• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.247-261
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• 1995

The purpose of this study was to quantitate differences in the nature of the correction of Angle's Class II div 1 malocclusion dependent on the patient's age at the time of treatment. The sample consisted of 27 female patients in the adolescent group with a mean initial records age of 11.8 years and 25 female patients in the adult group with a mean starting age of 21.1 yrs. Lateral cephalometric head films were taken before and after orthodontic treatment with four bicuspid extraction. The results were obtained as follows. 1. None of maxillary skeletal parameters exhibited a significantly different in treatment change between adolescents and adults. But, in mandibular skeletal measurements, there were significant differences between two groups. (P<0.05) 2. Measures of vertical dimension in the adults remained unchanged during treatment, reflecting the effective absence of growth. 3. The steepness of occlusal plane in the adults changed significantly.(P<0.05) In contrast, the adolescents displayed stability of the occlusal plane. 4. According to the Johnston analysis, there was a significant difference in the total molar correction between two groups.(P<0.05) 5. According to the Johnston analysis, differential mandibular growth in the adolescents contrubuted $63\%$ of the total molar correction, with orthodontic tooth movement accounting for the remaining $37\%$. In the adults, dental movement comprised $99\%$ of the correction.

• The korean journal of orthodontics
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• v.25 no.4
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• pp.425-432
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• 1995

The purposee of this study is to investigate the correlation between the horizontal and vertical discrepancy of facial bones and the horizontal and vertical position of glenoid fossa. For this study, the cephalograms were taken to the adults over 18 of age(96 men and 108women). The cephalograms were divided into three groups according to the ANB angle(below 0.5 degree, 0.5 to 4.0 degree and above 38 degree), and they were divided into three groups according to the SN-MP angle(below 30 degree, 30 to 38 degree and above 38 degree). The following conclusions were obtained : 1. In the horizontal discrepancy of facial bone(ANB), the horiontal position of glenoid fossa(X) was anterior position as the order of Class II, Class I, Cias III. 2. The horizontal position of glenoid fossa(X) showed the significant correlation with ANB and SNB, but not with SNA. 3. In the vertical discrepancy of facial bone(SN-MP), thee less anglee was the greater vertical position of glenoid fossa (X) and was followed by the medium and high angle in order. 4. The vertical position of glenoid fossa(Y) showed thhat the SN-FH was the most significant correlation, and it was followed as the order of SN-FH, SN-MP and SN-OP angle. 5. There was the samllest length of anterior cranial base in the Class III malocclusion.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.47-56
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• 2012

As attractive lips are important component of appealing faces, the study was conducted to investigate the association of mouth-breathing and thickness of lower lips in mouth-breathers and nasal-breathers. The subjects were 436 adolescent patients aged 8~18 years who took cephalometrics. The results were as follows. The ratio of lower lip thickness to that of upper lip thickness in mouth breathing and nasal breathing groups were $1.13{\pm}0.14$, $1.02{\pm}0.14$, respectively. According to subjects' skeletal pattern, the ratio in Class I sample was $1.05{\pm}0.09$. Class II subjects showed $1.20{\pm}0.12$, and Class III showed $0.97{\pm}0.11$. Mouth - breathers had higher lower/upper lip ratio than nasal breathers meaning their lower lips were thicker. Skeletal Class II patients group showed the most thickest lower lips among Class I, II, III subgroups.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.461-471
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• 2005

The purpose of this study is to develop soft tissue cephalometric standards in children with normal occlusion and to determine the differences between males and females and the differences according to age ranges of 9, 10 and 11 years. The lateral cephalometric radiographs of 169 children(82 boys, 87 girls) among the contestants in 2000-2004 Healthy Dentition Contest in Seoul were studied with several soft tissue profile analyses and cephalometric means and following results were obtained. 1. The sex differences were not statistically significant between males and females soft tissue parameters except for two soft tissue parameters(p>0.05). 2. Females had relatively more protrusive lower lip relative to the H line than males and middle third face height to lower third face height of females was larger than males(p<0.05). 3. The age differences in soft tissue parameters were not statistically significant according to age ranges of 9, 10 and 11 years(p>0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.147-157
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• 2019

