• The korean journal of orthodontics
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• v.27 no.2
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• pp.297-313
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• 1997

The purposes of this study were to compare the soft tissue changes following hard tissue change after surgery between the one jaw and two-jaw surgery in skeletal class III patients and to get the reference of the incisal inclination at presurgical orthodontics. For this study 24 patients for the two-jaw surgery group and 18 patients for one jaw surgery group were selected. Lateral cephalograms were taken at pretreatment, after presurgical orthodontic treatment, immediately after surgical treatment and at least 6 months after surgery. They were traced and analyzed on skeletodental structure and soft tissue. The results were as follows: 1. After surgery, maxilla, maxillary incisors and upper lip were moved anteriorly and superiorly in two-jaw surgery group. Mandible and mandibular incisors were moved posteriorly and superiorly, and thickness of lower lip was increased in both group but there were no statistically significant difference. Anterior facial height was more decreased in two-jaw surgery group (p<0.05). At least 6 months after surgery, by the postorthodontic treatment, maxillary incisors were moved labially 1.44mm, mandible and mandiibular incisors were moved lingually 1.43mrn, 1.26mm respectively in one jaw surgery group. But there was no statistically significant changes of hard tissue in two :jaw surgery group. 2. The correlation coefficients of maxillary hard and soft tissue horizontal changes were high in two jaw surgery group and the ratios for soft tissue to A point were 19% at Sri, 80% at SLS, 82% at LS. The ratios for soft tissue to B point were 92% at LI, 104% at ILS in one jaw surgery group, 89% at LI, 101% at ILS in two-jaw surgery group. 3. The correlation coefficients and change ratios of mandibular incisors and LL HS on lower lip horizontal changes were 0 0.89 and 75%, 85% in one jaw surgery group, 0.93, 0.90 and 76%, 87% in two-jaw surgery group. The correlation coefficients of maxillary incisors and Sn, SLS and LS on upper lip horizontal changes were 072, 0.76 and 0.75 in two jaw surgery group and ratios of changes were 57%, 58% and 59%. 4. The regression equations between skeletal horizontal discrepancy and incisal inclinaton were taken in one jaw surgery group. Those were FMIA=57.48-2.17ANB, U1-SN=-75.02+2.17SNB and $R^2$ were 0.63, 063 respectively. So if there is skeletal horizontal discrepancy by mandibular prognathism in one jaw surgery case, we consider attaining more labial inclination of maxillary incisors than normal and more lingual inclination of mandibular incisors than normal. But correlation coefficient of the regression equations in two jaw surgery group was low, so, that equation was not reliable.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.239-249
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• 1999

In orthognathic surgery to obtain proper functional and esthetic form after skeletal discrepancy treatment, precise diagnosis and treatment plan are essential. Especially in two jaw surgeries that have serious upper and lower jaw problems, maxilla and mandible are arranged in three dimensions. Based on the maxillary rearrangement, mandibular sagittal and transverse positions are determined, and thus new occlusal plane is established. The object of this study is to evaluate the stability of the indiviual ideal occlusal plane based on the architectural and structural craniofacial analysis of Delaires. The subjects of this study were 48 patients who underwent two jaw surgeries, and they were equally divided into two groups, A and B. A group was operated with ideal occlusal plane and B group was not. Two groups were compared at the preoperative, immediate postoperative (average 4.3days), and long-term postoperative (average 1.3years) lateral cephalometric radiographs. The following results were obtained: 1. ANS was lower than that of PNS for both A and B after the surgery. That is, maxilla and mandible are rotated in posterior and superior direction. 2. Significances were found between $T_2$ and $T_3$ for both A and B are HRP-Me at vortical measurements, articular angle(p<0.01), gonial angle(p<0.01), and Mn. plane angle(p<0.05) at angular measurement. Mn. plane angle is increased at HRP-Me is decreased for both A and B. 3. There is no significance in skeletal stability aster the surgery between group A and B. 4. Horizontal movements of B and Pog by surgery have statistically significant inverse correlations with horizontal relapse of B and Pog, and vertical relapse of PNS, as well as Mn. Plane angle, and gonial angle after the surgery.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.4
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• pp.389-403
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• 2008

