• Imaging Science in Dentistry
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• 제42권4호
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• pp.201-205
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• 2012

Purpose: This study was performed to assess the compatibility of cone beam computed tomography (CBCT) synthesized cephalograms with conventional cephalograms, and to find a method for obtaining normative values for three-dimensional (3D) assessments. Materials and Methods: The sample group consisted of 10 adults with normal occlusion and well-balanced faces. They were imaged using conventional and CBCT cephalograms. The CBCT cephalograms were synthesized from the CBCT data using OnDemand 3D software. Twenty-one angular and 12 linear measurements from each imaging modality were compared and analyzed using paired-t test. Results: The linear measurements between the two imaging modalities were not statistically different (p>0.05) except for the U1 to facial plane distance. The angular measurements between the two imaging modalities were not statistically different (p>0.05) with the exception of the gonial angle, ANB difference, and facial convexity. Conclusion: Two-dimensional cephalometric norms could be readily used for 3D quantitative assessment, if corrected for lateral cephalogram distortion.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제39권
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• pp.3.1-3.9
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• 2017

Background: The purpose of the study is to compare the effects on the pharyngeal airway space of skeletal anchored face mask with those of tooth-borne facemask. Methods: We used two types of facemask for maxillary protraction, the tooth-borne facemask (TBFM) and the skeletal anchored facemask (SAFM), and evaluated the effects of each facemask on the pharyngeal airway. Twenty-eight patients (mean age 10.3 years) were treated with the TBFM and 24 patients (mean age 11.2 years) were treated with the SAFM. Lateral cephalometric radiographs were taken before treatment (T1) and after treatment (T2) to assess changes in the dimensions of the upper airway. Statistical analysis was performed with independent t tests, matched t tests, Mann-Whitney U tests, and Kruskal-Wallis tests. Results: There were marked increases in upper airway dimensions in both groups following treatment, but the SAFM group had a significantly greater increase in airway dimensions than the TBFM group. Also, the SAFM subgroups showed more improved airway measurements than the TBFM subgroups in both the superior and inferior pharyngeal airways. Conclusions: SAFM is more effective than TBFM in increasing upper airway dimensions.

• 대한치과교정학회지
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• 제18권1호
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• pp.79-88
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• 1988

The purpose of this study was to investigate the factors which might be related to mandibular third molar eruption and to predict the possibility of whether or not it will be erupted. The material of this study was lateral cephalometric radiograms, pantomograms and dental casts obtained from 70 patients (19 males, 51 females) ranging in age from 18.0 to 32.1 years. They were devided into erupted group and impacted group of mandibular third molars. For the comparison of each group, a total of 20 measurement items were employed and the data were analyzed by means of computer statistical method. As a result of this study, the following conclusion can be made; 1. The longer mandibular body length and narrower mandibular ramus width, the higher eruption tendency of the lower third molar, but the degree of genial angle was not related to mandibular third molar eruption. 2. The lower percentage of posterior mandibular body height to anterior mandibular body height, the higher eruption tendency of the lower third molar. 3. The total tooth size, including the lower second molar, appeared to be larger in the impacted group than in the erupted group of the lower third molar. 4. The arch length discrepancy of the impacted group was more severe in contrast with the erupted group of the lower third molar.

• Imaging Science in Dentistry
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• 제51권4호
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• pp.407-412
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• 2021

Purpose: The purpose of this study was to evaluate the accuracy of virtual 3-dimensional (3D) cephalograms constructed using the principle of biplanar radiography by comparing them with cone-beam computed tomography (CBCT) images. Materials and Methods: Thirty orthodontic patients were enrolled in this study. Frontal and lateral cephalograms were obtained with the use of a head posture aligner and reconstructed into 3D cephalograms using biplanar radiography software. Thirty-four measurements representing the height, width, depth, and oblique distance were computed in 3 dimensions, and compared with the measurements from the 3D images obtained by CBCT, using the paired t-test and Bland-Altman analysis. Results: Comparison of height, width, depth, and oblique measurements showed no statistically significant differences between the measurements obtained from 3D cephalograms and those from CBCT images (P>0.05). Bland-Altman plots also showed high agreement between the 3D cephalograms and CBCT images. Conclusion: Accurate 3D cephalograms can be constructed using the principle of biplanar radiography if frontal and lateral cephalograms can be obtained with a head posture aligner. Three-dimensional cephalograms generated using biplanar radiography can replace CBCT images taken for diagnostic purposes.

