Orthodontics and Orthodontology Commons^™

Magnetic Forces For Intrusion Of Buccal Segments In Dolichofacial Individuals With Anterior Open Bite : A Report Of Six Cases, Rosa Maria I. Reimann-Blaseio

Loma Linda University Electronic Theses, Dissertations & Projects

The correction of anterior open bite in dolichofacial individuals with magnetic forces has been studied. The attempt was made to intrude buccal segments by using interarch magnets set in repulsion in order to correct the anterior open bite of six dolichofacial patients. It was expected to intrude the posterior sections with these magnetic forces, to autorotate the mandible and to close the anterior open bite by decreasing the lower facial height and rotating the facial axis closed. The magnets were placed in each arch only on those teeth that needed intrusion, mainly second premolars and existing molars, for a period …

The Incidence And Magnitude Of Tooth-Size Discrepancies In Caucasians, Blacks And Hispanics, Dana R. Shaltry

Loma Linda University Electronic Theses, Dissertations & Projects

The present investigation utilized the Bolton Analysis to determine the incidence and magnitude of tooth-size discrepancy in a sample of 227 orthodontic patients. Sliding calipers were used to measure the mesiodistal width of the permanent dentition on pretreatment study models of 120 Caucasian, 51 Black, and 56 Hispanic patients. The overall and anterior ratios were analyzed and the frequency and magnitude of excess maxillary and mandibular tooth structure was determined. Each racial group demonstrated a significant incidence of tooth-size discrepancy in the maxillary and mandibular arches of a magnitude (> 0.5mm) which would require some form of correction. In addition, …

A Study Of The Relationship Between Incisor Intrusion And Root Resorption, W. Michael Mcfadden

Loma Linda University Electronic Theses, Dissertations & Projects

This study examined the relationship between maxillary and mandibular incisor intrusion and root resorption. Age, sex, facial type, treatment time, extraction versus non-extraction therapy, width of the symphysis, and the angle of the incisors to skeletal reference planes were also studied for their relationship to intrusion and root resorption. Thirty-eight cases treated with utility arches for intrusion were selected. Root shortening was found to average 1.84 mm for maxillary incisors and 0.61 mm for mandibular incisors. Intrusion of incisors in a population that exhibited growth was found to be one of "holding against growth". No relationship was found to exist …

A Comparison Of Liquid And Gel Etchants Determining Shear And Tensile Bond Strengths Of Four Orthodontic Adhesives, Gary M. Edgmon

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to compare liquid and gel etchants (37% phosphoric acid) by measuring tensile and shear bond strengths of four orthodontic adhesive systems.

Four orthodontic adhesives were tested on 287 extracted human teeth, 144 of which were etched with liquid and 143 with gel. The four adhesives tested were Concise-3M, Challenge-Ormco (new product), Unite-Unitek (no mix), and Fuji Glass-ionomer filling material or cement.

To eliminate the use of wire for bracket engagement during testing, two devices were designed and machined for direct attachment to the Instron testing machine: a rigid push rod for shear force and …

Changes In The Cant Of The Occlusal Plane Evaluated In Treatment And Its Stability In Retention, Bruce S. Heinrich

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to test the hypothesis that occlusal plane changes induced by orthodontic treatment remain stable during retention, and to show that the occlusal plane cant is related to facial type and occlusal classification.

A comparison of facial type, occlusal classification, extraction status, and growth status was provided. The sample consisted of pretreatment, posttreatment, and postretention cephalometric radiographs of 156 orthodontic cases from the records of Loma Linda University School of Dentistry, Department of Orthodontics. Changes in the cant of the occlusal plane were evaluated by the Frankfort horizontal to occlusal plane angle.

Results showed that …

Bond Strength And Accuracy Of The Combined Agar-Alginate Impression System, Xavier Lepe

Master's Theses

No abstract provided.

