Primitive neuroectodermal tumor (PNET), which belongs to the Ewing's sarcoma (ES) family of tumors, is mainly seen in children and young adults. PNETs are extremely rare in the maxilla. Here, we report a case of PNET of the left maxillary sinus in an elderly male. Magnetic resonance imaging (MRI) revealed a slightly enhanced solid mass occupying the left maxillary sinus and infiltrating into the retroantral space. A partial maxillectomy was performed. Despite postoperative chemotherapy, follow-up computed tomography (CT) and MRI revealed a nodal metastasis in the submandibular space. Neck dissection was performed. However, the patient died 10 months after the second surgery because of distant metastasis to the liver. MRI and CT were particularly useful in detecting the extent of the tumor, recurrence, and metastasis. Further, a literature review of the previously reported PNET cases of the maxilla was carried out. In this paper, we also discuss the current approach for the diagnosis and management of these tumors.
Aged* ; Child ; Diagnosis ; Drug Therapy ; Follow-Up Studies ; Humans ; Liver ; Magnetic Resonance Imaging ; Male ; Maxilla ; Maxillary Sinus* ; Neck Dissection ; Neoplasm Metastasis ; Neuroectodermal Tumors, Primitive* ; Recurrence ; Sarcoma, Ewing ; Young Adult

PURPOSE: This study was performed to examine the effects of image filter on observer performance by counting the number of holes at each wedge step on a radiographic image. MATERIALS AND METHODS: An aluminum step wedge with 11 steps ranged in thickness from 1.5 mm to 16.5 mm in 1.5 mm increments was fabricated for this study. Each step had 10 notched holes with 1.0 mm diameter on the bottom of the step wedge which were ranged in depths from 0.1 mm to 1.0 mm in 0.1 mm increments. Digital radiographic raw images of the aluminum step wedge were acquired by using CCD intraoral sensor. The images were processed using several types of noise reduction filters and kernel sizes. Three observers counted the number of holes which could be discriminated on each step. The data were analyzed by ANOVA. RESULTS: The number of holes at each step was decreased as the thickness of step was increased. The number of holes at each step on the raw images was significantly higher than that on the processed images. The number of holes was different according to the types and kernel sizes of the image filters. CONCLUSION: The types and kernel sizes of image filters on observer performance were important, therefore, they should be standardized for commercial digital imaging systems.
Aluminum ; Noise ; Radiographic Image Enhancement ; Radiography, Dental ; Task Performance and Analysis

Actinomycosis is defined as a chronic, specific, suppurative, granulomatous disease caused mainly by the anaerobic, gram positive organism, Actinomyces israelii. Actinomycosis in the salivary gland is a rare disease that is caused by an inhabitant of the normal flora. We report the case of the actinomycosis of submandibular gland. A 53-year old man presented with the swelling on left submandiblar area. The lesion was not painful but had been increasing for about 10 days. In the CT view, the internal portion of the mass showed homogeneous moderate signal. The mass had continuities with the inferior portion of the left enlarged submandibular gland. In the MRI, there was a mass that showed a buldging pattern inferiorly in the left submandibular gland without bony invasion sign. The biopsy shows the colony of special organism. Many filaments are discovered with clubbed ends diffused from center of colony. We diagnosed this disease as actinomycosis in the submandibular gland by the postoperational biopsy.
Actinomyces ; Actinomycosis* ; Biopsy ; Humans ; Magnetic Resonance Imaging ; Middle Aged ; Rare Diseases ; Salivary Glands ; Submandibular Gland*

PURPOSE : To investigate the incidence and prevalence of C-shaped root canal using computed tomographic images of head and neck in Korean population. MATERIALS AND METHODS : Regardless of each examination purpose, randomly selected 268 examples which have serial axial computed tomographic images with 8 normal molars in maxilla and mandible were selected and investigated. Defined C-shaped root canal and we could get 82 proper image examples in view of this definition. These were detected and investigated of incidence and prevalence of C-shaped root canal. RESULTS : C-shaped root canals were found in 82 examples among 268 (30.6%) and 147 teeth. They were only found on molar area, and the highest incidence was 37.41% of left mandibular second molars, and the lowest was 2.04% of right maxillary second molars. On prevalence of tooth position, mandibular second molar was the highest, 65% of C-shaped root canal teeth and maxillary second molar was 6% the lowest. CONCLUSION : 31% of randomly selected CT images no considering check-up reason have C-shaped root canals. The C-shaped root canals of mandibular second molar are found most frequently and they are also detectable on maxilla. On Korean population, C-shaped root canals are one of conditions that have to concern with dental treatment for it appears at a high prevalence relatively.
Dental Pulp Cavity ; Head ; Incidence ; Mandible ; Maxilla ; Molar ; Neck ; Prevalence ; Tooth

