Evaluation of Web-Based Interactive Instruction in Intraoral and Panoramic Radiographic Anatomy.

The objective was to evaluate the effectiveness of Web-based interactive modules in the instruction of dental hygiene students on intraoral and panoramic radiographic landmarks. The experimental group studied these landmarks as presented on interactive Web-based modules instead of in classroom presentations. The control group (the previous year's class) received instruction in the traditional classroom format. The outcomes measures included quizzes, examinations and an in-class project. Independent samples t-tests compared the scores of the two groups. A survey was administered to the experimental group to determine their perceptions of instruction with the modules. There was no significant difference in scores between the two groups on the project (p = .926) or the intraoral quiz and exam scores (p = .1 22), but the experimental group scored significantly lower on the panoramic outcomes (p = .039). Only 26% of the students preferred computer-assisted instruction to classroom instruction. The narration and interactive quizzes in the intraoral module may have contributed to the similar performance of the experimental and control groups, while their absence may have adversely affected the effectiveness of the panoramic module.

A retrospective comparison of the location and diameter of the inferior alveolar canal at the mental foramen and length of the anterior loop between American and Taiwanese cohorts using CBCT.

PURPOSE: The aim was to retrospectively compare the measurements of the location and size of the inferior alveolar canal at the mental foramen and the length of the anterior loop between two cohorts of Americans and Taiwanese using cone-beam computed tomography (CBCT). METHODS: CBCT was performed with an I-CAT(®) Cone-Beam 3D Dental Imaging System and reconstructed into multiple-plane views to measure two populations. RESULTS: There was no statistically significant difference (P = 0.2681) in the distance from the mental foramen to the inferior border of the mandible (mandibular border height) between Americans (9.84 ± 2.01 mm) and Taiwanese (10.13 ± 1.66 mm). No significant difference was found (p = 0.1161) in the inferior alveolar canal diameter between these two cohorts (2.26 ± 0.67 and 2.13 ± 0.47 mm, respectively). However, the anterior loop length of Taiwanese (7.61 ± 1.81 mm) was significantly longer than that of Americans (6.22 ± 1.68 mm) (P < 0.0001). CONCLUSION: Our study indicated that (1) the location of mental foramen of Americans was closer to the inferior border of the mandible than Taiwanese; (2) the diameter of the inferior alveolar canal of Americans was larger than Taiwanese; (3) the anterior loop of Taiwanese was longer than Americans. These differences may be, at least partly, due to the racial influence and this information may possess potential valuable clinical relevance.

High-flow arteriovenous malformations of the mandible and the maxilla: report of 2 cases.

Arteriovenous malformations (AVMs) are rare vascular lesions that can be life-threatening due to potential massive hemorrhage. AVMs can be subdivided according to the type of vessel involved (capillary, venous, and arterial) and can be categorized, according to hemodynamic features, into high-flow and low-flow lesions. AVM of the jaws is an uncommon disease. Clinical signs and symptoms of AVM may include pain, erythematous gingiva, spontaneous gingival bleeding, resorption and mobility of teeth, soft tissue discoloration, facial swelling, and asymmetry. Radiographically, AVMs are osteolytic and frequently have indistinct margins. Computed tomography can demonstrate enhancement of the lesions, while angiography can depict distended feeder vessels and arteriovenous shunts. Magnetic resonance imaging can visualize flow voids in high-flow abnormalities. The purpose of this paper was to present 2 high-flow cases of arteriovenous malformations: one with a large AVM lesion in the mandible that presented clinically as a discoloration on the mucosa and gingiva with loss of lip sensation; and the second with a lesion in the maxilla discovered during an extraction of a root fragment. Management of the lesions was achieved by embolization.

Radiographic diagnosis of synovial chondromatosis of the temporomandibular joint: a case report.

Synovial chondromatosis is a rare, benign condition that usually affects the larger diarthroidal joints of the axial skeleton. Approximately 120 cases of synovial chondromatosis involving the temporomandibular joint (TMJ) have been reported. People with this condition may present with swelling, pain, intracapsular sounds and limitation of mandibular movement. Because it is important to differentiate synovial chondromatosis from other joint pathologies, a thorough history and appreciation of clinical features of these conditions are necessary. Radiographs are an important component of the diagnostic armamentarium for discerning conditions that mimic synovial chondromatosis. A case of synovial chondromatosis diagnosed radiographically with the aid of volumetric computed tomography is described, followed by a discussion of potential causative factors and management strategies. A brief review of the differential diagnosis of synovial chondromatosis involving the TMJ is also provided.

