• The korean journal of orthodontics
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• v.32 no.1 s.90
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• pp.9-18
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• 2002

The present study hypothesized that the double keyhole looped archwire plays a positive role for the sake of translatory movement and/or controlled tipping of upper 6 anteriors, and secures anchorage control as well. The purposes of the study were to evaluate the changes in lateral cephalograms during orthodontic treatment with DKHLs and to compare the skeletal & dental changes before- & after-treatment. The materials of this study were lateral cephalograms of 20 adult patients with upper dentoalveolar protrusion both in class I and in class II Division1 malocclusion. Lateral cephalograms were taken before and after orthodontic treatment with upper 1st bicuspid extraction and DKHLs. The results were obtained as follows : 1. There were no statistically significant differences in skeletal measurement except SNB and PTFH between before- & after-treatment. The major changes were in dentoalveolar region. 2. After treatment, there were statistically significant decrease in dental measurement except interincisal angle. 3. Both upper & lower lip protrusion was decreased. 4. There were statistically differences in upper anterior crown horizontal & root vertical dimension(7.08 ${\pm}$ 2.14 mm, 2.38 ${\pm}$ 1.15 mm, p<0.01). 5. There were statistically differences in upper posterior dental(both crown & root) horizontal dimension(2.48 ${\pm}$ 0.99 mm, 2.05 ${\pm}$ 0.91 mm, p<0.01).

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.185-194
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• 2001

This study was designed to evaluate the effects of angulation changes of head posture on the enlargement ratios of a lateral headfilm depending on the vortical or horizontal rotation of the objects. A device was constructed to measure regional changes of enlargement ratios. The device was held within the cephalostat and cephalograms recorded at each measured degrees of the device tilting, vertically and horizontally. The enlargement ratios of the horizontal, vertical, and angular measurements on the films taken at each tilted angulations were obtained and compared with those on the films taken without rotation. In summary, the enlargement ratios of the horizontal linear measurements were decreased during horizontal rotations. The enlargement ratios of vortical measurements of the right side on the film were increased and those of the left side were decreased by the horizontal rotations. Enlargement ratios of horizontal measurements were affected further than those of vertical measurements by the same angular changes of the horizontal rotations. Therefore, a disruption of parallelism between the object's midsagittal plane and the film could result in distortion of the image while vertical rotation around the object's porionic axis would not significantly affect the enlargement ratios on the headfilm.

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.743-760
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• 1997

This study was done to evaluate the correlations between the size, the form of the cranial base, head posture and the horizontal and vertical position of craniofacial structures. For this purpose, 100 cephalometric radiographs were taken from the sample composed of 51 male and 49 female, 12 measurement criteria and 37 reference points were established and digitized, then calculation was performed for the values of measurement variables and the horizontal and vertical position of reference points. The correlations be4ween them were analyzed statistically and mean facial diagrams were constructed and compared with the selected groups which were composed of 10 Samples each as large and small group from the measurement value. The following results were obtained: 1. The angles n-s-ba and n-s-ar as variables for the ion of cranial base correlated highly to the horizontal and vertical position of reference points in the cervical column with statistical significance($0.1\%$ level). 2. The angles n-s-ba and n-s-ar as variables for the form of cranial base correlated to the horizontal position of the reference points in the facial structure with statistical significance($1\%$ level), but not to the vertical position of them($5\%$ level). 3. The length n-s, s-ba, and n-ar as variables for the size of cranial base were correlated th the position of craniofacial structures in various ways, but in general, highly correlated to the horizontal and vertical position of midfacial structures around the teeth and alveolar area. 4. the angle NSL/CVT and NSL/OPT as postural variables tot the inclination of cranial base and cervical column were correlated to the horizontal position of the craniofacial structures with statistical significance($1\%$ level), but not to the vortical position of them($5\%$ level). 5. The angle OPT/HOR and CVT/HOR as postural variables lot the inclination of cranial base and true horizontal line were not correlated to the horizontal and vertical position of the craniofacial structures with statistical significance($5\%$ level). 6. The correlation between the measurement variables and horizontal and vortical positions of the reference poits in soft tissue were shown as similar to the related hard tissue points.

