PURPOSE: Upper cervical vertebrae are commonly imaged together with the jaw bones in panoramic radiography. There have been many studies investigating the possible role of mandible as an indicator of osteoporosis. But the result doesn't show unanimity. This study measured bone densities of mandible and second and third cervical vertebrae to find out any relationship between these two areas. These results may contribute in panorama being used as a screening method in detecting possible osteoporotic patient. MATERIALS AND METHODS: Randomly selected 226 digitized panoramic images with cervical vertebrae shadows from 156 dental patients between 5 to 80 years of age were used. And the bone densities of second and third cervical vertebrae, apical areas of first and second mandibular molars and interdental areas were measured. The bone density measurements were restricted to the cancellous bone and the average and standard deviations and paired t-tests were done to each measurements. RESULTS: All the measurements were statistically significantly related. The best relationship was found between the third cervical vertebrae and first and second mandibular apical areas. The average and standard deviations of the measured bone density ratios of these areas were 1.20+/-0.45 and 1.34+/-0.48 each. CONCLUSION: Patients whose panoramic bone density of the third cervical vertebrae are much below those of mandibular first or second molar apical areas may have osteoporosis.
Bone Density* ; Cervical Vertebrae* ; Female ; Humans ; Jaw ; Mandible* ; Mass Screening ; Molar ; Osteoporosis ; Radiography ; Radiography, Panoramic*

The author experienced 8 cases of pericoronal radiolucency involving an incomplete tooth crown that had not developed to form the cemento-enamel junction, and the underdeveloped crown sometimes appeared to be floating within the radiolucency radiographically. The first impression was that these cystic lesions had odontogenic keratocysts, but half of them turned out to be dentigerous cysts histopathologically. There has been no report concerning odontogenic cysts involving an incompletely developed crown. The purpose of this paper is to report that dentigerous cysts may develop before the completion of the cemento-enamel junction of a developing crown.
Crowns* ; Dentigerous Cyst ; Odontogenic Cysts ; Tooth Crown ; Tooth, Unerupted

PURPOSE: To find out the best imaging parameters for the diagnosis of disc in mri imaging. MATERIALS AND METHODS: Compare the diagnostic quality of the disc among the T1, PD and T2 images of same patients(12 joints, 223 images) by visual(I-IV grades) and gray level measurement (pre- and infra-discal area) method. RESULTS: PD images showed best results with 43.7% of the images belonging to grade III (good) and with statistically significant higher difference of the gray levels at pre- and infra-discal areas. But there were no grade IV(excellent) images. CONCLUSIONS: PD images are best method among T1, PD and T2 images in diagnosing the disc but since there were no excellent images further imaging parameters should be studied for better images.
Diagnosis ; Joints ; Magnetic Resonance Imaging* ; Temporomandibular Joint*

PURPOSE: To evaluate the relative diagnostic accuracy of panoramic radiography and Water's projection in maxillary sinus inflammatory diseases by comparing the radiodensities of the images with those of CT. MATERIALS AND METHODS: Panoramic radiographs, Waters' projection, and CT images from 55 subjects (110 sinuses) were included in this retrospective study. The radiodensity of each maxillary sinus in panoramic radiography was recorded separately as upper and lower divided horizontally by hard palate. In Waters' projection, the overall sinus radiodensity was recorded. The CT images were considered as gold standard. RESULTS: In panoramic radiography, 83 sinuses had same upper and lower radiodensity and 72 of these were consistent with those of CT, 26 sinuses had different upper and lower radiodensity and 15 of these, upper radiodensity was consistent with CT, the remaining 11, lower radiodensity was consistent with CT. One sinus had upper radiolucency with lower radiopacity and both were consistent with those of CT. Altogether 73 (66.4%) among 110 sinuses in panoramic radiography showed full agreement with CT, 26 (23.6%) showed partial agreement with CT. 9 sinuses had no lower image under the hard palate in panoramic radiography due to the smaller size of sinus. In Waters' projection, the radiodensity of 105 sinuses (95.5%) were consistent with that of CT. CONCLUSION: The panoramic radiography showed 90.0% of the sinus conditions fully or partially which may appear less accurate than that of Water's view (95.5%) but with more detailed information of the inferior part of sinuses.
Maxillary Sinus ; Palate, Hard ; Radiography, Panoramic ; Retrospective Studies ; Tomography, X-Ray Computed