• 치과방사선
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• 제12권1호
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• pp.49-56
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• 1982

The purpose of this study was to observe the anatomic variation of condylar head and the positional relationship between condylar head and other anatomic structures of head by means of cephalometry using the submentovertex cephalogram from each person in centric occlusion for producing a good quality of temporomandibular joint radiograph. The 100 submentovertex cephalograms of 100 Korean adults consisted of 50 females ranged from 20 to 24 years age and 50 males ranged from 22 to 30 years age, were studied and analyzed statistically. The results were as follows; 1. The mean of the horizontal angulation of condylar head to the transmeatal line (EE-LA) was 18.5° (S.D. 7.9°), and all measurements that indicate the horizontal angulation of condylar head showed considerable differences among individuals. 2. In the comparison of male vs. female in the measurements, statistically significant differences were found in the majority of measurement items, and with exception of R-LA and LA-LA, the rest of these measurements were larger in male than in female. 3. In the comparison of left vs. right in the measurements, statistically significant differences were found in the majority of measurement items, and with exception of PC-CC, the rest of these measurements were larger in right than in left. As above, because the majority of measurements that involve the horizontal angulation of condylar head varied among individuals, between male and female, and between left and right, the condition of various temporomandibular joint radiography should be determined by means of cephalometry using the submentovertex cephalogram for producing the accurate radiographic image of temporomandibular joint.

• 대한치과교정학회지
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• 제22권3호
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• pp.735-753
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• 1992

악골형태에 따른 상하악절치의 위치를 분석하기 위하여 18세 이상되는 정상교합자 60명과 II급 1류 부정교합자 40명, 그러고 III급 부정교합자 40명의 측모 두부방사선규격 사진을 설정한 계측점과 계측항목에 따라 분석하여 다음과 같은 결과를 얻었다. 저작계와 관련된 계측항목인 CI angle은 정상교합자군에서 $89.20{\pm}4.34^{\circ}$, II급 1류 부정교합자군에서 $81.68{\pm}5.95^{\circ}$, III급 부정교합자군에 $101.96{\pm}6.31^{\circ}$이었다. 상하악절치위치 계측항목의 악골형태별 비교에서 정상교합자군에 대한 II급 1류 부정교합군은 상악절치가 모든 계측항목에서 유의한 차를 보이며 순측경사져 있고(p<0.05), 하악절치도 ${\angle}LI-APog$, LI-APog(m), ${\angle}LI-AB$, LI-AB(mm)를 제외한 모든 계측항목에서 유의한 차이를 보이며 순측경사져 있었다(p<0.05). III급 부정교합자군은 상악절치가 ${\angle}UI-SN,\;{\angel}UI-OP$을 제외한 모든 계측항목에서 유의한 차를 보이며 순측경사져 있고 하악절치는 모든 항목에서 유의한 차이를 보이며 설측 경사져 있었다(p<0.05). 모든 악골형태에서 ${\angle}LI-SN,\;{\angel}LI-FH$가 악골계측항목과 비교적 상관성이 있었고, FMA가 하악절치위치계측항목과 비교적 상관성이 있었다. 악골형태에 상관없이 일정하게 적용할 수 있는 기준선은 상악절치 계측항목에서는 AB선, 하악절치 계측항목에서는 APog선이었다.

