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

OBJECTIVE: Screening tests for dysphagia have been introduced to prevent complications arising from dysphagia in stroke patients. Among them, Gugging swallowing screen (GUSS) was proven as an effective screening tests for dysphagia of stroke patients in 24 hours after onset. We compared several screening tests and clinical scales including GUSS. METHOD: Subjects were 37 stroke patients 3 months after onset. GUSS, 3 oz water test, Burke dysphagia screening test (BDST) and Standardized swallowing assessment (SSA) were carried out at bedside. VFS was performed in 24 hours after other studies were done. Functional dysphagia scale (FDS) and Penetration-aspiration scale (P/A scale) were derived from VFS. Clinical scales such as American Speech-Language-Hearing Association National Outcome Measurement System (ASHA NOMS) swallowing scale and Clinical dysphagia scale (CDS) were measured to see the correlation between GUSS and another dysphagia scales. RESULTS: GUSS had a sensitivity of 90.9% and a specificity of 69.2%. 3 oz water test had a sensitivity of 81.8% and a specificity of 76.9%. Sensitivity and specificity of BDST were respectively 90.9%, 61.5%. Sensitivity of SSA was 90.9%, specificity 61.5%. Correlation between GUSS and FDS was significant (r =-0.527, p<0.01). Correlation between GUSS and P/A scale also showed significance (r=-0.747, p<0.01). ASHA NOMS swallowing scale and GUSS showed significant correlation (r=0.432, p<0.01). CDS and GUSS showed significant correlation as well (r=-0.815, p<0.01). CONCLUSION: The screening ability of GUSS was equal to other screening tests for dysphagia of stroke patients. Correlations among GUSS and other VFS and clinical scales showed availability of GUSS as a clinical scale for dysphagia.

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: 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.

Postoperative maxillary cysts are locally aggressive lesions, usually developing as delayed complications many years after radical antral surgery. This report describes a case of bilateral postoperative maxillary cysts following orthognathic surgery performed approximately 21 years previously. The patient complained of stinging pain on her right cheek. Radiographic examination revealed low-attenuation lesions on both maxillary sinuses with discontinuously corticated margins without distinct expansion or bone destruction. The cysts were enucleated with the removal of metal plates and screws for pain relief. Histopathological examination confirmed the diagnosis of postoperative maxillary cysts lined by ciliated, pseudostratified columnar cells. The patient has remained asymptomatic thus far, and there was no evidence of local recurrence at 21 months of postoperative follow-up.
Bites and Stings ; Cheek ; Diagnosis ; Follow-Up Studies ; Humans ; Maxillary Sinus ; Orthognathic Surgery* ; Radiography ; Recurrence

PURPOSE: The purpose of this study was to compare the accuracy of postoperative maxillary cyst (POMC) diagnosis by panoramic radiographs versus computed tomography (CT) and by oral and maxillofacial radiologists versus non-specialists. MATERIALS AND METHODS: Sixty-five maxillary sinuses with POMCs and 63 without any lesion were assessed using panoramic radiographs and CT images by five oral and maxillofacial radiologists and five non-specialists on a five-point scale. The areas under receiver operating characteristic (ROC) curves were analyzed to determine the differences in diagnostic accuracy between the two imaging modalities and between the two groups of observers. The intra-observer agreement was determined, too. RESULTS: The diagnostic accuracy of CT images was higher than that of panoramic radiographs in both groups of observers (p<0.05). The diagnostic accuracy of oral and maxillofacial radiologists for each method was higher than that of non-specialists (p<0.05). CONCLUSION: The use of CT improves the diagnosis of POMC, and radiological training and experience leads to more accurate evaluation.
Diagnosis ; Maxillary Sinus ; Pro-Opiomelanocortin ; Radiography, Panoramic ; ROC Curve

