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At least 19 recordsLinked to original sources
PubMed1977

Relative discernment of lesions by intraoral and panoramic radiography.

Panoramic and intraoral periapical radiographs were compared for their demonstration of pathologic conditions in patients seeking general dental care. Panoramic views allowed additional detection of noteworthy lesions that were not detected by intraoral survey in 5.3% of the cases reviewed, with only 0.1% or one patient in 1,000 possibly requiring treatment. The paucity and lack of urgency of the pathologic conditions discovered solely by panoramic radiography suggest that the expectation of a high incidence of detection of such conditions cannot be used as the sole rationale for the routine use of this procedure as an adjunct to the intraoral survey.

Dental Care↗
PubMed2004

[Dose exposure from analog and digital full mouth radiography and panoramic radiography].

The present study investigated the dose exposition in the head and neck region by use of analog and digital radiographic dental systems. Four radiographic devices were tested: panoramic radiography (analog and digital) and 14-image full-mouth-survey (FMS, analog and digital). Organ doses were measured on a Rando-phantom by use of CaF2-dosimeters according to the IRCP-guidelines and the effective doses calculated. The results were the following: the value of E was lowest in digital FMS (41 microSv) and highest in analog FMS (78 microSv), i.e. dose was reduced by 47% by using a digital device. In panoramic radiography, doses were 17% lower using digital technique (digital 45 microSv vs. analog 54 pSv). Thus, FMS is no longer associated with higher doses than orthopantomography when conventional films are replaced by digital techniques.

Humans↗
PubMed2002

Comparison of panoramic radiography and panoramic digital subtraction radiography in the detection of simulated osteophytic lesions of the mandibular condyle.

OBJECTIVE: The aim of this study was to compare panoramic temporomandibular joint radiography, unenhanced and color-enhanced digital-subtraction radiography with respect to detectability of simulated osteophytic lesions of the mandibular condyle. METHODS: Three dry human skulls with no obvious temporomandibular joint pathology were selected. Four sizes of bone chips were placed on the anterior aspect of the condyle at medial, central, and lateral locations. Panoramic radiographs were made with and without the chips in place. These paired radiographs were digitized, and unenhanced and color-enhanced digital-subtraction images of the original panoramic images were obtained. Eight observers evaluated 72 randomized images of each modality for the presence or absence of simulated osteophytic lesions of the mandibular condyle, grading the images on a 100-point scale. RESULTS: A(z) values for overall diagnostic accuracy of the three imaging modalities were 0.5376 for panoramic radiography, 0.7861 for unenhanced digital subtraction radiography, and 0.7923 for color-enhanced digital-subtraction radiography. Digital-subtraction radiography improved the detection accuracy of the original panoramic films. CONCLUSION: Panoramic radiographs were significantly less accurate in the detection of simulated osteophytic lesions of the mandibular condyle than the two digital-subtraction techniques.

Analysis of Variance↗
PubMed1987

Comparison of focal trough dimensions and form by resolution measurements in panoramic radiography.

Panoramic focal trough dimensions affect both the number of patient structures seen in radiographs and the margin of error possible when positioning a patient to take a radiograph. This study compares the dimensions, or size, and position, or form, of the focal troughs of four machines by resolution measurements. There is a continued need for technicians to position the patient's anterior teeth accurately in the zones of sharpness of these machines, but the widths of the sharpness zones show an increase in dimensions over older panoramic machines.

Equipment Design↗
PubMed1984

An evaluation of rare-earth imaging systems in panoramic radiography.

Panoramic radiographs were made of ninety-nine consenting adult patients who had image-analysis test devices placed within their oral cavities. Quantitative characteristics and perceived image quality of eight screen-film combinations were investigated. The quantitative characteristics of the images evaluated included contrast, resolution (in three regions), and bead detection (a measure of noise). Perceived image quality assessed similar characteristics. In addition, expert observers rated the resultant patient radiographs for both general and specific diagnostic tasks. Calcium tungstate screen-film systems were found to have the highest contrast but with resolution comparable to rare-earth screen-film systems under clinical test conditions. Calcium tungstate systems required up to twice the radiation exposure of the patient. It was found that some rare-earth screen-film combinations may produce clinically acceptable panoramic radiographs while reducing the patient's radiation exposure.

Adult↗
PubMed2005

[Research methods in dentistry 9. Follow-up of permucosal implants in an edentate mandible using panoramic radiography].