In Angle's Class III malocclusion, which has higher incidence in Korean than Western, depressed midfacial profile with protruded lower lips and mandible may give rise to many functional, esthetic, psychological, social problems. Due to the different malocclusion incidence according to racial differences, many previous studies focused on the relationship between Class II malocclusion and nasal airway obstruction. Previous studies used lateral cephalography which has limitations of 2 dimensional image with projection error and identification error. Therefore, the purpose of this study was to analyze morphologic differences in the nasal airway between normal occlusion and Angle's Class III malocclusion patients using 3-dimensional facial computed tomography. Thirteen normal occlusion(7 men and 6 women) and sixteen skeletal Class III(7 men and 9 women) patients were selected and 3-dimensional facial computed tomography taking was performed. Comparison between two group in volume and sectional area of nasal airway were carried out. The results were followed. 1. In the comparison of absolute nasal airway volume, oropharyngeal space of experimental group were larger than control group but there are no significant difference in other. 2. In the comparison of relative nasal airway volume, oropharyngeal space of experimental group were larger than control group but there are no significant difference in other. 3. In the oropharyngeal space width on frontal and lateral view, the similar tendency was revealed between two groups. 4. In the lateral curvature of nasal airway, the similar tendency was revealed between two groups.

• The korean journal of orthodontics
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• v.27 no.4 s.63
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• pp.549-557
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• 1997

This study was designed to investigate the attrition pattern in Angle Class III malocclusion with facial asymmetry. The sample consisted of three groups, the 20 subjects of normal occlusion group(Group I), the 12 subjects of class III malocclusion without facial asymmetry group(Group II) and 17 subjects of Class III malocclusion with facial asymmetry group(Group III). Attrition areas from canine to second molar on both sides in upper and lower arch, totally twenty, was marked by pencil and mesured by computer system(INTERGRAPH CO. USA) 2 times and the average value was used for date processing. Attrition areas from canine to second molar on both sides in upper and lower arch, totally twenty, was marked by pencil and mesured by computer system(INTERGRAPH CO. USA) 2 times and the average value was used for date Processing. All attrition areas were measured 2 times and the average value was used for data processing The data were statistically analyzed by SAS program. The results of this study were as follows. 1. Total attrition area in Group I was larger than in Group II and III. 2. There was no significant difference in attrition area between right and left side in each group, but attrition area in Group III was larger than in Group I and II. 3. In Group I, Maxillary attrition area was larger than mandibular attrition area, but in Group ll and III, there was no significant difference in attrition area between maxilla and mandible. 4. In Group III, the attrition area of deviated side was target than undeviated side 5. There was no significant difference in attrition area between chewing side and non-chewing side in each group. 6. The total attrition area was unaffected by gender.

• The korean journal of orthodontics
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• v.28 no.3 s.68
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• pp.461-477
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• 1998

To evaluate the relapse pattern and long-term stabilities depanding on surgical methods following orthognathic surgery of Cl III patients, the author selected 24 subjects(10 male, 14 female) operated by SSRO and 26 subjects(10 male,16 female) operated by IVRO. Each subject took four lateral cephalograms : just before surgery(T1), within 48hrs after surgery(T2), 4-8 wks after surgery(T3), 6 month or more after surgery(T4), and the landmarks were digitized. The differences of relapse patterns in each interval between two groups were compared and the significance of correlation among the variables of each group was tested. The obtained results are as follows ; 1. Horizontal early relapse was forward movement of mandible in SSRO group, as compared to the backward movement in IVRO group, and there was a statistical significance between the two groups. 2. Vertical early and late relapses were decreases in anterior facial height in both groups and there was no statistical significance between the two groups. 3. There was a statistical significance in negative correlation between mandibular horizontal late relapse and surgical change of articular angle in SSRO group. 4. There was a statistical significance in negative correlation between amount of mandibular set-back and mandibular horizontal early relapse in both groups.

