Pericoronal radiolucency associated with incomplete crown

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.

Correlation of panoramic radiographs and cone beam computed tomography in the assessment of a superimposed relationship between the mandibular canal and impacted third molars

PURPOSE: This study evaluated the association between cone beam computed tomography (CBCT) and panoramic radiographs in the assessment of a superimposed relationship between the mandibular canal and impacted third molars. MATERIALS AND METHODS: The study samples consisted of 175 impacted third molars from 131 patients who showed a superimposed relationship between the mandibular canal and third molars on panoramic radiographs and were referred for the examination of the mandibular canal with CBCT. Panoramic images were evaluated for the darkening of the root and the interruption of the mandibular canal wall. CBCT images were used to assess the buccolingual position of the mandibular canal relative to the third molar, the proximity of the roots to the canal, and lingual cortical bone loss. The association of the panoramic and CBCT findings was examined using a Chi-square test and Fisher's exact test. RESULTS: Panoramic radiographic signs were statistically associated with CBCT findings (P<0.01). In cases of darkening roots, lingual cortical bone loss or buccally positioned canals were more frequent. In cases in which the mandibular canal wall was interrupted on panoramic radiographs, contact or lingually positioned canals were more frequent. CONCLUSION: The results of this study suggest that contact between the mandibular third molar and canal and a lingually positioned canal could be more frequently observed in cases of the interruption of the white line of the mandibular canal and that there could be more lingual cortical loss in cases of darkening roots.

Condylar bony changes in patients with temporomandibular disorders: a CBCT study

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.

Osteomas of the craniofacial region

PURPOSE: The purpose of this study was to present the clinical features of a case series of osteomas in the craniofacial region and to compare them with those described in the dental literatures. MATERIALS AND METHODS: A retrospective study of 18 patients diagnosed with osteomas in the craniofacial region was performed. The age, gender, location, symptoms, and the radiological findings were recorded. RESULTS: There were 13 women and 5 men from 18 years to 69 years of age (mean age, 42+/-27 years). Fourteen osteomas were found in the mandible (78%), two in frontal sinus, one in sphenoid bone, and one in maxilla. CONCLUSION: Osteomas are benign tumors composed of mature compact bone or cancellous bone. They are essentially restricted to the craniofacial skeleton and rarely, if ever, are diagnosed in other bones.

Central odontogenic fibroma: a case report

Central odontogenic fibroma is a rare odontogenic neoplasm that originates from odontogenic ectomesenchyme. Here, a case of central odontogenic fibroma in a 17-year-old male is reported. Since the present case showed a multilocular radiolucency with partially ill-defined border between the right mandibular condyle and the distal root of the right mandibular third molar, differential diagnosis involved a wide range of pathosis from benign lesions like ameoloblastic fibroma and odontogenic myxoma to more aggressive lesions such as desmoplastic fibroma, juvenile aggressive fibromatosis, or fibrosarcoma.

Maxillary sinus septa: comparison between panoramic radiography and CBCT / 대한구강악안면방사선학회지

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.

Maxillary sinus pneumatization after maxillary molar extraction assessed with cone beam computed tomography / 대한구강악안면방사선학회지

PURPOSE: The purpose of this study was to examine the inferior expansion of the maxillary sinus floor following maxillary molar extraction. MATERIALS AND METHODS: Cone beam computed tomographic images of 59 subjects were used to evaluate the height difference of the maxillary sinus floor between extraction sites and contralateral dentate sites. The height of the maxillary sinus floor was defined as the vertical distance to the Frankfort plane from the level of the anterior nasal spine to the most inferior point of the sinus floor. We examined the difference in sinus pneumatization according to the number of missing teeth and the vertical relationship of the molar roots to the sinus floor. RESULTS: The inferior expansion of the maxillary sinus floor was 1.20+/-1.86 mm on the maxillary first molar and 1.90+/-2.42 mm on the maxillary second molar. Increased expansion was observed in cases where two proximate molars were extracted. There was no significant difference in sinus pneumatization following extraction according to the vertical relationship of the molar roots to the sinus floor. CONCLUSION: The results of this study confirm that sinus pneumatization occurs following maxillary molar extraction. In situations where pneumatization can affect treatment after molar extraction, three-dimensional radiography should be considered.

Prediction of osteoporosis using fractal analysis on periapical and panoramic radiographs / 대한구강악안면방사선학회지

PURPOSE: The purpose of this study was to investigate whether fractal analysis of periapical and panoramic radiographs was useful in predicting osteoporosis risk. MATERIALS AND METHODS: 37 postmenoposal women between the age of 42 and 79 were classified as normal and osteoporosis group according to the bone mineral density of lumbar vertebrae and periapical and panoramic radiographs were taken. Fractal dimensions at periapical areas of mandibular first molars were calculated to differentiate the two groups. RESULTS: The mean fractal dimensions of normal group on periapical and panoramic radiographs were 1.413+/-0.079, 1.517+/-0.071 each. The mean fractal dimensions of osteoporotic group on periapical and panoramic radiographs were 1.498+/-0.086, 1.388+/-0.083 each. The mean fractal dimension from peripaical radiographs of osteoporotic group was statistically significantly higher than that of normal group. The mean fractal dimension from panoramic radiographs of osteoporotic group was statistically significantly lower than that of normal group. CONCLUSION: Fractal analysis using periapical and panoramic radiographs was useful in predicting osteoporosis.

