Thesis (M.S.)--University of Michigan, 1952.

Thesis (M.S.)--University of Manitoba, 1999. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M. S.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains x, 80 p.; also includes graphics (some col.). Includes bibliographical references. Available online via OhioLINK's ETD Center

Thesis (M.A.)--University of Pittsburgh. / Includes bibliographical references (leaves 203-209).

Thesis (M.A.)--University of Pittsburgh. / Bibliography: leaves 203-209.

Thesis (doctoral)--Universität Hamburg, 1979.

Objective: The purpose of this study was to develop a method of accurately quantifying the wear facet, and relating the wear facet size to the forces applied by the Iowa Tooth Wear Machine. Methods: Ten un-erupted third molars were used for this study. The teeth were mounted in the Iowa Tooth Wear Machine with opposing proximal surfaces. Samples were run with a 0.250mm stroke length for 645,120 cycles under 5 pounds of weight. An optical scanner was used to digitize the initial and final interproximal wear facets. AnSur© software (Regents, University of Minnesota) was used to process and analyze the interproximal surfaces in terms of area (mm2), volume (mm³), and depth (µm). Results: All samples were subject to identical magnitude and frequency of forces. The results show that there was considerable variation in volume loss between the samples. Results show similar amounts of volume loss in samples 3, 4, 6, 7, 8, 9, and 10 with 1, 2, and 5 showing a considerably greater amount of wear. Conclusions: The results suggest that there may be other compounding factors involved with facet formation, and the force magnitude and frequency alone does not determine the volume of enamel loss.

Indiana University-Purdue University Indianapolis (IUPUI) / Orthodontic treatment being provided by pediatric dentists and general practitioners in Indiana was investigated. A two page questionnaire constructed by the investigator was used to gather the data. The study sample consisted of 571 dentists. All 71 Indiana pediatric dentists primarily in private practice were surveyed. General practitioners (500) were chosen on the basis of age, year of graduation from dental school, geographic location and size of community in which they practiced. Seventy-eight percent of the questionnaires were returned; of this total, 93 percent of the pediatric dentists and 77 percent of the general practitioners responded. The study showed that currently in Indiana 62 percent of the pediatric dentists and 17.9 percent of the general practitioners surveyed provided comprehensive orthodontic treatment. These results are much higher than results of previous surveys of pediatric dentists and general practitioners. The study also found that pediatric dentists provide significantly more comprehensive orthodontic treatment and spend significantly more time providing orthodontic treatment than do general practitioners. Age of practitioner was found not to significantly affect the percentage of time spent providing orthodontic treatment, the orthodontic conditions treated or the type of appliances and techniques used. Population of the community in which the practice was located did have a significant effect. Practitioners in communities of over 100,000 provided significantly less comprehensive orthodontic treatment. Practitioners who practiced in communities of 5,000-25,000 spent significantly more time providing orthodontic services. Sixty-three percent of the practitioners surveyed had taken some type of continuing education course in orthodontics. An overwhelming majority of practitioners (over 90 percent) stated that their undergraduate orthodontic training in dental school inadequately prepared them for private practice. The majority of pediatric dentists (78 percent) also stated that their postgraduate education instruction in orthodontics was inadequate.

Indiana University-Purdue University Indianapolis (IUPUI) / A method was devised and described to study the tissue response as demonstrated by tooth movement to measured force loads in the range of from 25 to 150 grams force a side or from 50 to 300 grams distributed over the maxillary central and lateral teeth. Investigation was initiated in an attempt to establish the existence or non-existence of threshold force values for anterior tooth movement. Threshold forces are defined in this study as that force necessary to retract the maxillary central and lateral teeth one millimeter. Secondary objectives were to determine whether there is similar tooth movement demonstrated by individuals at given force values, the relation of force and pain response at low force values, whether there is movement of the anchor teeth and whether there is an optical range force for anterior retraction. An optimal range of force would be a range where there was maximum tooth movement with a minimum of pain response. Before and after records were taken on twenty-two children which consisted of models, lateral cephalometric radiographs and before treatment photographs. All the children possessed maxillary protrusions with space distal to the lateral teeth as a criterion for selection for the study. The maxillary central and lateral teeth were branded and brackets were placed at a determined distance from the incisal edge of the central teeth so as to standardize the force at the alveolar crest regardless of root length. The maxillary molar teeth were banded and a soldered lingual bar constructed to extend from light to left molar. Eyelets were welded to the buccal surface of these molar bands as fixed points of reference for measurement of the amount of movement of the maxillary four anterior teeth in relation to the molars. Measurement was made with a Korkhaus Three Dimensional Orthodontic caliper and by superimposition of lateral cephalometric headplates. Measurements were taken at seven, twelve, seventeen, twenty-two and twenty-seven days after activation of .008 X .030 closed coil springs in tension on the right and left side of the appliance. The load deflection of the coil springs was 13 grams per millimeter. The range of forces from 25 to 150 grams a side are termed low force values in this study. At these low force values there is similar tooth movement demonstrated by all individuals in the study. Threshold force values appear to be a range of force values of from 14 to 24 grams distributed to the four maxillary anterior teeth. These low force values of from 25 to 150 grams on the right and left side create no severe or prolonged problems for the patient. In no case was pain described as more than a slight soreness. There appears to be no movement of the anchor teeth as determined by the method used in this study. An optimal range of force values for the retraction of the four anterior teeth is in the range of from 50 to 75 grams a side or from 100 to 150 grams distributed over four teeth.

Indiana University-Purdue University Indianapolis (IUPUI) / This study was initiated to obtain quantitative information on the tendency of the maxilla to resist separation when subjected to lateral loads. It was hoped that a structural center of resistance for the maxilla could be determined. Strain gauges were placed in dry skulls and lateral loads were applied in five different anterior-posterior positions. The results show a highly significant position by gauge interaction (F= 3.467, P. < .005). A loading position at approximately the mesial of the first molar elicited the least variable (or most uniform readings), thereby indicating the approximate center of resistance of the maxilla to force application in the plane considered.