• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.1
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• pp.91-98
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• 1991

This study was made to analyze the positional relationship of mandible to hinge axis in normal subject as the diagnostic criteria of T.M.J. dysfunction. The author has conducted the study using the Cephalometric P-A view, and dental of 53 males and 51 females. By measurement, the standard value of cranio-facial and occlusal asymmetry in normal subject obtained. The following results were obtained: 1. Although the degree of the difference between right and left width in each measured line was small, asymmetry in normal subject could be identified. 2. In male, measurement between genial tubercle and hinge axis is 127.20±6.06㎜ in left, 125.83±6.25㎜ in right, and angle between genial tubercle and hinge axis is 48.48±3.53° in left, 49.58±3.72° in right. In female, measurement is 119.32±5.81㎜ in left, 118.82±5.35㎜ in right and angle is 48.06±2.15° in left, 48.17±2.31° in left, 48.17±2.31° in right. 3. In male, difference between left and right canine cusp tip of maxilla about X-bar is 0.70±0.59㎜, and that of central pit of first molar of maxilla is 0.98±0.75㎜. In female, difference is 0.64±0.52㎜ in canine and 0.92±0.76㎜ in molar.

• The Journal of the Korean dental association
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• v.47 no.5
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• pp.282-290
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• 2009

The purpose of this study was to evaluate the measurement error between conventional films, digital cephalographs and hardcopy. The material consisted of 29 cephalographs which used image modality of Asahi CX-90SP in the Kyung Hee University Dental Hospital. One observer measured fiducial measurements at an interval of four weeks. Measurement error was tested by Dahlberg's formula. A paired t-test was used to detect it between each modality. The results are as follows; 1. The monitor-displayed digital image showed enlargement compared with the conventional image. The cephalometric measurements of the monitor-displayed digital image and conventional image were no statistically significant difference except SNB. 2. In conventional image, measurement errors of linear and angular measurements were 0.23mm, $0.36^{\circ}$, respective. In monitor-displayed digital image, measurement errors of linear and angular measurements were 0.63mm, $0.48^{\circ}$ respective. 3. The reduction ratio of hardcopy was 1.01% compared to the monitor-displayed digital image. Based on the results, it indicates that the digital cephalographs and hardcopy using storage phosphor digital radiography showed the same accuracy as the conventional films in clinical use.

• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.159-172
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• 2001

Three dimensional analysis of malocclusion and craniofacial deformation is essential for the successful orthodontic treatment. But the orthodontists are not familiar with diagnosis and treatment plane based on lateral cephalometric analysis. Since orthodontists do not posses a sufficient knowledge in standard value of posteroanterior cephalometric anaysis and of clinical importance for transverse jaw growth. In this study male(n=130) and female(n=171) aged from 6 to 16 and diagnosed as Class I malocclusion were selected to analysis width of cranium, maxilla and mandible on the posteroanterior cephalogram. The changes as a function of chronologic age and cervical vertebrae maturity index(CVXI) were examined. The Proper regression model was selected by sex with polynominal regression models and method of variable selection. Mean of each measurements and 70% confidence interval of individual measurement according to age was assesed and a graphs were made. Results are as follows :1. All the measurements for the width are gradually incresed as increase in chronologic age and CVMI. From the total amount of change between age 6 and 16, there is a tendency that mandibular width is broader than maxillary width and the width of male is broader than female. 2. There is no statistically significant sexual difference in Mx-Mn difference, Mx-Mn width differential, Mx/Mn ratio according to age and CVMI. 3. Mean of each measurement and 70% confidence interval of individual measurement according to age and sex were assessed and graphs were made for maxillary width, mandibular width, Mx-Mn difference, Mx/Mn ratio. 4. The width of maxilla and mandible in Korean children are broader than Western children during growth period.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.3
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• pp.218-224
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• 2011

