Geometically standardaized dental radiographs were taken. We prepared Digital Cu-Equivalent Image Analyzing System for quantitative assessment of mandible bone. Images of radographs were digitized by means of Quick scanner and personal Mcquintosh computer. NIH image as software was used for analyzing images. A stepwedge composed of 10 steps of 0.1mm copper foil in tickness was used for reference material.This study evaluated the effects of step numbers of copper wedge adopted for calculating equation, kVp and exposure time on the coefficient of determination(r2)of the equation for conversion to Cu-equivalent image and the coefficient of variation and Cu-Eq value(mm) measured at each copper step and alveolar bone of mandible. The results were as follows: 1. The coefficients of determination(r2) of 10 conversion equations ranged from 0.9996 to 0.9973(mean=0.9988) under 70kVp and 0.16 sec. exposure. The equation showed the highest r2 was Y=4.75614612-0.06300524x +0.00032367x2 -0.00000060x3. 2. The value of r2 became lower when the equation was calculated from the copper stepwedge including 1.0mm step. In case of including 0mm step for calculation, the value of r2 showed variability. 3. The coefficient of variation showed 0.11, 0.20 respectively at each copper step of 0.2, 0.1mm in thickness. Those of the other steps to 0.9 mm ranged from 0.06 to 0.09 in mean value. 4. The mean Cu-Eq value of alveolar bone was 0.14+/-0.02mm under optimal exposure. The values were lower than the mean under the exposures over 0.20sec. in 60kVp and over 0.16sec. in 70kVp . 5. Under the exposure condition of 60kVp 0.16sec., the coefficient of variation showed 0.03, 0.05 respectively at each copper-step of 0.3, 0.2mm in thickness. The value of r2 showed over 0.9991 from both 9 and 10 steps of copper. The Cu-Eq value and the coefficient of variation was 0.14+/-0.01mm and 0.07 at alveolar bone respectively. In summary, A clinical application of this system seemed to be useful for assessment of quantitative assessment of alveolar provided high coefficient of determination is obtained by the modified adoption of copper step numbers and the low coefficient of variation for the range of Cu-Equivalent value of alveolar bone from optimal kVp and exposure time for each x-ray machine.
Copper ; Humans ; Mandible ; Radiography* ; Ticks

PURPOSE: To evaluate the effect of variable scanning protocols of computed tomography for evaluation of pre-implant site of the mandible through the comparison of the reformatted cross-sectional images of helical CT scans obtained with various imaging parameters versus those of conventional CT scans. MATERIALS AND METHODS: A dry mandible was imaged using conventional nonoverlapped CT scans with 1 mm slice thickness and helical CT scans with 1 mm slice thickness and pitches of 1.0, 1.5, 2.0, 2.5 and 3.0. All helical images were reconstructed at reconstruction interval of 1 mm. DentaScan reformatted images were obtained to allow standardized visualization of cross-sectional images of the mandible. The reformatted images were reviewed and measured separately by 4 dental radiologists. The image qualities of continuity of cortical outline, trabecular bone structure and visibility of the mandibular canal were evaluated and the distance between anatomic structures were measured by 4 dental radiologists. RESULTS: On image qualities of continuity of cortical outline, trabecular bone structure and visibility of the mandibular canal and in horizontal measurement, there was no statistically significant difference among conventional and helical scans with pitches of 1.0, 1.5 and 2.0. In vertical measurement, there was no statistically significant difference among the conventional and all imaging parameters of helical CT scans with pitches of 1.0, 1.5, 2.0, 2.5 and 3.0. CONCLUSION: The images of helical CT scans with 1 mm slice thickness and pitches of 1.0, 1.5 and 2.0 are as good as those of conventional CT scans with 1 mm slice thickness for evaluation of pre-dental implant site of the mandible. Considering the radiation dose and patient comfort, helical CT scans with 1 mm slice thickness and pitch of 2.0 is recommended for evaluation of pre-implant site of the mandible.
Dental Implants ; Humans ; Mandible ; Tomography, Spiral Computed ; Tomography, X-Ray Computed

