• The Journal of the Korean dental association
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• v.37 no.10 s.365
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• pp.726-730
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• 1999

지난 호까지 3회에 걸쳐 두부계측 부석과 모교정의 진단법인 ODI/APDI/CF에 관한 소개를 하였습니다. 이번 호에는 CF(Combination Factor)에 관하여 알기 쉽게 설명을 드리겠습니다.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.2
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• pp.147-153
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• 2017

This study assessed the association between ectopic eruption of the maxillary first permanent molar and skeletal malocclusion in 5- to 10-year-old children. As subjects, 786 children who attended the Wonkwang University Dental Hospital for orthodontic diagnosis were included. Children with unerupted first permanent molars or fully erupted second permanent molars were excluded. The study group demonstrated ectopic eruption of the maxillary first permanent molar, while the control group did not. Cephalometric radiographs taken between January 2003 and August 2015 were analyzed. Skeletal class III malocclusion was detected in 57.0% of the study group, which differed significantly from that in the control group (p<0.05). The SNA, ANB angles, and A to N-perpendicular distance were significantly smaller, whereas the A-B plane angle and APDI were significantly greater in the study group than in the control group (p<0.05). The SNB and mandibular plane angles were not significantly different between the groups. Thus, maxillary undergrowth is a risk factor for ectopic eruption of the maxillary first permanent molar.

• The korean journal of orthodontics
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• v.31 no.4 s.87
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• pp.439-445
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• 2001

The Purpose of this study was to compare the dento-skeletal characteristics between functional and skeletal anterior cross-bite patients. Twenty-eight functional anterior cross-bite patients and thirty-one skeletal anterior cross-bite patients were selected as a test and a control group. Mean ages of the test and the control group were $9.6{\pm}1.8$ and $9.9{\pm}1.9$, respectively. Lateral cephalograms were taken. Forty-nine cephalometric variables were measured and statistical analysis was performed to find the morphological differences between the groups. Statistically significant differences were found in the cephalometric variables of cranial deflection, maxillary depth, ANB, convexity, NPo-AB, APDI, Mx 1-SN, Mx 1-NA angle, Mx 1-NA, Md 1-NB angle and Md 1-NB. The test group showed more Class III growth potential, more protruded maxilla, lesser maxillo-mandibular difference, more uprighted and retruded maxillary central incisor, more labially tipped and protruded mandibular central incisor.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.197-208
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• 1997

Class III malocclusion patients can be approached with many different types of treatment methods, and thus, each patient's problems must be accurately evaluated to allow selection of the best possible treatment method. Cephalometric analysis is an essential part of diagnosis and treatment planning of orthodontic patients, and it would certainly be helpful if reliable cephalometric guidelines could be set. The author divided 482 Class III malocclusion patients(253 males and 229 females) into fourgroups according to different types of treatment methods they have received to correct imbalance between upper and lower jaws: 1) orthopedic appliance (face mask & RPE), 2) camouflage treatment with fixed appliance, 3) surgical-orthodontic treatment, 4) cross-bite correction with removable plates/ functional appliance. Cephalometric values at the time of first clinical examination were compare among the four groups. Cephalometric analysis indicates the following results: 1)the amounts of antero-posterior and vertical skeletal discrepancies and dental compensation were greatest in surgery group 2) SNB, Wits, distance from Nasion Perpendicular Plane to point a facial angle, facial convexity, and APDI were greater in orthopedic appliance group than fixed appliance(camouflage) group, but there was no statistical difference 3) removable plates/ functional appliance group showed least amounts of skeletal discrepancies and dental compensation with statistical significance.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.19-29
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• 1995