This study aimed to evaluate skeletodental characteristics of patient with maxillary lateral incisor agenesis (MLIA) in mixed dentition. It involved the children in early mixed dentition who visited Pusan National University dental hospital for orthodontic purposed and had intact primary canines. 38 children with MLIA and 38 controls with the same chronological age satisfying the inclusion criteria were selected. The craniofacial structures and dental arch dimensions of the MLIA were evaluated using model & cephalometric analysis and compared to controls. The rate of unilateral MLIA was high in male and the rate of bilateral MLIA was high in female. In model analysis, the width / length ratio of maxillary anterior portion of the MLIA group were higher and arch perimeter of the maxilla of the MLIA group were smaller than those of the control group (p = 0.003, 0.04). Cephalometric analysis showed that there were no significant differences in terms of skeletal, dental analysis. In soft tissue profile, nasolabial angle was larger in MLIAs than in controls (p = 0.039). Considering these skeletodental characteristics of MLIA, early diagnosis and proper management is highly recommended to minimize the possibility of functional defect.

• The korean journal of orthodontics
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• v.35 no.6 s.113
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• pp.475-484
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• 2005

This study was performed to investigate the reproducibility of the horizontal and midsagittal planes, and to suggest a stable coordinate system for three-dimensional (3D) cephalometric analysis. Eighteen CT scans were taken and the coordinate system was established using 7 reference points marked by a volume model, with no more than 4 points on the same plane. The 3D landmarks were selected on V works (Cybermed Inc., Seoul, Korea), then exported to V surgery (Cybermed Inc., Seoul, Korea) to calculate the coordinate values. All the landmarks were taken twice with a lapse of 2 weeks. The horizontal and midsagittal planes were constructed and its reproducibility was evaluated. There was no significant difference in the reproducibility of the horizontal reference planes, But, FH planes were more reproducible than other horizontal planes. FH planes showed no difference between the planes constructed with 3 out of 4 points. The angle of intersection made by 2 FH planes, composed of both Po and one Or showed less than $1^{\circ}$ difference. This was identical when 2 FH planes were composed of both Or and one Po. But, the latter cases showed a significantly smaller error. The reproducibility of the midsagittal plane was reliable with an error range of 0.61 to $1.93^{\circ}$ except for 5 establishments (FMS-Nc, Na-Rh, Na-ANS, Rh-ANS, and FR-PNS). The 3D coordinate system may be constructed with 3 planes; the horizontal plane constructed by both Po and right Or; the midsagittal plane perpendicular to the horizontal plane, including the midpoint of the Foramen Spinosum and Nc; and the coronal plane perpendicular to the horizontal and midsagittal planes, including point clinoidale, or sella, or PNS.

• The korean journal of orthodontics
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• v.32 no.3 s.92
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• pp.155-163
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• 2002

This study was performed to assess the accuracy of computer-based treatment prediction for soft tissue profile using Quick Ceph Image $Pro^{TM}\;&\;Quick\;Ceph\;2000^{TM}$ in bimaxillary protrusion cases. The Ore- and post-treatment lateral cephalograms of 21 female adults treated by low first premolar extraction were imaged and 9 landmarks and 27 specific soft tissue mesurements were digitized for comparing actual treatment results with computer simulations. The results of this study showed that Quick Ceph Image $Pro^{TM}\;&\;Quick\;Ceph\;2000^{TM}$ tends to overestimeate horizontal changes and underestimate vertical changes. In the computer simulation, upper lip showed rolling tendency. The upper lip measurements were disposed to be regular direction hut lower lip measurements were varied case by case even if it was statistically insignificant.