Panoramic radiographs are frequently used for routine follow-up of mandibular implants. The objective of this study was to determine whether measurement on a panoramic radiograph of the vertical dimension of the mandible near by an implant, using the known implant length as a reference, is a reliable method. In 11 patients, 2 permucosal implants were placed in the anterior part of the edentulous mandible. During the first year after implantation, 2 panoramic radiographs and 2 sets of standardized oblique lateral cephalometric radiographs were made. Oblique lateral cephalometric radiographs are the golden standard for measuring the vertical dimension of an edentulous mandible. The length of the implants and the vertical dimension of the mandible dorsally to the implants were measured on all oblique lateral cephalometric radiographs. The measured and known implant length were used to calculate the image enlargement factor. This factor was used to calculate the real vertical dimension of the mandible. The same measurement procedures were performed on the panoramic radiographs. Using a paired t-test, the calculated values of the vertical dimensions of the mandibles found on panoramic radiographs were compared with the calculated values found on oblique lateral cephalometric radiographs. No statistically significant differences were found. It was concluded that under the described circumstances, panoramic radiographs can be used for reliable measurement of the vertical dimension of the mandible near by permucosal implants.

Cephalometry↗
PubMed1986

Kodak T-Mat G film in rotational panoramic radiography.

Panoramic radiographs were taken of a tissue-equivalent phantom to evaluate T-Mat G and Ortho G films in combination with rare earth screens. The radiographs were compared to radiographs made with high-speed calcium tungstate screens and Kodak XRP film. The reduction in the amount of radiation necessary for the use of rare earth screens (50% to 70%) was accomplished by lowering the mA and adding filtration. All evaluated films were diagnostically acceptable. There was a marked preference of the T-Mat radiographs over the Ortho G radiographs and a slight preference over radiographs made with the standard calcium-tungstate screen-film system.

Humans↗
PubMed1990

Diagnostic imaging of diseases affecting the mandible with the use of computed panoramic radiography.

Computed panoramic radiography was performed on patients with bone cyst, osteomyelitis, gingival cancer, and fibrous dysplasia, respectively, to determine the best imaging procedure for disease processes affecting the mandible. Gradational enhancement images for detection of density changes and frequency enhancement images for detecting changes in the margin and texture were effective in aiding the diagnosis of diseases of the mandible with the use of computed panoramic radiography.

Bone Resorption↗
PubMed1984

Rare earth screens for panoramic radiography.

Six panoramic radiographs, each made with a different screen/film combination, were compared for "periapical visibility" by fourteen dentists. Two combinations (a par-speed and a high-speed) used calcium tungstate screens, and three used rare earth screen systems four times faster than par-speed. One other combination consisted of a single rare earth screen plus a single-coated detail film. The radiographs produced by the faster rare earth screen/film combinations were found to be similar in quality to those produced by calcium tungstate screens. Rare earth screens could be used for panoramic radiography while maintaining quality and reducing exposure.

Adult↗
PubMed1990

Digital gray-level transformation for the reduction of redundant shadows in rotational panoramic radiography.

In rotational panoramic radiography, the tomographic motion in combination with a slit scanning method make an image layer wide. But some objects outside the image layer are hard to blur and they result to redundant shadows. The gray-level transformation, as one form of digital image processing for the reduction of these redundant shadows, was evaluated. Two methods, the gamma transformation and the histogram flattening method, were examined. A drum scanner was used as the image scanner. The panoramic image on the x-ray film was turned into an 8 bit digital image on the image memory, which had the size of a 512 x 480 matrix. In rotational panoramic radiography, there are low density and contrast regions where redundant shadows of the cervical vertebrae and the mandibular ramus are superimposed on the tomographic image. The histogram of the gray-level was suppressed for the lower gray-levels. The stretching of this gray-level distribution was effective in the reducing redundant shadows. When processed by gamma transformation, the smaller gamma coefficient below 1.0 clarified the tomographic image, and when processed by the histogram flattening method, the setting of the level (L) value around 64-128 effectively reduced the redundant shadows. However, the effectiveness of both gray-level transformations was greatest in restricted cases in which the area where redundant shadows were superimposed on the tomographic image was comparatively large.

Artifacts↗
PubMed1990

Reversed layer position in rotational panoramic radiography.

In rotational panoramic radiography, the image layer is generally positioned between the rotation center of the beam and the film. It is also possible to create a layer that is positioned between the rotation center and the x-ray source. The reversed layer position is useful clinically and gives rise to image properties that are somewhat different from the conventional geometry.

Humans↗
PubMed1984

Intraoral or panoramic radiography?

When panoramic radiographs are used to replace full-mouth radiographic series for the pediatric patient, certain advantages and disadvantages of this technique should be understood. The panoramic exposure offers ease of operation, shorter working time, and greater coverage than does the intraoral full-mouth series. However, certain shortcomings are noted. Rotations of maxillary premolars appear where there are none, and confusion exists in the anterior region about rotated teeth. Supernumerary teeth are frequently missed on the panoramic film in the anterior region. Because of this it is wise to supplement the panoramic image with anterior periapical films. Posterior bitewing films are a necessary supplement to the panoramic examination and with them interproximal caries, periapical lesions, and other details not visualized on the panoramic film are noted. It is imperative that the dentist understand confusing panoramic images that result from motion, superimposed structures, and apparent rotations, so that missed diagnoses do not occur.

Child↗
PubMed1996

Panoramic radiography in dental diagnostics.