• 대한치과교정학회지
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• 제30권5호
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• pp.543-552
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• 2000

본 연구는 natural head posture(NHP)를 이용하여 정모 두부 방사선 규격사진 촬영시 재현도를 알아보기 위하여 시행되었다. 두개 안면부의 기형이 없는 25세 전후의 성인 남녀 30명을 대상으로 통상적인 방법(술자 유도법)과 NHP에서 Head Posture Aligner를 이용한 방법(HPA법)으로 정모 두부 방사선 사진을 각기 2주 간격으로 촬영한 후 5개의 고경 계측항목과 9개의 폭경 계측항목을 선정하여 t 검정으로 각 계측항목의 재현도를 비교하는 한편, 정모와 측모 두부 방사선 사진으로3차원 상을 합성시 오차의 요인이 되는 두부의 상하회전 정도 차이를 촬영 방법별로 비교 분석하여 다음과 같은 결과를 얻었다. 1. 시간 간격을 두고 술자 유도법으로 2회 촬영한 정모 두부 방사선 사진의 계측치는 모든 고경 계측항목에서 서로 차이를 나타내어 낮은 재현도를 보였다. 2. 시간 간격을 두고 HPA법으로 2회 촬영한 정모 두부 방사선 사진의 계측치는 모든 고경 계측항목에서 통계적으로 유의한 차이를 나타내지 않아 재현도가 높음을 보였다. 3. 폭경 계측항목의 경우 2회 계측치의 차이를 통하여 살펴 본 재현도에서 술자유도법과HPA방법간에 두드러진 차이를 보이지 않았다. 4. 정모 및 측모 두부 방사선사진으로 3차원상을 합성하기 위한 수직적 두부 위치 보정각을 계산한 결과, 술자 유도법의 경우 $2.5^{\circ}$인 반면, HPA법은 $0.8^{\circ}$로 작게 나타났다. 이상의 결과는 정모 두부 방사선 규격 사진 촬영시 두부 위치의 재현도를 증가시키기 위하여 HPA의 사용이 필요함을 시사하였다.

• 대한치과교정학회지
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• 제29권5호
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• pp.575-587
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• 1999

골격성 II급 부정교합자 중 성장이 완료되었다고 생각되는 만 18세 이상의 여자 37명, 만 20세 이상의 남자 23명을 선정하여 정상 성인의 안면비를 기준으로 hyperdivergent group(n=30)과 hypodivergent group(n=30)으로 나누어 두부방사선규격사진의 투사도를 작성하였으며 두개안면골격 및 혀의 크기, 높이 그리고 자세를 나타내는 항목을 계측하였고, 두 군간의 차에 대한 유의성 검정 및 혀와 두개안면골격 그리고 악간공간 사이의 상관관계를 조사하여 다음과 같은 결론을 얻었다. 1. 두 군의 혀와 악간공간의 계측항목 비교시 악간공간에 대한 혀의 면적비(TS/IS)는 hyperdivergent group에서 더 크게 나타났으며, PIH(posterior intermaxillary height)와 IS(intermaxillary space)는 hypodivergent group에서 더 크게 나타났으나 혀의 높이와 자세를 나타내는 항목에서는 두 군간에 유의할 만한 차이가 없었다. 2. 혀와 두개안면골격의 상관관계 비교시 두 군 모두에서 혀의 면적(TS), 길이(TGL) 그리고 높이(TH)를 나타내는 계측항목이 전안모고경 (AFH)과 가장 높은 상관관계를 나타냈으며, 또한 hypodivergent group에서는 후안모고경(PFH)과도 높은 상관성을 보였다(p<0.01). 3. 혀와 악간공간의 상관관계 비교시 두 군 모두 혀에 관한 대부분의 항목(H-P제외)이 악간공간(IS)과 가장 높은 상관성을 보였으며, 혀의 높이 (TGH)와 면적 (TS)을 나타내는 항목은 악간공간의 AIH 및 PIH와 높은 상관성을 보였다(p<0.01).