Improvement in medical consultation responses with a structured request form.

Physicians often do not provide adequate information regarding patients' medical conditions when presented with consultation requests (CR) generated by dental students and their instructors about the students' patients. We hypothesized that a structured CR form, which requests specific information by providing a checklist and/or closed-ended questions for physicians to answer, would lead to better communication and improved responses. We also hypothesized that providing in-service education to clinical faculty on the conditions that require and don't require CRs would reduce the number of unwarranted CRs sent to physicians. We assessed the responses obtained with the new form and compared them to findings over a similar period using our older, unstructured CR forms. We also evaluated the numbers of CRs written unnecessarily during both time periods. Improvements in the appropriateness of information provided by physicians were noted with the new CR forms for diabetes mellitus, hypertension, heart murmur, and anticoagulant therapy. The number of CRs written for conditions that did not need a consultation was approximately the same after provision of instruction as before. We conclude that structured CR forms improve the flow of information between dentists and physicians and should enhance student knowledge and skills in soliciting relevant information. Greater efforts must be taken to inform clinical faculty about the indications for CRs.

Accuracy of Cone-beam Computed Tomographic Image Interpretation by Endodontists and Endodontic Residents.

INTRODUCTION: Limited field cone-beam computed tomography (CBCT) imaging has become a modality frequently used by endodontists to evaluate the teeth and surrounding tissues of their patients. Accurate image interpretation is vital to obtain needed treatment information as well as to discern coincidental findings that could be present. The goal of this study was to determine the accuracy of CBCT volume interpretation when performed by endodontists and endodontic residents. METHODS: Eighteen deidentified limited field CBCT scans were obtained and evaluated by an oral and maxillofacial radiologist and an endodontist experienced in reading CBCT images. Their collective findings were combined as the "gold standard" of interpretation for this investigation. Using standard CBCT software, 4 practicing endodontists and 5 second-year endodontic residents evaluated each scan and recorded any notable findings and whether or not each scan warranted referral to a radiology specialist. Their interpretations were then compared with the gold standard to determine accuracy and any significant differences among the groups. RESULTS: The overall accuracy was 58.3% for endodontists and 64.3% for residents. Paired t tests showed no statistically significant differences in accuracy between the 2 groups for findings in teeth or in bone, but residents were significantly better for maxillary sinus findings. Endodontists agreed with the gold standard 38.9% of the time and residents 49.8% of the time on necessity of referral. The Cohen kappa coefficient showed moderate agreement between the groups. CONCLUSIONS: Endodontists and residents had similar accuracy in CBCT scan evaluation. More training and experience are warranted for both groups in order to maximize image assessment accuracy.

American Heart Association 2007 guidelines on prevention of infective endocarditis.

The American Heart Association has recently released a new set of guidelines for prevention of infective endocarditis with major changes and clarifications regarding who should receive antibiotic prophylaxis and who does not require it. The new guidelines are based on the current available evidence and deviate greatly from the previous ones. A summary of the changes and the evidence and philosophy behind this statement is presented in this article. Along with it is the current status of often-conflicting topics on other uses of antibiotic prophylaxis in dentistry. Special notes on heart murmur, patient information sheets, and continuing education questions are also included.

Accuracy of film-based, digital, and enhanced digital images for endodontic length determination.

OBJECTIVE: This study compared the accuracy of D- and F-speed intraoral radiographs and digital and enhanced digital radiographic images for endodontic file length determination. STUDY DESIGN: Size 15 K-files were bonded in 51 canals of 34 human cadaver teeth. The distance from file tip to root apex was measured on D- and F-speed film and on unenhanced and enhanced digital images. The quality of the images was rated by the observers. Overlying cadaver bone and root structure were subsequently removed to expose the file tip for actual measurement to the apex. The distance measured on each image was compared with the actual measurement. ANOVA, Kruskal-Wallis, sign test, and Pearson correlation statistical analyses were applied. RESULTS: There were no significant differences in measurement accuracy among the 4 image types (P < or = .05). Subjective ratings showed a preference for the quality of enhanced digital images. Conclusion All 4 image types were similar in accuracy of file measurement. The image quality of enhanced digital images was subjectively superior to the others.

Evaluation of 4 Commercial Viewing Devices for Radiographic Perceptibility and Working Length Determination.

