The prevalence, clinical and radiographic characteristics of cemento-osseous dysplasiain Korea

조봉혜,정연화,나경수 대한영상치의학회 2007 Imaging Science in Dentistry Vol.37 No.4

Purpose: This study was intended to estimate the prevalence of cemento-osseous dysplasia (COD) in the Koreanpopulation and to assess the clinical and radiographic characteristics of this condition.Materials and Methods: Panoramic radiographs from 10,646 patients(4,982 males and 5,664 females, age rangefrom 6 to 91 years) were reviewed for evidence of COD. Their demographics, clinical characteristics, and radio-graphic features were retrospectively assessed.Results: Of 10,646 panoramic radiographs, 33 radiographs(0.31%) exhibited evidence of COD. The prevalence ofplasia(FCOD) and 17 had focal COD. Due to the multiplicity of FCOD, a total of 63 COD lesions were assessed.These lesions were most common in the mandibular molar area. Most of the COD lesions examined (61.9%) wereless than 10mm and the majority(82.5%) showed radiopacity.Conclusion : COD has a predilection for the mandibular molar area of middle-aged and older women. (Korean JOral Maxillofac Radiol 2007; 37 : 185-9)

Diagnostic performance of dental students in identifying mandibular condyle fractures by panoramic radiography and the usefulness of reference images

조봉혜 대한구강악안면방사선학회 2011 Imaging Science in Dentistry Vol.41 No.2

Purpose : The purpose of this study was to evaluate the diagnostic performance of dental students in detection of mandibular condyle fractures and the effectiveness of reference panoramic images. Materials and Methods : Forty-six undergraduates evaluated 25 panoramic radiographs for condylar fractures and the data were analyzed through receiver operating characteristic (ROC) analysis. After a month, they were divided into two homogeneous groups based on the first results and re-evaluated the images with (group A) or without (group B) reference images. Eight reference images included indications showing either typical condylar fractures or anatomic structures which could be confused with fractures. Paired t-test was used for statistical analysis of the difference between the first and the second evaluations for each group, and student?s t-test was used between the two groups in the second evaluation. The intra- and inter-observer agreements were evaluated with Kappa statistics. Results : Intra- and inter-observer agreements were substantial (k=0.66) and moderate (k=0.53), respectively. The area under the ROC curve (Az) in the first evaluation was 0.802. In the second evaluation, it was increased to 0.823 for group A and 0.814 for group B. The difference between the first and second evaluations for group A was statistically significant (p⁄0.05), however there was no statistically significant difference between the two groups in the second evaluation. Conclusion : Providing reference images to less experienced clinicians would be a good way to improve the diagnostic ability in detecting condylar fracture.

Osteoarthritic changes and condylar positioning of the temporomandibular joint in Korean children and adolescents

조봉혜,정연화 대한영상치의학회 2012 Imaging Science in Dentistry Vol.42 No.3

Purpose: To investigate the prevalence of osteoarthritic changes and condylar positioning of the temporomandibular joint (TMJ) in Korean children and adolescents with or without temporomandibular disorders (TMDs). Materials and Methods: A total of 101 asymptomatic and 181 symptomatic children and adolescents aged 10 to 18 years old were included in the study. Osteoarthritic changes such as flattening, sclerosis, osteophytes, or erosion, and the parasagittal positioning of the condyle were assessed using cone-beam computed tomography (CBCT) images. Results: The overall prevalence of osteoarthritic changes was higher in symptomatic (26.8%) than in asymptomatic adolescents (9.9%) (p⁄0.05). In the symptomatic group, the frequency was higher in males (33.3%) than in females (23.0%) (p⁄0.05). Erosion was the most common change for the symptomatic group (15.6%), whereas sclerosis was the most common change for the asymptomatic group (5.4%). Posterior condylar position was more frequently observed in the symptomatic group (p⁄0.05). Erosion was more common in the samples with TMJ pain or mouth opening limitations as compared to those without them (p⁄0.05). Conclusion: This study showed that osteoarthritic changes in TMJ were common in children and adolescents, with a much higher prevalence in symptomatic patients. Purpose: To investigate the prevalence of osteoarthritic changes and condylar positioning of the temporomandibular joint (TMJ) in Korean children and adolescents with or without temporomandibular disorders (TMDs). Materials and Methods: A total of 101 asymptomatic and 181 symptomatic children and adolescents aged 10 to 18 years old were included in the study. Osteoarthritic changes such as flattening, sclerosis, osteophytes, or erosion, and the parasagittal positioning of the condyle were assessed using cone-beam computed tomography (CBCT) images. Results: The overall prevalence of osteoarthritic changes was higher in symptomatic (26.8%) than in asymptomatic adolescents (9.9%) (p⁄0.05). In the symptomatic group, the frequency was higher in males (33.3%) than in females (23.0%) (p⁄0.05). Erosion was the most common change for the symptomatic group (15.6%), whereas sclerosis was the most common change for the asymptomatic group (5.4%). Posterior condylar position was more frequently observed in the symptomatic group (p⁄0.05). Erosion was more common in the samples with TMJ pain or mouth opening limitations as compared to those without them (p⁄0.05). Conclusion: This study showed that osteoarthritic changes in TMJ were common in children and adolescents, with a much higher prevalence in symptomatic patients.