• 대한치과교정학회지
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• 제15권1호
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• pp.123-140
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• 1985

Variation in the facial pattern and effect of the rotational jaw growth on the facial proportion were studied in serial cephalometric radiographs of 40 Korean children (25 boys, 15 girls) ranging in age from 6 to 13 years. According to Y-axis (N-S-Gn) growth change during the 7 years of period, the subject who had exhibited 'wave-like' manner of Y-axis growth change within ${\pm}\;2^{\circ}$ was classified to the Parallelwise group and the subject who had exhibited Y-axis increase more than $+2^{\circ}$ was classified to the Clockwise rotation group and the subject who had exhibited Y-axis decrease more than $-2^{\circ}$ was classified to the Counterclockwise rotation group. For the comparison of each group, a total of 22 morphologic variables were employed and the data were analyzed by means of computer morphometrics and statistical methods. On the basis of the finding of this study, the following trends were established. 1. The Parallelwise group was $75\%$, the Clockwise rotation group was $12.5\%$ and the Counter-clockwise rotation group was $12.5\%$. 2. The growth pattern of cranial base was related to the rotation of mandible. 9. Maxillary prognathism was occured in the Counterclockwise rotation group and the rotation of palatal plane was occured in the Clockwise rotation group. 4. Mandibular prognathism was occured in the Parallelwise and the Counterclockwise rotation groups, especially in the Counterclockwise rotation group. 5. The degree of maxillo-mandibular divergency was constant in the Clockwise rotation group but decreased in the Counterclockwise rotation and the Parallelwise groups, especially in the Counterclockwise group. 6. There were no differences in the size of the anterior upper facial height (N-ANS) and the posterior lower facial height ((Go-Me)-PNS) but there were differences in the size of the anterior lower facial height (ANS-Me) and the posterior upper facial height ((S-N)-PNS) between each group. 7. The growth increment and the size of the facial depth was not related to the growth pattern of the face but the growth increment and the size of the facial height was related to the growth pattern of the face. 8. Proportional change due to the facial growth rotation was concentrated in the anterior lower face. 9. The most apparent difference between each group was happened in the size of the posterior cranial base (S-Ba) and the facial length (S-Gn).

• 대한소아치과학회지
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• 제29권3호
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• pp.295-303
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• 2002

대부분의 악악면 부조화는 혼합치열기에 시작되는데 혼합치열기는 영구치열에서 이상적인 교합을 형성하는데 매우 중요한 역할을 하며 이 시기에 교합유도를 성공적으로 수행하기 위해서는 두부방사선 계측학적 표준치가 중요하다. 따라서 소아치과영역에서 큰 비중을 차지하는 부정교합치료에 참고자료로 사용하기 위하여 Downs 분석법에 의한 표준치가 과거와 비교해서 변화가 있는지를 알아보고 인종간의 차이를 알아보고자 정상교합에 해당하는 혼합치열기 아동을 대상으로 두부방사선 계측학적 표준치를 조사하여 다음과 같은 결과를 얻었다. 1. Downs 분석법에 의해 한국인 성장기 아동의 연령군별 남녀별 두부방사선 규격사진 계측치의 기준치를 설정하였다. 2. 각 군에서 계측항목별로 남녀간의 유의한 차이는 없었으나 교합평면각, 상하악중절치각, 하악중절치와 교합평면이 이루는 각, 상악 중절치와 A-Pog간의 거리에서는 연령에 따라 유의한 차이가 있었다. 3. 안면각, AB plane angle, Y-axis, 하악중절치와 교합평면이 이루는 각, 하악중절치와 하악평면이 이루는 각, 상악중절치와 A-Pog간의 거리는 연령이 증가함에 따라 커졌으며, angle of convexity, 하악평면각, 교합평면각, 상하악중절치각등은 연령이 증가함에 따라 감소하였다. 4. 인종간 비교시 본 연구 결과가 백인과 그리스인보다 상하악절치각만 작았을 뿐 모든 계측치에서 전반적으로 크게 나타났으며, 일본, 이스라엘 흑인, 중국인과는 모든 항목에서 비슷한 수치를 나타냈다.