• The korean journal of orthodontics
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• v.32 no.5 s.94
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• pp.361-373
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• 2002

The purpose of this study was to evaluate the morphological changes of olveolar bone and mandibular symphysis of lower incisor by presurgical orthodontic treatment and orthognathic surgery in skeletal class III malocclusion. The sample consisted of 30 adult class III malocclusion patients who have received bilateral sagittal split mandibular osteotomy. Lateral cephalograms were taken before treatment, after presurgical orthodontic treatment and 3 months after orthognathic surgery. Skeletal and symphyseal measurements were compared and the relationships between them were analysed. The results were as follow : 1. The labial and lingual alveolar bone height in presurgical and postsurgical group were decreased than that of pretreatment group. 2. The vertical measurements of the craniofacial skeleton showed reverse correlationship with anteroposterior width of basal alveolar bone, but IMPA showed correlatiionship (p<0.01) 3. The craniofacial skeleton and the change of symphyseal measurements(symphyseal length, symphyseal width) showed no correlationship. 4. The labial alveolar bone height showed correlationship with lingual alveolar bone height(p<0.001), and negative correlationship with lingual alveolar crestal width(p<0.01). Labial and lingual alveolar crestal width has negative correlationship (p<0.05). Mandibular symphyseal length and width has positive correlationship(p<0.01). 5. IMPA, LISA showed negative correlationship with labiolingual alveolar bone height and lingual alveolar width and positive correlationship with labial alveolar base bone width.

• The korean journal of orthodontics
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• v.34 no.5 s.106
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• pp.380-393
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• 2004

The Purpose of this study was to investigate the dentoalveolar compensation according to anteroposterior skeletal discrepancy in normal occlusion and to evaluate cephalometric parameters that quantitatively describe dental compensations. The study consisted of 90 subjects (50 males. 40 females) who were selected among specimens of normal occlusion at Seoul National, University Dental Hospital, Dept. of Orthodontics. Lateral cephalograms in centric occlusion were traced and digitized for each subject. According to the anteroposterior skeletal pattern the sample was divided into three groups. Cephalometric data were analyzed for the three groups using the SPSS program. Independent t-test, correlation analysis and regression analysis were carried out. The results were as fellows: Dentoalveolar compensation was found in upper and lower incisor inclination and occlusal plane inclination. As the mandible located anterior to the maxilla, the maxillary incisors incisors more labially. the mandibular incisors more lingually, and the occlusal plane continued to flatten. The dental parameters most correlated with anteroposterior skeletal discrepancy were L1 to SN and L1 to FH. Among the compensatory dentoalveolar changes, lower incisor inclination was strongly related to the anteroposterior jaw relationship and played au imposrtant role in obtaining a normal incisor relationship U1 to PtGn and L1 to APog were constant irrelevant to anteroposterior skeletal discrepancy.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.45-54
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• 1997

The purpose of this study was to evaluate the indications of bionator in Class II division 1 malocclusion, The 48 subjects were classified into good result group(group1) and poor result group(group2) in reference to posttreatment molar relation, posttreatment overbite and overjet, posttreatment profile, and relapse. Pretreatment lateral cephalograms were calculated and evaluated by t-test stepwise discriminant analysis. The results were as follows ; 1. In jaw bone relationship, ANB, facial convexity angle, AB to facial plane angle were significantly different between two treatment groups. In denture pattern, L1 to facial plane, L1 to A-Pog, FMIA, and U1 to facial plane were significantly different and m soft tissue profile, protuberance of lower lip and upper lip were significantly different between tw o treatment groups. 2. The results in according to discriminant analysis stated that L1 to facial plane, ANB, FMIA and protuberance of lower lip help prediction of treatment result of bionator. 3. 3 major influential variables were obtained by stepwise discriminant analysis - L1 to facial plane, articular angle and ANB difference. And Fisher discriminant function was made by these three major variables.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.21-33
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• 1997

The purpose of this study was to investigate the factors affecting the postsurgical mandibular stability for both one- and two jaw surgery. 18 for one-jaw surgerys and 24 for two-jaw surgerys among skeletal class III malocclusion patients who experienced orthodontic treatment and orthognathic surgery at Pusan National University Hospital were selected. Lateral cephalograms taken at the first visit, after presurgical orthodontic treatment, immediately after surgery and follow-up over 6 months, were traced. Based ANOVA, multiple linear regression analysis was completed for one-jaw surgery with postsurgical stability as the criterion and the magnitude of mandibular setback, the change of mandibular incisor height during surgery, the changes of mandibular plane angle and mandibular incisor angle during presurgical orthodontic treatment as affecting factors. Same analysis was completed for two-jaw surgery with postsurgical stability as the criterion and the magnitude of mandibular setback as affecting factor. The results were as follows : 1. In the one-jaw surgery cases, the magnitude of mandibular setback, the change of mandibular incisor height during surgery, the changes of mandibular plane angle and mandibular incisor angle during presurgical orthodontic treatment explained the variability in postsurgical stability with a significant $R^2$ value of 0.84. 2. In the two-jaw surgery cases, the magnitude of mandibular setback explained the variability in postsurgical stability with a significant $R^2$ value of 0,28.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.12 no.1
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• pp.81-103
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• 1982