PURPOSE: To analyze the radiographic and HRCT findings of Pneumocystic carinii pneumonia. MATERIALS AND METHODS: We reviewed the medical records and retrospectively analysed the chest radiographs(n=31) and HRCT scans(n=17) of 31 patients with Pneumocystis carinii pneumonia who had been followed up at our institute between, 1993 and March 1998. Pneumocystis carinii pneumonia was confirmed by cytologic evaluation of sputum stained with methenamine silver(n=25) or on the basis of clinical history(n=6). The study group included 17 men and 14 women aged 28 -78(average, 53.6) years. Twenty-eight patients had underlying conditions such as hematologic diseases(n=13), AIDS(n=8), malignancy(n=2), DM(n=2) and malnutrition(n=1), and three were free from underlying diseases. RESULTS: Twenty patients had pure Pneumocystis carinii pneumonia and 11 had combined lung diseases, namely pulmonary tuberculosis(n=4), pulmonary metastasis(n=2), bacterial pneumonia(n=2), atypical mycobacterial infection(n=1), pulmonary edema(n=1), and Kaposi's sarcoma(n=1). Chest radiographic findings of 20 cases of pure Pneumocystis carinii pneumonia included consolidation(n=12), l inear-reticular opacity(n=8), ill defined haziness(n=7), and nodules(n=6), with bilaterality in is cases and zonal predominance in ten [central(n=5), lower(n=5)]. Ancillary findings included pleural effusion(n=10), cysts(n=5), lymphadenopathy(n=4) and pneumothorax(n=1). In two patients, findings were entirely normal. HRCT findings in ten cases of pure Pneumocystis carinii pneumonia included ground-glass opacity(n=6), consolidation(n=6), linear-reticular opacity(n=8), and nodules(n=5), with bilaterallity in seven cases and zonal predominance in five [central(n=5), lower(n=2)]. Ancillary findings among these cases included pleural effusion(n=4), lym-phadenopathy(n=2), cysts(n=1), and pneumothorax(n=1). HRCT findings in seven cases of Pneumocystis carinii pneumonia combined with other lung diseases included nodules(n=6), ground-glass opacity(n=5), linear-reticular opacity(n=4), and consolidation(n=3). CONCLUSION: Although ground-glass opacity in both pure Pneumocystis carinii pneumonia and this same condition combined with other lung diseases is a common radiologic finding, the possibility of variable radiologic findings in cases of Pneumocystis carinii pneumonia and other lung diseases with which it frequently combines is essential for approximate diagnosis of Pneumocystis carinii pneumonia.
Diagnosis ; Female ; Fluconazole ; Humans ; Lung Diseases ; Male ; Medical Records ; Methenamine ; Pneumocystis carinii* ; Pneumocystis* ; Pneumonia ; Pneumonia, Pneumocystis* ; Radiography, Thoracic ; Retrospective Studies ; Sputum ; Thorax

PURPOSE: The purpose of this study was to develop a system for the measurement and simulation of the TMJ movement and to analyze the mandibular movement quantitatively. MATERIALS AND METHODS: We devised patient-specific splints and a registration body for the TMJ movement tracking. The mandibular movements of the 12 subjects with facial deformity and 3 controls were obtained by using an optical tracking system and the patient-specific splints. The mandibular part was manually segmented from the CT volume data of a patient. Three-dimensional surface models of the maxilla and the mandible were constructed using the segmented data. The continuous movement of the mandible with respect to the maxilla could be simulated by applying the recorded positions sequentially. Trajectories of the selected reference points were calculated during simulation and analyzed. RESULTS: The selected points were the most superior point of bilateral condyle, lower incisor point, and pogonion. There were significant differences (P<0.05) between control group and pre-surgical group in the maximum displacement of left superior condyle, lower incisor, and pogonion in vertical direction. Differences in the maximum lengths of the right and the left condyle were 0.59+/-0.30 mm in pre-surgical group and 2.69+/-2.63 mm in control group, which showed a significant difference (P<0.005). The maximum of differences between lengths of the right and the left calculated during one cycle also showed a significant difference between two groups (P<0.05). CONCLUSION: Significant differences in mandibular movements between the groups implies that facial deformity have an effect on the movement asymmetry of the mandible.
Congenital Abnormalities ; Displacement (Psychology) ; Humans ; Incisor ; Mandible ; Maxilla ; Splints ; Temporomandibular Joint ; Track and Field

Acquired facial lipoatrophy is a rare disease with an unclear etiology and pathological pathway. The distinct causative factors of this disease have been not elucidated, but it is suspected to be associated with immune systemrelated diseases, most notably AIDS. Although the management of facial lipoatrophy is very important for patients’ social life and mental health, no treatment framework has been developed due to the unknown nature of the disease manifestation. The present case report was designed to provide sequential imaging to visualize the disease progression. The clinical backgrounds of the patients are also introduced, helping characterize this disease entity more clearly for maxillofacial specialists.