Pre-Orthodontic Radiography Of The Temporomandibular Joint, Stephen G. Tracey

Loma Linda University Electronic Theses, Dissertations & Projects

The dental profession has given increased attention to temporomandibular joint problems in recent years. Many orthodontists have shown professional concern by taking pretreatment lateral tomograms to assess developmental abnormalities, previous injury, pathology, and condylar position. The purpose of this study was to determine the consistency of orthodontists in evaluating lateral tomograms and panoramic films, particularly when used prior to treatment. Lateral tomograms and panoramic films of 60 single joints were evaluated by 4 orthodontists on two separate occasions. A questionnaire was completed for each radiograph observed and responses were compared for interobserver and intraobserver [aggreement]. Statistically, results showed little to …

Amount Of Root Shortening Related To Type Of Fixed Appliance : A Comparison Of The 0.018" And 0.022" Bracket Slot, Thomas L. Thompson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine if a different incidence and severity of maxillary incisor apical root resorption occurs in cases treated with the 0.018 inch versus 0.022 inch slot in standard edgewise mechanics. A consecutively treated sample of 240 patients (98 boys and 142 girls), with a mean age of 13.4 years from the orthodontic clinic at Loma Linda University were studied. 120 of the cases were treated using 0.018" bracket slot with standard edgewise mechanics and 120 were treated using 0.022" non-torqued full banded standard edgewise mechanics. 60 of the cases in each of the above …

Axial Morphology And Angulation Of The Condyle In Relation To Malocclusions In Different Age Groups, Gerald P. Tadej

Loma Linda University Electronic Theses, Dissertations & Projects

Recent studies have shown that forces applied to the mandible during functional appliance and other orthodontic therapies produce measurable changes in the TMJ. It was postulated that specific malocclusions might also apply forces that could produce specific changes in the horizontal morphology of the TMJ. This study involved 104 pretreatment orthodontic patients, 44 males and 60 females. A submento-vertex analysis was performed and correlated with clinical findings including age, sex, malocclusion type, facial type, TMJ symptoms, tooth eruption sequence, crossbites and midline discrepancies. All possible correlations between the radiographic findings and the clinical malocclusions were tested with ANOVA. The width …

Effects Of Lateral Mandibular Expansion On Mandibular Morphology In The Growing Rat : A Comparative Study Of Treatment Effects With Orthopaedic And/Or Surgical Procedures, Eric Looi

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to investigate the effects of mandibular expansion by orthopaedic and surgical procedures in the growing rat mandible.

Sixty-four 35 day old Sprague Dawley Harlan rats were divided into four groups of 16 rats each and categorized as the control, orthopaedic expansion, surgery without graft and surgery with graft respectively. Prefabricated appliances were used for orthopaedic expansion of the mandibles and maintaining surgical expansion at the symphysis in the respective groups. Oxytetracycline were given intraperitoneally to mark areas of bone remodeling. Half the number of rats from each group were sacrificed at the end of …

Quick Ceph™, A Computer Program For Cephalometric Analysis And Treatment Planning, Günther Blaseio

Loma Linda University Electronic Theses, Dissertations & Projects

The quantification of cephalometric radiographs is an integral part of orthodontic treatment planning. Numerous computer programs have been designed to digitize headfilms and to provide accurate graphic output and exact measurements. Yet these early systems were either huge, bulky and expensive or were limited in their practical use. The aim of this development was to combine modern computer and electronic equipment with advanced software engineering. The result is a universal cephalometric program written in the computer language "C" with presently seven standard and virtually limitless user definable analyses, growth forecasting, mouse-driven interactive VTO, arch length calculation, superimpositions, table of values …

Corticotomy Facilitated Orthodontic Treatment In Adults : A Report Of Two Cases, Randall E. Hoff

Loma Linda University Electronic Theses, Dissertations & Projects

The corticotomy procedure is a surgical technique that has been used to facilitate orthodontic treatment for many years. Proponents of this technique contend that occlusal results are more stable and treatment time is reduced. In this study, two cases of dento-alveolar abnormality are presented that were successfully treated in a relatively short time by using the combined efforts of the surgeon and the orthodontist. Although corticotomy has limited applications, it has a place in the armamentarium of the modern orthodontist.

Key Words: Corticotomy, Adult Orthodontics, Osteotomy.

