Updated quality assurance self-assessment exercise in intraoral and panoramic radiography. American Academy of Oral and Maxillofacial Radiology, Radiology Practice Committee.

This updated self-assessment exercise for the dental team by the Radiology Practice Committee of the American Academy of Oral and Maxillofacial Radiology is intended to produce the highest quality diagnostic radiographs while keeping patient exposure as low as is reasonably achievable. To continue to provide the best radiographic services to patients, those involved in dental radiography need to be aware of the latest changes and advances in dental radiography and need to use them in their practice.

Conditions and tools for evidence-based dental practice.

Before evidence-based dentistry becomes a norm in practice, several conditions must be met. These include an attitude of questioning authority and training in how to use the literature, a supportive environment from colleagues and practice-based research. Some new tools--in the form of journals with more user-friendly formats and direct access to databases--are also necessary.

Short-term changes of condylar position after sagittal split osteotomy for mandibular advancement.

OBJECTIVE: The goal of this study was to quantify condylar position changes after mandibular advancement surgery with rigid fixation (screws). Radiographic changes in condylar position were determined in all planes (X, Y, and Z). Computed tomography with image reconstruction was used. STUDY DESIGN: A consecutive population of patients who elected to have rigid fixation for surgical stabilization method were studied (n = 21). Computed tomography data were acquired in the axial plane through use of abutting 1.5-mm-thick slices. Data acquisition occurred 1 week preoperatively and 8 weeks postoperatively. Measurements were made from 2-dimensional reconstructions. RESULTS: The averages were as follows: lateral displacement from midline, 1.2 mm (55% of patients); medial displacement from midline, 1.5 mm (45% of patients; range, 3.2 mm); condyle angle increase from coronal plane, 3.5 degrees (60% of patients); condyle angle decrease from coronal, 4.3 degrees (40% of patients; range, 8.5 degrees); superior rotation of proximal segment, 3.2 degrees (39% of patients); inferior rotation of proximal segment, 8.6 degrees (61% of patients; range, 15.6 degrees); superior displacement, 1.2 mm (60% of patients); inferior displacement, 1.0 mm (40% of patients; range, 2.5 mm); anterior displacement, 1.6 mm (33% of patients); posterior displacement, 1.6 mm (67% of patients; range, 2.8 mm). CONCLUSIONS: Changes occurred in all planes, but the most common postoperative condyle position was more lateral; with increased angle, the coronoid process was higher and the condyle was more superior and posterior in the fossa.

A taxonomy for lay risk perceptions of dentistry.

OBJECTIVE: This paper aims to develop and organize a set of variables that can be used to: (1) test the widely held but unproven assumption that lay risk perceptions can adversely affect dental care, (2) investigate the possible influence of lay risk perceptions on dental care and (3) permit the evaluation of risk communication strategies in dentistry. METHODS: We reviewed the literature regarding risk perception and risk communication in health care and technology. We then selected a set of variables that could be measured in a study of the general public and organized these in a taxonomy to suggest likely relationships among the variables. RESULTS: The central relationship of the proposed taxonomy is between a lay person's perception of dental risk and a set of measurable outcomes that could affect that person's dental care. The taxonomy lists three possible influences on the lay person's risk perception: attributes of the individual, attributes of the dental procedure or technology perceived as risky, and attributes of the dental practice. CONCLUSIONS: Systematic testing of the proposed variables should demonstrate whether lay risk perceptions substantially influence dental care, and if so, which factors most strongly influence risk perceptions. A model of lay risk perceptions of dentistry then could be developed and strategies could be devised to minimize the detriment, if any, to dental care from risk perception.

Advanced imaging methods.

Recent developments in imaging sciences have enabled dental researchers to visualize structural and biophysical changes effectively. New approaches for intra-oral radiography allow investigators to conduct densitometric assessments of dento-alveolar structures. Longitudinal changes in alveolar bone can be studied by computer-assisted image analysis programs. These techniques have been applied to dimensional analysis of the alveolar crest, detection of gain or loss of alveolar bone density, peri-implant bone healing, and caries detection. Dental applications of computed tomography (CT) include the detailed radiologic anatomy of alveolar processes, orofacial soft tissues and air spaces, and developmental defects. Image analysis software permits bone mass mineralization to be quantified by means of CT data. CT has also been used to study salivary gland disease, injuries of the facial skeleton, and dental implant treatment planning. Magnetic resonance imaging (MRI) has been used extensively in retrospective and prospective studies of internal derangements of the temporomandibular joint. Assessments based on MRI imaging of the salivary glands, paranasal sinuses, and cerebrovascular disease have also been reported. Magnetic resonance spectroscopy (MRS) has been applied to the study of skeletal muscle, tumors, and to monitor the healing of grafts. Nuclear imaging provides a sensitive technique for early detection of physiological changes in soft tissue and bone. It has been used in studies of periodontitis, osteomyelitis, oral and maxillofacial tumors, stress fractures, bone healing, temporomandibular joint, and blood flow. This article includes brief descriptions of the technical principles of each imaging modality, reviews their previous uses in oral biology research, and discusses potential future applications in research protocols.

