• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.3 no.1
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• pp.35-38
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• 1973

The authors have interpreted one patient's full mJuth intra-oral films, oblique- lateral film of the left mandible and orthopantomograph which revealed 6 radicular and 1 residual cysts. As a results of interpretation of these serial films, we have drawn following conclusions: 1. Radicular cyst arose from the cell rests contained in an apical granuloma which was sequel to advanced pulpitis due to dental caries. 2. Residual cyst was developed from remaining cell rests after the extraction of a tooth with such a radicular cyst or apical dental granuloma. 3. Cyst grew in size by absorption of fluid into cystic cavity due to difference in osmotic pressure between the cystic fluid and adjacent tissue fluid.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.71-75
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• 1981

The author has studied on the gonical angles in cephalometric roentgenograph and orthopantomograph. Lateral cephalometric roentgenograms and orthopantomograms were taken from 62 patients who were consisted of 32 boys and 30 girls with dentoalveolar Class I malocclusion. Genial angles were measured on cephalograms and orthopantomograms respectively, and calculated the mean values and standard deviations and 't' test was performed on the relationship between the cephologram and orthopantomogram. Results were as followings; 1. Mean value of genial angles was $126.47^{\circ}\;{\pm}\;5.62$ in cephalgram. In orthopantomograms the gonial angle was $125.23^{\circ}\;{\pm}\;6.68$ in left side and $126.47^{\circ}\;{\pm}\;6.85$ in the right side. 2. Result of 't' test showed no significant differences on the level of 1 percent.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.1
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• pp.137-143
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• 1991

In the study of the focal trough of panoramic radiograph using Panoura Eight-S (the Yoshida company), a series of 63 X-ray films were taken with the 8-19 metal pins placed in the holes of the plastic model plate and evaluated by 4 observers. The author analized the focal trough defined by the sharpness criteria and calculated dimension of focal trough in the horizontal plane. The results were as follows; 1. Focal trough was not continued in the anterior region within a very high degree of sharpness. 2. With optional sharpness, the width of anterior and posterior focal trough was approximately l3㎜ and 60㎜ respectively. 3. The focal trough was narrow in the anterior region and was flared laterally with symmetry in posterior region. 4. Sharp image began to show at the position of 18㎜ posteriorly from the most anterior position of chin rest.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.153-161
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• 1984

Orthopantomograph는 치과진료에서 가장 일반적인 국외촬영방법으로 이용되고 있다. 저자는 1983년 서울대학교병원 치과진료부 치과방사선과에 래원한 환자중 Orthopantomogram을 촬영한 2,160명을 대상으로 골경화증의 성별, 연령별 발생빈도와 발생부위, 경화상의 크기, 모양등을 분류하고 특발성 골경화증과 condensing osteitis에 관하여 관찰하였든 바 다음과 같은 결과를 얻었다. 1. Idiopathic osteosclerosis의 발현율은 16.0%, condensing osteitis의 발현율은 9.8%였고 남녀간의 차이는 없었다. 2. 골경화증의 호발부위는 하악소구치, 대구치부위였고, 상악에서의 발생율은 적었다. 3. 골경화상의 크기는 idiopathic osteosclerosis는 10㎜이내였고, condensing osteitis는 10-20㎜의 폭경을 가지고 있었다. 4. 골경화상의 형태, 건강골과의 경계 및 발현되는 상태는 일정하지 않았다.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.4 no.1
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• pp.39-44
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• 1974

The purpose of this study is to obtain the horizontal magnification rate of orthopantomography. The subjects were consisted of 30 Korean adults who had Angle's classification I occlusion by using measuring wire set On the incisal edges of anterior teeth and the occlusal surfaces of premolars and molars along the dental arch. The results are as follows; 1. The average rate of total magnification was 115%. 2. The average rates of local magnification were the anterior teeth region was 90%, the canine region was 96%, the premolar region was 104%, the 1st molar region was 117% and the 2nd molar region was 124%.

