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Biomedical subjects

W K Collett

Publications and source records attributed to W K Collett.

At least 19 recordsLinked to original sources
PubMed1991

Healing of periapical radiolucencies after nonsurgical endodontic therapy.

Eighty-nine periapical radiolucencies treated by nonsurgical endodontic therapy were evaluated to better understand the healing rates of these lesions. After at least 3 months after treatment, radiographs revealed that 46.1% of the lesions had resolved, 48.3% had undergone partial resolution, 2.2% were unchanged, and 3.4% were larger. The average radiographic rate of repair was 3.2 mm2/mo. Less than 6 months after treatment, 17.6% of lesions demonstrated complete radiographic resolution, whereas 70.6% showed radiographic resolution at 12 months or longer.

Adult↗
PubMed1990

Effect of environmental factors on film badge dosimetry readings of dental office personnel.

Inadvertent exposure of film badges to environmental factors may produce fogging of the film and yield higher radiation exposure readings. Common environmental factors in everyday living were studied to assess their effect on film badge readings. Only heat appeared to have any significant effect, because moisture, chemicals, pressure, cold temperature, and non-work-related electromagnetic radiation did not substantially alter film badge readings. Therefore not all unexplained high readings on personnel film badge reports may be due to heat or other common environmental factors evaluated in this study.

Automobiles↗
PubMed1988

Chondrosarcoma. I. A selected literature review.

More than 200 articles and texts relating to chondrosarcoma in the general skeleton, in the head and neck area, and in extraskeletal soft tissues, were reviewed and summarized. In the interest of space conservation and avoidance, to the extent possible, of distracting referential interjections in the text, the entire list of materials reviewed has not been referenced. For example, articles that contribute essentially nothing more than single case reports are not included in the list of references. Effort has been made, however, to include articles of historical significance, articles reporting series of cases, and articles exploring ideas and concepts. The authors believe this review to be a comprehensive summary of the chondrosarcoma literature. An analysis of 37 cases of chondrosarcoma of the jaws will be published as Part II.

Bone Neoplasms↗
PubMed1988

Chondrosarcoma. II. Chondrosarcoma of the jaws: analysis of 37 cases.

Analysis was made of 37 cases of chondrosarcoma of the maxilla or the mandible. The most common complaint at initial presentation was the presence of a mass. Pain was a presenting symptom in less than half of the patients. The usual roentgenographic appearance was an ill-defined radiolucency with mottled areas of calcification. When teeth were involved, some cases showed a widened periodontal membrane space on periapical dental radiographs. Histologically, the tumors usually showed recognizable cartilage and a lobular growth pattern, but cellular evidence of malignancy was often subtle. Radical surgery was the treatment of choice. Prognosis appears best when such surgery is performed soon after the onset of symptoms. Also, patients presenting with mandibular tumors and with tumors of the better differentiated histologic grades enjoy a better survival time. Neck dissection is probably not warranted for chondrosarcoma of the jaws. Contrary to the relationship between these two tumors in other skeletal sites, the overall prognosis for chondrosarcoma of the jaws does not appear to be as good as that for osteosarcoma of the jaws.

Adolescent↗
PubMed1988

Pathological sequelae of "neglected" impacted third molars.

An NIH conference on "Removal of Third Molars" debated the need for removal of asymptomatic impacted teeth with no evidence of pathology but stressed the need for long-range studies. The assumption is that "neglected" impacted third molars (ITMs) will sometime cause serious pathology. Examination of panoramic radiographs of 11,598 patients revealed 1,756 patients with 3,702 impacted teeth; average age 47 years, and an average retention period approximately 27 years. Dentigerous cystic changes occurred in about 30 ITMs (0.81%), internal resorption in 16 (0.43%), periodontal ligament damage and bone loss distal to the 2nd molar 166 times (4.48%), and pressure resorption of the 2nd molar 113 times (3.05%). No great surge in pathology occurred with increasing age. Some type of pathological change can be expected eventually in approximately 12.0% of an impacted 3rd molar population and 1.82% of the general population. A reappraisal of routine removal of ITMs might be indicated.

Adult↗
PubMed1987

Panoramic ghosts.

The panoramic artifact of ghost images is discussed and explained. The three-dimensional area within which an object must be to produce a ghost image is depicted for three panoramic machines. The radiographic features of ghosts and the objects or anatomic structures that cause them are listed.

Humans↗
PubMed1985

Dental radiologic survey of Virginia and Florida.

The results of a survey of 2,257 dental offices recording dental radiology practices are presented and compared to earlier surveys. In many practices patients were exposed to radiographs at predetermined intervals; the variables of manual processing are not well controlled, and darkrooms had excessive light.

Adult↗
PubMed1985

A method to review and revise the dental curriculum.

A major problem in dental education has been the inability of dental educators to add to, delete from, and modify the curriculum efficiently. This has been especially true in the case of deleting material that no longer is appropriate and whose presence hinders the addition of new material. Continuous modification of the core curriculum in a systematic and equitable manner is essential to meeting the needs of future graduates. In conjunction with a flexible, modular core curriculum, the review/revision process at the University of Florida College of Dentistry appears to be successful. This paper describes the organizational and operational aspects of this system, discusses experiences with its use over the past ten years, and projects further refinements of the process.

Curriculum↗
PubMed1985

Suggested revisions in the radiology curriculum based on probable future trends.

Based on the trends noted in a recent survey of dental practitioners, the following areas in the predoctoral dental radiology curriculum should be emphasized: clinical use of rectangular cones; clinical use of E speed intraoral film; theory, maintenance, and use of automatic processors; theory and clinical use of panoramic machines; and opportunities to teach clinical techniques to others.

Curriculum↗
PubMed1980

Intraoral radiographic errors in films submitted for orthodontic consultation.

Radiographic surveys submitted by referring dentists to an orthodontic office for consultation are evaluated for their diagnostic value, and the observed errors are categorized as to technique, processing, and film-aging problems. The distribution of technique errors by anatomic location is identified. These results are compared with data from similar studies involving both dental and hygiene students.

Adolescent↗
PubMed1980

A survey of panoramic radiographs for evaluation of normal and pathologic findings.

Six thousand seven hundred eighty panoramic radiographs were screened to monitor the incidence of normal and pathologic findings. Three different types of panoramic radiograph were used in this study: Panorex, Orthopantomograph, and Panelipse. Visualization of four different anatomic landmarks was used for a statistical comparison of the diagnostic value of the three films: the temporomandibular joint compartments, the external oblique ridge, the mental foramen, and the mandibular canal. The orthopantomograph was judged to be slightly more reliable in producing radiographs for the visualization of the selected anatomic structures. The most common form of pathosis detected was impacted teeth, seen in 22.3 percent followed by retained roots, which appeared in 12.6 percent of the films. Comparing these survey data with three other major studies suggests that confining the previous radiographic examinations to certain selected groups of people may have distorted the incidence of some pathologic conditions in the population. The panoramic radiograph is still considered a supplement to, not a substitute for, the intraoral radiograph.

Humans↗
PubMed1978

A progress report on six year's experience with a flexible, modular dental curriculum.

A flexible, modular curriculum, using self-instructional teaching packages, was implemented in 1972 with the first class of students at the University of Florida College of Dentistry. With only minor modifications in design, this program has been utilized continuously since that time. A reaction to the preconceived advantages and disadvantages of this system is presented. In general, the program has been well received, and is considered a feasible and appropriate approach to dental education.

Curriculum↗