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Biomedical subjects

S R Matteson

Publications and source records attributed to S R Matteson.

At least 37 records · Page 2Linked to original sources
PubMed1987

Effects of rare-earth filters on patient exposure and image contrast.

Minimizing patient exposure while maintaining a diagnostically acceptable radiograph is a major goal in diagnostic radiography. Rare-earth filters may be the means to achieve this goal due to their "band-pass effect". The purpose of this study was to examine the image contrast effects and exposure reductions for various thicknesses of aluminum, samarium, gadolinium, gadolinium oxysulfide, and gadolinium oxysulfide added to 2.5 mm of aluminum. Trials were conducted on an intra-oral dental x-ray unit (range, 65 to 90 kVp). When compared with conventional aluminum, all of the rare-earth filters provided lower radiation exposures, with gadolinium in the metallic or oxysulfide form providing the lowest exposures. Samarium, at a thickness of 0.127 mm, yielded the highest image contrast. Gadolinium or gadolinium oxysulfide added to 2.5 mm of aluminum resulted in a slight loss of contrast when compared with conventional aluminum filtration. This loss may not be clinically significant, and when coupled with the reduced exposure afforded by these filters, they become viable as acceptable alternatives to aluminum filtration.

Aluminum↗
PubMed1985

Evaluation of condylar position from temporomandibular joint radiographs.

This investigation evaluated the accuracy of three different transcranial TMJ radiographic records of condylar position and joint space dimension. In addition, the study evaluated how reliably observers determined condylar position and joint space dimensions from the radiographs. The results of this investigation support the following conclusions. The classification of condylar position is not the same at different sagittal locations within a TMJ. Skull position and radiographic projection must be identical if joint space measurements from serial radiographs are to be compared. The actual joint space dimensions and the anatomic anterior/posterior position of the condyles in the glenoid fossae cannot be accurately recorded by the radiographic techniques used in this investigation. Condyle/fossa relationships cannot be classified reliably by subjective evaluation of TMJ radiographs.

Cephalometry↗
PubMed1985

Bone scanning with 99mtechnetium phosphate to assess condylar hyperplasia. Report of two cases.

Condylar hyperplasia poses a problem in planning treatment because it is a self-limiting process for some but not all patients. Continued growth creates a progressive deformity that requires condylectomy, whereas an enlarged condyle can be left in place after hyperplastic growth ceases, even if ramus surgery is needed to correct asymmetry. Bone scan with 99mtechnetium phosphate can be used to assist in making the differential diagnosis. In the two patients reported here, abnormal metabolic activity revealed by bone scans supported clinical and historical evidence that the condylar hyperplasia was active and required surgical correction, including condylectomy. The two cases demonstrate different approaches to postsurgical orthodontic treatment, depending on the amount of normal growth expected.

Adolescent↗
PubMed1985

Radiographic appearance and population distribution of the pneumatized articular eminence of the temporal bone.

The pneumatized articular eminence of the temporal bone (PAT) is a cavity similar to that seen in the mastoid process that occurs in the zygomatic process of the temporal bone. Panoramic radiographs of 1061 dental school patients were reviewed to determine the radiographic appearance and population characteristics of this finding; PAT was found in 28 patients (2.6%). The mean age of the patients was 32.5 years; there was no sex predilection and four patients showed this defect bilaterally. Two radiographic types of PAT were identified, unilocular and multilocular. Panoramic radiography appears to be an efficacious method to display the articular eminence for visualization of PAT. Due to the relatively common occurrence of PAT and the increasing amount of surgery of the temporomandibular joint, visualization of this defect becomes important for the clinician planning surgical manipulation of the articular eminence.

Adolescent↗
PubMed1983

A survey of radiographs obtained at the initial dental examination and patient selection criteria for bitewings at recall.

This paper reports the results of a 1980 survey of a 27% simple random sample of all practicing dentists in North Carolina. The objective of the survey was to establish current practice standards regarding panoramic, full-mouth series, and bitewing radiographs. A total of 414 dentists (76.2% of those surveyed) responded. A questionnaire recorded demographic data on the dentists, age-specific prevalence data on the type of radiograph most often done at a patient's initial visit, and prevalence of radiographs based on need as perceived by the dentist and assessed separately for a variety of patient characteristics (age, oral hygiene, caries activity, fluoride treatment, and systemic medical problems). Results of the survey of a subset of 338 dentists in general practice showed the median age to be 40 with a median length of experience of 13 years. At an initial visit, for patients younger than 12, bitewing radiographs only were most commonly taken; for patients older than 12, bitewings plus a panoramic radiograph were taken. Full-mouth series plus bitewings were rarely performed among patients younger than 6 years (2.1% of the time), but were more commonly performed as patients aged (29.0% for patients aged 40 and older). A variety of patient characteristics were considered for their impact on the need for bitewing radiographs on recall. Caries activity was ranked most important by the general dentist, followed by oral hygiene and periodontal activity.

Adolescent↗
PubMed1982

Application of direct magnification radiographic technique to the jaws.

Direct magnification radiography is widely applicable to situations in which enhanced definition and enlarged images are desirable. This technique is capable of providing high subject resolution when conventional radiography is not definitive. It serves as a variable supplementary radiograph for the diagnosis of conditions in the oral and maxillofacial region. The general mechanics of the technique as well as its possible use as a supplementary high detail film are discussed. Three cases are reported in which this technique was applied in the diagnosis of oral and maxillofacial surgery patients.

Aged↗
PubMed1982

Extreme distal migration of the mandibular second bicuspid. A variant of eruption.

A five-year study of 26,264 panoramic radiographs found distal positioning of the mandibular second bicuspid associated with a missing adjoining first molar in one of every 505 patients. Following early removal of the first molar, there is a 5% to 10% chance that the second bicuspid will migrate distally. It usually continues until it contacts the root of the second molar, and then rotates up into occlusion adjacent to the parallel with that tooth. Mesial drift seldom occurs in this circumstance; the resulting space between lower first and second bicuspids remains. Early conservative management can be very important in these cases, making periodic x-ray examination advisable whenever a molar has been lost and the adjoining bicuspid has not yet erupted.

Bicuspid↗
PubMed1980

Bone-scan appearance of benign oral pathologic conditions.

Bone scans and dental examinations were completed on 22 patients. Results indicate that periodontal and periapical inflammation, healing wounds, traumatized alveolar ridges, and multiple cementomas result in positive scans. These areas should be recognized as benign dental disease and not misinterpreted as malignant lesions.

Alveolar Process↗