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 summarized 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.
Artifacts ; Magnetic Resonance Imaging*

The present case illustrates an arteriovenous malformation of the cheek in a 25-year-old male. The clinical presentation, radiographic findings, differential diagnosis, treatment and histopathologic description are presented. Diagnosis of the lesion was confirmed by angiography, and the lesion was treated by angiographically controlled vascular embolization followed by complete surgical excision.
Adult ; Angiography ; Arteriovenous Malformations* ; Cheek ; Diagnosis ; Diagnosis, Differential ; Humans ; Male

Leiomyosarcoma is extremely rare in the oral cavity and especially in the mandible. At first, the case of this report was diagnosed as odontogenic fibroma but after approximately 3.5 years, it was diagnosed as leiomyosarcoma. Conventional radiograph of the first time showed an ill-defined radiolucent lesion in the mandible. After local recurrence, CT images showed a large irregular soft tissue mass with some necrotic areas. These findings were not specific for leiomyosarcoma, but they suggested that this lesion was a recurrent soft tissue sarcoma. Histopathological examinations using H & E staining, immunohistochemical staining and Masson's trichrome staining confirmed this case as leiomyosarcoma. Deciding its malignany or benignancy, defining the tumor extent and its relationship to the surrounding anatomic structures, and evaluating the distant metastasis are more important role of radiographic examination than finding out the name of disease.
Fibroma ; Leiomyosarcoma* ; Mandible* ; Mouth ; Neoplasm Metastasis ; Recurrence ; Sarcoma

Malignant fibrous histiocytoma is one of the most common soft tissue sarcomas in late adult life, but its incidence in oral and maxillofacial region is extremely rare. We report a case of malignant fibrous histiocytoma which occurred in the infratemporal fossa. Conventional radiograph of this case showed an ill-defined radiolucent lesion in the alveolar bone of the right maxillary first molar area, the lateral wall of the maxillary sinus, and the ascending ramus of mandible. MRI demonstrated well defined mass of intermediate signal intensitiy in T1 weighted images but T2 weighted images showed two distinctive regions of different characteristics. Infratemporal portion of the lesion was of hyperintense signal but under that region, the signal intensity decreased clearly, which might mean this case composed of two different subtypes, though it couldn't be confirmed by histopathological examination. Biopsy was taken in the only soft tissue of the maxillary posterior alveolar region and confirmed the lesion as the storiform-pleomorphic type of malignant fibrous histiocytoma. Histopathological subtype was well consistent with the relatively aggressive imaging findings of that region. We expect more detailed analysis of the nature of malignant fibrous histiocytoma with improvement of the imaging modality and the identification of the relationship between diagnostic imaging and histopathologic findings.
Adult ; Biopsy ; Diagnostic Imaging ; Histiocytoma, Malignant Fibrous* ; Humans ; Incidence ; Magnetic Resonance Imaging ; Mandible ; Maxillary Sinus ; Molar ; Sarcoma

PURPOSE: To determine the clinical and radiological features of peripheral osteoma of the mandible (POM) in a Korean population and to compare with previous reports. MATERIALS AND METHODS: Sixteen cases of POM found in 15 Korean patients who visited Seoul National University Dental Hospital between 1980 and 1998 were reviewed to determine their clinical and radiological features. RESULTS: The 15 patients, five males and ten females, ranged in age from 22 to 69 years, with a mean age of 40.7 years. Six POMs were located on the buccal side of the mandibular body and five on the lingual aspect of the mandibular body and five on the lower border of the mandible. The duration of the lesion ranged between 1 and 10 years. The size of the lesions, in their great diameter, ranged from 6 mm to 26 mm, with a mean of 14.1 mm. Six POMs were pedunculated, nine sessile, and one bell-shaped. Eleven POMs were compact types and five were cancellous ones. CONCLUSION: The clinical and radiological features of these Korean series were broadly consistent with those of non-Korean populations reported previously. The principal difference was that all POMs under 35 year-old age were compact types.
Adult ; Female ; Humans ; Male ; Mandible* ; Osteoma* ; Seoul