Purpose: The purpose of this study is to evaluate the post-operative skeletal stability after surgical correction of patients with mandibular prognathism by bilateral sagittal split ramus osteotomy (BSSRO) and to evaluate the horizontal relapse tendency after the surgery. Methods: Twenty-six patients with Class III dental and skeletal malocclusion were selected for this retrospective study. Fifteen of them underwent BSSRO for mandibular setback and eleven of them underwent two-jaw surgery (Lefort I and BSSRO). In each patient, lateral cephalometric radiographs were taken pre-operatively, post-operatively within 1 week, and post-operatively after eight months. After tracing of the cephalometric radiographs, various parameters were measured. The analyses were done by linear measurement to evaluate the change in position of hard tissue B point, pogonion and mandibular plan angle by examination on lateral cephalograms. Results: The horizontal relapse rate was 27.1% at B point and 31.6% at pogonion in patients who underwent BSSRO. The horizontal relapse rate of the group where the amount of correction exceeded 10 mm was 25.69% at B point. Conclusion: There were no statistical differences on the magnitude of setback and direction of rotation of the mandible in mandibular stability. There were also no statistical differences between single mandibular surgery and two-jaw surgery for mandibular stability.

• The korean journal of orthodontics
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• v.19 no.1 s.27
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• pp.169-185
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• 1989

The purpose of this study was to establish Korean norms that will be valuable aids for diagnosis in orthognathic surgery patients. Lateral cephalometric measurements were established for adult Koreans (60 males, 62 females) with normal occlusion and acceptable profiles. The results were as follows: 1. Means, standard deviation and sexual differentiation were included within each measurement. 2. In skeletal measurements, FH to SN and SN to mandibular plane measurements in females were larger than those in males while all linear measurements in males were larger than those in males were larger than those in females. 3. Significant differences were observed between male and female groups on all of the items that showed vertical relationship in dental measurements. And the measurements of ADH, PDH and overbite in males were larger than those in females while the measurements of incisor exposure in females were larger than those in males. 4. In all measurements of soft tissue except NLA, that is, of FCA, UFH, ULL and LLL, males were larger than those in females.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.109-123
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• 1981

The author studied and analyzed statistically 112 adults female ranging in age from 18 to 20 years with normal occlusion, 56 adults female ranging in age from 18 to 24 years with deep overbite and 53 adults female ranging in age from 18 to 28 years with open bite by vertical cephalometric analysis. The results were as follows; 1. In comparing normal occlusion with deep overbite and open bite, skeletal linear measurements were more significant than dentoalveolar linear measurements. SN-MP angle, SN-OP angle, PP-OP angle and Xi angle (ANS-Xi-Pog) were significant in anglular measurements. 2. Upper posterior facial height (SE-PNS), upper anterior alveolar height, lower posterior alveolar height, lower posterior alveolar height/lower anterior alveolar height and SN-PP angle were non significant between deep overbite and open bite. 3 The most significant items between deep overbite and open bite were lower anterior facial height (ANS-ME) and SN-MP angle. 4. Correlation coefficients of angular measurements were higher in deep overbite, while that of linear measurement total anterior facial height (N-ME) was higher in open bite. 5. In the multiple regression equation, significant variables were total anterior facial height (N-ME), lower anterior alveolar height, upper anterior alveolar height, upper posterior alveolar height, Xi angle (ANS-Xi-Pog) and ramus height (AR-Go) in deep overbite, and total anterior facial height (N-Me), lower anterior alveolar height, ramus height (AR-Go), lower posterior alveolar height, PP-MP angle and upper posterior facial height (SE-PNS) in open bite.

• Journal of the korean academy of Pediatric Dentistry
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• v.5 no.1
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• pp.64-75
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• 1978

In order to know cephalometric norms for the preschool children, this roentgeno cephalometric study was undertaken in each 50 Korean male and female children of primary dentition age from 4 to 5 year. The following results were obtained. 1. In the skeletal analysis, there was no significant difference between male and female in angular measurement and the linear measument of the male was generally greater than that of the female. 2. Saddle angle was $122.3^{\circ}$, articular angle was $147.6^{\circ}$, gonial angle was $119.4^{\circ}$ and the sum of each angle was $396.1^{\circ}$ in male and $396.6^{\circ}$ in female. 3. The ratio of mandibular body to anterior cranial base was about 1 : 0.91. 4. In the primary dentition, suggested that the nasion and point A move forward relative to sella turcica in a fashion, pogonion and point B are equal in angular position relative to plan S-N, bony chin and chin button was yet underdeveloped, and the forward growth of mandible was seen rapid than maxilla after 4 years. 5. Suggested that the percentage of anterior facial height to the posterior facial height were 64.4% in male and 64.1% in female. 6. Maxillary primary incisors was more upright than the permanent incisors, mandibular primary incisors was inclined lingually relative to the permanent incisor, and primary incisors was more upright than the permanent incisors. 7. Maxillary primary incisors in female was inclined labially than male. 8. In the the relationship of the upper lip and lower lip to the esthetic line, the upper lip was 2.11mm and the lower lip was 2.33mm front of the esthetic line.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.430-440
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• 1998

