PURPOSE: To find out the effects that different tomographic angles have on the osteophytic lesion detectability of condyle head by comparison the individualized lateral tomographic image with the various tomographic angled images using SCANORA . MATERIALS AND METHODS: This study is performed to simulate osteophytic lesions by a series of dentin chips placed at six locations on condyle head. The control angle is 15 and from this angle, tomographic angle were varied with -10 , +10 , +20 . All the images with each sized dentin chip were scored by three dental radiologists with the use of confidence levels for presence or absence of the lesion, each examiner viewed one of the images twice. A rating scale from 0 to 2 (0, lesion definitely not present; 1, uncertain if lesion is present; 2, lesion definitely present). Responses were assessed by Tukey's multiple comparison method and kappa value. RESULTS: 1. The lesion size of 0.3 mm could not be detected in all the tomographic angles. As the size of the lesion increased the average value of lesion detectability also increased. Therefore the average value for the lesion size of 2.0 mm was the highest in every angle. 2. In the leson sizes of 0.7 mm there was statistically significant difference between the 15 control angle and the altered tomographic angles (p<0.05). In 1.0 mm lesion there was no significant difference in the 10 altered angles (p>0.05), but there was significant difference in the +20 altered angle (p<0.05). In the lesion sizes of 0.3 mm and 2.0 mm there was no significant difference between the 15 control angle and all the altered angles (p>0.05). 3. In the medial, superocentral, lateral area of the condyle there was no significant difference between the 15 control angle and all the altered angles (p>0.05). In the anteromedial, anterosuperior, anterolateral area there was no significant difference between the 15 control angle and the 10 altered angle (p>0.05), but in the comparison with the +20 alterd angle there was significant difference (p<0.05). CONCLUSION: When imaging the lateral tomography of the temporomandibular joint used by SCANORA , it can be considered that in the osteophytic lesion size of 2 mm and above, the tomographic angle difference within +20 to the horizontal angle of the condyle, has little effect on the lesion detectability. And in the lesion size of 1 mm, the altered angle within 10 also has little effect on the lesion detectability.
Dentin ; Head ; Mandibular Condyle* ; Radiography, Dental, Digital ; Temporomandibular Joint

PURPOSE: The purpose of this study was to compare the qualities of the four different processing chemicals(solutions). MATERIALS AND METHODS: With EP 21 films(Ektaspeed plus film, Kodak Co., USA), nine unexposed and nine exposed films of a step wedge were processed utilizing automatic film processor(XR 24, Durr Co., Germany) for 5 days. During 5 days, the total number of processed films including out-patient's intraoral films were about 400-500 for each brand. Base plus fog density, film density, contrast of processed films were measured with densitometer(model 07-443 digital densitometer, Victoreen Co., USA). These measurements were analyzed for comparison. RESULTS: The results were as follows, 1. For the base plus fog density, there was significant difference among the four chemicals (p<0.05). The sequence of the base plus fog densities was in ascending order by Kodak, X-dol 90, Agfa and Konica. 2. For the film density, all chemicals showed useful range of photographic densities(0.25-2.5). The sequence of the film densities was in ascending order by Kodak, X-dol 90, Konica and Agfa. But there was no statistically significant difference of film density between X-dol and Kodak (p<0.05). 3. The sequence of the contrasts was in ascending order by Konica, X-dol 90, Kodak and Agfa. But there was no statistically significant difference of contrast between X-dol and Konica (p<0.05). CONCLUSION: These results indicated that the four processing chemicals had the clinically useful film density and contrast, but only Kodak processing chemical had useful base plus fog density.
Dentistry* ; Weather

PURPOSE: To compare radiographic images of Digora system and Ektaspeed Plus film obtained from normal adults. MATERIALS AND METHODS: Storage phosphor plate(SPP) was placed in a film holder behind Ektaspeed Plus film package without lead foil. The effect of film on SPP was studied in a separate in vitro experiment. Forty-seven sets of images were prepared for the evaluaton. The regions of interest(ROI) for evaluation were designated at seven sites including normal anatomical structures. The image quality for each ROI was evaluated on enhanced and unenhanced storage phosphor(SP) images and Ektaspeed Plus film. RESULTS: Two film-SPP configurations showed significantly different grey levels at each step of the aluminum step wedge(p<0.05). The contrasts were comparable. Enhanced SP images were significantly superior to unenhaned images and film in all anatomical sturctures(p<0.01). The differences between unenhanced SP images and film were significant(p<0.05) except root canal and cortical bone on alveolar crest. For anatomical items, there were statistically significant difference among five observers(p<0.05). CONCLUSIONS: The image quality of enhanced SP images were superior to Ektaspeed Plus film, and Digora system is potentially applicable to clinical diagnosis.
Adult ; Aluminum ; Dental Pulp Cavity ; Diagnosis ; Humans ; Radiography, Dental, Digital