The relationship between the position of mesiodens and complications / 대한구강악안면방사선학회지

PURPOSE: The purpose of this study was to evaluate the relationship between the position of mesiodens and its complications. MATERIALS AND METHODS: The subjects for this study consisted of 172 patients with mesiodens. Panoramic radiographs and cross-sectional tomography were taken of all of the subjects. Their clinical records and radiographs were analyzed in order to study the direction and vertical and sagittal position of mesiodens, as well as complications caused by mesiodens. RESULTS: The number of mesiodens was one in 112 cases (65.1%) and two in 60 cases (34.9%). Complications were found in 121 mesiodentes (52.2%), with being median diastema the most frequent. The incidence of complications was high in erupted mesiodens (75.0%), in horizontal mesiodens (89.8%) and in mesiodens located within the arch (75.7%), but was low in mesiodens impacted above apex (29.8%), in normal position (34.4%) and in palatally positioned mesiodens (46.5%). CONCLUSION: It was suggested that the frequency of complications was different according to the vertical position, the direction of the crown and the sagittal position.

The ability of panoramic radiography in assessing maxillary sinus inflammatory diseases / 대한구강악안면방사선학회지

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.

The value of panoramic radiography in assessing maxillary sinus inflammation / 대한구강악안면방사선학회지

Purpose: To evaluate the value of panoramic radiography in diagnosing maxillary sinus inflammation. MATERIALS AND METHODS: A total of 214 maxillary sinuses from 114 panoramic radiographs were assessed in this study. Two independent experienced oral radiologists evaluated the images in random order for sinus inflammation. Using Cone beam CT images as the gold standard, the sensitivity and specificity of panoramic radiography were calculated, and inter- and intraobserver agreement for panoramic interpretation were obtained. RESULTS: The mean sensitivity and specificity of panoramic radiography were 81.0% and 85.6%, respectively. The weighted kappas for inter- and intraobserver agreement of panoramic radiography were 0.56 and 0.60, respectively. CONCLUSION: Panoramic radiography is a reasonably accurate method for diagnosing maxillary sinus inflammation and can be used for screening. However, additional examinations should be considered in patients with potentially significant pathology.

Assessment of the relationship between the mandibular third molar and the mandibular canal using panoramic radiograph and cone beam computed tomography / 대한구강악안면방사선학회지

PURPOSE: The purpose of this study is to evaluate the position of the mandibular canal in relation to the mandibular third molar by cone beam CT in cases showing a close relationship between the third molar and the mandibular canal on the panoramic radiograph. MATERIALS AND METHODS: The panoramic images and cone beam CT scans of 87 impacted mandibular third molars in 60 patients were evaluated to assess the tooth relationship to the mandibular canal. The clearness of the canal wall and the vertical depth of the lower third molar were evaluated on panoramic radiographs. The lower third molars were assessed using cone beam CT to determine the proximity and position of the canal relative to the roots. RESULTS: In the 66 cases where the canal wall was unclear on the panoramic radiographs, 58 (87.9%) of the third molars had contact between the canal and root; 34 (51.5%) canals were showed an inferior position and 22 (33.3%) showed a linguoinferior position on cone beam CT. CONCLUSION: Interruption of the canal wall on panoramic radiographs was highly predictive of contact between the mandibular canal and the third molar. Cross sectional CT may be indicated for localization of the mandibular canal in such cases.

Prediction of osteoporosis using fractal analysis et cetera on panoramic radiographs / 대한구강악안면방사선학회지

PURPOSE: The purpose of this study was to investigate whether panoramic radiographs were useful in predicting osteoporosis. MATERIALS AND METHODS: 50 postmenoposal women between the age of 41.8 and 78.5 were classified as normal and osteoporosis groups according to the bone mineral density of lumbar vertebrae. Panoramic radiographs were taken. Age, body mass index, remaining mandibular teeth, mandibular cortical thickness and morphology, and fractal dimensions at periapical areas of mandibular first molars were evaluated to differentiate the two groups. RESULTS: The age of osteoporotic group was statistically significantly higher than that of normal group (p<0.05), but not the body mass index or number of remaining mandibular teeth. The mean fractal dimension of osteoporotic group was 1.391+/-0.085, and was significantly lower than that of the normal group, which was 1.523+/-0.725 (p<0.01). Thick mandibular cortical thickness was common in normal group, whereas thin or very thin mandibular cortical thickness was common in osteoporotic group and the difference was significant (p<0.05). C2 pattern was common in normal group followed by C1, whereas C2 was common in osteoporotic group followed by C3. The difference was statistically significant (p<0.01). CONCLUSION: Age, mandibular cortical thickness and shape, fractal dimension on panoramic radiographs were useful in predicting osteoporosis.