Osteopetrosis is an uncommon hereditary bone disorder whose prominent radiologic feature characterized by increased bone density. The authors reported a 7-year-old male patient who referred from local dental clinic for dental problems such as early exfoliation of deciduous teeth(#54,73,83) and delayed eruption of permanent teeth(#31,41,36,46). The patient appeared as a poorly developed. Dental X-ray films showed early exfoliation of deciduous teeth, delayed eruption of permanent teeth, and rampant caries. Lateral view of skull demonstrated increased opacity of calvarium, facial bones, and skull base. Generally the skeletal density is greatly increased throughout all bones. Facial CT showed poor development of paranasal sinuses and mastoid air cells. No hematopoietic and neurologic complications such as anemia, thrombocytopenia, blindness and deafness were found. Also mental retardation was not found. The final diagnosis of this case was a osteopetrosis tarda. Sometimes patient with osteopetrosis tarda may be developed dental problems prior to severe systemic symptoms. The dentist can be the first clinician to see the patient. It is very important for the dentist to have the knowledge of the osteopetrosis and to care the patient's dental problems to prevent complication such as osteomyelitis of jaws.
Anemia ; Blindness ; Bone Density ; Child ; Deafness ; Dental Clinics ; Dentists ; Diagnosis ; Facial Bones ; Growth Disorders ; Humans ; Intellectual Disability ; Jaw ; Male ; Mastoid ; Osteomyelitis ; Osteopetrosis* ; Paranasal Sinuses ; Skull ; Skull Base ; Thrombocytopenia ; Tooth ; Tooth Eruption ; Tooth, Deciduous ; X-Ray Film

PURPOSE: This study was to evaluate the effects of Aloe, Gelfoam, and Plaster of Paris on bone healing. MATERIALS AND METHODS: Four experimental defects were created for placement of the three materials in the right femur of dogs. One defect served as an empty control site. The evaluation was performed at 1-, 6-, and 12-weeks by light microscopy and NIH image program. RESULTS: Radiographic and Histologic examinations showed new bone formation in the presence of Aloe, Gelfoam, and Plaster of Paris and similar bone healing reactions. CONCLUSION: On the basis of these findings, it was concluded that Aloe, Gelfoam, and Plaster of Paris may be adequate agents for use in bone procurement.
Aloe* ; Animals ; Calcium Sulfate ; Dogs ; Femur ; Gelatin Sponge, Absorbable* ; Microscopy ; Osteogenesis*

OBJECTIVES: To evaluate the anatomic variations of the paranasal sinuses on computed tomographs. MATERIALS AND METHODS: The author examined the CT images of the paranasal sinuses retrospectively in 500 patients who visited Chonbuk National University Hospital between January 1996 and December 1997. RESULTS: The highest incidence of anatomic variation of the paranasal sinuses in bilateral structures was agger nasi cell(73.2%), followed by concha bullosa(31.1%), Onodi cell(24.0%), Haller cell(19.8%), maxillary sinus septum(13.0%), paradoxical middle turbinate(2.5%), pneumatized uncinate process(2.0%), and bent uncinate process. The highest incidence of anatomic variation in midline structures was nasal septum deviation(53.2%), followed by nasal septumaerated(29.4%), bulla galli(24.7%) asymmetric intersphenoid septum(22.3%), and nasal septum spur(13.8%). The correlation between anatomic variation and paranasal sinusitis was not found. CONCLUSIONS: The results of this study will aid in the diagnosis and treatment of paranasal sinus diseases, especially in the treatment planning before functional endoscopic surgery.
Anatomic Variation* ; Diagnosis ; Humans ; Incidence ; Jeollabuk-do ; Maxillary Sinus ; Nasal Septum ; Paranasal Sinus Diseases ; Paranasal Sinuses ; Retrospective Studies ; Sinusitis