Clinical usefulness of two-dimensional reformatted and three-dimensionally rendered computerized tomographic images: literature review and a survey of surgeons' opinions.

PURPOSE: This study compares the usefulness of axial computed tomography (CT) with two-dimensional (2D) reformats and three-dimensionally (3D) rendered CT data in the treatment planning and management of patients. PATIENTS AND METHODS: Twenty-nine patients who had been studied with CT were grouped into the following four clinical problems: 1) temporomandibular joint assessment (n = 8), 2) growth and development assessment (n = 4), 3) posttrauma and postoperative assessment (n = 13), 4) "other" (n = 4). The clinicians who treated these patients were surveyed for their opinions of the usefulness of CT with and without 2D/3D reformatting. RESULTS: In a majority of the cases within each of the four clinical groups, the clinicians believed that 2D and/or 3D reformatting of the CT data provided additional useful information for patient management. In most of the cases, 3D imaging provided information in addition to that provided by the axial or reformatted 2D images. CONCLUSION: 2D and 3D CT images can be useful to the clinician in diagnosis and treatment planning. These methods enhance the accuracy of diagnostic decisions and the establishment of appropriate treatment plans.

Clinical comparison of two panoramic modalities and posterior bite-wing radiography in the detection of proximal dental caries.

A clinical study was designed to examine whether the Philips OrthOralix SD (Gendex Dental Systems, Monza, Italy) orthogonal panoramic projection could improve diagnostic accuracy over standard projections in the detection of proximal surface caries. Thirty-five sets of radiographs that demonstrated optimal image characteristics were selected. Using a five-point scale, 18 viewers evaluated whether specified lesions were present or absent. Viewer data was then compared with a consensus radiographic assessment of the state of the proximal areas. Receiver operating characteristic curves were generated with the use of a maximum-likelihood method of fit. The area under the receiver operating characteristic curve was used as the index of diagnostic accuracy. The mean receiver operating characteristic areas for orthogonal and standard projection panoramic and bite-wing radiography to detect the presence of proximal dental caries were 0.68 +/- 0.03, 0.69 +/- 0.03, and 0.79 +/- 0.03 respectively. Critical ratio analysis was used to compare the means for all possible pairings of imaging modalities. In overall performance, conventional bite-wing radiographs gave a significantly greater diagnostic yield for proximal caries than the Philips OrthOralix SD orthogonal or standard panoramic modalities (p > 0.05). The orthogonal projection did not improve diagnostic accuracy in the detection of proximal carious lesions compared with the standard projection.

Immunohistochemical identification of superoxide dismutases, catalase, and glutathione-S-transferases in rat femora.

We used light microscopic immunohistochemistry to locate manganese superoxide dismutase, copper zinc superoxide dismutase, catalase, and glutathione-S-transferases in demineralized femora from rats of 4-14 weeks of age. Immunoblots confirmed the specificity of the polyclonal antibodies for the rat proteins of interest. Each of the enzymes exhibited a unique staining pattern. Copper-zinc superoxide dismutase was detected within some articular and epiphyseal chondrocytes of younger animals. Manganese superoxide dismutase was detected within some articular and epiphyseal chondrocytes, within some osteoprogenitor cells and osteoblasts, within many osteoclasts, and within some vascular smooth muscle cells. Catalase was identified within articular chondrocytes, epiphyseal chondrocytes, and osteocytes, whereas staining at the periphery of hypertrophic chondrocytes suggested extracellular and/or cell membrane-associted catalase. Glutathione-S-transferases were detected within and at the periphery of epiphyseal and articular chondrocytes and less prominently within cortical osteocytes. There were no major age-related changes in antioxidant enzyme distribution.

Asymptomatic, radiologically detected chondrometaplasia in the temporomandibular joint.

Asymptomatic loose bodies were detected in the temporomandibular joint of a 62-year-old woman during an examination before comprehensive dental care. The radiologic interpretation was synovial chondrometaplasia (synovial osteochondromatosis). A histologic diagnosis was not obtained, because surgery was unwarranted in view of the lack of symptoms and the benign differential diagnosis. Review of the literature revealed 62 reported cases of temporomandibular joint chondrometaplasia, all of which included one or more of the following: swelling, pain, joint noise, and limited mandibular movement. These reports have described this entity as a rare lesion, but the rate of reports has increased, perhaps because of greater practitioner awareness and increased sensitivity of diagnostic tests.