A Comparison Of Indirect Lingual Bracket Placement By Practitioners And A Commercial Laboratory As It Relates To Height And Angulation, Steven F. Brizendine

Loma Linda University Electronic Theses, Dissertations & Projects

With the increase in use of lingual appliances a more accurate assessment is needed of exactly where the brackets are being placed. This study was undertaken in order to see if it makes any difference who places the brackets. Three groups of participants were selected. One, the commercial laboratory which offers a bracket placement service. Two, clinicians experienced with the lingual appliance, and three, clinicians with no clinical experience with the appliance.

Four sets of patient models were selected from eighty cases Ormco used in the original development of their lingual bonded appliance. These were duplicated and the four sets …

Corrosion Of Orthodontic Brackets: Cost, Cold Worked, And Powdered Metal, Timothy C. Ballweber

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to evaluate the relative corrosion rates of 316-L stainless steel cast metal, cold worked, and powdered metal brackets. This is done using potentiodynamic anodic polarization to measure the voltage difference between the samples and a reference electrode. Corrosion layers effect current flow and by plotting how the current responds to an applied voltage it is possible to determine the corrosion rate of a sample. The point at where the applied voltage breaks down the passivation or oxidation layer is recorded and the relative corrosion rate is figured using the formula: Corrosion Rate _(mpy) (in …

Stability In Mechanical Expansion Of The Maxilla With Surgical/Mechanical Expansion Of The Mandible In An Adult Baboon, Robert D. Mitchell

Loma Linda University Electronic Theses, Dissertations & Projects

Expansion of the maxilla at the midpalatal suture has had much investigation and is a recognized option in orthodontic therapy. Lateral expansions of the mandible through surgical separation at the symphysis have been done in animal studies. A combination of these procedures has not yet been done together.

The purpose of this study was to expand both the maxilla and the mandible of a baboon simultaneously while maintaining occlusion. The amount of expansion and stability was studied using photographs, models, cephalograms, and tetracycline bone labels using U.V. microscopy.

A young adult baboon with full dentition and normal occlusion was used. …

Analysis Of The Time-Dependent Force Loss Of Orthodontic Wires, David Jaekwan Jo

Loma Linda University Electronic Theses, Dissertations & Projects

In testing the force loss of five brands of orthodontic wire under a variety of stress modes, it was found that; 1) heat treatment reduced force loss in all the wires; 2) the amount of time-dependent force loss increased when the magnitude of force was raised.

A further indication was that a sharp bend on the tested wire did not affect force loss. Force applied to unwind a loop produced force losses from 180 to 350% above the loss that occurred when force was applied to wind a loop.

The force loss data collected during a 72-hour period was analyzed …

Evaluation Of The Modulus Of Elasticity Of Stainless Steel Orthodontic Wire By The Acoustic Pulse-Propagation Technique, John Rick Neilson

Loma Linda University Electronic Theses, Dissertations & Projects

Confusion exists in the orthodontic literature when the modulus of elasticity of standard orthodontic wire is reported to either increase, decrease, or remain constant when that wire is heat treated or work hardening.

The objectives of this work include: 1. Introducing the acoustic pulse-propagation technique as a test for determining the modulus of elasticity in orthodontic wire, and 2. Determining if the modulus of elasticity of stainless steel orthodontic wire changes when a wire is subjected to heat treatment and work hardening.

Five sizes of stainless steel wire were evaluated: .014, .016, & .018 inch round, .016 x .016 inch …

Predictive Value Of Radiographic Analysis Of Menton, Hyoid Bone, And The Third Cervical Vertebra Angle, Kalfred G.S. Chun

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to determine if the hyoid bone could be used as a reliable and stable reference landmark. Previous researchers have used cranial landmarks to determine the hyoid bone position. The results of these studies have shown a large variability in hyoid position. To determine the hyoid bone position, an analysis called the hyoid triangle was used. The hyoid triangle is formed by joining the cephalometric points retrognathion (the most inferior posterior point on the mandibular symphysis), hyoidale (the most superior anterior point on the body of the hyoid bone), and C3 (the most anterior inferior …

Cephalometric Soft Tissue Profile Analysis Of Young Adult Koreans And Comparison With Caucasians, Joong-Chul Ahn

Master's Theses

No abstract provided.

