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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Leadership and dental aesthetics of adults as perceived by laypersons

Montgomery, E. Britton 18 May 2009 (has links)
The purpose of this study was to determine if dental aesthetics is perceived by adults to affect an individual’s ability to emerge as a leader. An electronic survey was constructed using facial frontal smiling photographs of 10 patients. Statements were formulated to evaluate four leadership characteristics: intelligence, self-confidence, friendliness, and trustworthiness. Evaluators indicated their level of agreement with each statement for each subject using a 100mm Visual Analog Scale (VAS). Data was obtained from 214 evaluators. Picture ratings were analyzed using repeated-measures mixed-model analyses. Evaluator factors and picture factors were considered when testing for crooked vs. straight teeth differences. There was a significant difference in perception of individuals with straight versus crooked teeth for the characteristics of intelligence, trustworthiness, and self-confidence. No difference found for the characteristic of friendliness. The gender and race of the evaluators influenced the rating of the subjects. Results from this study may support the importance of good smile aesthetics for adults who seek a leadership role.
92

Importance of Pumice Prophylaxis for Orthodontic Bonding with Self-etch Primer: An in vivo Study

Lill, Daniel J. 01 January 2005 (has links)
Self-etching primers (SEP) have recently simplified the orthodontic bonding process and questions have arisen regarding their reliability and efficiency. The goal of this study was to assess the importance of a pumice prophylaxis prior to bonding with SEP (Transbond Plus, 3M Unitek, Monrovia, CA) in reducing bond failures. Thirty orthodontic patients volunteered to participate in this split-mouth prospective clinical trial. A pumice prophylaxis experimental group and a non-pumice control group of teeth were randomly assigned in a contralateral quadrant pattern within each patient. A total of 508 teeth were bonded and monitored over 3 months for bond failures. There were 35 total failures (6.9%) with 6 (2.4%) in the pumice group and 29 (11.4%) in the non-pumice group. Bond failures were compared as a total number between groups and also as the number of patients who experienced bond failures with each method using Chi-square analysis. There were statistically significant differences both in the total number of bond failures (P < .001) and in the number of patients with bond failures between groups (P < .01). A significantly lower and clinically acceptable bond failure rate was demonstrated when using Transbond Plus SEP after pumice prophylaxis. This study produced strong evidence to suggest the need for pumice prophylaxis in orthodontic bonding when using SEP.
93

Effects of Unilateral Extraction Treatment on Arch Symmetry and Occlusion

Struhs, Theodore William 01 January 2005 (has links)
Occlusal asymmetries are common in orthodontic patients. A treatment option for correcting moderate asymmetries is asymmetric extractions. This study evaluated post-treatment dental arch symmetry in patients treated with unilateral premolar extractions. Post-treatment casts of 60 patients were divided into four treatment groups based on the history of occlusal asymmetry and the treatment plan. DesignCAD3000 software (Upperspace Corporation, Pryor, OK) was used to evaluate asymmetrically treated arches for symmetry. The four treatment groups were compared to identify differences in arch asymmetry based on treatment. The lateral incisor and canine were found to be more palatal on the extraction side in patients treated with unilateral extractions (P < .001). Arch length increased (P < 0.001) and area under the arch decreased (P < 0.01) on the extraction side. On average, patients with asymmetric extractions did not finish with more arch asymmetry than those without asymmetric extractions.
94