악관정 내장증 환자의 최대 개구시 하악과두 운동량에 대한 자기공명영상 평가 : 경두개촬영법과의 비교 comparison with transcranial view

조봉혜 大韓口腔顎顔面 放射線學會 2001 Imaging Science in Dentistry Vol.31 No.4

Purpose : To evaluate the condylar movement at maximal mouth opening on MRI in patients with internal derangement. Materials and Methods : MR images and transcranial views for 102 TMJs in 51 patients were taken in closed and maximal opening positions, and the amount of condylar movement was analyzed quantitatively and qualitatively. Results : For MR images, the mean condylar movements were 9.4 ㎜ horizontally, 4.6 ㎜ vertically and 10.9 ㎜ totally, while those for transcranial views were 12.5 ㎜, 4.6 ㎜, and 13.7 ㎜ respectively. The condyle moved forward beyond the summit of the articular eminence in 41 TMJs (40.2%) for MR images and 56 TMJs (54.9%) for transcranial views. Conclusion : The horizontal and total condylar movements were smaller in MR images than in transcranial views. (Korean J Oral Maxillofac Radiol 2001; 31 : 185-92)

임플란트 매식부의 고경 평가 : 파노라마 촬영법과 나선형 전산화 단층촬영법의 계측 비교

조봉혜,Cho Bong-Hae 대한영상치의학회 2002 Imaging Science in Dentistry Vol.32 No.2

Purpose: To compare the bone height of implant sites measured using panoramic radiography and spiral CT. Materials and Methods : The available bone height was determined for 263 maxillary and mandibular implant sites in 59 patients. Distortion was calculated using the metal bar for the panoramic radiographs. Results: Significant differences in mean bone height between the two imaging modalities were found in maxillary and mandibular anterior regions (p<0.05). The mean difference in bone height recorded by the two techniques was smallest in the maxillary and mandibular molar areas (0.8 mm), and greatest in the mandibular anterior region (1.3 mm). With the exception of the mandibular anterior region, ninety percent of all the sites showed measurement differences within 2 mm. Conclusion: A safety margin of 2 to 3 mm is called for when utilizing panoramic radiography, otherwise additional imaging modality such as computed tomography is necessary to obtain accurate measurements.

중첩 불일치 평가기준으로서의 계수공제영상의 계조도 표준편차 연구

조봉혜 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.2

Purpose : The aim of this study was to assess the validity of standard deviation of gray scale histogram in digital subtraction radiography as a test parameter for superimposition error. Materials and Methods : Twenty periapical radiographs were used as baseline images and they were copied to exclude the influence of exposure geomety and contrast differences. These subsequent images were linearly displaced by 0.1-0.5 mm in the x-, y- and xy-directions, rotated by 0.5-3°and distorted by angular contraction of 1-5° in x- and y-axis before subtraction. The standard deviations of gray levels in the subtraction images were obtained and paired t-tests were performed. Pearson correlation coefficients(r) were calculated between the standard deviations and the superimposition errors. Results : Linear displacement showed high correlation coefficients of 0.997, 0.997 and 0.995 in x-, y- and xy-axis respectively. Statistically significant different standard deviation existed among all linearly displaced groups(p<0.05). Distortion showed relatively low correlation coefficients of 0.982 and 0.959 in x- and y-axis. The standard deviations between the two distortion groups were statistically significant different(p<0.05). Conclusion : Standard deviation of gray level distribution in digital subtraction images is satisfactory but not perfect similarity measure to assess the superimposition errors.(J Korean Oral Maxillofac Radiol 1999;29:417-422)