Force Relaxation In Matched Light Titanium And Stainless Steel Wires, Granville Gene Wilson

Loma Linda University Electronic Theses, Dissertations & Projects

Force relaxation was constantly monitored in light titanium alloy and stainless steel wires over a 7 day period in a simulated use test. The smallest dimension of round titanium wires now available were matched with round stainless steel wires in dimensions that most closely approximated the same stiffness. The .016" NITINOL (Unitek) and TITANAL (Lancer Pacific) wires were compared to .012" Standard Permachrome (Unitek) wire. The .016" TMA (Ormco) wire was compared to .014" Standard Permachrome (Unitek) wire. Six samples were tested for each wire type.

Each wire was ligated with Alastic modules (Unitek) into .018" x .025" slots of …

A Comparison Of Enamel Detachments After Debonding Between Unitek's "Dynalok" Bracket And A Foil-Mesh Bracket: A Scanning Electron Microscope Study, Robert E. Meister

Loma Linda University Electronic Theses, Dissertations & Projects

The intent of this paper was to: 1. Evaluate the mode of adhesive failure when debonding both flexible and rigid base orthodontic brackets. 2. Evaluate the bracket bases for enamel detachments. 3. Measure the enamel detachments.

After preforming shear test on flexible and rigid base orthodontic brackets mounted to extracted human teeth it was determined that failure occurred at the enamel/adhesive interface 30% of the time, at the bracket/adhesive interface 10% of the time and a combination of these 60% of the time for both groups.

Five brackets from each group were evaluated for enamel detachments using energy dispersive x-ray …

Orthodontists' Attitudes Toward Expanding Career Opportunities For The Dental Hygienist In Orthodontics, Julie A. Foster

Dental Hygiene Theses & Dissertations

The purpose of this survey was to determine attitudes of orthodontists toward employing dental hygienists. A self-designed, 33 item questionnaire was used to obtain descriptive data. The questionnaire was mailed to a random sample of orthodontists chosen from the United States portion of the Orthodontic Directory of the World (N=500). Data were obtained from 298 orthodontists for a 58.6 percent response rate.

The study suggests that although orthodontists believe dental hygienists are important oral health professionals (96.2 percent) and important parts of the orthodontic practice (32.6 percent), only 10.9 percent of orthodontists surveyed employ dental hygienists. Factors determined to be …

Temporomandibular Joint Relations Of Bone And Lateral Pterygoid Muscle : A Computerized Tomography Study, Duane K. Yamashiro

Loma Linda University Electronic Theses, Dissertations & Projects

This study utilized the imaging technique of computerized tomography (CT). Scans taken with a GE CT/N 8800 scanner of an adult cadaver and a 12-patient group were obtained through the Loma Linda University School of Dentistry, TMJ Department, and Loma Linda University Medical Center, Department of Neuroradiology.

The lateral scout image and a lateral cephalogram of the cadaver were compared using six angular measurements for facial type from Ricketts' Cephalometric Analysis. The six measurements, Maxillary Depth, Facial Depth, Mandibular Arc, Mandibular Plane, Lower Face Height and Facial Axis, were found to be similar. This allowed the investigator to rely exclusively …

A Comparison Of Indirect Lingual Bracket Placement By Practitioners And A Commercial Laboratory As It Relates To Crown Torque, Randy E. Buchmiller

Loma Linda University Electronic Theses, Dissertations & Projects

Four sets of patient models were selected from the eighty cases Ormco Corporation used in the development of their lingual bonded appliance. These four sets of models were duplicated and identical sets of four models were sent to each practitioner and the laboratory. The practitioners and the laboratory were to position the lingual brackets on the models from second bicuspid to second bicuspid upper and lower and return them to Loma Linda University Department of Orthodontics for evaluation.

The laboratory chosen for placement of the brackets was the Ormco laboratory in Glendora, California. The laboratory ran these four cases through …

Cephalometric Changes In The Soft Tissue Chin After Orthodontic Treatment, Ruchi Nanda Singh

Loma Linda University Electronic Theses, Dissertations & Projects

This study was performed to cephalometrically assess the soft tissue chin changes from orthodontic treatment and after 5 years post-treatment. Variability in the soft tissue chin structure between the different facial types and between the sexes was also evaluated.

