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Biomedical subjects

L L Otis

Publications and source records attributed to L L Otis.

14 recordsLinked to original sources
PubMed2000

Dental optical coherence tomography: a comparison of two in vitro systems.

OBJECTIVE: To compare the imaging results obtained with two different in vitro prototype dental optical coherence tomography (OCT) systems. METHODS: Two prototypes were evaluated: an 850 nm wavelength, 700 microW OCT system with a relatively low numerical aperture (0.03) and a 1310 nm wavelength, 140 microW system with a higher numerical aperture (0.20). RESULTS: Using the 850 nm system a characteristic scattering signal was observed that correlated with the depth of a periodontal probe. There was, however, insufficient light penetration to create images with adequate resolution. Improved image quality was achieved with the 1310 nm OCT system; these images had sufficient resolution to allow identification of anatomical structures important for the diagnostic assessment of oral structures. CONCLUSIONS: These results illustrate the improvement in imaging dental structures that can be obtained with a prototype 1310 nm OCT system. The feasibility of OCT as a dental imaging technique is verified.

Amplifiers, Electronic↗
PubMed2000

Imaging of the oral cavity using optical coherence tomography.

Optical coherence tomography is a new method for noninvasively imaging internal tooth and soft tissue microstructure. The intensity of backscattered light is measured as a function of depth in the tissue. Low coherence interferometry is used to selectively remove the component of backscattered signal that has undergone multiple scattering events, resulting in very high resolution images (< 15 microns). Lateral scanning of the probe beam across the biological tissue is then used to generate a 2-D intensity plot, similar to ultrasound images. This imaging method provides information that is currently unobtainable by any other means, making possible such diverse applications as diagnosis of periodontal disease, caries detection, and evaluation of restoration integrity. This chapter presents an overview of this exciting new imaging technique and its current application to dental diagnosis.

Dental Caries↗
PubMed2000

Optical coherence tomography: a new imaging technology for dentistry.

BACKGROUND: Optical coherence tomography, or OCT, is a new diagnostic imaging technique that has many potential dental applications. The authors present the first intraoral dental images made using this technology. METHODS: The authors constructed a prototype dental OCT system. This system creates cross-sectional images by quantifying the reflections of infrared light from dental structures interferometrically. RESULTS: We used our prototype system to make dental OTC images of healthy adults in a clinical setting. These OCT images depicted both hard and soft oral tissues at high resolution. CONCLUSIONS: OCT images exhibit microstructural detail that cannot be obtained with current imaging modalities. Using this new technology, visual recordings of periodontal tissue contour, secular depth and connective tissue attachment now are possible. The internal aspects and marginal adaptation of porcelain and composite restorations can be visualized. CLINICAL IMPLICATIONS: There are several advantages of OCT compared with conventional dental imaging. This new imaging technology is safe, versatile, inexpensive and readily adapted to a clinical dental environment.

Adult↗
PubMed1994

Disorders of the temporomandibular joint.

Diagnostic imaging, however impressive and informative, is only one aspect of the diagnostic evaluation required to render an accurate assessment of temporomandibular disorders. A thorough patient history, detailed clinical examination, and correlation of radiographic information are essential to formulate the diagnosis, prognosis, and treatment plan.

Arthritis, Rheumatoid↗
PubMed1991

Corrected TMJ tomography: effectiveness of alternatives to SMV tracing.

An axial (SMV) radiograph has been widely used to determine parasagittal head position in TMJ tomograms. The purpose of this study was to investigate the efficacy of alternative anatomic methods for patient positioning in TMJ tomograms. The positioning methods studied included (1) rotation of the patient's head toward the film plane on the basis of the condylar orientation as determined by an SMV radiograph, (2) arbitrary rotation of the patient's head 20 degrees toward the film plane, (3) placement of the zygomatic arch parallel to the film plane, and (4) positioning of the posterior occlusal plane parallel to the film plane. Statistical analysis of the accuracy of the positioning techniques revealed no differences in the SMV, the zygomatic arch, and the arbitrary 20 degrees positioning. Aligning the posterior occlusal plane did not adequately align the mandible into a favorable radiographic position.

Analysis of Variance↗
PubMed1990

Axial temporomandibular joint morphology: a correlative study of radiographic and gross anatomic findings.

In degenerative diseases of the temporomandibular joint the mandibular condyle demonstrates changes in contour, including flattening and enlargement, resulting in an increased diameter of the articular surface. The purpose of this study was to determine if such alterations in the shape of the mandibular condyle can be visualized in submentovertex (axial) radiographs and correlated with pathologic changes of the temporomandibular joint. Submentovertex radiographs of 18 human cadaver specimens were made. The radiographic condylar dimensions, morphologic condylar outline, and angle of the condylar axis with respect to the transmeatal line were determined. The specimens were dissected and disarticulated, and radiographic findings were compared to anatomic structure. Osseous abnormalities were found in 21 of the 36 joints studied (58%). Perforations of the disk were found in nine of 31 joints (29%) investigated. No statistically significant differences between the normal condyles and condyles displaying osseous abnormalities were found in any of the radiographic parameters studied.

Adult↗
PubMed1989

Prevalence of perforations in disposable latex gloves during routine dental treatment.

Durability of gloves with respect to reducing cross-contamination and decreasing the risk of occupationally acquired infections was studied. In this study, pinholes were found in 1.8% of unused surgical latex gloves and 2.0% of latex examination gloves. The incidence of pinhole defects in gloves emphasizes the importance of operative techniques that minimize stress to the glove and the need to change gloves, especially for procedures lasting more than 2 hours.

Acrylic Resins↗
PubMed1985

The granulocytopenic patient: another consideration for antimicrobial prophylaxis.

Infection in the granulocytopenic patient is often life-threatening, and the frequency and severity of infection are increased regardless of the cause of leukocyte suppression. Trimethoprim-sulfamethoxazole plus nystatin is known to be effective in preventing colonization and infection by the primary pathogens responsible for the morbidity and mortality associated with granulocytopenia. When treating granulocytopenic patients, clinicians should use proper barrier techniques to minimize nosocomial colonization. When foci of oral infection are present or bacteremia is predictable, appropriate antibiotics should be prescribed.

Agranulocytosis↗
PubMed1982

Identification of T lymphocytes by a histochemical stain for alpha naphthyl acetate esterase activity.

Lymphocyte suspensions and peripheral blood smears from 20 normal individuals were examined for nonspecific esterase activity, using alpha naphthyl acetate as substrate and hexazotized pararosanilin stain. Lymphocytes show intense, focal, red "dot-like" activity; monocytes show diffuse reddish granulation. B lymphocytes do not react. Critical variables of the procedure include: use of proper anticoagulant; fixation for 30-180 seconds; incubation with substrate 3-5 hours; and pH 5.8. Comparison of results with conventional E rosette methodology showed 53-63% rosettes; 50-58% esterase-positive lymphocytes in cytocentrifuge preparations and 47-59% esterase-positive lymphocytes on peripheral blood films. Technical advantages of the procedure favor it as an alternative method for assessing T lymphocytes.

Esterases↗