• Journal of Oral Medicine and Pain
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• v.16 no.1
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• pp.73-84
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• 1991

저자는 연령을 추정하기 위한 기본자료를 얻기 위하여 상하악의 대구치, 소구치의 발육정도를 평가하였다. Orthopantomograph를 촬영한 722명의 3,464개 치아를 대상으로 crown-root ratio를 측정하여 발육정도를 평가하였으며, 다음과 같은 결론을 얻었다. 1. 완전히 형성된 치아의 crown-root ration에는 남녀간에 유의한 차이가 없었다. 2. 발육중인 치아의 crown-root ratio에는 좌우측간에 유의한 차이가 없었다. 3. 각 치아의 crown-root ratio를 이용한 연령추정의 회귀방정식은 다음과 같다. 남자: 여자 : 하악좌측 제 2대구치 : Y=4.599X+7.832(r=0.8337) 하악 좌측 제 2대구치 : Y=4.857X+7.429(r=0.8975) 제 1대구치 : Y=5.179X+2.324(r=0.7948) 제 1대구치 : Y=5.919X+2.018(r=0.8144) 제 2소구치 : Y=3.863X+7.432(r=0.8638) 제 2소구치 : Y=3.679X+7.275(r=0.8819) 제 1소구치 : Y=3.472X+7.120(r=0.8352) 제 1소구치 : Y=4.001X+6.544(r=0.9024) 하악우측 제 2대구치 : Y=4.447X+7.938(r=0.8045) 하악 우측 제 2대구치 : Y=4.653X+7.365(r=0.8598) 제 1대구치 : Y=5.954X+1.495(r=0.7777) 제 1대구치 : Y=5.449X+2.012(r=0.7553) 제 2소구치 : Y=3.894X+7.253(r=0.8689) 제 2소구치 : Y=3.772X+7.025(r=0.8719) 제 1소구치 : Y=4.189X+6.717(r=0.8370) 제 1소구치 : Y=4.327X+6.193(r=0.8524) 상악좌측 제 2대구치 : Y=4.430X+7.722(r=0.7538) 상악 좌측 제 2대구치 : Y=4.876X+7.606(r=0.8311) 제 1대구치 : Y=4.645X+2.886(r=0.6894) 제 1대구치 : Y=6.754X+1.891(r=0.5378) 제 2소구치 : Y=4.391X+6.686(r=0.7700) 제 2소구치 : Y=1.245X+10.575(r=0.1908) 제 1소구치 : Y=5.564X+6.037(r=0.9032) 제 1소구치 : - 상악우측 제 2대구치 : Y=4.587X+7.966(r=0.7882) 상악 우측 제 2대구치 : Y=4.454X+7.803(r=0.8443) 제 1대구치 : Y=4.047X+4.124(r=0.6352) 제 1대구치 : Y=6.336X+2.911(r=0.4688) 제 2소구치 : Y=2.920X+8.089(r=0.7277) 제 2소구치 : Y=3.105X+8.082(r=0.6381) 제 1소구치 : Y=3.264X+6.970(r=0.7292) 제 1소구치 : - 4. Orthopantomograph상의 crown-root ratio를 이용한 연령의 추정에는 상악치아들 보다 하악치아들이 더 정확하게 사용될 수 있다.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.1 no.1
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• pp.5-11
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• 1971

The author has observed the orthopantomograms of the maxillary sinus which were taken by special exposure method to study mesiodistal dimension, shape, symmetrical relationship, bony septum of the maxillary sinus and relationship between upper. 1st molar and the maxillary sinus, that were selected 56 cases of 23 to 27 years old male, who have good. systemic conditions and no missing teeth on upper posterior molar in normal occlusion, and obtained following conclusions: 1. Mesiodistal dimensions of the maxillary sinus are shown as follows; The mean of left dimension is 50.94±8.34㎜ and of right dimension is 49.50±9.87㎜. 2. To the shape of the maxillary sinus, V or U shape are 33cases(29.5%) and W shape are 77 cases(70.5%). 3. In the ralationship between upper 1st molar and floor of the maxllary sinus, superimposition are 62 cases (55.36%) and aproach are 50 cases (44.64%). 4. In the right and left symmetrical relationship of the maxillary sinus, symmetry are 37cases (66.07%) and asymmetry are 19 cases (33.93%). 5. The bony septums in the maxillary sinuses revealed that presence of bony septums are 29 cases (25.8%) and absence are 83 cases (74.11%).

