Isolable small-molecule cysteine sulfenic acid.

An isolable small-molecule cysteine sulfenic acid (Cys-SOH) protected by a molecular cradle was synthesized by direct oxidation of the corresponding cysteine thiol and its structure was established by X-ray crystallographic analysis. Studies on biologically relevant reactivity indicated its usefulness as a biorepresentative small-molecule sulfenic acid model.

Modeling of the Bioactivation of an Organic Nitrate by a Thiol to Form a Thionitrate Intermediate.

Thionitrates (R-SNO₂) have been proposed as key intermediates in the biotransformation of organic nitrates that have been used for the clinical treatment of angina pectoris for over 100 years. It has been proposed and widely accepted that a thiol would react with an organic nitrate to afford a thionitrate intermediate. However, there has been no example of an experimental demonstration of this elementary chemical process in organic systems.

Influence of voxel size and scan field of view on fracture-like artifacts from gutta-percha obturated endodontically treated teeth on cone-beam computed tomography images.

Objective: To determine the optimal scan settings (scan mode and position of field of view [FOV]) for cone beam computed tomography to reduce root fracture-like artifacts that are often observed in teeth filled with gutta-percha cones (GPCs).

Study Design: Fracture-like artifacts that appeared on cone beam computed tomography images of 9 extracted human mandibular premolars filled with GPCs were analyzed using I-mode (FOV, 102 mm; voxel size, 0.2 mm) and D-mode (FOV, 51 mm; voxel size, 0.

Diagnosis of retrodiscal tissue in painful temporomandibular joint (TMJ) by fluid-attenuated inversion recovery (FLAIR) signal intensity.

Aims: The purpose of the present study is to analyze the fluid-attenuated inversion recovery (FLAIR) signal intensity of the retrodiscal tissue in a painful temporomandibular joint (TMJ), and to develop a diagnostic system based on FLAIR data.

Methodology: The study was based on 33 joints of 17 patients referred for MR imaging of the TMJ. Regions of interest were placed over retrodiscal tissue and gray matter (GM) on FLAIR images.

Radiopacity Measurement of Restorative Resins Using Film and Three Digital Systems for Comparison with ISO 4049: International Standard.

This study compared Ultra Speed Occlusal Film (USOF) and 3 digital systems in determining the radiopacity of 5 different restorative resins in terms of equivalents of aluminum thickness. Whether those digital systems could be used to determine whether radiopacity was in line with International Organization for Standardization (ISO) recommendations was also investigated. Disks of each of 5 restorative resins and an aluminum step wedge were exposed at 65 kVp and 10 mA on USOF and imaged with each digital system.

Root canal filling materials spread pattern mimicking root fractures in dental CBCT images.

Objective: To clarify the cause of artificial tooth-root fracture lines in cone beam computed tomography (CBCT) images caused by root canal filling materials and to enhance the diagnostic performance of CBCT.

Study Design: We analyzed the CBCT images of 18 extracted human teeth (9 upper central incisors and 9 lower premolars) that were filled with a size 50 gutta-percha cone and inserted into tooth sockets in a human skull.

Results: The CBCT images of the incisors displayed artificial lines in the oblique directions, notably the mesiobuccal, distolingual, distobuccal and mesiolingual directions, but only rarely in the cross-directions (buccal, lingual, mesial, and distal).

Characteristic findings on panoramic radiography and cone-beam CT to predict paresthesia after extraction of impacted third molar.

The purpose of this study was to compare findings on the relationship between impacted molar roots and the mandibular canal in panoramic and three-dimensional cone-beam CT (CBCT) images to identify those that indicated risk of postoperative paresthesia. The relationship between impacted molars and the mandibular canal was first classified using panoramic images. Only patients in whom the molar roots were either in contact with or superimposed on the canal were evaluated using CBCT.

Effect of display monitor devices on intra-oral radiographic caries diagnosis.

Objectives: Recent developments in digital computer technology have enabled radiological diagnosis to be performed using a monitor screen. In medical radiography, the importance of monitors has been shown in many diseases. Digital imaging and communication in medicine (DICOM)-compatible monitors are widely used.

