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 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: 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*

PURPOSE: To investigate and compare the prevalence, size, and location of maxillary sinus septa on panoramic and cone beam computed tomography (CBCT) images. MATERIALS AND METHODS: Two hundred patients who had taken both panoramic and CBCT images were included. The location of maxillary sinus septa on the panoramic radiographs were recorded and confirmed on the CBCT images. Also the size of septa was measured on the reformatted CBCT images. RESULTS: The prevalence of the patients who had maxillary sinus septa was 51.0% and they showed 179 septa totally. Among them 51.0% of the patients had one septum, 32.4% two septa, 13.7% three, and 2.9% four. The measured heights of the septa were 4.37+/-2.87 mm, 3.51+/-2.47 mm, and 3.04+/-2.37 mm in the medial, middle, and lateral areas, respectively. It was revealed that 1.0% was located at canine region, 18.0% at first premolar, 25.0% at second premolar, 22.7% at first molar, 19.8% at second molar, and 14.0% at third molar region. Among 213 septa depicted by the panoramic radiographs, only 69.0% were confirmed at the CBCT images. CONCLUSION: Since various heights and courses of the septa can develop in all parts of the maxillary sinus, adequate assessment of the inner aspect of the maxillary sinus is essential to avoid complications during sinus augmentation procedures. CBCT scanning is the preferred radiographic method for detecting the presence of sinus septa.
Bicuspid ; Cone-Beam Computed Tomography ; Humans ; Maxillary Sinus ; Molar ; Molar, Third ; Prevalence ; Radiography, Panoramic

The authors examined the condylar position and shape of condylar process from the transcranial radiographs and polytomographs of the 130 temporomandibular joints of 65 patients who complained symptoms of temporomandibular disorder and the followings were obtained ; 1. The age and sex distribution of the 65 patients showed peak incidence in 2nd decade (27.7%) followed by 3rd (18.5%) and 4th decade (18.5%) and female predominance (87.7%). 2. In polytomography 64 joints (49.2%) showed consistent condylar position from lateral to medial and 39 joints (30.0%) of them showed agreement with those of transcranial radiographs. Among the 66 joints (50.8%) which showed changes in condylar position, 48 joints (36.9%) showed agreement with lateral and central tomographic and transcranial radiographic position. 41 joints (31.5%) showed disagreement in condylar position between the polytomographic and transcranial radiographic images. 3. When the condylar position was classified as anterior, central and posterior, the posterior position was the most frequent position, that is , 42.3% of the transcranial radiography and 42.3%, 49.2% and 38.5% of the lateral, central and medial polytomographic radiographs. 4. In polytomography 84 joints (64.6%) showed consistent condylar shape from lateral to medial and 74 joints (56.9%) of them showed agreement with those of transcranial radiographs. Among the 46 joints (35.4%) which showed changes in condylar shape, 40 joints (30.1%) showed agreement with lateral and central tomographic and transcranial radiographic shape. 41 joints (31.5%) showed disagreement in condylar shape between the polytomographic and transcranial radiographic images.
Female ; Humans ; Incidence ; Joints ; Radiography* ; Sex Distribution ; Temporomandibular Joint ; Temporomandibular Joint Disorders

The author examined bone changes from 1274 polytomographic images of 182 temporomandibular joints which showed symptoms of temporomandibular disorder and the following results were obtained ; 1. The number of temporomandibular joints which showed bone changes were 64 (35.2%) among 182 joints. 2. The age and sex distribution of 64 joints which had bone changes showed the prevalence of female (90.6%) and thrid decade (25.0%) followed by fourth (21.2%) and second decade (17.2%). 3. The 252 images which showed bone changes consisted of 56 images from lateral side (22.2%), 118 images from center (46.8%) and 78 images from medial side (30.9%). 4. The most frequently observed bone changes were flattening (22.7%) followed by sclerosis (19.3%) and cortical unsharpness (19.3%)
Female ; Humans ; Joints ; Prevalence ; Sclerosis ; Sex Distribution ; Temporomandibular Joint ; Temporomandibular Joint Disorders*

PURPOSE: Diagnosis of osteoarthritis most commonly depends on clinical and radiographic findings. The present study attempted to observe the bony changes in temporomandibular joint (TMJ) patients from all age groups. MATERIALS AND METHODS: The first-visit clinical records and cone beam computed tomography (CBCT) data of 440 TMJs from 220 consecutive TMJ patients were reviewed retrospectively. RESULTS: The most frequent condylar bony change observed was sclerosis (133 joints, 30.2%) followed by surface erosion (129 joints, 29.3%), flattening of the articular surface (112 joints, 25.5%), and deviation in form (58 joints, 13.2%), which included 33 TMJs in a cane-shape, 16 with a lateral or medial pole depression, 6 with posterior condylar surface flattening, and 3 with a bifid-shaped condyle. Fifty-three joints (12.0%) showed hypoplastic condyles but only 1 joint showed hyperplasia. Osteophyte was found in 35 joints (8.0%) and subcortical cyst in 24 joints (5.5%), 5 of which had surface erosion as well. One hundred nineteen joints (27.0%) had only one kind of condylar bony change, 66 joints (15.0%) had two, 52 joints (11.8%) had three, 12 joints (5.0%) had four, and 6 joints (1.4%) had five kinds of condylar bony changes at the same time. Eighty-five (65.9%) of 129 joints with surface erosion had pain recorded at the chief complaint. CONCLUSION: With more widespread use of CBCT, more specific or detailed guidelines for osteoarthritis are needed.
Cone-Beam Computed Tomography ; Depression ; Humans ; Hyperplasia ; Joints ; Osteoarthritis ; Osteophyte ; Sclerosis ; Temporomandibular Joint

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*

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*