• Korean Journal of Biological Psychiatry
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• v.22 no.1
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• pp.14-19
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• 2015

Objectives The purpose of this study is to find the cephalometric variables which are significantly correlated with the apnea-hypopnea index (AHI) in suspected Korean obstructive sleep apnea (OSA) patients. Methods We examined lateral cephalogram and attended-full night laboratory polysomnography of the 40 participants who complained of OSA symptoms. The correlation analysis was conducted to find the cephalometric variables which are significantly correlated with the AHI. Results The correlation analysis showed that the higher AHI was associated with the longer distance between hyoid and mandibular plane (p = 0.023), the longer distance between C3 and hyoid (p = 0.014), the longer tongue length (p = 0.003), the larger inferior tongue area (p = 0.008), the larger anterior displacement of the hyoid bone (p = 0.024), the longer distance between posterior nasal spine and the tip of the soft palate (p = 0.021), and the larger cross-sectional area of soft palate (p = 0.001) of cephalogram in erect position. The higher AHI was correlated with the longer distance between hyoid and mandibular plane (p = 0.008), the longer tongue length (p = 0.037), the larger inferior tongue area (p = 0.013), the thicker uvula (p = 0.004), the longer distance between retrognathion and hyoid (p = 0.025), and larger cross-sectional area of soft palate (p = 0.001) of cephalogram in supine position. Conclusions The present preliminary results showed the candidate measurements of cephalogram which are significantly correlated with the AHI in suspected OSA.

• Journal of Korean Neurosurgical Society
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• v.54 no.4
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• pp.275-279
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• 2013

Objective : This study was designed to determine the most reliable cephalometric measurement technique in the normal population and patients with basilar invagination (BI). Methods : Twenty-two lateral radiographs of BI patients and 25 lateral cervical radiographs of the age, sex-matched normal population were selected and measured on two separate occasions by three spine surgeons using six different measurements. Statistical analysis including intraclass correlation coefficient (ICC) was carried out using the SPSS software (V. 12.0). Results : Redlund-Johnell and Modified (M)-Ranawat had a highest ICC score in both the normal and BI groups in the inter-observer study. The M-Ranawat method (0.83) had a highest ICC score in the normal group, and the Redlund-Johenll method (0.80) had a highest ICC score in the BI group in the intra-observer test. The McGregor line had a lowest ICC score and a poor ICC grade in both groups in the intra-observer study. Generally, the measurement method using the odontoid process did not produce consistent results due to inter and intra-observer differences in determining the position of the odontoid tip. Opisthion and caudal point of the occipital midline curve are somewhat ambiguous landmarks, which induce variable ICC scores. Conclusion : On the contrary to other studies, Ranawat method had a lower ICC score in the inter-observer study. C2 end-plate and C1 arch can be the most reliable anatomical landmarks.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.543-552
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• 2000

The purposes of this study were to evaluate the reproducibility of posteroanterior(PA) cephalograms obtained by two methods, the Head Posture Aligner(HPA) method in natural head posture and the conventional method(operator-guided method), and to compare the vertical rotational differences of the head Posture between lateral and PA cephalograms according to the method. The sample was consisted of 30 adults. At first day, a PA cephalogram and a lateral cephalogram were obtained from each subject by two methods to investigate the difference of vertical rotational posture between lateral and PA cephalograms. Two weeks later, another PA cephalogram was obtained using each method to evaluate the reproducibility of head posture. Five height measurements and nine width measurements were used in the paired t-test to compare the reproducibility of the PA cephalometric measurements between two methods. The differences of vertical rotational posture between lateral and PA cephalograms were calculated from a computer program and compared according to the method used, and following results were obtained. 1. Height measurements obtained by operator-guided method showed significant differences according to the time interval and revealed low reproducibility. 2. Height measurements obtained by HPA method did not show significant differences according to the time interval and presented high reproducibility. 3. In the comparison of width measurement, two methods did not show distinct differences in reproducibility. 4. The difference of vertical rotational posture between lateral and PA cephalograms showed $0.8^{\circ}$ in the HPA method, more less than $2.5^{\circ}$ in the operator-guided method. The results of the present study suggest that the HPA may be helpful in the PA cephalometric radiography in terms of reproducibility.

