• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.3
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• pp.343-350
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• 2000

The goal of this study is the comparison of upper airway size and change of skeletal Class I group and skeletal Class III group (before operation, within 2 weeks after operation, 6 months after operation) respectively. At first, we measured the lines between selected upper air way landmarks on lateral cephalometric x-ray film of skeletal Class I 40 persons whoes age were 23-26 years old, ,and did the same lines of landmarks of skeletal Class III 44 persons who had not been operated yet, were within 2 weeks after operation, were 6 months after operation. And we compared it respectively and analyzed it with paired t-test. We studied the relationship of those on produced data. 1. Skeletal Class III group was narrower in nasopharyngeal air way space than that of skeletal Class I group, and increased in thickness of oropharyngeal, hypopharyngeal wall within 2 weeks after operation, and reduced in nasopharyngeal, oropharyngeal air way space, and did in thickness of nasopharngeal, hypopharyngeal wall 6 months after operation. 2. Skeletal Class III group reduced in nasopharyngeal, oropharyngeal air way space, and increased in thickness of nasopharyngeal, oropharyngeal, hypopharyngeal wall within 2 weeks after operation, restored the thickness of nasopharyngeal, oropharyngeal wall, but did not restored nasopharyngeal, oropharyngeal, hypopharyngeal air way space. 3. Vertical length from hyoid bone to mandibular plane did not have signifacant difference from Class I group but after operation, it increased more than Class I group significantly. 4. The size of airway reduced after operation. Among this, oropharyngeal airway most reduced.

• The korean journal of orthodontics
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• v.37 no.3 s.122
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• pp.220-230
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• 2007

Objective: The purpose of this study was to determine the changes of mandibular anterior alveolar bone thickness with age. Methods: Cephalometric radiographs of 160 skeletal class I patients (male 80, female 80) with normal vertical growth pattern was investigated by measuring the buccolingual thickness of mandibular alveolar bone on the basis of root axis. Results: As the age increases, both male and female showed a significant decrease in buccolingual width of the mandibular anterior alveolar bone and in the width of mandibular anterior lingual alveolar bone except the CEJ area of females. However, there was no significant difference in the thickness of mandibular anterior buccal alveolar bone and in the width of maximum prominence of mandibular symphysis with age. Conclusion: From the above results, it is concluded that Korean children whose growth pattern is sagittally skeletal class l with a vertical normal growth pattern have a greater mandibular anterior lingual alveolar bone width than Korean adults; therefore, lingual movement of mandibular incisors, which is usually accompanied in extraction treatment, is considered to be more preferable in younger patients.

• The korean journal of orthodontics
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• v.39 no.6
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• pp.402-419
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• 2009

Successful treatment of the non-growing patient with an open bite of either dental skeletal pattern often presents a difficult challenge. The morphologic pattern in anterior open bite is characterized by longer vertical dimensions, an increase in development of the maxillary posterior dento-alveolar structure and a steep mandibular plane. In such cases, molar intrusion would be a good remedy for treatment. This article reports the successful treatment and retention of two anterior open-bite cases. We used orthodontic mini-implants for treatment and a circumferential retainer with posterior bite block or skeletal fixed retainer for retention. The diagnostic criteria and mechanics for appropriate treatment are discussed. Our results suggest that open bite can be reduced successfully with intrusion of molars using orthodontic mini-implants (OMI) without orthognathic surgery, and that circumferential retainer with posterior bite block and skeletal fixed retainer are effective for retention.

• The korean journal of orthodontics
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• v.37 no.4
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• pp.260-271
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• 2007

The purpose of this study was to evaluate the relationships between the occlusal plane angle and craniofacial skeletal pattern in relation to anterior overbite. Methods: Lateral cephalograms of 90 adults with skeletal class III malocclusions were traced and measured to analyze skeletal factors and occlusal plane angles. In terms of anterior overbite, all patients were classified into 3 subgroups of positive overbite, edgebite, and negative overbite groups. All measurements were evaluated statistically by ANOVA and Duncan's Post Hoc, and correlation coefficients were evaluated among measurements. Results: In this study, some skeletal measurements (saddle angle, articular angle, Y axis, AFH, SN-FH, SN-Mn, FH-Mn) showed a significant difference among the 3 groups in relation to overbite changes. Correlation coefficient showed that PFH/AFH, SN-Mn, Mx-Mn, and FH-Mn showed a significant difference with FH-Occ, Mx-Occ, and Mn-Occ. Regression analysis showed that Mx-Mn had a determination coefficient of 0.714, 0.560, and 0.677 in relation to FH-Occ, Mx-Occ, and Mn-Occ, respectively. Conclusion: This study suggests that consideration of the occlusal plane in relation to the maxillomandibular vertical skeletal state enable the establishment of a more predictable orthognathic surgery result.