Prediction of osteoporosis using fractal analysis et cetera on panoramic radiographs / 대한구강악안면방사선학회지

PURPOSE: The purpose of this study was to investigate whether panoramic radiographs were useful in predicting osteoporosis. MATERIALS AND METHODS: 50 postmenoposal women between the age of 41.8 and 78.5 were classified as normal and osteoporosis groups according to the bone mineral density of lumbar vertebrae. Panoramic radiographs were taken. Age, body mass index, remaining mandibular teeth, mandibular cortical thickness and morphology, and fractal dimensions at periapical areas of mandibular first molars were evaluated to differentiate the two groups. RESULTS: The age of osteoporotic group was statistically significantly higher than that of normal group (p<0.05), but not the body mass index or number of remaining mandibular teeth. The mean fractal dimension of osteoporotic group was 1.391+/-0.085, and was significantly lower than that of the normal group, which was 1.523+/-0.725 (p<0.01). Thick mandibular cortical thickness was common in normal group, whereas thin or very thin mandibular cortical thickness was common in osteoporotic group and the difference was significant (p<0.05). C2 pattern was common in normal group followed by C1, whereas C2 was common in osteoporotic group followed by C3. The difference was statistically significant (p<0.01). CONCLUSION: Age, mandibular cortical thickness and shape, fractal dimension on panoramic radiographs were useful in predicting osteoporosis.

The prevalence, clinical and radiographic characteristics of cemento-osseous dysplasia in Korea / 대한구강악안면방사선학회지

PURPOSE: This study was intended to estimate the prevalence of cemento-osseous dysplasia (COD) in the Korean population 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 range from 6 to 91 years) were reviewed for evidence of COD. Their demographics, clinical characteristics, and radiographic features were retrospectively assessed. RESULTS: Of 10,646 panoramic radiographs, 33 radiographs (0.31%) exhibited evidence of COD. The prevalence of COD increased to over 1% in women over 40-years old. Of these 33 patients, 16 had florid cemento-osseous dysplasia (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%) were less than 10 mm and the majority (82.5%) showed radiopacity. CONCLUSION: COD has a predilection for the mandibular molar area of middle-aged and older women.

The location of the mandibular canal in prognathic patients compared to subjects with normal occlusion / 대한구강악안면방사선학회지

PURPOSE: The purpose of this study was to compare the location of the mandibular canal in Class III malocclusion to its location in normal occlusion for adults. MATERIALS AND METHODS: For this study 32 skeletal Class III patients and 26 normal patients were observed. Four measurements were taken on cross sectional tomography between the first and second molars: the distance from the mandibular canal to the inner surface of both the buccal and lingual cortices, the distance from the mandibular canal to the inferior border of the mandible, and the buccolingual width of the mandible. The buccolingual location of the canals was classified as lingual, central, or buccal. Each measurement was analyzed with an independent t test to compare Class III malocclusion to normal occlusion. RESULTS: Compared to the control group, the prognathic group had a shorter distance from the canal to the inner surface of the lingual cortex and to the base of the mandible. A higher percentage of the canals were located lingually in the prognathic group. CONCLUSION: This study showed that the mandibular canal was located more lingually and inferiorly in prognathic patients than in patients with normal occlusion. These results could help surgeons to reduce injuries to the inferior alveolar nerve.

Unusual Stafne bone cavity mimicking infected cyst or neural origin tumor / 대한구강악안면방사선학회지

The radiographic diagnosis of typical Stafne bone cavity could be done easily with cyst-like round or oval radiolucency near the angle of the mandible, under mandibular canal with or without involving mandibular base, and no symptoms. However there are some atypical cases suggesting possible variations of this entity. We report a quite unusual case, where Stafne bone cavity was lastly included in the differential diagnosis list. Histological examination of salivary gland tissues confirmed the final diagnosis.

Magnetic resonance imaging-based temporomandibular joint space evaluation in temporomandibular disorders / 대한구강악안면방사선학회지

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.

Projection angles of mandibular condyles in panoramic and transcranial radiographs / 대한구강악안면방사선학회지

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.

Necrotizing sialometaplasia: Report of 2 cases / 대한구강악안면방사선학회지

Necrotizing sialometaplasia (NS) was defined by Abrams et al. in 1973 as a reactive necrotizing inflammatory process involving minor salivary glands of the hard palate. Before that recognition, many patients with this condition had been improperly treated because of its clinical and histologic resemblance to malignancy such as mucoepidermoid carcinoma and squamous cell carcinoma. We report two cases of necrotizing sialometaplasia. One case involved a 58-year-old male who had an ulcerative palatal lesion exposing underlying bone which has the typical features of the above mentioned condition. Another case involved a 59-year-old male who developed a necrotizing sialometaplasia in association with a dome-shaped palatal swelling which was proved as an adenoid cystic carcinoma after operation biopsy.