• The korean journal of orthodontics
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• v.29 no.5 s.76
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• pp.575-587
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• 1999

This study was designed to evaluate the correlations between tongue with skeletal pattern and intermaxillary space in Class II malocclusion adult patients. Craniofacial skeletal pattern was analyzed on the lateral cephalometric radiograph and the subjects were devided two groups by facial ratio, the 30 subjects of hyperdivergent group and the 30 subjects of hypodivergent group. The size and posture of tongue and intermaxillary space were measured on the lateral cephalometric radiograph. These data were statistically analyzed to examine significant differences between both groups and compared the correlation between tongue with skeletal measurements and intermaxillary space in each group. The results of this study were as follows. 1. In comparison of the tongue and intermaxillary space, the measurement of TS/IS showed significantly larger in hyperdivergent group and PIH and IS showed significantly larger in hypodivergent group. There were no statistically significant differences in the measurements of the height and posture of tongue. 2. In correlation between tongue with craniofacial skeletal measurements, the length and height of tongue showed the highest correlation with AFH(anterior facial height) in both groups(p<0.01). And that measurements showed high correlation with PFH(posterior facial height) in hypodivergent group. 3. In both groups, most measurements of tongue showed high correlation with intermaxillary space and the height and space of tongue showed high correlation with AIH and PIH(p<0.01).

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.16 no.1
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• pp.69-79
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• 1986

The purpose of this investigation was to know correlation of mean values between centric occlusion and centric relation by the cephalogram in Angle's Class Ⅰ and Ⅲ malocclusion subjects. 22 adults with Angle's Class Ⅰ malocclusion (17 men and 5 women, 21 to 27 years of age) and 14 adults with Angle's Class Ⅲ malocclusion (10 men and 4 women, 21 to 27 years of age) were selected from the dental students in Yonsei University. Each subject was given two lateral cephalometric radiographies and cephalometric analysis was performed. All data from these analyses was recorded and statistically processed with CYBER computer system. 1. The results were obtained as follows: There was a strong positive correlation between centric occlusion and centric relation in all subjects with Angle's Class Ⅰ and Ⅲ malocclusion. 2. In Angle's Class Ⅰ malocclusion, measurements in lower facial height revealed significant difference between centric occlusion and centric relation (P<0.05). In Angle's Class Ⅲmalocclusion, measurements in facial axis angle, mandibular plane angle, convexity of A point, lower incisor protrusion, lower facial height revealed significant difference between centric occlusion and centric relation (P<0.05). 3. When the mandible was moved from centric occlusion to centric relation, the mean distance of mandibular movement was 1.27㎜ (0.2-2.8㎜) in Angle's Class Ⅰ malocclusion, 1.70㎜ (0.55-4.15㎜) in Angle's Class Ⅲ malocclusion, and 1.44㎜ (0.2-4.15㎜) in all subjects.

• The korean journal of orthodontics
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• v.28 no.6 s.71
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• pp.937-946
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• 1998

The patient with an anterior open bite has one of the most difficult orthodontic problem to correct. Previous studies have yielded different conclusions as to exactly where the morphologic problems associated with vertical dysplasia-high angle cases are located. In order to identify the cephalometric features of high angle cases and highlight the measurements that characterize high angle cases, 109 pretreatment cephalograms, 35 high angle, 37 average angle, and 37 low angle cases, were analyzed and compared statistically. As the mandibular plane was steeper, the anterior facial height, especially lower anterior facial height, became greater, and the posterior facial height became smaller. All the dentoalveolar vertical dimensions, especially in upper, increased. And all the skeletal angular measurements increased. Especially Lower genial angle had most positive correlation to mandibular Plane angle. Upper incisor was lingually inclined, and lower incisor was labially inclined in high angle cases.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.93-104
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• 2000