PURPOSE: The objective of this study was to compare clinical examination of of dental caries and secondary caries with panoramic examination, and to examine bone lesions and dental anomaly of unerupted state. MATERIALS AND METHODS: In this study, clinical records and panoramic radiographs were available for 89 first grade students in elementary school. Dental caries of occlusal surfaces, proximal surfaces, and buccolingual surfaces were examined . Secondary caries was examined too. In addition, the central lesion and dental anomaly of unerupted state were examined in panoramic radiographs. RESULTS: The obtained results were as followed : 1. Carious detectability of clinical examination in occlusal and buccolingual surface was higher than that of panoramic examination, but it is statistically insignificant(p>0.05). In proximal surface, carious detectability of panoramic examination was higher than that of clinical examination, and it is statistically significant(p<0.01). 2. In contrast to clinical examination only, when the two examination methods were combined, there was additional detection of dental caries(26.7% in occlusal surface, 48.2% in proximal surface, 33.3% in buccolingual surface, and 38.3% totally). 3. In detection of secondary caries, panoramic examination had lower ability than clinical examination in all three surfaces, but in case that both methods were combined, totally 36.0% extra carious lesions were detected. 4. In panoramic examination, detectability of secodary caries in upper teeth is lower than lower teeth. 5. In panoramic examination, it was possible to detect the central lesions and dental anomalies of unerupted state which cannot be detected in clinical examination. CONCLUSION: It is useful to combine the panoramic examination with clinical examination in order to increase carious detectability and to evaluate the central lesions and dental anomalies of unerupted state
Dental Caries* ; Diagnosis* ; Humans ; Radiography, Panoramic* ; Tooth

OBJECTIVES: The purpose of this study was to evaluate the optimal distance and angle of observers by modulation transfer functions(MTFs) and receiver operating characteristics(ROCs). MATERIALS AND METHODS: Digital periapical radiograms were taken from 43 patients who have dental diseases(19 patients : dental caries, 12 patients : periapical lesions, 12 patients : periodontal diseases). Segmental images(4x4cm) were evaluated by 4 MTFs and ROC analysis. RESULTS: The optimal distance(magnification) using MTF by Mannos & Sakrison was 12.97, and those by Nill, Ngan and Rao were 8.39, 4.78, 5.84 respectively. The optimal distance obtained from 4 radiologists by ROC analysis was 32cm(Az value : 0.89), and it was 40cm(Az value : 0.78) from 4 non-radiologists. There were significant differences of Az values between 4 radiologists and 4 non-radiologists at 24, 32 and 40cm (p<0.05). No significant differences of optimal distances were observed using 4 MTFs among +20, +10, 0, -10, -20 degrees(p>0.05). The optimal angle obtained from 4 radiologists by ROC analysis was +20 degrees (Az value : 0.91), and no significant differences of Az values were observed among +20, +10, 0, -10 and 20 degrees(p>0.05). The optimal angle obtained from 4 non-radiologists by ROC analysis was 0 degree(Az value : 0.81), and no significant differences of Az values were observed among +20, +10, 0, -10 and 20 degrees(p>0.05). And there was significant difference of Az value between 4 radiologists and 4 non-radiologists at +20 degree(p<0.05), but no significant differences of Az values were observed among +10, 0, -10 and -20 degrees(p>0.05).
Dental Caries ; Humans ; ROC Curve

PURPOSE: The objective of this study was to evaluate the possibility of substitution of the zonography for the full-mouth periapical radiography in aspect of radiation protection. MATERIALS AND METHODS: Rando phantom and LiF TLD chips were used for dosimetry. The absorbed doses at brain, skin above the TMJ, parotid gland, bone marrow in the mandibular body, and thyroid gland during the full-mouth periapical radiography, panoramic radiography, and zonography were measured. RESULTS: From the zonography, the absorbed doses to the brain, the skin over the TMJ, and the parotid gland were relatively high, but the absorbed doses to the bone marrow in the mandibular body and, especially, the thyroid gland were very low. CONCLUSION: The zonography can be an alternative to the full-mouth periapical radiography in aspect of radiation protection.
Bone Marrow ; Brain ; Parotid Gland ; Radiation Protection ; Radiography* ; Radiography, Panoramic* ; Skin ; Temporomandibular Joint ; Thyroid Gland ; Tomography, X-Ray*

The purpose of this study was to investigate whether a radiometric analysis of radicular cysts and periapical granulomas is useful in the differential diagnosis. In this experiment, twenty-nine periapical radiographs of the radicular cyst and those periapical granuloma were used. The periapical radiography was taken by intraoral paralleling device. The X-ray film was digitized and digitally filtered to reduce film-grain noise. We estimated density difference of the inner/outer area, roundness or circularity, bone profile or scan line of the margin and cumulative percentage frequency curve of radicular cyst & periapical granuloma. The obtained results were as follows ; 1. The differences in density between ROIs of inner and outer area of radicular cysts were smaller than those of periapical granulomas. 2. The equivalent circular diameter was over 6.3mm, there was significant difference between periapical cyst and periapical granuloma. 3. In differential diagnosis of radicular cyst and periapical granuloma using bone profile, sensitivity, spicificity and accuracy were considerably high(0.83, 0.86, 0.86) respectively. 4. Cumulative percentage frequency curve of the radicular cyst was closer to the pseudo-pixel value of 50 than average curve, whereas periapical granuloma was closer to that of 0. Hence we conclude that digital radiometric features might be useful in the differential diagnosis between radicular cyst and periapical granuloma.
Diagnosis, Differential ; Noise ; Periapical Granuloma* ; Radicular Cyst* ; Radiography ; X-Ray Film