PURPOSE: To evaluate the true projection angles of film-side mandibular condyles in panoramic and transcranial radiographs. MATERIALS AND METHODS: 52 panoramic and transcranial radiographs of 4 condyles from two human dry mandibles with gradual horizontal and vertical angle changes were taken. The results were compared with the standard panoramic and transcranial radiographs and the identical pairs were selected. RESULTS AND CONCLUSION: Panoramic radiography projected 10 degrees to the film-sided condyles both horizontally and vertically. Transcranial radiography projected 15 degrees to the film-sided condyles vertically. The medial and lateral poles were not forming the outline of condylar images in both projections when the horizontal angles of condyles were not sufficiently big enough.
Humans ; Mandible ; Mandibular Condyle* ; Radiography ; Radiography, Panoramic ; Temporomandibular Joint

In order to compare the accuracy of impression technique using the addition silicone putty and improved heavy body material, impression were taken for the natural 6 maxillary anterior teeth, and for the metal mast model that has full arch shape with 4 cylindrical abutment teeth, Marginal gingiva was retracted by routine method using retraction cord, and two techniques were tried to compare the length of impression materials in the gingival sulcus. This was aimed to see the effect of viscosity and hydraulic pressure of impression materials for the subgingival impression. Impressions for the full arch-shaped metal master model were taken to compare the linear stability of the different impression materials and their related techniques. The conclusions were as belows : 1. The one-step impression technique showed longer extension of impression material in gingival sulcus than two-step impression technique. 2. High viscosity and hydraulic pressure of impression material were useful to take subgingival impression. 3. There was no statistically significant difference for the two-dimensional accuracy of impression technique, but two-step technique showed better trend than one-step technique.
Gingiva ; Silicones ; Tooth ; Viscosity

PURPOSE: To evaluate the clinical and radiographic features of unilateral hyperplastic mandibular condyles for some useful preliminary diagnostic recommendations. MATERIALS AND METHODS: Clinical records, radiographs and histologic diagnoses of 35 cases with asymmetric mandibular condyles due to apparent unilateral condylar hyperplasia were evaluated retrospectively. RESULTS: Among 35 cases, 28 were true hyperplastic conditions of condyles whereas the remaining 7 were unilateral internal derangement occurring on the short side. 17 of the 28 hyperplastic condyles showed a mass or irregular radiographic shadow with histologic diagnosis including osteochondroma and osteoma. Only 5 of these cases showed facial asymmetry. 2 out of the 17 cases showed hyperplastic round shaped irregular condyles consistent with ankylosis and their histologic diagnoses were osteochondromas. 11 of the 28 cases showed smooth enlargement of condylar head with elongation of the neck causing facial asymmetry, but histologic diagnoses were not available because the surgical operation conserved the condyles. CONCLUSION: The hyperplastic conditions of the mandibular condyles include not only true hyperplasia, osteochondroma, osteoma, and ankylosis, but also unilateral internal derangement occurring on the short side.
Ankylosis ; Diagnosis ; Facial Asymmetry ; Head ; Hyperplasia ; Mandibular Condyle* ; Neck ; Osteochondroma ; Osteoma ; Retrospective Studies ; Temporomandibular Joint Disorders