PURPOSE: To investigate the relationship between three-dimensional (3D) bone imaging parameters and trabecular strength in the mandible. MATERIALS AND METHODS: Bone specimens were obtained from the mandibles of five male pigs weighing around 110 kg each. Of those, 43 samples were selected for 3D analysis and measured by micro-computed tomography. The five morphometric parameters were trabecular thickness (Tb.Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI) and degree of anisotropy (DA). Through destructive mechanical testing, strength parameters were obtained. RESULTS: BV/TV, SMI, BS/BV, and Tb.Th showed significant correlations with strength parameters. DA did not show any correlation with the other parameters. In multiple linear regression analysis, BV/TV alone explained 43% of the variance in Young's modulus. By stepwise inclusion of SMI, the variance in the Young's modulus was better explained up to 52%. CONCLUSIONS: Predicting trabecular strength in the mandible through architectural analysis would be possible. Further study is needed to establish the tendency and variety of trabecular architecture and strength according to the locations within the mandible.
Anisotropy ; Compressive Strength ; Elastic Modulus ; Humans ; Linear Models ; Male ; Mandible* ; Swine ; Tomography Scanners, X-Ray Computed ; X-Ray Microtomography*

PURPOSE: This study was performed to evaluate the reproducibility of panoramic radiographs of dentulous and edentulous patients. MATERIALS AND METHODS: The reproducibility of panoramic radiographs was evaluated using the panoramic radiographs acquired from 30 anterior dentulous patients by using a common biting positioning device (dentulous group) and 30 anterior edentulous patients by using chin-support devices to take a panoramic radiograph (edentulous group), respectively; these patients had undergone 3 or more panoramic radiographs. The widths and angles between the designated landmarks were measured on the panoramic radiographs, and the reproducibility was evaluated using the intraclass correlation coefficient (ICC) and the coefficient of variation. RESULTS: In the dentulous and edentulous groups, the ICCs of the mandibular ramus and mandibular angle areas were higher than the condylar head and zygomatic areas. The mandibular ramus and angle areas showed statistically lower mean coefficients of variation than the condylar head and zygomatic areas in the dentulous group. The mandibular angle area showed a significantly lower mean coefficient of variation than the zygomatic area in the edentulous group. By comparing the two groups, each ICC of the edentulous group was lower than that of the dentulous group, and the mean coefficients of variation of the mandibular ramus area, zygomatic area, left condylar inclination, and ramus ratio between the right and the left in the edentulous group were significantly higher than those in the dentulous group. CONCLUSION: Biting positioning for dentulous patients provided better positioning reproducibility than chin-support positioning when performing panoramic radiography for edentulous patients.
Head ; Humans ; Radiography, Panoramic ; Reproducibility of Results

PURPOSE: We want to identify the appearance of the buccolingual root dilaceration teeth in the panoramic views and specify the characteristics of these teeth. MATERIALS AND METHODS: One thousand-six patients were examined on the basis of both panoramic and CT image criteria. We diagnosed and excluded certain teeth from the samples; both prosthodontic or pathologic lesion appearing teeth and mesiodistally dilacerated ones. We meticulously discerned buccolingually dilacerated teeth in the CT images and total 48 samples were selected. The degree of severity in dilaceration was standardized by 2 types of criteria. The samples were differentiated into 3 groups and again categorized into six types showing from the panoramic views: irregular view on the root apex area, clear blunt on the root tip, stepping on root tip, double lamina dura or double tip, arrow-target shaped root, bull's eye, normal view. RESULTS: The types of teeth selected from total 48 buccolingual root dilaceration samples were mandibular first and second molar, premolars, canines, and lateral incisors. The direction of dilaceration was an even percentage to each buccal and lingual side for most selected teeth, however, that of both canines and lateral incisors were directed in almost a buccal side. In the panoramic views, the root types of the buccolingually dilacerated teeth were irregular view on the root apex area, clear blunt on the root tip, stepping on root tip and normal types were almost always normal view. The more severity in dilareated degree, the more chances of observation in the panoramic views were clear blunt on the root tip and stepping on root tip. CONCLUSION: As observed in the shape of stepping on root tip or double lamina dura in the panoramic views, there can be much more probability to diagnose as a buccolingually dilacerated root.
Bicuspid ; Eye ; Humans ; Incisor ; Meristem ; Molar ; Prosthodontics ; Tooth