Sixty patients, treated by Dr. Ricketts, were selected from the Rocky Mountain Data system files. Pretreatment, post-treatment and 5 year post-treatment cephalograms were taken on each patient and the soft tissue chin thickness was measured at six points around the symphysis. Means and standard deviations were calculated for each point on the symphysis by sex and facial type.

The post-treatment data …

Third Molar Eruption Prediction, Michael L. Jacobsen

Loma Linda University Electronic Theses, Dissertations & Projects

The diagnosis and treatment of third molars has often been cited as a special problem to the orthodontist. If the prognosis of third molars could be determined, orthodontic treatment could progress on a more positive basis.

This study was designed to provide a method of deciding whether developing third molars will erupt or become impacted.

Records from 130 orthodontically treated cases of Dr. Fredsall⁸ were studied. Several factors were evaluated and measured using the patients' cephalometric radiographs.

The actual fate of the third molars were recorded in the hope it could be used to predict what to expect from …

A Comparison Of The Nance Holding Arch And Kloehn Headgear In Maxilliary Molar Anchorage, Michael J. Fillman

Loma Linda University Electronic Theses, Dissertations & Projects

A sample of thirty first bicuspid extraction patients, ages 9 through adult, were evaluated for maxillary molar anchorage loss during cuspid retraction. The Nance Holding Arch and Kloehn cervical headgear were compared as anchorage devices. A control group received no anchorage mechanics during cuspid retraction. All cuspids were retracted with Hilger's loop retractors.

Anchorage loss was measured cephalometrically by comparing the difference in the 6 to PTV measurement on the initial and post cuspid retraction lateral head films.

Anchorage loss, as the dependent variable, was compared to the study groups, Angle class, facial type, treatment length, palatal angle and distance …

An Evaluation Of 17-4 Precipitation-Hardenable Stainless Steel Alloy For Use As An Orthodontic Wire, Martin G. Martz

Loma Linda University Electronic Theses, Dissertations & Projects

17-4 precipitation-hardenable stainless steel, a high strength alloy developed for aircraft applications, has been examined for possible use in orthodontics. The effects of solution treatment, various refrigeration treatments, and various aging treatments on standard tensile properties were measured. Comparisons were made with the tensile properties of 18-8 stainless steel and a Co-Cr alloy presently used in orthodontics.

Solution treatment was found to decrease ultimate strength by 37.8%, 0.2% yield strength by 45.9%, and (YS)/E ratio by 36.7%, while having almost no effect on elastic modulus or percentage elongation. Refrigeration treatments had statistically significant but small effects on tensile properties. Aging …

Effects Of Stress Relief To Decrease Force Loss In Retraction Springs, Richard Earl Dunn

Loma Linda University Electronic Theses, Dissertations & Projects

Orthodontic wire may be heat treated to relieve residual stresses resulting from the formation of bent configurations. This study utilized electronic equipment to detect and record the initial amount of activation force, and the amount of force lost due to the intrinsic properties of the wire. The information was gathered at three hour intervals over fifteen one-week periods. The data were statistically analyzed by a computer to deter mine means and standard deviations. A general linear hypothesis was utilized to test covariants and the main effects.

A total of forty-eight wires were tested. Closed he lix retraction springs fabricated from …

Mandibular Repositioning With Frankel Appliance Therapy, Clark E. Schneekluth

Loma Linda University Electronic Theses, Dissertations & Projects

A sample of twelve Frankel appliance (FR-2) treated patients, in the mixed dentition stage, were selectively chosen by an orthodontist based on the Class II correction and evaluated from before treatment and end of treatment laminagraphic and lateral cephalometric radiographs. The average treatment period was 22 months (1 yr. 10 mos.). The average pre-treatment age was 9.5 years with a range from 8 to 11 years old, while the average post-treatment age was 11.3 years with a range of 10 to 13 years.

Frankel appliance therapy was the only form of mechanics used in this study.

The before treatment lateral …