PURPOSE: Disc and condylar position were observed on MRIs of temporomandibular joint disorder patients and condylar position agreement between MRI and tranascranal radiography was evaluated. MATERIALS AND METHODS: MRI and transcranial radiographs of both TM joints from 67 patients with temporomandibular disorder were used. On MRI, the position and shape of disc and condylar position as anterior, middle, posterior was evaluated at medial, center, and lateral views. On transcranial radiographs, condylar position was evaluated using the shortest distance from condyle to fossa in anterior, superior, and posterior directions. RESULTS: 1. On MRI, 96 joints (71.6%) of 134 had anterior disc dispalcement with reduction and 38 joints (28.4%) without reduction. 2. Fourteen (14.6%) of 96 reducible joints showed anterior condylar position, 19 (19.8%) showed central position, 63 joints (65.6%) showed posterior position. Two joints (5.3%) of 38 non-reducible joints showed anterior condylar position, while 9 (23.7%) showed central position, and 27 (71.1%)-posterior position. 3. In 85 joints (63.4%) of 134, the transcranial condylar position agreed with that of the central MRI view, 10 joints (7.5%) with that of medial, 16 joints (11.9%) with that of lateral, and 23 joints (17.2%) disagreed with that of MRI. CONCLUSION: On MRI, most of the reducible and non-reducible joints showed posterior condylar position. Transcranial radiographs taken with machine designed for TMJ had better agreement of condylar position with that of MRI. Extremely narrow joint spaces or very posterior condylar positons observed on transcranial radiographs had a little more than fifty percent agreement with those of MRIs.
Humans ; Joints ; Magnetic Resonance Imaging ; Mandibular Condyle ; Radiography ; Temporomandibular Joint Disorders* ; Temporomandibular Joint*

PURPOSE: To evaluate the magnification error percentage in repeatedly taken panoramic radiographs of same patient and machine. MATERIALS AND METHODS: 92 panoramic radiographs from 46 patients were traced and 30 horizontal and vertical measurements were made with digital sliding caliper. The results were compared with paired t-test. RESULTS: There was no statistically significant difference between the two measurements. The overall difference as percentage error was 6.19+/-5.60%. The largest error as 14.61+/-12.44% was found at condylar height 1, and smallest as 1.86+/-1.61% at mandibular height. Overall vertical error excluding condylar height 1 was 3.76+/-3.97%, and the horizontal error 6.88+/-5.92%. CONCLUSION: Repeatedly taken panoramic radiographs of the same patient and machine was reliable since there was no significant percentage error difference but the percentage error ranged from 1.86+/-1.61% to 14.61+/-12.44% indicating the error depends on the measuring site.
Diagnostic Imaging ; Humans ; Radiography, Panoramic*

PURPOSE: 1. Retrospectively evaluate the accuracy of tentative diagnosis or impression from the clinico-radiographic materials of jaw lesions which showed mixed lesions associated with teeth. 2. To observe the diagnostic importance of the calcified part of the lesions which appear as radiopaque areas. MATERIALS AND METHODS: 14 cases of jaw lesions which showed mixed lesions associated with teeth were reviewed. These lesions were mostly diagnosed as adenomatoid odontogenic tumors (6 cases) or calcifying odontogenic cysts with (4 cases) or without odontomas (4 cases). The calcified elements of the lesions which demonstrated various sizes and patterns of radiopaque shadows resembled odontoid tissues in some cases but could not be defined in some other cases radiographically. RESULTS: The final histopathologic diagnosis confirmed adenomatoid odontogenic tumors in 4 of the 6 cases. The remaining 2 cases turned out to be odontoma and ameloblastic fibroodontoma. The 4 cases of calcifying odontogenic cysts with odontomas were correct in 3 cases but remaining 1 case was just odontoma. The 4 cases of calcifying odontogenic cysts were proved to be odontogenic keratocyst, calcified peripheral fibroma, unicystic ameloblastoma and squamous cell carcinoma. CONCLUSION: The diagnostic accuracy of the adenomatoid odontogenic tumors and calcifying odontogenic cysts were high when the lesions show typical appearance. The calcifications which show radiopaque areas could be odontomas or dystrophic calficifations or remnants of bone fragments from resorption.
Ameloblastoma ; Ameloblasts ; Carcinoma, Squamous Cell ; Diagnosis ; Fibroma ; Jaw* ; Odontogenic Cyst, Calcifying ; Odontogenic Cysts ; Odontogenic Tumors ; Odontoma ; Retrospective Studies ; Tooth*