• The korean journal of orthodontics
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• v.33 no.4 s.99
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• pp.293-305
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• 2003

The pharynx have significant locations and functions because it forms a part of the unit in which respiration and deglutition are carried out. Because of the closed relationship between the pharynx and the dentofacial and craniofacial structure, many studies are carried out on this subjects. The purpose of this study were to compare the airway size including pharynx, soft palate, tongue and hyoid bone between normal and hyperdivergent skeletal pattern and to evaluate the change of those size in different age. The sample of this study were consisted of 51 subjects in normal group, 52 subjects in hyperdivergent group. Each was divided into two subgroups by age , child group(9-l2yr old) and adult group(18yr old over). The lateral cephalometric radiographs were taken and the distance, angle and ratio of the facial skeleton, pharynx, soft palate, tongue and hyoid bone were measured and evaluated statistically. The result obtained were summarized as follows : 1 SN-Mn angle, FMA, and Pal-Mn angle were significantly larger in child group than adult group, but the lower anterior facial height(LAFH) and facial height ratio(FHR) were significantly smaller in child group than adult group. Occlu-Mn angle was significantly steep in hyperdivergent group than normal, but not significantly different between child group and adult group. 2. Hyperdivergent group and child group had the stronger correlation between SN-Mn angle, FMA, Pal-Mn angle, LAFH and FHR and airway size than normal group and adult group. Hyperdivevgent child group had significant negative correlation between SN-Mn angle, FMA, Pal-Mn angle and sagittal skeletal dimension of nasopharynx and sagittal depth of nasopharyngeal lumen. Significant positive correlation were seen between LAFH and vertical measurement of airway. 3. There was no difference of the linear measurement of airway size between hyperdivergent group and normal group. 4. Adult group had smaller posterior pharyngeal wall, target nasopharyngeal depth longer nasopharyngeal height and longer pharyngeal length than child group. 5. The sagittal measurement of hyoid bone had no difference between child group and adult group. But adult group had larger vertical measurement of hyoid bone than child group.

• The korean journal of orthodontics
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• v.32 no.4 s.93
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• pp.241-255
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• 2002

This study was performed to evaluate horizontal and vertical characteristics according to lateral cephalometry of adult Korean skeletal Class II patients using a selected horizontal and vortical reference planes of Koreans. 60 males and 60 females consisting of freshman of Yonsei University from 1996 to 1997 and patients with history of orthognatic surgery at the Dental Hospital of Yonsei University with a skeletal Class II profile were chosen and compared with 70 males and 70 females with normal occlusion. The skeletal Class R group had the following conditions : 1. Profile composed of a retrognathic mandible or protrusive maxilla; 2. Class II molar and canine key; 3. ANB-greater than $4^{\circ}; 4$. Wits appraisal-greater than 1.0mm; Cephalometric analysis consisted of 22 skeletal, 25 soft tissue, 12 dental measurements. The results were as follows. 1. There was no considerable vortical measurement difference between the skeletal Class II malocclusion group and the normal occlusion group in skeletal analysis. But, some variations were found between the two groups in soft tissue analysis. 2. Mandibular length of the skeletal Class II malocclusion group was smaller than that of the normal occlusion group. Mandible was more posteriorly positioned in the Class II malocclusion group than in the normal occlusion group. 3. The length and antero-posterior position of the maxilla were not different between the Class II malocclusion and the normal occlusion group. 4. The antero-posterior position of the nose, upper lip and maxillary soft tissue, and nasolabial angle were not different between the two groups. 5. Mandibular soft tissue of the Class H malocclusion group was more posteriorly positioned than that of the normal. 6. The vertical measurements of the incisors(U1-HP, L1-HP) were bigger in the Class II malocclusion group than in the normal, but those of the molars(U6-HP, U6-MP) showed no significant difference between the two groups. 7 Classifying the skeletal Class II malocclusion group according to the antero-posterior position of both jaws, normally positioned maxilla and retruded mandible was 43.3%, both normally positioned maxilla and mandible 28.3%, both retruded maxilla and mandible 20.0%..