• The korean journal of orthodontics
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• v.25 no.4
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• pp.465-485
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• 1995

The purpose of this study is to locate the proper position of the lower occlusal plane according to individual skeletal pattern. Cephalometric films of 234 subjects of the control group, 358 of the pretreatment group and 358 of the treated group were analyzed to study proper relationships between vertical dimension ratio(VDR) and lower occlusomandibular plane angle(LOM). The control group was divided into two subgroups by the age. The first subgroup consisted of 113 subjects of the age 14 years and under and with the mean age of 10.82 years. The other subgroup consisted of 113 subjects of the age 18 years and above with the mean age of 23.76 years. The pretreatment group was divided into three subgroups by the age. The first subgroup consisted of 274 subjects of the age 14 years and under with the mean age of 11.36 years. The second subgroup consisted of 54 subjects of the age 14 through 18 years with the mean age of 15.4 years. The last subgroup consisted of 30 subjects of the age 18 years and above with the mean age of 21.35 years. The treated group was also divided into three subgroups by the age. The first subgroup consisted of 145 subjects of the age 14 years and under with the mean age of 12.91 years. The second subgroup consisted of 166 subjects of the age 14 through 18 years with the mean age of 15.64 years. The last subgroup consisted of 47 subjects of the age 18 years and above with the mean age of 21.61 years. Cephalometric films of the sample were traced. Measurements were made to a hundredth using a program specifically prepared for this study, and the results were entered into a 486DX PC. Means and Standard deviations of all the veriables were calculated for each group. Correlation coefficients between pertinent variables were calculated. Significance tests on those coefficients, one-way ANOVA and t-tests between variables or groups were performed. On the basis of the results studied above, certain subjects were selected from the control and the treated groups to locate the proper position of the occlusal plane, and designated as the optimal occluaion group. The subjects of this optimal occlusion group had 1-3 mm overbite, 1-3 mm of overjet and less than 1.75 mm of curve of Spee. A total subjects of 187 in this group consisted 104 treated subjects and 83 control group. Regression analysis was carried out between VDR and LOM, and regression equations were tabulated for this optimal occlusion group. The results were as follows : 1. Highly significant correlations were observed between various variables useful for identifying vertical component of skeletal frame, but any one particular variable did not accurately indicate the magnitude of anterior vertical overbite. 2. Of the variables useful identifying vertical component of skeletal frame, The VDR showed the highest correlation to the LOM. 3. Of the total sample, 80 percent had overbite within the normal range, irrespective of VDR. 4. The optimal occlusion group was divided into 9 subgroups by the age and the anteroposterior skeletal pattern, and correlation coefficient and determination coefficient between VDR and LOM of each group were calculated. Correlation coefficients and determination coefficients were found to be significantly high in all groups. 5. Regression equation was induced for each of the optimal occlusion group to find proper LOM according to the VDR. 6. It was found that the mean value of the cant of occlusal plane itself is not enough for a diagnosis and a treatment plan. Rather, It is very important to locate the proper occlusal plane for an Individual skeletal pattern.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.420-426
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• 2009

The purpose of this study was to evaluate skeletal and soft tissue changes that occur after using a facemask for treatment of skeletal class III malocclusion, and to assess the relapse pattern when no retention appliance was used. Fifteen skeletal class III malocclusion patients were treated with a facemask for an average of 12 months. No retention appliance was used during the 1 year follow-up period. Cephalograms were taken during pretreatment, posttreatment, and the 1 year follow-up. Cephalograms were traced, analyzed, and the results were compared between cephalograms. All patients showed significant sagittal skeletal changes after treatment, but they also showed a significant relapse during the 1 year follow-up period when no retention appliance was used. Despite the relapse, the sagittal skeletal changes that remained were still significant. Vertical skeletal change was also significant after treatment, but the total change was not significant after a 1 year follow-up due to relapse. In soft tissue changes, facial convexity and upper lip position improved after treatment and this change remained significant after the 1 year follow-up period. Facemask therapy is therefore an effective method for treatment of skeletal class III malocclusion, however, retention is imperative to maintain the treatment effect.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.649-656
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• 2005

The present study was designed to formulate cephalometric norms of normal occlusion for usage in orthodontic diagnosis of malocclusion in Korean children. Thirty two children, aged 4 to 6, with normal occlusion were chosen for this study, Sagittal and vertical relations were analyzed using lateral cephalogram and clinical photos and the measurements were compared with those of adults. On skeletal sagittal analysis, the mean values of the SNA and SNB angles were $83^{\circ}\;and\;78.72^{\circ}$. It showed that the mandible was retrognathic and retropositioned in comparison to those of adults. On skeletal vertical analysis, the mean values of the genial angle was $127^{\circ}$. This showed high angle pattern in children and reduction of genial angle due to counterclockwise rotation of the mandible is expected with growth. On soft tissue analysis, children showed convex pronto, obtuse nasolabial angle. On dental analysis, the mean values of the U1 to SN and IMPA were $91.04^{\circ}\;and\;86.57^{\circ}$. This showed retroclined upper and lower deciduous teeth in comparison to adults. For skeletal values, the liner values were generally greater in males than females.