PURPOSE: to evaluate the usefulness of the panoramic radiography, generally used in dental clinic, for the detection of the maxillary sinus pathosis due to the inflammation and tumor, through the comparison with CT findings as the absolute standard. MATERIALS AND METHODS: 150 maxillary sinuses of 75 patients with or without particular signs and symptoms and showing soft tissue lesions or destruction of maxillary sinus walls in at least one sinus in CT, were selected as subject samples, and the panoramic radiography of the same patients were interpretated by 3 dental radiologists and 3 non dental radiologist given no previous informations. Using the CT findings as the absolute standard, the diagnostic ability of panoraimc radiography in the mucosal thickening, maxillary sinus haziness, inferior wall destruction, medial wall destruction, posterolateral wall destruction and the superior wall destruction was evaluated using the ROC curve and the difference between dental radiologist group and non dental radiologist group was also evaluated. RESULTS: 1. When dental radiologist group interpretated the destruction of inferior wall and posterolateral wall, the kappa value which shows interobserver's coincidence was above 0.75. 2. The diagnostic ability according to site of interpretation was the highest when the inferior wall was interpretated in both observer groups and there was a statistically significant difference between the dental radiologist group and non dental radiologist group in interpretating the mucosal thickening, haziness, destruction of the inferior and medial wall(p<0.05). 3. The diagnostic ability in detecting the destruction of the sinus walls was better than in soft tissue lesions in both groups and between the groups there was a statistically significant difference(p<0.05). CONCLUSION: When detecting the destruction of inferior and posterolateral wall of the maxillary sinus there was coincident with that of CT findings, and so it is considered that diagnostic ability of panoramic radiography is high in this point. But in interpretating the destruction of medial wall and soft tissue lesions, diagnostic ability of the panoramic radiography was relatively low and there was a significant difference between the dental radiologist group and non dental radiologist group. Therefore CT or other auxiliary diagnostic method will be necessary when evaluating thorough pathosis of maxillary sinus objectively.
Dental Clinics ; Humans ; Inflammation ; Maxillary Sinus* ; Radiography ; Radiography, Panoramic* ; ROC Curve

PURPOSE: The purpose of this study was to calculate the size and CT number of both normal parotid and submandibular gland, and evaluate its relation to sex, age and obesity using computed tomography. MATERIALS AND METHODS: The computed tomography was performed parallel to the Frankfurt plane in 46 subjects with healthy salivary gland. The subjects were divided into the three groups(young, middle, old) according to their ages. The size of salivary gland was determined as maximum cross-sectional area and the CT number of salivary gland was determined as the mean CT number of three ROI's. The body mass index was calculated from weight and height. RESULTS: The mean maximum cross-sectional area was 7.79(+/-1.26) cm2 on parotid gland and 4.12(+/-0.83) cm2 on submandibular gland. The mean CT number was -4.43(+/-23.87) HU on parotid gland and 50.01(+/-15.63) HU on submandibular gland. There were decreasing pattern of the maximum cross-sectional area of submandibular gland and the CT number of both parotid and submandibular gland according to age(p<0.05). As the body mass index increased, the maximum cross-sectional area of parotid gland increased and CT number of both parotid and submandibular gland decreased(p<0.05). The maximum cross-sectional area of submandibular gland in male was larger than that in female(p<0.05). As the maximum cross-sectional area and CT number of left salivary gland increased, those of right gland increased(p<0.05). CONCLUSION: Intra-individual differences in salivary gland size and CT number is considered in the age and individual obesity.
Aging ; Body Mass Index ; Humans ; Male ; Obesity ; Parotid Gland ; Salivary Glands* ; Submandibular Gland

PURPOSE: This study was to investigate the age and sex differences of the fractal dimension of the normal parotid glands in the digitized CT images. MATERIALS AND METHODS: The six groups, which were composed of 42 men and women from 20`s, 40`s and 60`s and over were picked. Each group contained seven people of the same sex. The normal parotid CT images were digitized, and their fractal dimensions were calculated using Scion ImagePC program. RESULTS: The mean of fractal dimensions in males was 1.7292(+/-0.0588) and 1.6329(+/-0.0425) in females. The mean of fractal dimensions in young males was 1.7617, 1.7328 in middle males, and 1.6933 in old males. The mean of fractal dimensions in young females was 1.6318, 1.6365 in middle females, and 1.6303 in old females. There was no statistical difference in fractal dimension between left and right parotid gland of the same subject(p>0.05). Fractal dimensions in male were decreased in older group(p<0.05) and larger than female in same age group(p<0.05). But fractal dimensions in female had a tendency to decrease in older group but no statistical difference between ages(p>0.05). CONCLUSIONS: The fractal dimension of parotid glands in the digitized CT images will be useful to evaluate the age and sex differences.
Female ; Fractals* ; Humans ; Male ; Parotid Gland* ; Sex Characteristics