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.17-27
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• 1998

Study on growth change of dental arch is considered to both an important data in orthodontic diagonsis and treatment planning as well as analysis of treatment results , also, arch form is important in anthropology and dentistry, even more so in prosthodontics and orthodontics. In the field of orthodontics, studies on the functional aspect of upper and lower teeth and maintenance of stability of dentition and occlusion were carried out from the early days. Some of the early studies include explanation of growth change in dental arch from measuring directly fom human stroll, and afterwards, cephalometrics x-rays were introduced; accordingly, studies using cephalometric measurement and linear measurements of study models were often performed. By this method, arch width, arch depth and perimeters were measured, and growth change or dental arch was studied. The subject ror this study were sn children(boys and girls or ages from 3 yens to 12 years from Kang-won district and Seoul, who has no history of orthodontic treatment and who show healthy status and normal growth and development. Cephalometric x-ray, panoramic x-ray, and study model were taken for each subject consecutively for 2 years, and the subjects are still followed up. 400 pairs of study models from the past two years were used in this study; mesio-distal diameater of each tooth, intercanine width, intermolar width, canine depth, molar depth and arch perimeters were measured. Afterwards, mean value and each standard deviation of each age group and each gender were obtained, and representation graph were drawn. The following conclusion were obtained. 1. Intercanine width showed gradual increase until the age of 10-years and after that, showed no increase. 2. Intermolar width in upper arch showed gradual increase : intermolar width in lower arch showed no significant chang, and after the age of 9-years, showed increase. 3. Cainine arch depth showed relatively rapid increase after the age of 6-years, and this pattern was more obvious in lower arch. 4. Molar arch depth increased gradually in both archs and it decrease after the age of 10-years : this phenomenon was more prominent in the lower arch. 5. Arch perimeter showed gradual inerease and convert to plateau at the age of 10-years, after that, it decreased. this pattern was more prominent in lower arch.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.291-297
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• 2003

While making diagnosis and the treatment plan for the growing children who visited at Chonnam National University Hospital for orthodontic treatment, authors obtained 8 lateral cephalometric measurements in antero-posterior and vertical relationship such as APDI, WITS, ANB, SN-MP, ODI, PFH/AFH, Y-axis, SUM for children aged 7 to 9 with class III malocclusion and compared them with these of 73 children of elementary school aged 7 to 9 with proper profile and normal occlusion in Gwangju. The results were as follows: 1. Between normal occlusion and class III malocclusion, ANB, SN-MP, ODI, SUM, except PFH/AFH and Y-axis showed statistically significant differences(p<0.05). 2. Between mesurements to describe skeletal disorder of antero-posterior relationship such as APDI, WITS, ANB and skeletal disorder of vertical relationship such as SN-MP, ODI, PFH/AFH, Y-axis, SUM, all of them in both normal occlusion and Class III malocclusion showed significant correlation, except Y-axis, SUM correlation(p<0.01). 3. Wald' statistics of WITS, ANB and APDI expressing skeletal disorder of antero-posterior relationship showed 7.118, 5.148, 0.741, respectively and Wald' statistics of ODI, Y-axis, PFH/AFH, SN-MP, SUM were presented 28.348, 2.238, 1.376, 0.090, 0.089, respectively. Therefore, WITS and ODI could be considered as useful diagnotic measurements for class III malocclusion.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.591-598
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• 2000