Bonding Properties of Newly Erupted and Mature Human Premolars

Almy, Diana Marie-Skinner 01 January 2004 (has links)
Following eruption of a tooth into the oral cavity, enamel is thought to continue to calcify. The continued calcification and maturation of enamel is described as "post-eruptive enamel maturation." It is believed that an observed decrease in enamel pore size and increase in the calcification of enamel matrix over time can be attributed to this process. In recent years, there has been a significant increase in the number of adult patients seeking orthodontic treatment. Since orthodontic attachments are bonded directly to the etched enamel using composite resin, post-eruptive enamel maturation may affect the bonding process. The purpose of this study was to determine whether there were differences in bond strength between mature and newly erupted teeth when using both conventional and self-etching primer techniques for bonding orthodontic appliances. The nature of adhesive bond failure among the groups was also compared using an adhesive remnant index (ARI). Etched surfaces were examined under scanning electron microscopy (SEM) and representative photomicrographs were taken. Human premolars were collected and bonded randomly with either the conventional or self-etching technique. Brackets were debonded using an Instron testing machine in shear-testing mode. There were no statistically significant differences in the bond strengths between the self-etching primer and conventional etching groups. ARI scores showed differences between mature and newly erupted teeth. Mature teeth had more cohesive bond failures whereas newly erupted teeth had more adhesive failures at the enamel-composite resin interface. Scanning electron micrographs (SEMs) of self-etched enamel revealed smooth areas of resin with filler particles. Conventionally etched enamel had rougher surfaces. There were no differences in etch pattern of new versus mature enamel. Further research may be needed as new bonding materials and techniques become available to determine the effects, if any, of post-eruptive enamel maturation on their success.
95

Overbite Correction and Smile Esthetics

Lewis, Shannon Michelle 01 January 2004 (has links)
Achievement of optimum smile esthetics during orthodontic treatment has recently been the focus of several published articles in the orthodontic literature. Authors speculate that overbite correction, specifically maxillary incisor intrusion, will lead to flattening of the smile arc and consequently reduce smile attractiveness. The purpose of this prospective clinical study was to investigate differences in outcomes from two common treatment modalities used to reduce deep overbite: maxillary incisor intrusion using an intrusion arch and posterior tooth eruption using an anterior bite plate. Pre-treatment and post-overbite correction records were gathered from 20 patients who presented with deep overbite malocclusions to the Virginia Commonwealth University orthodontic clinic. Both the intrusion arch and bite plate treatment modalities effectively reduced overbite significantly over a relatively short period of treatment. Intrusion arch patients displayed significant reductions in maxillary incisor display (lip to tooth) accompanying documented incisor intrusion. Half of the patients in both groups experienced flattening of the smile arc in agreement with previous studies showing similar changes in orthodontic patients in general. There was no greater tendency for flattening to occur in either group. Changes in the smile arc are likely due to other factors involved in orthodontic tooth alignment and are not necessarily attributable to the overbite correction method employed during treatment.
96

Alternative Orthodontic Bonding Protocol Using Self Etching Primer

Caldwell, Rush-Baker Gaines 01 January 2008 (has links)
The purpose of the current study was to develop a bonding method that can achieve clinically acceptable bond strength values while leaving a minimum amount of adhesive on the tooth surface during the debonding process. One hundred teeth were randomly assigned into groups. Five different enamel surface preparation protocols were tested (N = 20, each): Conventional acid etch, standard SEP, SEP applied with a light brush stroke (altered SEP 1), SEP applied directly to the composite of pre-coated bracket (altered SEP 2), and Primer Only groups. Brackets were debonded using an Instron universal testing machine (Instron, Canton, MA) in shear mode and the mean shear bond strength values were calculated. In addition, enamel surfaces were examined under light microscope to determine the location of failure using ARI. The Primer Only group had significantly lower mean shear strength (0.14 MPa, P0.05). With respect to ARI values, there was a significant difference among these four groups. 85% of samples in the altered SEP 2 group had 10% or less composite resin left on their surfaces. This group had also a mean shear bond strength value of 11.43 MPa, significantly above the minimal strength needed for orthodontic attachment bonding, and the lowest ARI values overall. Therefore, application of SEP directly to the composite resin of the pre-coated brackets may be an ideal bonding method by providing adequate bond strength and leaving a minimum amount of composite resin on the tooth surface during debonding. It should be kept in mind that future in-vivo studies would be needed to confirm the findings obtained from the current in-vitro study.
97