Panoramic radiography was studied with the aim to answer some questions about technical and diagnostic properties regarding dental diagnostics. A unit with an intraoral X-ray tube was studied regarding radiation beam area, absorbed doses, and image quality for various screen-film combinations. The beam area for lateral views was wider than optimal and the contact dose high. Modifications of shielding cylinders would reduce both radiation beam and contact dose. One screen-film combination was most sensitive and produced radiographs with best subjectively perceived image quality. Agreement between panoramic (rotational and intraoral X-ray tube techniques) and intraoral radiography in diagnosis of periapical pathology, assessment of marginal bone height, and caries diagnosis was evaluated in 400 patients. Average agreement between panoramic and intraoral radiographs in periapical diagnosis was 55% for the rotational and 46% for the intraoral tube technique. Agreement in marginal bone height was 55% and 49%, respectively and in caries diagnosis 34% and 46%. Radiographs from 40 patients were used to evaluate a procedure starting with rotational panoramic radiography followed by intraoral radiographs considered necessary to achieve a comprehensive examination of teeth and surrounding bone. The number of intraoral radiographs, information loss, and monetary costs with this procedure were evaluated. Mean number of adjunct intraoral radiographs was 5.1 per patient whilst 8.5 should have been chosen to satisfy a "gold standard" used. Monetary costs were similar for an optimal combination of panoramic and intraoral radiography as for a survey with 20 intraoral images Sensitivity for a combination of radiographs was 80-96% in periapical diagnosis and marginal bone loss assessment, and 42-96% in caries diagnosis. Specificity was 95-97% for periapical and caries diagnosis and 50-92% for marginal bone loss. Radiographs from six conventional units and two programs ("dental" and "jaw" panorama) of a new multi-modal unit were compared in diagnostic quality of periapical and crestal bone areas. Number of adjunct intraoral radiographs to achieve a comprehensive evaluation of periapical and marginal bone was estimated. Quality of the "dental" panorama was significantly better than that of other machines/programs. There were no significant differences between images obtained with conventional units and the "jaw" panorama. Number of adjunct intraoral radiographs was lowest for the "dental" panorama. Quality obtained with an old unit was similar to that from modern machines. Rotational and intraoral X-ray tube panoramic radiography perform equally well. Agreement between panoramic and intraoral radiography is not sufficient for panoramic radiography to be used alone to diagnose periapical lesions, marginal bone loss and caries. It is possible to perform a full-mouth survey with a combination of panoramic and intraoral radiography but when limited regions need to be examined intraoral radiography is the method of choice.

Alveolar Bone Loss↗
PubMed1977

Panoramic radiography in dentistry.

Examples of panoramic radiography equipment in use are briefly reviewed and the differences pointed out between those operating on the principle of tomography and other "panoramic" instruments. The various uses to which panoramic radiography is put are described and the problems involved in using them explained. The advantages and disadvantages of panoramic radiography are listed and comparisons drawn between the degree of clarity and precision for diagnosis obtained with it as against that obtained using normal periapical radiographs.

Adult↗
PubMed2000

[Dose measurements comparing conventional and digital panoramic radiography].

OBJECTIVE: The purpose of our study was to measure and compare patient exposure by direct digital and conventional panoramic radiography. MATERIAL AND METHODS: Dose measurements were carried out on an anthropomorphic phantom, which was specially developed for dental radiography. Panoramic radiographs were taken with three different conventional devices (Orthopantomograph 10E, Orth Oralix FD, Siemens Orthophos) and two direct digital devices (Orthopantomograph 100 Digipan, Siemens Orthophos DS Ceph). The exposure conditions were according to clinical routine. The energy dose was measured at 28 places inside and on the surface of the phantom by using a set of 108 thermoluminescence detectors. Additionally, exposure time, tube voltage, central-beam dose, and dose-area products were measured. The effective doses were calculated on the basis of the absorbed doses. RESULTS: In each case, the highest energy doses were recorded at the parotid gland, the mandibular angle, the submandibular gland, and the skin in the neck. Panoramic radiographs taken with the conventional units yielded in effective doses in the range of 16-21 microSv, the digital units caused 5 or 14 microSv. CONCLUSION: In comparison with conventional techniques, patient exposure can be reduced by direct digital panoramic radiography. The extent of dose reduction depends on the device employed and is generally smaller than the dose reduction that can be achieved by digital imaging devices in intraoral radiography.

Humans↗
PubMed1993

Dose reduction in panoramic radiography.

A modern programmable panoramic radiography unit was used to irradiate an anthropomorphic phantom in order to assess the variation in organ absorbed dose and calculated effective dose with program selection. The results of the measurements for five of the 12 programs available are presented, together with those obtained from an older, non-programmable unit. The results of dosimetry measurements are compared between units, between programs, and with previous data. Variations in radiation dose and their implications are discussed, and the opportunities for reductions in organ dose and effective dose of up to 85% and 50%, respectively, demonstrated.

Humans↗