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.801-813
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• 1997

A comparative study was made on the chewing movements of normal occlusion and skeletal class m malocclusion. Thirty normal occlusion subjects and twenty skeletal class III malocclusion patients were given chewing gums for the study : using BioPAK system, the chewing movement on the frontal plane was recorded and analyzed. With a typical chewing path chosen representing each subject, chewing width, opening distance, opening and closing angles, maximum opening and closing velocities were observed. Seven characteristic patterns were classified based on the types of chewing paths. The followings are the results : 1. Compared with the normal occlusion group, the skeletal class III malocclusion group showed more varied and vertical chewing patterns. 2. In comparision of chewing widths, skeletal class m malocclusion group showed narrower path than the normal occlusion group(p<0.01). 3. In opening distance, skeletal class III malocclusion group appeared shorter than the normal occlusion group without statistical significance(p>0.05). 4. In opening and closing angles, skeletal class III malocclusion group showed more acute angles than the normal occlusion group(p<0.01). 5. In maximum opening and closing velocities, skeletal class III malocclusion group was slower than the normal occlusion group but with no statistical significance(P>0.05). 6. In the classification of chewing movement pattern, the normal occlusion group had Type II as the highest rate at 73.4% ; in skeletal class III malocclusion group, the highest rate was Type III at 35.0%, followed by Type II at 30.0% 7. In the classification of chewing movement pattern, Type IV(chopping type)of skeletal class III malocclusion group showed a higher rate with 25.0% over 3.3% of normal occlusion group.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.317-325
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• 1999

In proper diagnosis of skeletal Class III malocclusion, it was important to know the pattern of three dimensional skeletal & facial disharmony. The purpose of this study was to obtain P-A cephalometric characteristics in skeletal Class III malocclusion comparing with normal occlusion. The samples were consisted of 120 subjects, divided into four groups : Male normal occlusion, Female normal occlusion, Male skeletal Class III malocclusion, Female skeletal Class III malocclusion. Posteroanterior and lateral cephalogram were taken from the subjects with a x-ray apparatus (ASHAI CX90SP, Japan) and traced on acetate paper with routine manner. The transverse and vertical values from posteroanterior cephalometry, the sagittal values from lateral cephalometry and their ratio were obtained. The results were as follows: 1. The anteroposterior discrepancy in skeletal Class III group was not due to short maxillary length(Cd-A), but to longer mandibular length(Cd-Gn) than normal occlusion group. 2. The faces of skeletal Class III group were longer than normal occlusion group. It was not due to increase of upper face height(Cg-ANS) but to increase of the lower face height(ANS-Me) especially mandibular height(Cd-Me). 3. There was no difference in the facial width values between normal occlusion group and skeletal Class III group, except upper molar width(U6-U6), lower molar width(L6-L6) and mandibular width(Ag-Ag) of female skeletal Class III group which were larger than normal occlusion group. 4. The increase of mandibular length of skeletal Class III group was reflected in the increase of lower facial height but did not have an effect on the mandibular width.

• The korean journal of orthodontics
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• v.18 no.1 s.25
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• pp.175-188
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• 1988

The purposes of the present study were to describe the vortical and anteroposterior facial dysplasia, and to identify morphologic differences associated with various facial patterns. Anteroposterior dysplasia was classified by traditional Angle's malocclusion classification and according to vertical relationships based on the SN-MP angle, facial pattern was subclassified to 3 vertical groups in each malocclusion group. Each vertical group composed of 20 samples and total 180 samples aged from 9 to 14 years. The results were as follows; 1. The skeletal differences that lead to disportionate lower facial height in vortical and anteroposterior facial dysplasia were closely related to mandibular morphology. 2. Hyperdivergent group, compared with hypodivergent group, demonstrated decrease of SNA and SNB and linguoversion of maxillary and mandibular central incisors in all malocclusion groups. 3. Irrespective of rotation of the jaws, Wits appraisal was a useful measurement in evaluation of relative anteroposterior relationship of maxilla and mandible. 4. As SN-MP angle increased, anterior facial height, especially lower anterior facial height, demonstrated significant increase and intermaxillary space also tended to increase. 5. The correlation coefficients of SN-MP angle and PTFH/ATFH demonstrated the highest value in all malocclusion groups.