INTRODUCTION: This study compared images displayed on 1 desktop monitor, 1 laptop monitor, and 2 tablets for the detection of contrast and working length interpretation, with a null hypothesis of no differences between the devices. METHODS: Three aluminum blocks, with milled circles of varying depth, were radiographed at various exposure levels to create 45 images of varying radiographic density. Six observers viewed the images on 4 devices: Lenovo M92z desktop (Lenovo, Beijing, China), Lenovo Z580 laptop (Lenovo), iPad 3 (Apple, Cupertino, CA), and iPad mini (Apple). Observers recorded the number of circles detected for each image, and a perceptibility curve was used to compare the devices. Additionally, 42 extracted teeth were imaged with working length files affixed at various levels (short, flush, and long) relative to the anatomic apex. Observers measured the distance from file tip to tooth apex on each device. The absolute mean measurement error was calculated for each image. Analysis of variance tests compared the devices. Observers repeated their sessions 1 month later to evaluate intraobserver reliability as measured with weighted kappa tests. Interclass correlation coefficients compared interobserver reliability. RESULTS: There was no significant difference in perceptibility detection between the Lenovo M92z desktop, iPad 3, and iPad mini. However, on average, all 3 were significantly better than the Lenovo Z580 laptop (P values ≤.015). No significant difference in the mean absolute error was noted for working length measurements among the 4 viewing devices (P = .3509). CONCLUSIONS: Although all 4 viewing devices seemed comparable with regard to working length evaluation, the laptop computer screen had lower overall ability to perceive contrast differences.

Radiation dose-reduction techniques in North American dental schools.

OBJECTIVE: The purpose of this investigation was to describe the extent to which dental schools use materials, equipment, and quality-assurance protocols that reduce radiation exposure to patients. STUDY DESIGN: Questionnaires soliciting information regarding intraoral and extraoral radiographic practices and quality-assurance procedures were sent to the directors of oral and maxillofacial radiology (OMR) at the 65 schools of dentistry in the United States and Canada. RESULTS: The response rate was 100%. E-speed film is used at 86% of institutions. Direct digital radiography is used at 58% of institutions for intraoral imaging and 11% for extraoral radiography. Other dose-reducing techniques include long source-film distances (88%), rectangular beam limitation (47%), leaded aprons (95% for extraoral films; 85% with thyroid collars for intraoral films), and rare earth intensifying screens (100%). The most commonly used tube potential is 70 kVp (88%). The director of OMR is solely responsible for radiographic policies at approximately 75% of institutions. Regular tests for film fog, speed, and contrast are done at roughly 75% of schools, while over 90% test darkroom lighting and x-ray equipment. CONCLUSIONS: Some dose-reducing strategies are commonly used in dental schools, while others have not gained wide acceptance.

Necrotizing stomatitis: report of 3 Pseudomonas aeruginosa-positive patients.

Necrotizing oral lesions have been described in immunosuppressed patients, usually in association with gingival and periodontal pathoses. The etiology of these lesions has not been completely elucidated. We present 3 patients with a type of necrotizing stomatitis in which clinical patterns appear distinct from the periodontal forms of the disease. The lesions yielded bacterial cultures positive for Pseudomonas aeruginosa and reverted to no growth in 2 patients after proper antibiotic therapy. We propose that P aeruginosa may be responsible for selected necrotizing oral lesions with a clinical presentation lacking typical necrotizing periodontal disease and that this condition may represent the intraoral counterpart of ecthyma gangrenosum. In such cases, bacterial culture of the lesion becomes imperative because the disease does not respond to typical periodontal and antimicrobial therapy.

The effect of automated nonroller processing on the sensitometric characteristics of 3 intraoral film types.

OBJECTIVES: We sought to compare the sensitometric characteristics of 3 intraoral film types processed in an automated roller solution with the characteristics of the films processed in 4 automated nonroller solutions. STUDY DESIGN: Eastman Kodak Ultra-Speed, Flow X-ray EV-57, and Eastman Kodak InSight films were exposed to varying levels of radiation and processed in 1 automated roller solution and in 4 nonroller solutions. Speed and contrast were measured at various density levels and ranges. RESULTS: With the exception of 1 nonroller solution, there was little difference in speed between roller and nonroller processing chemicals at various density levels. Some nonroller solutions were faster than the roller chemicals for all films. Nonroller processing mostly increased contrast compared with roller processing over various ranges. CONCLUSIONS: Sensitometric properties of films processed in automatic nonroller solutions are comparable in many cases to those in roller solutions, sometimes resulting in greater speed and contrast. Different adjustments in exposure factors are required for specific film/processing combinations.