• The korean journal of orthodontics
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• v.33 no.1 s.96
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• pp.63-72
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• 2003

Over the Past decades, the number of Patients seeking orthodontic treatment has increased markedly with socioeconomic development and change of recognition on appearance. The purpose of this study was to provide an epidemiologic data base related to the orthodontic treatment need. We could take an adequate information regarding the characteristics of orthodontic patients, and the changing trends about treatment mordality. Distrubution and treands were Investigated in 676 patients who had been examined and diagnosed at Department of orthodontics, Dental Hospital, Seoul National University from January to June in 1992 and 2002. 1. Sex distribution of patients changed from 1:2.1 to 1:1.5 (male female). 2. In 2002, are distribution had shown $7\~12$ year-old group being the largest$(32.0\%)$ and percentage of $19\~24,\;13\~18,\;over\;25,\;4\~6,\;0\~3$ year-old group were $24.0\%,\;21.6\%,\;14.2\%,\;5.8\%,\;2.4\%$ respctively. Compared with data in 1992, the number of adult patients highly increased. 3. With regard to Angle classification, each percentage of Class I, Class II div 1, Class II div 2, and Class III malocclusion were $25.0\%,\;20.9\%,\;3.4\%,\;and\;48.1\%$ respectively in 2002. 4. Geographic distribution showed that most of the patients visited $(37.0\%)$ lived in northeast of Seoul in 2002. 5. Mandibular prognathism showed the highest percentage in chief complaints. The percentages of crowding and facial asymmetry were $14.2\%\;and\;11.8\%$ in 2002. Patients with facial asymmetry increased significantly. 6. Percentages of patients treated with fixed appliance and orthognathic surgery were $38.0\%\;and\;25.0\%$ in 2002. Patients needed to observe the growth pattern comprised $13.0\%$ with increasing trends. The use of chin cap reduced and the percentage of ortognathic surgery and growth observation increased significantly.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.283-296
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• 1997

Stomatognathic system is a complex one that is composed of TMJ, neuromuscular system, teeth and connective tissue, and all its components are doing their parts to maintain their physiological relationships. Mandible, in particular, performs various functions such as mastication, speech, and deglutition, the muscular activities that determine such functions are signalled by numerous types of proprioceptors that exist in periodontal membrane, TMJ, and muscles to be controlled by complicated pathways and mechanics of peripheral and central nervous system. Orthodontic treatment, especially when accompanied by orthognathic surgery, brings dramatic changes of stornatognat is system such as intraoral proprioceptors and muscle activities and thus, changes in patterns of mandibular function result The author tried to analyze changes in patterns of mandibular movement and physiologic activities of surrounding muscles in Skeletal Class III ortlrognathic surgery patients who presently show a great increase in numbers. The purpose of this study was to draw some objective guidelines in evaluating funclierual aspects of orthognathic surgery patients. Mandibular functional analysis using Biopak was performed for skeletal Class III prognathic patients who underwent IVRO(lntraoral Vertical Ramus Osteotmy), and the following results were obtained: 1. Resting EMG was greater in pre-surgical group than the control group, and it showed gradual decrease after the surgery. Clenching EMG of masseter and anterior temporalis of pre-surgical group was smaller than those of control group, they also increased post-surgically, and significant difference was found between pre-surgical and post-surgical(6 months) groups. 2. Resting EMG of anterior ternporalis was greater than that of all the other muscles, but there was no significant difference. Clenching EMG of anterior temporalis and masseter were greater than those of the other muscles with statistical difference. In swallowing, digastric muscle showed the highest EMG with statistical significance. 3. Limited range of mandibular movement was shown in pre-surgical group. Significant increase in maximum mouth opening was observed six months post-surgically, and significant increase in protrusive movement was observed three months post-surgically.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.3
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• pp.256-262
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• 1998

