lip seal. In the presented two cases, the patients were considered mouth breathers and to have incompetent lips, and one patient with maxillary incisal protrusion and the other with open bite. They were instructed to wear the oral screen with lip seal exercise. After wearing the appliance for 1 and 2 years respectively, mouth breathing was decreased and lip length and strength were increased, the maxillary incisors were retruded and open bite reduced.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.219-237
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• 1999

This study was designed to evaluate the frequency and the severity of root resorption of the permanent teeth before orthodontic treatment by means of radiograph in the malocclusion patients. In this study the author analysed the frequency and the severity of root resorption in individual teeth, the relationships of the frequency and the severity of root resorption and age, sex, Angle's classification, overjet, overbite, and maxillary and mandibular incisor inclination, and the relationships of the frequency of root resorption and the characteristics of malocclusion and marked occlusal attrition showed in individual teeth. The results were as follows. 1. All of the persons examined showed some evidence of root resorption in one or more of the permanent teeth, $35.84\%$ of the teeth examined and more frequent in female group than male group(p<0.01). 2. On the susceptibility of the root resorption in individual teeth in this study, the author found the mandibular incisors and the maxillary incisors, in the order named, to be most susceptible in all affected teeth, but maxillary central incisors, maxillary first bicuspids, and maxillary lateral incisors, in the order named, were more susceptible to marked root resolution. 3. The more proclined maxillary Incisors the more affected root resorption in four maxillary incisors and the more proclined mandibular incisors the more affected root resorption in four mandibular incisors. 4. Overbite more affected root resorption than overjet, and the higher tender to openbite the more frequent was root resorption. 5. On the characteristics of malocclusion showed in individual teeth, the openbite teeth combined with crossbite, were most frequent in root resolution.

• The korean journal of orthodontics
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• v.30 no.2 s.79
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• pp.143-157
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• 2000

To investigate the developmental stages of dental and skeletal maturation by ages and the correlations among dental maturity, skeletal maturity of cervical vertebrae, and that of hand-and-wrist, the author used the cephalograms, orthopantomograms, and hand-and-wrist radiograms of 1055 patients (male 458, female 597) aged 7 to 20 years old. In the cephalograms, the skeletal maturity stages of each bone were mainly assessed by Hassel and Farman's cervical vertebrae maturation indicators (CVMI) method. In the orthopantomograms, the dental maturity stages of each tooth were mainly assessed by Nolla's tooth calcification stages method. In the hand-and-wrist radiograms, the skeletal maturity stages of each bone were mainly assessed by Fishman's skeletal maturity indicators (SMI) method. The results were as follows. 1. There was a high correlation among dental maturity, skeletal maturity of cervical vertebrae, and that of hand-and-wrist in the both sexes (P<0.001). 2. There was a high correlation (r=0.91-0.93) between skeletal maturity of cervical vertebrae and that of hand-and-wrist. 3. There was a high correlation (r>0.8) between skeletal maturity of hand-and-wrist and maturity of upper and lower canine, first premolar, and second premolar. 4. There was high a correlation(r=0.8) between skeletal maturity of cervical vertebrae and maturity of upper canine. 5. By the ages, dental maturity, skeletal maturity of cervical vertebrae, and that of hand-and-wrist were obtained in the both sexes. In summary, dental maturity, skeletal maturity of cervical vertebrae, and that of hand-and-wrist we of sufficient diagnostic worth as an index to predict adolescent growth.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.209-218
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• 2019