Orthodontic treatment in conjunction with second-molar extraction has been a controversial issue among orthodontists over many decades. The aim of this study was to investigate the treatment effects of upper second molar extraction cases. The sample included 19 upper second molar extraction orthodontic cases(ten Angle's Class I's and nine Class II's, average age=13Y 6M) cared at Kyung-Hee University Department of Orthodontics. Lateral cephalometric radiographs were taken before and immediately after treatment. Seventy-nine points were digitized on each cephalogram and 38 cephalometric parameters were computed comprising 22 angular measurements, 13 linear measurements, and 3 facial proportions. The data obtained from each malocclusion group were analyzed by paired t-test. The statistical results disclosed that there was no significant change in skeletal pattern after treatment except for that accountable by growth while there was statistically significant change in dentoalveolar and soft tissue patterns. There were no significant changes in Bjork sum, posterior facial height /anterior facial height and lower anterior facial height /anterior facial height. No significant changes in anteroposterior position of maxilla and palatal plane were manifested. Although facial axis and lower facial height was slightly increased and the mandible was rotated backward and downward, there was no remarkable change in the mandibular plane. There were statistically significant changes in distal movement of upper first molar, molar key correction and overjet reduction while there was no change in the occlusal plane. The upper lip was slightly retracted simultaneously with slight increase in nasolabial angle. These results signify that distalization of upper dentition with the second molar extraction does change occlusal relationship without gross modifications in the craniofacial skeletal configurationson. Henceforth the second molar extracted would be recommended to treat severe anterior crowding and protrusion with minor skeletal discrepancy.

• The korean journal of orthodontics
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• v.8 no.1
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• pp.19-26
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• 1978

This study was undertaken to estabish the cephalometric standards of Hellman dental age III A group of Korean on the roentgenocephalometry. The subjects consisted of 26 males and 29 females with the normal occlusion and acceptable profile. The following conclusions were obtained; 1) The tables of mean and standard deviation were made from the measurements of both male and female. 2) A ll linear measurements in male were greater than those in female. 3) Mandibular growth rate of female was greater than that of male. 4) Comparision of the childern in Hellman dental age III A with those in the late primary dentition indicated the tendency of facial vertical growth.

• The korean journal of orthodontics
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• v.16 no.2
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• pp.81-97
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• 1986

The purpose of this study was to investigate the factors which cause the differences in the percentage of anterior overbite in spite of normal molar relationship in terms of skeletal, dental and dentoalveolar relations. The models and cephalograms taken from 154 subjects, 89 of shallow overbite and 65 of deep overbite ranging from 18 to 29 years of age were studied and analyzed statistically. The results were as follows. 1. In determining the percentage of anterior overbite, the significant differences were higher in the dental and dentoalveolar factors than in the skeletal factors and were higher in the proportional and angular measurements than in linear measurements. 2. The factor which had the greatest influence on the percentage of anterior overbite was the proportional parts of the dental and dentoalveolar heights. 3. The most influencing factor which determined the percentage of anterior overbite was the SN-MP angle among the skeletal factors.

• The Journal of the Korean dental association
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• v.18 no.1 s.130
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• pp.65-70
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• 1980

Lateral cephalometric head film measurements on forty schoolboys and forth-nine schoolgirls with excellent occlusions in Korean were compared with similar measurements on Caucasoids. The following conclusions were obtained. 1. The cranio-facial skeletal pattern of Korean students was measured and compared with Caucasoids. 2. In cranio-facial observation, ANB and SN-Palatal plane was not significant in girls only, Gonial angle and 1 to NA were not significant in girls and boys, compared with Caucasoids. 3. In dentition area observation, the mean posterior dental height (A＋B) and occlusal plane length was not significant in girls only, the mean anterior vertical dimension and P angle was not significant in boys, Q angle was not significant in boys in boys and girls, compared with Caucasoids.