Optimization of parameter settings in cine-MR imaging for diagnosis of swallowing.

Videofluorography is frequently used to evaluate swallowing and is considered the "gold standard" among imaging modalities. This modality, however, has several disadvantages, including radiation exposure and limitations in the detection of soft tissues. Conversely, magnetic resonance imaging (MRI) offers excellent contrast resolution in soft tissue without radiation exposure.

Signal intensity on fluid-attenuated inversion recovery images of condylar marrow changes correspond with slight pain in patients with temporomandibular joint disorders.

Objectives: Edema and necrosis of the temporomandibular joint (TMJ) have been described in terms of bone marrow signal abnormalities in magnetic resonance imaging (MRI). However, painful joints often show no such signaling abnormalities, making the diagnosis of TMJ disorders difficult in the clinical setting. An association has been suggested between TMJ bone marrow change and TMJ pain, but even when such change results in slight pain, it may be too slight to be visually apparent on MR images.

Comparison of accuracy of intravoxel incoherent motion and apparent diffusion coefficient techniques for predicting malignancy of head and neck tumors using half-Fourier single-shot turbo spin-echo diffusion-weighted imaging.

Purpose: To evaluate the use of the intravoxel incoherent motion (IVIM) technique in half-Fourier single-shot turbo spin-echo (HASTE) diffusion-weighted imaging (DWI), and to compare its accuracy to that of apparent diffusion coefficient (ADC) to predict malignancy in head and neck tumors.

Patients And Methods: HASTE DW images of 33 patients with head and neck tumors (10 benign and 23 malignant) were evaluated. Using the IVIM technique, parameters (D, true diffusion coefficient; f, perfusion fraction; D*, pseudodiffusion coefficient) were calculated for each tumor.

Relationships between third-molar juxta-apical radiolucencies and mandibular canals in panoramic and cone beam computed tomography images.

Objective: This study aimed to determine the relationship between third-molar juxta-apical radiolucencies and mandibular canals on panoramic and cone beam computed tomography (CBCT) images.

Study Design: Forty-two patients were included in this retrospective study. The root apices and the relationships of the juxta-apical radiolucencies to the mandibular canals were evaluated on both panoramic and CBCT images.

Potential of fluid-attenuated inversion recovery MRI as an alternative to contrast-enhanced MRI for oral and maxillofacial vascular malformations: experimental and clinical studies.

Objective: To determine the potential of fluid-attenuated inversion recovery (FLAIR) imaging of oral and maxillofacial vascular malformations as an alternative to contrast-enhanced magnetic resonance imaging (MRI), we investigated the influence of differences in T1 and T2 values on image contrast in FLAIR images and evaluated the diagnostic utility of such images.

Study Design: FLAIR imaging and heavily T2-weighted (hT2-weighted) imaging were performed using a phantom. FLAIR and hT2-weighted images of 32 lesions (11 mucous cysts, 12 vascular malformations, and 9 tumors) were also studied retrospectively.

Imaging findings of benign peripheral nerve sheath tumor in jaw.

Objective: The aim of this study was to investigate the imaging characteristics of peripheral nerve sheath tumors (PNSTs) in the jaw.

Study Design: Imaging studies of 6 patients were retrospectively reviewed. Conventional radiography, computed tomography, and magnetic resonance imaging were performed in all patients.

Analysis of elements in a minimal amount of temporomandibular joint fluid on fluid-attenuated inversion recovery magnetic resonance images.

Objective: The aim of this study was to elucidate possible elements in minimal amounts of fluid (MF) in the temporomandibular joint by analyzing signal intensities in T2-weighted and fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) images.

Study Design: Fifteen joints (15 patients) with MF were subjected to MR imaging to obtain T2-weighted and FLAIR images. Regions of interest were placed on MF, cerebrospinal fluid (CSF), and gray matter (GM), and their signal intensities were measured on both images.

Composition of the blood supply in the sublingual and submandibular spaces and its relationship to the lateral lingual foramen of the mandible.

