Orthodontics and Orthodontology Commons^™

A Shear Bondstrength Evaluation Of Five Orthodontic Light-Cured Adhesives, Perry M. Unruh

Loma Linda University Electronic Theses, Dissertations & Projects

In this study, the shear bondstrengths of five commercially available orthodontic light-cured adhesives were evaluated with respect to two types of curing lights and various cure-times. A total of 160 Transcend brackets (mechanical retention) were utilized. The brackets were individually bonded to knurled stainless steel testing rings via the respective adhesives. Each bracket was sheared from the testing ring using an Instron machine. For each adhesive a 2, 5, 10, and 20 second cure-time, and an immediate, 5 minute, 20 minute, and 24 hour shear test time was employed. The adhesives were cured using high intensity and low intensity visible …

A Pilot Study On The Evaluation Of Short Term Effects Of Jasper Jumper Therapy, Eric D. Fraser

Loma Linda University Electronic Theses, Dissertations & Projects

Lateral cephalometric radiographs were obtained for ten patients treated with Jasper Jumper appliances from three locations. Pre and post-appliance measurements were compared to determine the cephalometric effects seen in this group of patients. All patients in this study exhibited mesofacial to brachyfacial growth patterns and were all of growing age. All patients were treated to Class I along the complete buccal segment. The results yielded the following conclusions: 1) the facial axis did not open and the lower face height did not increase significantly for this group of patients, 2) there is an intrusive effect delivered to the upper first …

Force Systems From T-Loop Orthodontic Space Closure Springs: The Effects Of Asymmetric Placement And Angulation On The Alpha-Beta Moment Differential, Andrew J. Kuhlberg

SoDM Masters Theses

No abstract provided.

New In Vivo And In Vitro Techniques For Quantification Of Lateral Force Levels That Cause Implants To Fail : A Progress Report On Monkey Research, V. Leroy Leggitt

Loma Linda University Electronic Theses, Dissertations & Projects

Two new techniques for quantification of forces generated by an expansion screw apparatus placed between pairs of cylindrical endosseous titanium implants are described, along with preliminary data gained from their use in Macaca rhesus monkeys. Strain gages were bonded to the expansion apparatus and were calibrated either directly by micro load cell, or indirectly by Instron Machine to reflect the applied force.

Immediate loads of up to 6 kilograms have been applied to the implants with no increase in mobility as verified by a Periotest device. No previous studies on the orthodontic uses of implants have evaluated in vivo forces …

An Evaluation Of Surface Enamel Damage Following The Debonding Of Ceramic Brackets : A Follow-Up Study, B. Scott Hood

Loma Linda University Electronic Theses, Dissertations & Projects

To evaluate surface enamel damage after debonding ceramic brackets using their manufacturer's recommended methods, sixty four bicuspid teeth were bonded with three different types of ceramic brackets and one type of metal bracket. All the brackets tested utilized mechanical retention only. The brackets were debonded in the mouth seven to ten days after bonding, extracted and evaluated with a scanning electron microscope. The study concluded that: 1) all brackets alter the surface enamel, 2) there is a significant difference in surface enamel damage between the metal bracket and the ceramic brackets utilizing a tensile debonding method, 3) there is no …

Soft Tissue Changes Of The Upper Lip Following Isolated Le Fort I Osteotomies, Kendall E. James

Loma Linda University Electronic Theses, Dissertations & Projects

Pre-operative (T-1) and post-operative (T-3) radiographs were obtained and traced for fifty-one non-growing patients who had undergone isolated Le Fort I osteotomies. These tracings were then digitized with the results arranged in a data file and subjected to statistical analysis. The purpose of this study was to establish ratios for certain hard to soft tissue movements that could be used to aid the clinician in post-surgical soft tissue profile prediction. The results showed that even though a large sample was used, individual patient variability remained high particularly in the horizontal directions. Most ratios found in this study were consistent with …

Condylar Angulations As Related To Submental-Vertex Radiographs, Jady L. Chiakowsky

Loma Linda University Electronic Theses, Dissertations & Projects

Pretreatment submental-vertex radiographs were obtained for 637 adolescent patients (307 males, 330 females) who had presented themselves for orthodontic treatment. The purpose of this study was to: (1) determine the relationship between condylar angulations and depth of cut with the variables: age, sex, and race, and (2) establish normative values for the categories studied. The results indicated that no significant differences existed between the condylar angulations for the variables measured. However, significant differences did exist between the depth of cut for the variables measured and there was significant interaction between age and race with respect to the depth of cut. …

Predicting Post-Treatment Maxillary Lip Position : A Comparison Of Two Techniques, Kevin J. Andrews

Loma Linda University Electronic Theses, Dissertations & Projects

The objective of this study was to compare the "drape" technique as proposed by Economides with the Holdaway technique in predicting post-treatment maxillary lip position and to determine which method was more accurate. Pre and post-treatment lateral cephalograms were traced for ninety (Caucasian) cases equally divided by sex into three treatment groups: a) non-extraction with at least 4mm of upper incisor retraction, b) extraction of upper first bicuspids only, and c) extraction of all first bicuspids. VTO's were constructed as outlined by Economides (drape) and Holdaway for prediction of post-treatment maxillary lip position. The predicted lip positions were compared to …