자기공명영상(Magnetic Resonance Imaging)의 기본원리

조봉혜 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.1

자기공명영상은 내부의 안정된 자기 핵과의 상호작용을 통하여 반복주사 없이 횡단면, 시상면, 관상면등 원하는 단면의 영상을 얻을 수 있는 촬영법이다. 현재까지 알려진 특별한 위해 작용은 없으며 병리학적으로 정상과 비정상조직을 구별해 낼 수 있으므로 연조직 분석에 특히 유용하다. 그러나 물리화학적 변화에 민감하여 적절한 pulse sequence의 선택과 적용방법이 까다롭다. 자기공명은 화학분석이 가능하여 의학적 사용 외에 물리, 화학, 생화학 분야에도 많이 이용되고 있으며 향후 많은 발전이 있을 것으로 예상된다. Magnetic resonance imaging with its superior soft tissue contrast resolution and absence of beam hardening artifacts, combined with its ability to perform multiplanar imaging, is now effective tool in diagnostic imagings. Magnetic resonance is primarily a phenomenon that involves atomic nuclei. It provides totally new clinical informations with no known hazards through the use of very weak interactions with endogenous stable magnetic atomic nuclei. This article briefly summarizes the basic mechanism of generation and detection of the signals and general sorts of tissue properties which can influence the signals and thereby give rise to tissue contrast. It also describes how the machine-operating parameters can be used to manipulate the tissue contrast observed in the image.(J Korean Oral Maxillofac Radial 1999:29:7-20)

Aggressive central odontogenic fibroma in the maxilla: A case report

조봉혜,정연화,황재준 대한영상치의학회 2022 Imaging Science in Dentistry Vol.52 No.4

A central odontogenic fibroma is a rare benign tumor composed of mature fibrous connective tissue with variable amounts of odontogenic epithelium. It appears at similar rates in the maxilla and mandible. In the maxilla, it usually occurs anterior to the molars. Radiographically, central odontogenic fibroma commonly presents as a multilocular or unilocular radiolucency with a distinct border. This paper reports a case of an aggressive central odontogenic fibroma involving the right posterior maxilla of a 53-year-old man. Radiographs showed an extensive soft tissue mass involving the entire right maxilla with frank bone resorption. The patient had a history of 2 operations in the region, both more than 2 decades ago. Although it was impossible to confirm the previous diagnoses, it was presumed that this case was a recurrent lesion.

치아종

조봉혜,김애지,나경수 치과연구사 1989 치과연구 Vol.26 No.3

측두하악관절 내장증에서의 관절원판 전상방부착부의 자기공명영상

조봉혜,정연화 대한구강악안면방사선학회 2006 Imaging Science in Dentistry Vol.36 No.2

Purpose : To describe the MRI findings of the antero-superior attachment of the disc in patients with internal derangement. Materials and Methods : One hundred fifty-six MR images from 40 normal subjects and 55 abnormal subjects were classified into three study groups of normal, anterior disc displacement with reduction and anterior disc displacement without reduction. On both closed- and open-mouth proton density sagittal images, the depiction of the antero-superior attachment of the disc and its demarcation from the disc were evaluated in three cuts of lateral, central and medial one thirds of the condyle. Results : The depiction of antero-superior attachment was more frequent by the order of normal, anterior disc displacement with reduction and anterior disc displacement without reduction groups, and the significant differences were found on lateral cut of the closed images and lateral and central cuts of the open images. In study for the demarcation between the antero-superior attachment and the disc the lateral cut of the closed images and all three cuts of the open images showed significant differences. Conclusion : Open images are useful to show the difference in depiction of the antero-superior attachment of the disc among the TMJ groups.