This study was performed to establish the cephalometric standards and to compare measurement of Korean children in the Field I, II, III, IV, V, VI to Japanese and Caucasians by the Ricketts' analysis. Lateral cephalograms of 24 males and 27 females with normal occlusion and acceptable profile 9 years of age were obtained and statistically analyzed. 1. Norms of Korean males, females and both sexes at 9 years old were established. 2. Significant differences between male and female exist in incisor overjet, maxillary incisor protrusion, mandibular incisor inclination, cranial deflection, corpus length. Maxillary incisor of male was more protrude and overjet was larger than female 3. Korean was similar to Japanese but different from Caucasian. Compare with facial axis and facial depth, chin was retruded dolichofacial pattern and due to large mandibular plane angle and small corpus length, mandibular plane was inclined and mandible body was short. Compare with porion location, ramus position and posterior facial height, ramus was long and located posterior. Compare with maxillary depth and maxillary height, maxilla was located posterior and inferior. The distance between the upper molar and PTV was short, the amount of distalization is limited. Maxillary and mandibular incisor were more protruded and also lower lip was more protruded to esthetic line 4. In comparison between 9 and 11 years old, growth changes of facial depth, mandibular plane angle, corpus length and upper molar position were larger than that of Japanese and Caucasians.

• Imaging Science in Dentistry
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• v.47 no.1
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• pp.1-9
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• 2017

Purpose: This retrospective study aimed to evaluate the nasopharyngeal and oropharyngeal dimensions of individuals with skeletal class II, division 1 and division 2 patterns during the pre-peak, peak, and post-peak growth periods for comparison with a skeletal class I control group. Materials and Methods: Totally 124 lateral cephalograms (47 for skeletal class I; 45 for skeletal class II, division 1; and 32 for skeletal class II, division 2) in pre-peak, peak, and post-peak growth periods were selected from the department archives. Thirteen landmarks, 4 angular and 4 linear measurements, and 4 proportional calculations were obtained. The ANOVA and Duncan test were applied to compare the differences among the study groups during the growth periods. Results: Statistically significant differences were found between the skeletal class II, division 2 group and other groups for the gonion-gnathion/sella-nasion angle. The sella-nasion-B-point angle was different among the groups, while the A-point-nasion-B-point angle was significantly different for all 3 groups. The nasopharyngeal airway space showed a statistically significant difference among the groups throughout the growth periods. The interaction among the growth periods and study groups was statistically significant regarding the upper oropharyngeal airway space measurement. The lower oropharyngeal airway space measurement showed a statistically significant difference among the groups, with the smallest dimension observed in the skeletal class II, division 2 group. Conclusion: The naso-oropharyngeal airway dimensions showed a statistically significant difference among the class II, division 1; class II, division 2; and class I groups during different growth periods.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.65-74
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• 2018

The aim of this study was to obtain the traceability of the software used to analyze lateral cephalometry and to calculate the uncertainty of the measurements. Furthermore, this study aimed to provide a basis for obtaining standard references for measurement values for orthodontic treatment in children. Cephalometric data were collected from 100 children diagnosed with class I malocclusion between the ages 6 to 13 years who visited the pediatric dentist at Seoul National University Dental Hospital. To ensure traceability, a phantom device was created. Correction values were calculated by measuring the length and angle of the phantom device using the software. Type A uncertainty was calculated by obtaining the standard deviation of cephalometric measurements of 100 persons and the standard error of repeated measurements. Determination of the type B uncertainty was induced by minimum resolution and the position of the head. Using these, the combined standard uncertainty was obtained and the expanded uncertainty was calculated. The results of this study confirm that the currently used software has high accuracy and reliability. Furthermore, the uncertainty of orthodontic measurements in Korean children aged 6 to 13 years was calculated, and distribution range for class I malocclusion with 95% confidence interval was suggested.