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

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: 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: Obstructive and inflammatory disease often occurs in the major salivary glands, and no predictive treatment has yet been developed for this condition. The aim of this report was to introduce an intraductal irrigation procedure and to illustrate its application to practical patient cases. MATERIALS AND METHODS: Two patients complaining of pain and swelling in the parotid gland during meals who underwent sialography were diagnosed as having sialodochitis with sialadenitis. Intraductal irrigation was then performed on the parotid gland on the side of the complaint. The irrigation procedure was conducted in the same manner as the sialography procedure, except that saline was used as the filling solution. Symptom severity was evaluated with a numerical rating scale (NRS) at the initial visit and a month after the irrigation. RESULTS: The initial NRS value of patient 1 was 10. The value decreased to 6 and then to 0 after 2 irrigation procedures. The NRS value of patient 2 regarding the symptoms involving the left parotid gland decreased from 4-5 to 1 after 4 irrigation procedures performed at 1-month intervals. CONCLUSION: Intraductal irrigation of the salivary gland may be a simple, safe, and effective treatment option for patients with obstructive and inflammatory disease of the salivary gland that is capable of resolving their symptoms.
Humans ; Meals ; Parotid Gland ; Salivary Glands* ; Sialadenitis ; Sialography ; Therapeutic Irrigation

PURPOSE: The aim of this study was to determine whether the panoramic mandibular index (PMI) is useful for assessing bone mineral density. We also analyzed the potential correlations between PMI parameters and patient age. MATERIALS AND METHODS: Four observers measured the PMI of both sides of the mental foramen using a picture archiving and communication system and images in the Digital Imaging and Communications in Medicine format. They studied 300 panoramic radiographic images of patients belonging to the following age groups: 40–49 years, 50–59 years, 60–69 years, 70–79 years, and 80–89 years. The observers were allowed to zoom in or out and to adjust the contrast of the images. Further, they were instructed to record the reasons for any measurements that could not be made. Then, we conducted a reliability analysis of the measured PMI and assessed the correlations between different patient age groups and the 3 parameters used for determining the PMI from the available data. RESULTS: Among the 600 data items collected, 23 items were considered unmeasurable by at least 1 observer for the following 4 reasons: postoperative state, lesion, unidentified mental foramen, and alveolar bone loss. The intraobserver reproducibility of the measurable data was 0.611-0.752. The mandibular cortical width (MCW) decreased significantly as patient age increased. CONCLUSION: PMI had limited usability when the margin of the mental foramen was not clear. In contrast, MCW, a parameter used for determining the PMI, had fewer drawbacks than the PMI with respect to bone mineral density measurements and exhibited a significant correlation with patient age.
Alveolar Bone Loss ; Bone Density ; Humans ; Mandible ; Radiography

Desmoplastic ameloblastoma is a rare histologic variant of ameloblastoma. It shows important differences in anatomic distribution, histologic appearance, and radiographic findings compared with the general type of ameloblastoma. It is histologically characterized by an abundance of densely collagenous stroma and radiographically a mixed radiolucent-radiopaque lesion. We present three cases of desmoplastic ameloblastoma. All the patients complained on buccal swelling with or without pain and the sites of occurrence were the anterior and the premolar region. Plain radiographs showed mixed radiopaque-radiolucent lesion with ill-defined or diffuse sclerotic margin and no external root resorption. Additionally, CT scans revealed buccal expansion and relatively well-defined margin of the lesions. The clinical and radiographic features of the presented cases were compared with those of the desmoplastic ameloblastoma in the previous literatures.
Ameloblastoma* ; Bicuspid ; Collagen ; Humans ; Radiography, Panoramic ; Root Resorption ; Tomography, X-Ray Computed

PURPOSE: To investigate the validity of digital image processing on panoramic radiographs in estimating bone quality before endosseous dental implant installation by correlating bone quality in radiographic images with clinical bone quality classification. MATERIALS AND METHODS: An experienced surgeon assessed and classified bone quality for implant sites with tactile sensation at the time of implant placement. Including fractal dimension eighteen morphologic features of trabecular pattern were examined in each anatomical sites on panoramic radiographs. Finally bone quality of 67 implant sites were evaluated in 42 patients. RESULTS: Pearson correlation analysis showed that three morphologic parameters had weak linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.276, -0.280, and - 0.289, respectively (p<0.05). And other three morphologic parameters had obvious linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.346, -0.488, and -0.343 respectively (p<0.05). Fractal dimension also had a linear correlation with clinical bone quality classification with correlation coefficients -0.506 significantly (p<0.05). CONCLUSION: This study suggests that fractal and morphometric analysis using digital panoramic radiographs can be used to evaluate bone quality for implant recipient sites.
Classification* ; Dental Implants ; Fractals ; Humans ; Radiography, Panoramic ; Sensation

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*