The aim of this study was to investigate the variation in shape, size and area of the pharynx and adenoids, and to analyze the relationship between pharyngeal cavity and upper facial cranium which effected on morphology of those parts in Korean. Age changes and sex differences in those areas were comprised in this study. Materials included 272 lateral cephalograms, which were divided into 4 groups by age; (1) 7-year-old group consisted of 29 males and 30 females, (2) 12-year-old group consisted of 30 males and 30 females, (3) 17-year-old group consisted of 30 males and 40 females, (4) 20-year-old group consisted of 37 males and 46 females. In subjects each variable was measured and evaluated statistically introducing 17 reference points and 17 reference lines respectively. Conclusions from this study were as follows. 1. Linear measurements of the bony nasopharynx revealed that the depth and height were larger in male than those in female in 17 and 20-year-old groups. 2. Linear measurements of the upper facial cranium were larger in male than those in female in all age groups. 3. Angular measurements of the bony nasopharynx and upper facial cranium did not show, on an average, sex differences in each age group. 4. As regards area of the bony nasopharynx, it increased gradually with age in both sexes. And the area was greater in male than that in female in 17 and 20-year old groups. 5. There were sex differences in area of the adenoids of which the area was larger in male than that in female in 17 and 20-year-old groups. And the area reached a peak at 17-year-old group in male and at 12 year-old group in female. 6. Area of the pharyngeal cavity increased gradually with age in both sexes, but no sex differences were noted in each age group. 7. Rate of area of the adenoids to that of the pharyngeal cavity decreased continually with age, and no sex differences were noted in all age groups. 8. In amounts and its differences of the growth, there were sex differences in the posterior upper facial height, and were not in area of the bony nasopharynx, pharyngeal cavity and adenoids in each age group.

• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.123-137
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• 2001

Background: The purpose of this study is to evaluate the accuracy of measurements obtained from 3-dimensional computerized tomography and 3-dimensional cephalogram constructed by using the frontal and lateral cephalogram of six human dry skulls. Materials and Methods: After CT scans and each cephalograms were taken, 3-dimensional coordinates (X, Y, Z) of landmarks were obtained using computer programs. In this study, the accuracy of both methods were determined by means of 14 linear measurements compare with caliper measurements. Results: The standard deviation of landmarks of 3-dimensional CT and 3-dimensional cephalogram were 0.23 mm, and 0.30 mm in X axis, 0.27 mm and 0.25 mm in Y axis, and 0.27 mm and 0.31 mm in Z axis. In both methods, the standard deviation were less than 0.5 mm in all landmarks, and the most of landmarks showed less than 1 mm in range. Concerning the accuracy, the mean difference between 3-dimensional CT and manual measurements was 0.33 mm, and 1.13 mm between 3-dimensional cephalogram and manual measurements. The distance between RGo and LGo showed the largest difference (2.03 mm). There were highly significant, and large correlation with manual measurements in both methods (p<0.01). Conclusion: It is concluded that closeness of repeated measures to each skulls reveal the precision of both methods. Computerized tomography and cephalogram for 3-dimensional measurement of maxillofacial structure are equivalent in quality to caliper measurements.

• The Journal of Korean Medicine
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• v.40 no.3
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• pp.198-223
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• 2019

Objectives: The purpose of this study was to investigate the effect of Korean medicine treatment on facial asymmetric treatment in 5 cases of facial asymmetry correction by non - surgical treatment such as acupucture, chuna treatment, FCST (Functional cerebrospinal technique) and cranial osteopathy. Methods: We analyzed the initial charts of 5 patients who had undergone facial asymmetry in a Korean medicine clinic and measured the position and distance using the photograph, lateral cephalograms, and whole body radiograms. The results were as follows. Results: To quantify both soft and hard tissues to confirm the results of Korean medicine treatment of facial asymmetry, soft tissues quantitatively measure the displacement of the face, the slope of the left and right eyes, and the slope of the lip in order to grasp the positional displacement of the mandible. As a result, on the average, the correction effect as measured by the angle difference between A and C is $1.8{\pm}0.57$, the correction effect as measured by the angle difference between B and C is $1.4{\pm}0.89$, and the angle difference between D and the horizontal plane is $1.9{\pm}0.89$, and the angle difference between E and the horizontal plane is $1.9{\pm}0.89$. The result of reduced angle difference between A and C means that the head position shifted from the center of the body to the unilateral side was shifted to the center. The decrease in the angle difference between B and C means the restoration of the maxillary distortion relative to the mandible. In hard tissues, numerical values were measured based on the skull standard. The average distortion of the skull was $1.9{\pm}0.67$, and the distortion of the lower eye was $1.4{\pm}0.41$. Conclusion: General studies on facial asymmetric treatment are limited to treatments such as surgery and orthodontics. However, this study confirmed the possibility that facial asymmetry could be corrected by Korean medical treatment consisting of reversible non-surgical treatment rather than irreversible treatment such as surgery or orthodontic treatment. In particular, Korean medicine treatment is effective for muscular asymmetry, soft asymmetry, functional asymmetry, etc. The facial asymmetric treatment of Korean medicine is not limited to the face-centered correction, but the asymmetry of the whole body may be corrected as well.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.414-424
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• 2021