The aim of this study was to evaluate treatment plan and treatment procedure such as bone graft material, timing of bone graft and orthodontic treatment in 31 alveolar cleft bone graft patients treated at the Department of Oral and Maxillofacial Surgery of Chonnam University Hospital from Jan. 1992 to Dec. 1996. Results obtained were as follows : In total 31 patients of alveolar bone grafts, males(64.5%) were more than females(35.5%). The patients' age ranged between 2 - 33 years of age. Secondary bone grafting was the highest incidence(58.1%) when procedures were undertaken in patients between 6 - 16 years of age. In distribution of cleft side, unilateral clefts(93.5%) were the major part with the left side was larger than the right side. The Missing teeth were found most in lateral incisor, the supernumary teeth were found most between lateral incisor and canine. The most common occlusion before operation was class III malocclusion and anterior cross-bite(65.1%), orthodontic treatment was performed similarly between before and after the bone graft. The most common combined operation with alveolar bone graft was secondary cheiloplasty. The complications were 6 cases of bone defect, a case of oronasal fistula, 3 cases of dehiscence. PMCB and DFDB were used bone graft materials. In marginal bone height after operation, PMCB grafts were higher than DFDB grafts and marginal bone level was increased in the PMCB group but not in the DFDB group.

• The korean journal of orthodontics
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• v.35 no.3 s.110
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• pp.216-226
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• 2005

The purpose of this study was to test and compare the accuracy and reliability of soft tissue profile predictions generated from two computer software programs (Quick Ceph Image $Pro^{TM}$ (ver 3.0) and $V-Ceph^{TM}$(ver 3.5)) for mandibular set-back surgery. The presurgical and postsurgical lateral cephalograms of 40 patients (20 males and 20 females) were traced on the same acetate paper with the reference taken as the cranial base outline. The presurgical skeletal outlines were digitized onto each computer program and the mandible was moved to mimic the expected surgical procedure with reverence to the mandibular anterior border and lower incisor position of the actual postsurgical skeletal outline. The soft tissue profile was generated and the amount and direction of skeletal movement was calculated with each software. The predicted soft tissue profile was compared to the actual postsurgical soft tissue profile. There were differences between the actual and the predicted surgical soft tissue profile charges in the magnitude and direction, especially the upper lip. lower lip and the soft tissue chin (P<0.05). Quick Ceph had more horizontal measurement errors and thickness errors for the upper lip and lower lip, but V-Ceph had more vertical measurement errors of the lower lip (P<0.05). There was a positive correlation between the prediction errors and the amount of mandibular movements in the vertical position of Sn, the horizontal position of Ls and the upper lip thickness for V-Ceph, and there was a negative correlation in the horizontal position and the thickness of the lower lip for Quick Ceph (P<0.05). However all of the Prediction errors of both imaging softwares were ranged within 3mm, and this was considered to be allowable clinically.

• The korean journal of orthodontics
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• v.30 no.3 s.80
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• pp.343-355
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• 2000

The purpose of this study was to evaluate the amount and interrelationship of hard and soft tissue changes after mandibular setback osteotomy and reduction genioplasty in mandibular prognathism with long anterior facial height. The control group (Group A) consisted of 20 patients who had severe horizontal discrepancy. They experienced Presurgical orthodontic treatment and orthognathic surgery via mandibular setback. The experimental group (Group B) consisted of 20 patients who had severe horizontal and vertical discrepancy. They experienced presurgical orthodontic treatment and orthognathic surgery via mandibular setback and reduction genioplasty. The presurgical and postsurgical lateral cephalograms were evaluated. The computerized statistical analysis was tarried on with EXCEL 97 program. The results were as follows : 1. The correlation of hard and soft tissue horizontal changes in lower 2/3 of lower anterior facial height were high for both groups. The correlation coefficients of hard tissue changes and Ls, Stm, Li changes in Group B were moderately higher than Group A. 2. The correlation of hard and soft tissue vortical changes in Group B were lower than Group A. (except for pointB-Ils, Me-Me') 3. The ratio for soft tissue to Pog in Group B was lower than Group A. The ratios of hard and soft tissue vertical changes were 32% at Ils, 54% at Pog', and 60% at Me'. 4. The ratio of lower anterior facial height to total anterior facial height was reduced for both groups. But ratio of upper 1/3 of lower anterior facial height to total anterior facial height did not changed significantly in Group B. 5. Reduction genioplasty combined with mandibular setback procedure showed no change in upper one third(Sn-Stm) and significant decrease(Stm-Me') in the lower two thirds of the soft-tissue anterior lower facial height