This study was performed to compare the size of soft palate, tongue and airway according to the types of the malocclusion and evaluate the correlation between the size of soft palate, tongue, airway and dentofacial skeleton respectively. The sample of this study was 98 malocclusion female patients between the ages 12 and 17 years. The lateral cephalometric radiographs were taken and the distance, angle, ratio and area of the dentofacial skeleton, soft palate, tongue and airway were measured and evaluated statistically. The results obtained were as follows: 1. There was significant difference in SNB, ANB, facial angle, facial convexity, A-B plane angel, Y axis to FH, SN-MP, Wits appraisal, ODI and APDI according to the types of malocclusion. 2. The hyoid bone was more posteriorly positioned in Class II malocclusion group than other two groups and superio-inferior position of the hyoid bone was not different according to the malocclusion types. 3. The nasopharyngeal area of Class II and Class III malocclusion group was smaller than that of Class I malocclusion group, and the pharyngeal area of Class II malocclusion group was smaller than that of Class I and Class III maocclusion group. There was no difference of the area of the soft palate, tongue, oropharynx and hypopharynx according to malocclusion types. 4. The ramal height and mandibular body length(Go-Me) showed positive correlation with the area of tongue, nasopharynx, oropharynx, and pharynx. SNA did not correlated with the area of tongue and airway but SNB showed positive correlation with the area of hypopharynx and pharynx. The anterior, posterior facial height, upper and lower central incisor position to facial plane showed positive correlation with tongue area.

• The korean journal of orthodontics
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• v.31 no.4 s.87
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• pp.403-414
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• 2001

The purpose of this study was to evaluate treatment effects of the modified Teuscher appliance (MTA) in early Class II division 1 malocclusion. For this purpose, treatment effects of the bionator were compared with those of the MTA. The twenty subjects who were treated excellently with bionator and MTA were selected in each group. In pre- and post-treatment lateral cephalograms, 50 variables were measured, and then the differences between pretreatment and posttreatment data of the bionator and the MTA were statistically evaluated by t-test. The results were as follows : 1. The linear measurements that showed large difference between the bionator group and the MTA group are U1 to FH, U1 to PP, U6 to FH, U6 to PP, Ar-Pog, ramus height, L1 to A-Pog, L1 to facial plane (p<0.05). 2. The angular measurements that showed large difference between the bionator group and the MTA group are SNB, SNA, FABA, APDI (p<0.05). 3. The measurements of the growth pattern such as facial height ratio, FMA, SN-MP angle showed no difference between two groups (p>0.05). These results suggest that the bionator influence the mandiblar growth and lower dentoalveolar structures more than the MTA, and the MTA influence upper jaw and upper dentoalveolar structures more than the bionator comparatively in early Class II division I malocclusion.

• The korean journal of orthodontics
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• v.25 no.2 s.49
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• pp.153-163
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• 1995

In this study, Receiver Operating Characteristic(ROC) analysis was used to evaluate the ability of cephalometric measurements to identify patients with Class III malocclusions. ROC analysis is the method for determining the validity of a diagnostic measure and for evaluating the relative value of diagnostic tests. The sample consisted of 496 patients with malocclusion. Class III malocclusion is defined as the dental relationship for which The mesiobuccal groove of the lower first molar is deviated mesially from the mesiobuccal cusp of the upper first molar. Of the total sample of 496 patients, 245 had Class III malocclusions. 16 cephalometric measurements were selected, each of which was treated as a diagnostic test. The ROC curves were generated for each cephalometric measurement with intervals of $1.0^{\circ}$ for angular measurements, 1.0mm for linear measurements. The area under the ROC curves was measured for direct comparison among different diagnostic tests. The results were as follows; 1. The 'Wits' appraisal was found to be a better diagnostic criterion for the presence of Class III malocclusion than any other commonly'used cephalometric measurement. 2. AB plane angle, ANB angle, App-Bpp distance, AF-BF distance, APDI, Distance of point A and Pog to N perpendicular, maxillomandibular differential had high diagnostic value. 3. Cephalometric measurements which evaluate the position of the mandible had moderate diagnostic value. 4. Cephalometric measurements related to the maxilla discriminated least between patients with and without Class III malocclusion.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.203-217
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• 1998