This study was aimed to evaluate orofacial morphologies on the cases of developmental disorders of maxillary first molars. Panoramic radiographs, lateral cephalographs, and clinical photos of 2983 children who attended the Pediatric Dental Clinic of Pusan National University Dental Hospital from 2006 to August 2017 were assessed retrospectively. 34 patients were selected whose maxillary first molars were missed or developmentally delayed unilaterally or bilaterally. Demirjian's method was used for estimating dental age, then which was compared to chronologic age of children. Parameters expressing skeletal and dentoalveolar disharmony were checked and compared with control. Additionally, occlusion relationship was evaluated. Maxillary dental age was significantly delayed compared to chronologic age. Several parameters which show skeletal open-bite tendency and skeletal class III malocclusion with maxillary retrusion were statistically significant. Anterior crossbite and edge-bite were expected in most of these cases, but compensation by occlusion and soft tissue was also verified which might mask skeletal class III tendency. Congenital missed or developmentally delayed maxillary first molars might be related with declined growth of maxilla. If developmental disorders of maxillary first molars were verified during clinical examination, careful monitoring of orofacial growth was necessary during puberty and timed orthopedic and orthodontic intervention were considered.

• Restorative Dentistry and Endodontics
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• v.29 no.1
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• pp.13-22
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• 2004

본 연구는 치수강 상아질 부위 및 상아질 접착제 종류에 따른 결합 강도를 측정하고 이들 사이의 상관관계를 구명하고자 시행되었다 45개의 대구치를 포매 후, 대조군에서는 교합면 법랑질 제거 후 ＃600 SiC paper까지 순차연마하여 상아질을 노출시켰고, 실험군에서는 치수강 개방 후 1시간동안 NaOCl에 보관 후 axial wall과 pulpal floor를 노출시켰다. 노출된 상아질 면에 상아질 접착제를 적용한 후 Z-100을 충전한 다음 40초간 광중합하였다. 사용된 상아질 접착제는 Scotchbond Multi-Purpose와 Single Bond, Clearfil SE Bond였다. $37^{\circ}C$ 증류수에 24시간 보관 후, 저속 diamond saw를 이용하여 0.7mm 두께로 수직절단하고 고속 diamond point(#104)로 단면적 $1{mm}^2$가 되도록 시편을 제작하고, Universal testing machine에서 미세인장 결합강도를 측정하였다. 1. 모든 상아질 접착제의 미세인장강도는 대조군, axial wall군, pulpal floor군 순으로 감소하는 경향을 보였다. 2. 대조군에서 SM과 BB는 SE에 비해 유의성 있게 높은 결합강도를 나타내었다(p<0.05). 3. SM과 SB는 대조군에 비해 axial wall군과 pulpal floor군에서 유의성있게 낮은 결합강도를 보였으나, SE에서는 pulpal floor군만이 유의성 있게 낮은 결합강도를 보였다(p<0.05). 4. Axial wall군과 pulpal floor군에서는 상아질 접착제의 종류에 따른 유의차를 보이지 않았다. 5. 전자현미경 소견에서는 대조군에 비해 axial wall군과 pulpal floor군이 더 부드러운 접착 계면을 나타내었다. 혼성층의 두께는 결합강도의 감소와는 관련이 없었다.

• The korean journal of orthodontics
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• v.29 no.5 s.76
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• pp.627-635
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• 1999

Soft tissue changes that occurred between presurgery to 5-years post-surgery in 49 orthognathic surgery patients whose maxillae were moved upward by Le Fort I osteotomy were examined by lateral cephalometric film. The objective of this paper was to document soft tissue changes at long-term follow-up after superior repositioning of the maxilla and to relate soft tissue and hard tissue changes in this group. The results were as follows. 1. On average, soft tissue landmarks in the nose and the upper lip were not changed statistically significantly except superior movement of superior labial sulcus and forward movement of pronasale between presurgery and 5 years postsurgery. 2. Upward and forward movement of the lower lip were found at 5 years postsurgery in comparison with presurgery and genioplasty added this effects. 3. Upper lip length and vertical dimension of upper vermilion didn't show any significant changes, but increase of lower lip length and decrease of vertical dimension of lower vermilion were statistically significant between presurgery and 5 years post-surgery. 4. The decrease of upper incisor exposure and interlabial distance from presurgery to 1 year were continued from 1 year to 5 years and the amount of the decrease was more than that of vertical movement of the maxilla by surgery. 5. Long term changes in soft tissue landmarks from 1 to 5 years postsurgery exceeded hard tissue changes, meaning soft tissue moved down more than skeletal changes.