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

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.

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: 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.

PURPOSE: The purpose of this study was to investigate appropriate contrast reference values (CRVs) by comparing the contrast in phantom and clinical images. MATERIALS AND METHODS: Phantom contrast was measured using two methods: (1) counting the number of visible pits of different depths in an aluminum plate, and (2) obtaining the contrast-to-noise ratio (CNR) for 5 tissue-equivalent materials (porcelain, aluminum, polytetrafluoroethylene [PTFE], polyoxymethylene [POM], and polymethylmethacrylate [PMMA]). Four panoramic radiographs of the contrast phantom, embedded in the 4 different regions of the arch-form stand, and 1 real skull phantom image were obtained, post-processed, and compared. The clinical image quality evaluation chart was used to obtain the cut-off values of the phantom CRV corresponding to the criterion of being adequate for diagnosis. RESULTS: The CRVs were obtained using 4 aluminum pits in the incisor and premolar region, 5 aluminum pits in the molar region, and 2 aluminum pits in the temporomandibular joint (TMJ) region. The CRVs obtained based on the CNR measured in the anterior region were: porcelain, 13.95; aluminum, 9.68; PTFE, 6.71; and POM, 1.79. The corresponding values in the premolar region were: porcelain, 14.22; aluminum, 8.82; PTFE, 5.95; and POM, 2.30. In the molar region, the following values were obtained: porcelain, 7.40; aluminum, 3.68; PTFE, 1.27; and POM, - 0.18. The CRVs for the TMJ region were: porcelain, 3.60; aluminum, 2.04; PTFE, 0.48; and POM, - 0.43. CONCLUSION: CRVs were determined for each part of the jaw using the CNR value and the number of pits observed in phantom images.
Aluminum ; Bicuspid ; Dental Porcelain ; Diagnosis ; Incisor ; Jaw ; Molar ; Phantoms, Imaging ; Polymethyl Methacrylate ; Polytetrafluoroethylene ; Quality Assurance, Health Care ; Radiography, Panoramic ; Reference Values* ; Skull ; Temporomandibular Joint

A 15-year-old patient, who had been diagnosed and treated as Burkitt cell type acute lymphoblastic leukemia (ALLL3) already, visited our department. He complained of gingival enlargement and loosening teeth 1 month ago. The clinical examination revealed anterior open bite, gingival enlargement, and nontender swelling particularly in molar regions of both jaws. Deep periodontal pockets and severe mobility was shown on most of the teeth. The panoramic radiographs showed severe bone destruction and extrusion of the molars. The contrast enhanced CT showed multiple enhanced mass and bone marrow obliteration in both jaws. Chemotherapy was done and the swelling was subsided at 1 month later. In conclusion, radiologic findings of leukemia with soft tissue mass, known as chloroma or granulocytic sarcoma, mimic those of lymphoma, so blood test may be needed for the final diagnosis.
Adolescent ; Bone Marrow ; Diagnosis ; Drug Therapy ; Hematologic Tests ; Humans ; Jaw ; Leukemia ; Lymphoma ; Molar ; Open Bite ; Periodontal Pocket ; Precursor Cell Lymphoblastic Leukemia-Lymphoma* ; Sarcoma, Myeloid ; Tooth

PURPOSE: This study was performed to determine the optimal tile size for the fractal dimension of the mandibular trabecular bone using a tile counting method. MATERIALS AND METHODS: Digital intraoral radiographic images were obtained at the mandibular angle, molar, premolar, and incisor regions of 29 human dry mandibles. After preprocessing, the parameters representing morphometric characteristics of the trabecular bone were calculated. The fractal dimensions of the processed images were analyzed in various tile sizes by the tile counting method. RESULTS: The optimal range of tile size was 0.132 mm to 0.396 mm for the fractal dimension using the tile counting method. The sizes were closely related to the morphometric parameters. CONCLUSION: The fractal dimension of mandibular trabecular bone, as calculated with the tile counting method, can be best characterized with a range of tile sizes from 0.132 to 0.396 mm.
Bicuspid ; Fractals ; Humans ; Incisor ; Mandible ; Molar ; Trabecular Meshwork

BACKGROUND: The safety of repeated mechanical thrombectomy within the acute stroke period has not yet been clearly demonstrated. We describe herein a patient who was successfully treated with repeated mechanical thrombectomy within the acute index stroke period. CASE REPORT: A 50-year-old woman with atrial fibrillation presented with left-sided weakness caused by occlusion of the right middle cerebral artery (MCA). Emergent mechanical thrombectomy with the Solitaire device achieved complete recanalization. The left MCA occlusion redeveloped at 6 days after the first treatment, at which time her international normalized ratio (INR) was 2.3. Endovascular thrombectomy was reattempted rapidly and complete recanalization was achieved again. Her neurologic symptoms resolved after the thrombectomy. CONCLUSIONS: This case demonstrates that repeated mechanical thrombectomy can be safely and successfully performed even in a patient with a high INR and a recurrent stroke during the acute period after the index stroke.
Atrial Fibrillation ; Female ; Humans ; International Normalized Ratio ; Middle Aged ; Middle Cerebral Artery ; Neurologic Manifestations ; Stroke* ; Thrombectomy*

PURPOSE: To investigate the relationship between 3D bone architectural parameters and direction-related elastic moduli of cancellous bone of mandibular condyle. MATERIALS AND METHODS: Two micro-pigs (Micro-pig(R), PWG Genetics Korea) were used. Each pig was about 12 months old and weighing around 44 kg. 31 cylindrical bone specimen were obtained from cancellous bone of condyles for 3D analysis and measured by micro-computed tomography. Six parameters were trabecular thickness (Tb.Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI), degree of anisotropy (DA) and 3-dimensional fractal dimension (3DFD). Elastic moduli of three orthogonal directions (superiorinferior (SI), medial-lateral (ML), andterior-posterior (AP) direction) were calculated through finite element analysis. RESULTS: Elastic modulus of superior-inferior direction was higher than those of other directions. Elastic moduli of 3 orthogonal directions showed different correlation with 3D architectural parameters. Elastic moduli of SI and ML directions showed significant strong to moderate correlation with BV/TV, SMI and 3DFD. CONCLUSION: Elastic modulus of cancellous bone of pig mandibular condyle was highest in the SI direction and it was supposed that the change into plate-like structure of trabeculae was mainly affected by increase of trabeculae of SI and ML directions.
Elastic Modulus ; Finite Element Analysis ; Fractals ; Mandible ; Mandibular Condyle