Sella turcica contains pituitary gland that has influence on craniofacial growth. So, if the volume of sella turcica correlate to the function of Pituitary gland, we can assume that the volume of sella turcica in skeletal Class III patients has some difference to that of normal occlusion group. The purpose of this study was to evaluate the difference of shape and volume of sella turcica between normal occlusion group and Class III patients. The shape of sella turcica was Classified by Inaba method and the volume of sella turcica was measured in lateral and P-A cephalograms by Di Chiro method. To find out the possibility of the volume of sella turcica as diagnostic aid to predict Class III growth pattern, the correlation coefficients between the volume of sella and cephalometric variables were calculated. The results were as follows. 1. The volume of sella turcica in Class III patients is larger than that of normal occlusion groups 2. The volume of sella turcica in female was larger than that of male in Class III patients 3. The volume of sella turcica has close correlation with APDI, ANB, SNA, SNB, ODI, gonial angle, post. cranial base length 4. Sella Index (volume of sella / ant. cranial base length) can be a more accurate indicator that represent Class III growth pattern than volume of sella itself. 5. The morphologic pattern of sella turcica had no significant difference between two groups.

• The korean journal of orthodontics
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• v.28 no.3 s.68
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• pp.343-351
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• 1998

The purpose of this study was to investigate the pretreatment and posttreatment dentofacial characteristics of non-extraction patients with Class I malocclusion. And to compare this result with matched non-orthodontic normal occlusion and Class I premolar extraction patients. Such comparison might help identify morphologic characteristics of the non-extraction patients. Initial and final cephalometric evaluation were compared in a sample of 22 patients with Class I malocclusions treated in non-extraction manner with edgewise appliance and MEAW The mean age of the total population was 14 years 9 months and the average treatment time was 2 years 8 months. 32 landmarks were located and digitized on each cephalogram. From these landmarks, 24 linear and angular dimension were obtained. Student's t-test were used to compare the pretreatment - posttreatment results, Nonextraction - Normal groups, and nonextraction Extraction groups. Significance was predetermined at $p{\leq}0.05$. The results were as follows. 1. Before treatment, the mean value of the $ODI\;was\;69.9^{\circ},\;APDI\;was\;82.1^{\circ},\;CF\;was\;152^{\circ},\;EI\;was\;152^{\circ}$ in the non-extraction groups. 2. The skeletal pattern of the non-extraction groups were similar with non-orthodontic normal groupsr, but the non-extraction groups had larger interincisal angle. 3. Comparison between groups treated with and without extraction indicated at pretreatment, the extraction groups had more protrusive lips, smaller interincisal angle, and EI. 4. After treatment, there was no significant changes in the skeletal pattern of the non-extraction groups, but uprighting of the maxillary and mandibular first molar and decrease of the interincisal angle were seen.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.1
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• pp.85-94
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• 2022

This retrospective study aimed to evaluate the difference in measurement between conventional orthodontic analysis and artificial intelligence orthodontic analysis in pediatric and adolescent patients aged 7 - 15 with the mixed and permanent dentition. A total of 60 pediatric and adolescent patients (30 mixed dentition, 30 permanent dentition) who underwent lateral cephalometric radiograph for orthodontic diagnosis were randomly selected. Seventeen cephalometric landmarks were identified, and 22 measurements were calculated by 1 examiner, using both conventional analysis method and deep learning-based analysis method. Errors due to repeated measurements were assessed by Pearson's correlation coefficient. For the mixed dentition group and the permanent dentition group, respectively, a paired t-test was used to evaluate the difference between the 2 methods. The difference between the 2 methods for 8 measurements were statistically significant in mixed dentition group: APDI, SNA, SNB, Mandibular plane angle, LAFH (p < 0.001), Facial ratio (p = 0.001), U1 to SN (p = 0.012), and U1 to A-Pg (p = 0.021). In the permanent dentition group, 4 measurements showed a statistically significant difference between the 2 methods: ODI (p = 0.020), Wits appraisal (p = 0.025), Facial ratio (p = 0.026), and U1 to A-Pg (p = 0.001). Compared with the time-consuming conventional orthodontic analysis, the deep learning-based cephalometric system can be clinically acceptable in terms of reliability and validity. However, it is essential to understand the limitations of the deep learning-based programs for orthodontic analysis of pediatric and adolescent patients and use these programs with the proper assessment.