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.63-70
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• 1980

This study was to determine the incidence of pulp stone in each tooth by means of analyzing 375 orthopantomograph taken from 375 patients (252 male), 125 female). The pictures were grouped by age, 20s, 30s, 40s, 50s, and sex. The results were as follows 1. In the group of 20s, male showed the highest incidence in the first molar (40~50%) and the second highest was in the 2nd molar about 35%~50%. In the female group, the first molar and the second molar showed 25%~40%. 2. In the group of 30s, the highest value was found on the first molar and the next was the 2nd molar which appeared 30%~40% in male. In the female, the first molar was 55%~70% and the 2nd molar 30%~50% 3. In the group of 40s, the first molar represented highest value about 45%~60% and the 2nd molar was 40~60% in the male. Female group also showed in the first molar 30%~50% and the second molar 25~30%. 4. In the group of 50s, the highest incidence was 40%~60% on the first molar and next was 35%~50% on the second molar in male, in femalegroup showed 30%~50% on the first molar and 25%~50% on the second molar. 5. The incidence in upper was higher than that of lower. 6. Comparison between right and left showed right was slightly higher than left side.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.133-139
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• 2020

Purpose: This study compared 2 cone-beam computed tomography (CBCT) systems in the detection of mechanically simulated peri-implant buccal bone defects in dry human mandibles. Materials and Methods: Twenty-four implants were placed in 7 dry human mandibles. Peri-implant bone defects were created in the buccal plates of 16 implants using spherical burs. All mandibles were scanned using 2 CBCT systems with their commonly used acquisition protocols: i-CAT Gendex CB-500 (Imaging Sciences, Hatfield, PA, USA; field of view [FOV], 8 cm×8 cm; voxel size, 0.125 mm; 120 kVp; 5 mA; 23 s) and Orthopantomograph OP300 (Intrumentarium, Tuusula, Finland; FOV, 6 cm×8 cm; voxel size, 0.085 mm; 90 kVp; 6.3 mA; 13 s). Two oral and maxillofacial radiologists assessed the CBCT images for the presence of a defect and measured the depth of the bone defects. Diagnostic performance was compared in terms of the area under the curve (AUC), accuracy, sensitivity, specificity, and intraclass correlation coefficient. Results: High intraobserver and interobserver agreement was found (P<0.05). The OP300 showed slightly better diagnostic performance and higher detection rates than the CB-500 (AUC, 0.56±0.03), with a mean accuracy of 75.0%, sensitivity of 81.2%, and specificity of 62.5%. Higher contrast was observed with the CB-500, whereas the OP300 formed more artifacts. Conclusion: Within the limitations of this study, the present results suggest that the choice of CBCT systems with their respective commonly used acquisition protocols does not significantly affect diagnostic performance in detecting and measuring buccal peri-implant bone loss.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.40.1-40.7
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• 2019

Background: Through the analysis of clinical data, we attempted to investigate the etiology and determine the risk of severe iatrogenic lingual nerve injuries in the removal of the mandibular third molar. Methods: A retrospective chart review was performed for patients who had undergone microsurgical repair of lingual nerve injuries. The following data were collected and analyzed: patient sex, age, nerve injury side, type of impaction (Winter's classification, Pell and Gregory's classification). Ratios for the respective lingual nerve injury group data were compared with the ratios of the respective data for the control group, which consisted of data collected from the literature. The data for the control group included previous patients that encountered various complications during the removal of the mandibular third molar. Results: The lingual nerve injury group consisted of 24 males and 58 females. The rate of female patients with iatrogenic lingual nerve injuries was significantly higher than the control groups. Ages ranged from 15 to 67 years, with a mean age of 36.5 years old. Lingual nerve injury was significantly higher in the patient versus the control groups in age. The lingual nerve injury was on the right side in 46 and on the left side in 36 patients. There was no significant difference for the injury side. The distoangular and horizontal ratios were the highest in our lingual nerve injury group. The distoangular impaction rate in our lingual nerve injury group was significantly higher than the rate for the control groups. Conclusion: Distoangular impaction of the mandibular third molar in female patients in their 30s, 40s, and 50s may be a higher risk factor of severe lingual nerve injury in the removal of mandibular third molars.