This study was designed to analysis the airway which affects to breathing, speech and facial growth pattern in unilateral cleft lip and palate patients. Upper airway and the position of hyoid bone pattern were analyzed on the lateral cephalometric radiographs of the 78 subjects of complete unilateral cleft lip and palate group and each group was divided two sub-groups by circumpubertal growth peak and gender. These data were statistically analyzed to examine the difference between pre-circumpubertal growth peak group and post-circumpubertal growth peak one, and between male and female group. The results of this study were as follows: 1. After circumpubertal growth peak stage, the position of hyoid bone was lower than before in both male and female group. 2. After circumpubertal growth peak stage, the measurement were increased in CV3ia-APH, PNS-ad which related to the volume of pharyngeal space. This was due to the decrease of adenoid and anteroiferior growth of mandible and affected to breathing and speech after circumpubertal growth peak. 3. During circumpubertal growth peak stage, all measurements increased more in male than female group, which due to the different amount of growth in different gender. 4. The position of hyoid bone was lower in male than female group in all age group. 5. After circumpubertal growth peak stage, CV3ia-APH increased more in male. This was due to the more growth in madible of male which resulted in the activation of digastric muscle.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.4
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• pp.321-329
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• 2001

To establish systematic diagnosis and treatment planning of dentofacial deformity patient including facial asymmetry or hemifacial microsomia patient, comprehensive analysis of three dimensional structure of the craniofacial skeleton is needed. Even though three dimensional CT has been developed, landmark identification of the CT is still questionable. In recent, a method for correcting cephalic malpositioning that enables accurate superimposition of the landmarks in different stages without using any additional equipment was developed. It became possible to compare the three-dimensional positional change of the maxillomandible without invasive procedure. Based on the principle of the method, a new program was developed for the purpose of diagnosis and treatment planning of dentofacial deformity patient via three dimensional visualization and structural analysis. This program enables us to perform following menu. First, visualization of three dimensional structure of the craniofacial skeleton with wire frame model which was made from the landmarks observed on both lateral and frontal cephalogram. Second, establishment of midsagittal plane of the face three dimensionally, with the concept of "the plane of the best-fit". Third, examination of the degree of deviation and direction of deformity of structure to the reference plane for the purpose of establishing surgical planning. Fourth, simulation of expected postoperative result by various image operation such as mirroring, overlapping.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.6
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• pp.490-496
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• 2011

Purpose: Dr. Marquardt made the facial 'phi' mask using golden ratio. Most class III patients have bulky faces and want a smaller face. Using a facial golden mask, this study estimated and compared frontal photographs before and after operation for soft tissue measurement. The golden mask can be considered as a reference tool for facial esthetic analyses especially in lower face. Methods: Forty patients who had undergone orthognathic surgery at Samsung Medical Center from January 2006 to December 2009 were included in this study. These patients had Class III malocclusion. Lateral cephalometric radiographs, frontal clinical photos of pre-op and 8~12 month later post-op, and the facial 'phi' mask using golden ratio, were used for analysis. Reduction of the lower face area, occlusal plane changes, amounts of mandible setback and amounts of maxilla posterior impaction were estimated. Results: Lower facial reduction ratio and mandibular setback amounts were significantly different between 1-jaw and 2-jaw groups. Average postoperative changes in the area of lower face between bilateral sagittal split ramus osteotomy (BSSRO) and BSSRO combined maxilla posterior impaction were compared by using an independent simple t-test and $P$ value was 0.016. Therefore, the lower facial reduction ratio and mandibular setback amount were significantly different in maxilla posterior impaction. Conclusion: The two-jaw surgery group showed more reduction of the lower facial area than the 1-jaw surgery group. The amount of lower facial reduction was more related with the amount of mandibular setback. There was no significant relation in lower facial reduction with amount of maxilla posterior impaction, pre-op occlusal plane, post-op occlusal plane and the mandibular angle. A relationship between the change in the lower facial area and the amount of maxilla posterior impaction or the change of mandibular angle occlusal plane at pre-op could not be found because of the difference in the amount of setback between two groups.