The purpose of this retrospective study was to evaluate the skeletal and dental maturity according to the vertical facial type and sex in Korean children in the developmental stage. In total, 184 participants aged 8 - 14 years were selected and divided into three groups based on the mandibular plane angle. For the comparison between the sexes, the three groups were each divided into male and female subgroups. The skeletal and dental maturity were assessed using lateral cephalograms, hand-wrist radiographs and panoramic radiographs. The vertical growth group showed significantly greater cervical vertebral and hand-wrist maturity than that in the horizontal growth group. Dental maturity was the highest in the vertical growth group. Girls showed greater skeletal maturity than boys, and no distinct difference was observed between the dental maturity of the sexes. Analysis of the vertical facial type in children can provide ancillary indicators that may help determine the optimal timing for orthodontic treatment initiation. Earlier initiation of orthodontic treatment may be considered for patients with vertical facial growth patterns.

• The korean journal of orthodontics
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• v.52 no.2
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• pp.150-160
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• 2022

Objective: To provide reliable prediction models based on dentoskeletal and soft tissue variables for customizing maxillary incisor positions and to optimize digitalized orthodontic treatment planning. Methods: This study included 244 Chinese women (age, 18-40 years old) with esthetic profiles after orthodontic treatment with fixed appliances (133 in group I: 1° ≤ The angle between the nasion [N]-A point [A] plane and the N-B point [B] plane [ANB] ≤ 4°; 111 in group II: 4° < ANB ≤ 7°). Dental, skeletal, and soft tissue measurements were performed on lateral cephalograms of the participants. Correlation and multiple linear regression analyses were used to determine the influence of dentoskeletal and soft tissue variables on maxillary incisor position. Results: The ideal anteroposterior position of the maxillary incisor varied between sagittal skeletal patterns. The position of the maxillary incisor correlated with the sagittal discrepancy between the maxilla and the mandible (ANB), protrusion of the midface, nasal tip projection, development of the chin, and inclination of both the maxillary and mandibular incisors. Distance from the maxillary central incisor to nasion-pogonion plane predicted using multiple linear regression analysis was accurate and could be a practical measurement in orthodontic treatment planning. Conclusions: Instead of using an average value or norm, orthodontists should customize a patient's ideal maxillary incisor position using dentoskeletal and soft tissue evaluations.

• The korean journal of orthodontics
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• v.54 no.2
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• pp.79-88
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• 2024

Objective: Alveolar bone loss is a common adverse effect of intrusion treatment. Mandibular incisors are prone to dehiscence and fenestrations as they suffer from thinner alveolar bone thickness. Methods: Thirty skeletal class II patients treated with mandibular intrusion arch therapy were included in this study. Lateral cephalograms and cone-beam computed tomography images were taken before treatment (T1) and immediately after intrusion arch removal (T2) to evaluate the tooth displacement and the alveolar bone changes. Pearson's and Spearman's correlation was used to identify risk factors of alveolar bone loss during the intrusion treatment. Results: Deep overbite was successfully corrected (P < 0.05), accompanied by mandibular incisor proclination (P < 0.05). There were no statistically significant change in the true incisor intrusion (P > 0.05). The labial and lingual vertical alveolar bone levels showed a significant decrease (P < 0.05). The alveolar bone is thinning in the labial crestal area and lingual apical area (P < 0.05); accompanied by thickening in the labial apical area (P < 0.05). Proclined incisors, non-extraction treatment, and increased A point-nasion-B point (ANB) degree were positively correlated with alveolar bone loss. Conclusions: While the mandibular intrusion arch effectively corrected the deep overbite, it did cause some unwanted incisor labial tipping/flaring. During the intrusion treatment, the alveolar bone underwent corresponding changes, which was thinning in the labial crestal area and thickening in the labial apical area vice versa. And increased axis change of incisors, non-extraction treatment, and increased ANB were identified as risk factors for alveolar bone loss in patients with mandibular intrusion therapy.