Factors Influencing Applicant Ranking of Orthodontic Programs

Payne, Michael D. 01 January 2004 (has links)
Orthodontic programs spend considerable amounts of time and energy to attract, recruit, and interview the best and brightest applicants. Applicants and programs submit ranked preferences, and resident positions are filled by a computerized matching system (Match). The specific aims of this study were to determine the relative importance of certain factors in applicants' Match ranking of orthodontic programs and to determine differences between orthodontic Program Directors perceptions and actual factors cited by applicants influencing their ranking of orthodontic programs.Surveys were mailed to 55 orthodontic Program Directors and 478 applicants participating in the 2002 orthodontic Match. Forty-nine Program Director (89%) and 224 applicant (47%) surveys were returned. Rankings and importance of factors cited by applicants in their decision-making process and perceptions of those factors cited by Program Directors were compared.Applicants' top three factors were: "satisfied current residents," "multiple techniques taught," and "good quality of clinical facility." Program Directors' perceived top three factors were: "satisfied current residents," "good program reputation," and "good impression of current residents at interview." Comparing Program Directors perceptions versus applicants' factors overall, the two groups were statistically different (P Despite these differences, there was generally a high level of overall agreement between Program Directors perceptions and factors actually influencing applicants' ranking of orthodontic programs.
98

Concurrent Whitening and Orthodontic Treatment

Gladwell, Jason Thomas 01 January 2007 (has links)
The aim was to evaluate whether a whitening system, when used during the final stages of orthodontics, would yield results comparable to whitening alone. Patients were assigned to either the control (n=20) or experimental (n=26) groups. At T1, patients were given a ten day supply of Trèswhite™ by Opalescence®, instructions on use, and initial shade determination was made and photographs were taken. At T2 and T3, shade determination was accomplished and updated photographs were taken. Whitening of the teeth occurred in both groups on average, but significantly more whitening was experienced in the experimental group (p < 0.004). An average of 87% of teeth whitened during orthodontic treatment compared to 97% of control teeth (p < 0.01) were judged to be uniform in appearance. In conclusion, the data do not contraindicate the concurrent accomplishment of teeth whitening during orthodontic treatment.
99

Orthodontic Faculty Recruitment and Retention: Goals and Perceptions

Peck, Sheldon L 01 January 2003 (has links)
There is a shortage of faculty in academic dentistry and orthodontics in particular. The purpose of this study was to quantify real and perceived differences in income, workload, and satisfaction between full-time academic and private practice orthodontists. Surveys were returned by 119 (70%) faculty, 79 (36%) private practitioners, and 160 (59%) orthodontic residents. Average annual income for faculty was less than half that of private practitioners. Faculty also reported working significantly more hours per week and taking less vacation time. Though both faculty and practitioners perceived their own jobs to be more satisfying overall, faculty felt academics was more stressful, involved more bureaucracy, and made it more difficult for them to obtain ABO certification. Residents reported educational debt averaging $132,120 and perceived it would take nearly twice as long to pay off in an academic career. Only residents felt that faculty were more respected than their private practice colleagues.
100

Orthodontic Bracket Bond Strength Using Self-Etching Primer With or Without Pumice or Acid Etch Pretreatment

DeCastro, Ana Paula 01 January 2008 (has links)
The purpose of this study was to compare the shear bond strength of orthodontic brackets to enamel in four bonding protocols: SEP without prior pumicing (None), Pre-etch and SEP without prior pumicing (Pre-etch), control: SEP with prior pumicing (Pumice), and Pre-etch and SEP with prior pumicing (Both). 80 extracted bovine incisors were randomly divided into 4 groups of 20, and brackets were bonded under the different experimental conditions. Debonding force was measured with an Instron universal testing machine. A two-way ANOVA comparing the four groups indicated that there was a significant difference in debonding force (P = 0.001). The SEP without prior pumicing group (17.69 ± 7.18 MPa) was statistically different from the SEP group with prior pumicing (25.82 ± 6.84 MPa). There was no statistical difference found among the other groups. Differences in the Adhesive Remnant Index (ARI) were analyzed by chi-square. ARI scores differed significantly (P =0.0048).

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