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Biomedical subjects

A Ruprecht

Publications and source records attributed to A Ruprecht.

At least 37 records · Page 2Linked to original sources
PubMed1999

Evaluation of maxillofacial fibrosarcoma using computer graphics and spiral computed tomography.

This paper describes the appearance of three cases of maxillofacial fibrosarcoma in multiplanar (MPR) and three-dimensional reconstructed computed tomography (3DCT). The images were analysed by two oral and maxillofacial radiologists and one neuroradiologist. All of the cases clearly demonstrated the usefulness of the interactive MPR and 3DCT in the diagnosis and evaluation of the extent of these maxillofacial tumors.

Cheek↗
PubMed1999

Frequency of portrayal of foramen transversarium of the second cervical vertebra on rotational panoramic radiographs.

OBJECTIVES: To determine the prevalence of portrayal of the foramen transversarium of the second cervical vertebra on rotational panoramic radiographs. METHODS: A stratified random sample of 1600 diagnostic-quality rotational panoramic radiographs were retrospectively reviewed. Approximately 100 radiographs each for males and females were reviewed for each of the decades of life up to age 69 and for subjects 70 or older. RESULTS: The foramen was portrayed 29.3% of all radiographs, 35% of females and 22.6% of males. However, when considering only those radiographs in which cervical vertebrae were visible, the foramen was more frequently portrayed in males than in females. Portrayal of the foramen did not differ substantially among age groups. CONCLUSIONS: The foramen transversarium is found sufficiently often on rotational panoramic radiographs that this structure should be identifiable by clinicians who use these images.

Adolescent↗
PubMed1999

Progression of maxillofacial squamous cell carcinoma evaluated using computer graphics with spiral computed tomography.

This report describes the appearance of maxillofacial squamous cell carcinoma in multiplanar (MPR) and three-dimensional (3D) images reconstructed from spiral CT using computer graphics and the importance of the computer software tools in permitting better visualization of the lesion. Two oral and maxillofacial radiologists and one neuroradiologist analysed the images. The usefulness of interactive reconstruction in the diagnosis, surgical planning and treatment evaluation, especially in the localization of the extent of these maxillofacial tumors, was demonstrated. Spiral CT-based computer graphics for displaying MPR and 3D images are an important adjunct in the evaluation of squamous cell carcinoma.

Aged↗
PubMed1998

Validation of spiral computed tomography for dental implants.

OBJECTIVES: To investigate the accuracy of 2DCT orthoradial reformatted images from spiral computed tomography (CT) for pre-surgical planning of dental implants in proximity to the mental foramen. METHODS: Eight cadaver heads were imaged by spiral CT (S/Xpress, Toshiba-America, Tustin, CA) with 1 mm thick axial slices by 1 mm/sec of table feed. The image data set was transferred to a networked computer workstation. Using computer graphics the data was analysed with 2D orthoradial reformatting using the ToothPix (Cemax, Fremont, CA, USA) protocol. Linear measurements were made by two oral radiologists independently from the superior border of the mental foramen to the crest of the alveolar process and from the inferior border of the mental foramen to the mandibular inferior border. The soft tissues were removed and physical measurements made using a 3 Space (Polhemus, Colchester, VT) electromagnetic digitizer with a personal computer running Windows 95. RESULTS: The differences between the measurements on orthoradial 2DCT images and the physical measurements were not statistically significant (P > 0.05). CONCLUSIONS: Two-dimensional spiral CT imaging allows highly accurate measurements for dental implant placement in proximity to the mental foramen. Computer graphics software, using reformatted reconstruction, is suitable for implant planning.

Aged↗
PubMed1996

Magnetic resonance imaging used to assess patients with trigeminal neuralgia.

To assess the value of magnetic resonance imaging in the evaluation of trigeminal neuralgia, 51 patients were studied by magnetic resonance imaging after a trigeminal protocol. Clinical and magnetic resonance imaging results were correlated. Seventeen (33%) nonvascular abnormalities and 27 (53%) vascular contacts or compressions of the trigeminal nerve were demonstrated. Of the patients younger than of 29 and 39 years of age, 100% and 45%, respectively, had a tumor or multiple sclerosis compared with 20% and 18% of those older than 40 and 60 years of age, respectively. One third of the patients with pain in more than one branch of the trigeminal nerve had tumors. On the basis of this study, magnetic resonance imaging may be useful in discovering underlying pathoses associated with trigeminal neuralgia if patients have failed to respond to an initial conservative treatment. The patients most likely to exhibit significant magnetic imaging resonance findings are young and with pain in more than one trigeminal branch.

Adolescent↗
PubMed1995

Comparison of two-dimensional orthoradially reformatted computed tomography and panoramic radiography for dental implant treatment planning.

The widespread use of dental implants in partially and completely edentulous patients has brought about a need to preoperatively depict and quantify accurate bone height and contour. A number of conventional intraoral and extraoral radiographic techniques have been used, including the relatively new modality of two-dimensional orthoradially reformatted computed tomography. Despite rapid advances in imaging technology, many clinicians continue to rely on techniques such as panoramic radiography that produce images that distort the jaws nonuniformly. This study compared bone height measurements of jaws made with these two imaging modalities. Nineteen sites in 10 patients were imaged with both techniques and mean bone height was determined for each imaging technique and site. Significant differences were found between mean bone heights measured with the two imaging modalities (p < 0.0005). Situations in which the use of dental implants would be particularly advantageous demonstrated the largest discrepancies, that is, when bone height measurements were less than 15 mm.

Alveolar Process↗
PubMed1993

The nasopharynx in oral and maxillofacial radiology. II. Malignant lesions.

As with part I of this series of articles, this is not a comprehensive review of all malignant lesions to be found that involve the nasopharynx. It is an overview of how malignant lesions may appear and spread in the region of the nasopharynx. Oral and maxillofacial radiologists are reminded that familiarity with this area on diagnostic images ensures that lesions that involve this region will be interpreted as accurately as possible.

Humans↗
PubMed1991

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.

Chondromatosis, Synovial↗
PubMed1991

The nasopharynx in oral and maxillofacial radiology. I. Benign lesions.

This is not a comprehensive review of all benign lesions that can be found in the nasopharynx, but merely a review of the relationship of the nasopharynx to its surroundings. It is also a reminder of the need for the oral and maxillofacial radiologist to be familiar with this area, because it often appears on radiographs made for other purposes, or to investigate problems that have extended to and from the nasopharynx and the oral and maxillofacial region.

Adenoids↗
PubMed1991

Transcranial radiography and linear tomography: a comparative study.

There is continual controversy concerning the use of radiographs to determine the position of the mandibular condyle within the glenoid fossa for the diagnosis and treatment of temporomandibular disorders. This study compared joint space measurements from transcranial radiographs and linear tomographs with the anatomic joint space to determine whether condylar position could be accurately recorded radiographically. Anterior, superior, and posterior joint space dimensions were measured from projected radiographs with a sonic digitizer, whereas anatomic joint space dimensions were recorded from the thickness of polyether impressions of the joint space. Posterior/anterior joint space ratios were used to classify relative condylar position as anterior, concentric, or posterior. The Pearson correlations (alpha = 0.05) were calculated to determine the consistency between radiographic and anatomic joint space ratios. The corrected and standard transcranial projections did not accurately reproduce the anatomic joint spaces or the relative condylar positions. Only the corrected tomographic projection accurately reflected the condyle-fossa relationships.

Arthrography↗