• Korean Journal of Cleft Lip And Palate
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• v.7 no.2
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• pp.77-91
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• 2004

본 연구의 목적은 반안면왜소증 환자의 하악골 신장술시 초기 치아골격 특성들 중에서 치료결과의 차이에 기여하는 인자를 찾는 것이다. 치료전의 치아골격 특성, 골신장술의 효과와 그 유지상태를 관찰하기 위하여 골신장술 직전(T0), 직후(T1), 추적 2년후(T2)에 측모와 정모 두부방사선 계측사진을 촬영하여 전후방, 수직치아, 비대칭 항목들을 계측하였다. T2 시기의 계측 결과에 따라서 환자들을 1군(양호군, 10명)과 2군(불량군, 9명)으로 분류하였다. 두 군에서 각 시기와 T0-T1, T1-T2 동안의 변화량의 차이를 Mann-Whitney U test, Wilcoxon signed independent t-test, rank test, ANOVA test를 사용하여 분석하였다. pruzansky type이 골신 장술의 성공과 실패 여부와 관계가 깊게 나타났다. T0 시기에 2군은 1군에 비하여 하악골이 후방위치되었고, 하악지 고경(ramus height)이 짧았고, 하악각(gonial angle)이 컸으며, 이환측 하악지가 내측경사되었고, 이환측으로의 이부변위(chin point deviation)가 크게 나타났다. 1군에서 골신장술의 주요한 효과는 하악지 고경의 증가, 하악골의 전방위치, 하악각의 증가, articular angle의 감소에 따른 하약골의 반시계방향 회전, 이환측의 하악지 경사의 증가, 교합면경사와 이부변위의 개선으로 나타났다. 그러나 2군에서는 골신장술을 시행했을 때 1군에 비하여 하악골이 시계방향으로 회전되었고 하악지 고경의 증가량이 작게 나타났다. T2 시기에 2군에서는 하악골의 반시계방향 회전이 나타났고, 하악지 성장이 일어나지 않았으나, 1군은 반대의 경향을 보였다. 이러한 인자들이 골신장술 결과의 차이에 기여하는 것으로 생각된다.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.517-523
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• 2000

Nasopharyngeal closure is a sphincter mechanism between the activities of the soft palate, lateral pharyngeal wall and the posterior pharyngeal wall, which divides the oral cavity and the nasal cavity. It participates in physiological activities such as swallowing, breathing and pronunciation. In case of an error in this mechanism, it is called a nasopharyngeal incompetence. The causes of this error are defects in (1) length, function, posture of the soft palate (2) depth and width of the nasopharynx, (3) activity of the posterior and lateral pharyngeal wall. The purpose of this study is to analyze the nasopharynx of cleft palate patients using lateral cephalograms and at the same time, evaluate the degree of hypernasality of each vowels to find its relationship with nasopharyngeal incompetence. The following results were obtained: 1. The length of the soft palate was markedly short than normal. 2. The adequate ratio was smaller than the normal value. 3. As the adequate ratio decreased, when articulating vowels, anatomic mVPI increased. 4. When articulating each vowels, anatomic VPI was in proportion with the degree of hypernasality. 5. The degree of hypernasality was greater in high vowels(/i/, /u/) than low vowel(/a/). From the above results, it can be concluded that in cleft palate patients, lateral cephalograms can be used effectively in diagnosing and evaluating nasopharyngeal incompetence. The anatomic structure of the nasopharynx has close relation to the degree of hypernasality.

• The korean journal of orthodontics
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• v.41 no.4
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• pp.255-267
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• 2011

Objective: The purpose of this study was to confirm the reliability of a cone beam computed tomography (CBCT)-generated panoramic view based on a CBCT 3D image and to find the most helpful 2D panoramic image compared with CBCT 3D image when examining the mesiodistal tooth axis. Methods: A test model was constructed according to cephalometric norms. The test model was repeatedly repositioned for CBCT and panoramic radiographic imaging. Panoramic radiographs were acquired at each of the following 3 occlusal plane positions: $-5^{\circ}$, $0^{\circ}$, and $+5^{\circ}$. Measurements of mesiodistal tooth axis in CBCT 3D image, CBCT-generated panoramic view, and panoramic radiographs were compared. Results: Compared with the CBCT-generated panoramic view, CBCT 3D image showed significant difference in the mesiodistal tooth axis in the premolars and no significant difference in the mesiodistal tooth axis in the incisors and canines. Mesiodistal tooth axis on the CBCT-generated panoramic view was significantly different from that on panoramic radiographs. Conclusions: CBCT-generated panoramic view can be a useful tool for evaluating mesiodistal tooth axis.