Objective: The purpose of this research was to contribute to minimizing arterial disruption during mandibular surgical procedures by clarifying the course of the arteries supplying the sublingual and submental regions.

Study Design: Heads of 75 human cadavers were dissected to identify the arterial supply of the sublingual and submental regions. Computed tomography scans were performed to visualize the lateral lingual foramina of the mandibles.

Comparison of various methods for quantification of apparent diffusion coefficient of head and neck lesions with HASTE diffusion-weighted MR imaging.

Objectives: The purposes of this retrospective study were to compare various methods of apparent diffusion coefficient (ADC) measurement for head and neck lesions in half-Fourier single-shot turbo spin-echo (HASTE) diffusion-weighted imaging (DWI) and determine the threshold ADC value for predicting malignancy.

Study Design: HASTE DW images of 46 lesions (10 cysts, 14 benign tumors, and 22 malignant tumors) were studied retrospectively. The ADC values were compared among the 0-1000 method, 500-1000 method, and weighted linear regression (WLR) fit.

Non-Hodgkin lymphoma involving the mandible: imaging findings.

Objective: The aim of this study was to investigate the imaging findings of non-Hodgkin lymphoma (NHL) involving the mandible.

Study Design: The imaging studies of 4 patients with NHL involving the mandible were retrospectively reviewed. Panoramic and computerized tomographic (CT) images were available for all patients.

Osteosarcoma of maxilla with unusual image findings in child.

Osteosarcoma of the head and neck is relatively rare and accounts for less than 10 percent of all osteosarcomas in general. We report a case of osteosarcoma in which imaging and histopathology of the hard palate of an 11-year-old boy yielded atypical findings. An approximately 8×15mm lesion found in the center of the palate was hard and healthy in color.

[Weighted-averaging multi-planar reconstruction method for multi-detector row computed tomography].

Development of multi-detector row computed tomography (MDCT) has enabled three-dimensions (3D) scanning with minute voxels. Minute voxels improve spatial resolution of CT images. At the same time, however, they increase image noise.

Potential of fluid-attenuated inversion recovery (FLAIR) in identification of temporomandibular joint effusion compared with T2-weighted images.

Objective: The purpose of this study was to determine the potential of fluid-attenuated inversion recovery (FLAIR) sequence images in the identification of joint effusion (JE) compared with T2-weighted images.

Study Design: A total of 31 joints (28 patients) with JE were investigated by magnetic resonance imaging (MRI). Regions of interest were placed over JE, cerebrospinal fluid (CSF), and gray matter (GM) on T2-weighted and FLAIR images and their signal intensities compared.

A case of zoster sine herpete of the trigeminal nerve.

Varicella-zoster virus reactivation causes zoster (shingles), a syndrome characterized by severe pain and a vesicular rash. The present report details a case of varicella-zoster virus reactivation of the maxillary and mandibular division of the right trigeminal nerve without evidence of vesicular rash (zoster sine herpete). It is difficult to identify owing to no typical clinical signs such as vesicular eruption.

Reliance on diagnostic elements in panoramic imaging with focus on ameloblastoma and keratocystic odontogenic tumor: psychometric study.

The purpose of this study was to investigate degree of observer reliance (RD) on specific diagnostic elements in differential diagnosis of ameloblastoma (AB) and keratocystic odontogenic tumors (KOT) on panoramic images. The RD for 12 diagnostic elements, including 2 clinical and 10 radiographic elements, as recorded by eight dental radiologists on an ordinal ranking scale, was determined for 9 ABs and 9 KOTs. Intraobserver (IaOC) and inter-observer concordance (IeOC) for both ABs and KOTs were statistically analyzed in terms of RD.

Effects of dose reduction on multi-detector computed tomographic images in evaluating the maxilla and mandible for pre-surgical implant planning: a cadaveric study.

Objective: To assess effects of dose reduction on image quality in evaluating maxilla and mandible for pre-surgical implant planning using cadavers.

Materials And Methods: Six cadavers were used for the study using multi-detector computed tomography (CT) operated at 120 kV and the variable tube current of 80, 40, 20 and 10 mA. A slice thickness of 0.