Neurilemmoma is a benign tumor of the nerve sheath that arises on cranial and spinal nerve roots as well as along the course of peripheral nerves. A case of a neurilemmoma that arose in the left infratemporal fossa of a 29-year-old male was presented. Plain radiographs, enhanced computed tomography scan, and magnetic resonance imaging demonstrated a large, well-circumscribed, heterogeneously enhanced mass with extension into the pterygopalatine fossa. Displaced by the large mass, bowing-in of the posterior maxillary antral wall was noted and a provisional diagnosis of a benign soft tissue tumor was made. The mass was completely excised and a diagnosis of neurilemmoma was confirmed.
Adult ; Diagnosis ; Head and Neck Neoplasms ; Humans ; Magnetic Resonance Imaging ; Male ; Maxillary Sinus* ; Neurilemmoma* ; Peripheral Nerves ; Pterygopalatine Fossa* ; Spinal Nerve Roots

PURPOSE: We wanted to determine the incidence of HGC (hereditary gastric cancer) in Korean under the minimal criteria of ICG-HGC (International Collaborative Group on Hereditary Gastric Cancer). MATERIALS AND METHODS: Tumor registry abstracts of 1752 patients who underwent operations for gastric cancer during the time period 1996 to 1998 in the Department of Surgery at Seoul National University College of Medicine were examined. Based on their family histories, candidate HGCs were identified. Their detailed family histories including diagnosis of cancer, age at diagnosis, and dates of birth and death were obtained from interviews by phone. Another study was performed on 195 patients with gastric cancer who admitted for operations in the same department during the time period April, 1999 to June, 1999. Their detailed family histories were also obtained from probands or nearest relatives during admission. Pedigree studies of documented families were conducted. Minimal Criteria of ICG-HGC we used for present study are as followings: At least three relatives with histologically verified gastric cancer; one of them should be a first-degree relative to the other two. At least two successive generations should be affected. In one of the relatives, gastric cancer should be diagnosed under 45 years of age. Suspected HGC fullfills only two of the above three criteria. HNPCC, FAP and Li-Fraumeni syndromes should be excluded. RESULTS: A total of 12 HGCs were identified in this study. In recent 3 years, during the time period 1996 to 1998, the incidence of true and suspected HGC accounted for 6 (0.3%) and 44 probands (2.5%) among 1752 patients (in 1996, 0.4% and 3.2%; in 1997, 0.3% and 1.8%; in 1998, 0.3% and 2.8%) respectively. In contrast, during the time period April, 1999 to June, 1999, the incidence of true and suspected HGC increased up to 3.1% (6 probands) and 11.3% (22 probands), respectively, out of 195 patients (in April, 1999, 0% and 11.7%; in May, 1999, 4% and 14.7%; in June, 1999, 5% and 6.7%). There was no difference in terms of the incidence even if the third criterion of age at diagnosis among Minimal Criteria of ICG-HGC was modified from 'under 45 years of age' to 50. Mean ages of 12 probands (46.3 8.8) were statistically younger than those of control gastric cancer patients (54.2 11.5) retrieved from database of Department of Surgery at Seoul National University College of Medicine. CONCLUSION: In the present study, the incidences of HGC were remarkably altered in accordance with study methods. Retrospective reviews of medical records revealed to be ineffective for this kind of study since their informations were often incomplete and some suspected patients were lost during follow-up. According to the Minimal Criteria of ICG-HGC, the incidence of true and suspected HGC was 3.1% (6 probands) and 11.3% (22 probands), respectively, out of 195 gastric cancer patients. We propose that families who meet the Minimal Criteria of ICG-HGC should be prospectively found in order to determine the exact incidence of HGC in Korean.
Diagnosis ; Family Characteristics ; Follow-Up Studies ; Humans ; Incidence* ; Korea ; Medical Records ; Parturition ; Pedigree ; Retrospective Studies ; Seoul ; Stomach Neoplasms*

PURPOSE: This study was performed to identify correlations between keratocystic odontogenic tumor (KCOT) data from CT sections, and data on the KCOT clinical manifestation and resulting dental expenses. MATERIALS AND METHODS: Following local Institutional Review Board (IRB) approval, a seven-years of retrospective study was performed regarding patients with KCOTs treated at the Seoul National University Dental Hospital. A total of 180 KCOT were included in this study. The following information was collected: age, gender, location and size of the lesion, radiological features, surgical treatment provided and dental expenses. RESULTS: There was no significant association between the size of the KCOT and age, gender, and presenting preoperative symptoms. In both jaws, it was unusual to find KCOTs under 10 mm. The correlation between the number of teeth removed and the size of the KCOT in the tooth bearing area was statistically significant in the mandible, whereas in the maxilla, no significant relationship was found. Dental expenses compared with the size of the KCOT were found to be significant in both jaws. CONCLUSION: The size of KCOT was associated with a significant increase in dental expenses for both jaws and the number of teeth removed from the mandible. These findings emphasize the importance of routine examinations and early detection of lesions, which in turn helps preserving anatomical structures and reducing dental expenses.
Cost of Illness ; Ethics Committees, Research ; Humans ; Jaw ; Mandible ; Maxilla ; Odontogenic Cysts ; Odontogenic Tumors ; Retrospective Studies ; Tooth ; Ursidae