Orthodontics and Orthodontology Commons^™

An Evaluation Of The Short And Long Term Effects Of Quad Helix Expansion, Sonja F. Finnie

Loma Linda University Electronic Theses, Dissertations & Projects

This study was conducted to examine, retrospectively, orthodontic and orthopedic changes resulting from quad helix expansion therapy in mixed and permanent dentition stages. Twenty-one subjects with an average age of 10.2 years who experienced an expansion of at least 3 mm with the quad helix appliance were selected for this study. The subjects were evaluated according to facial type and age for both short and long-term stability. Plaster dental casts and posteroanterior (frontal) radiographs were evaluated at the beginning of treatment (T1), at the completion of Phase 1 or full treatment (T2), and approximately two years following the completion of …

Failure Mode Of An Orthodontic Resin Alone And With Bonded Brackets, Marc Cody Dunn

Loma Linda University Electronic Theses, Dissertations & Projects

Since the introduction of bonded orthodontic brackets in the early 1960's spontaneous debonding has been a constant nemesis. Most attempts to avoid this problem by orthodontic manufactures have focused on "bond strength" issue. Whether they chose to address the materials, the bracket base or both, the common method used to evaluate improvements entailed the use of just one testing apparatus: a static universal testing machine such as the Instron.

Metal, ceramic and plastic bonded brackets were tested with the traditional shear/peel method as well as a new high strain rate impact test. The resin itself was also evaluated for physical …

Clinical Debonding Simulation Study Of One Metal And Two Ceramic Brackets, Hyunsup Shim

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to compare two mechanical debonding methods on ceramic brackets (TP MXi and 3M Clarity) and a metal bracket (GAC OmniArch) with four different bonding materials (light-cured, one-step chemical-cured, two-step chemical-cured, and Fuji GIC) in clinical simulation, where the diametral force was applied on the handle of the pliers. The effectiveness of mechanical debonding technique was determined by evaluating the following variables: the amount of force required to debond the bracket, the amount of residual adhesive remaining on the enamel surface, the frequency of unexpected bracket failure, and the prevalence of visible enamel damage. The …

Establishing Norms For A Mexican Group Using Ricketts, Steiner And Arnett Analyses, Mauricio Gonzalez Balut

Loma Linda University Electronic Theses, Dissertations & Projects

Most existing cephalometric analyses are based on norms for the Caucasian population. Therefore, they cannot be properly applied for Mexican or Hispanic patients. Ethnic variations in the normal positions of the maxilla and mandible influence and alter the diagnosis and treatment plan for each of the different type of malocclusions. Previous studies have addressed the difference between the Caucasian norms and the Hispanic norms, this indicates the variety of their skeletal, dental and facial features.

It is the purpose of this study to establish specific cephalometric standards for the native Mexican group, using the Steiner and Ricketts analyses along with …

A Cephalometric Study Of The Class Ii Correction Effects Of The Eureka Spring, Ernest L. Stromeyer

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of the Eureka Spring appliance, was investigated on 37 consecutively treated, non compliant, bilateral Class II malocclusions, requiring at least 3 mm or more of additional molar correction. The mean pretreatment age of this sample was 13.9 years. All patients were treated by a single clinician utilizing the Eureka Spring. Lateral cephalographs were taken at start of orthodontic treatment (T1), at insertion of Eureka Springs (T2), and at removal of the Eureka Springs (T3). The average treatment interval between T2 and T3 was 4 months. Class II correction occurred almost entirely by dentoalveolar movement, 33% in the maxilla …

A Pilot Study On The Short Term Effects Of The Herbst Appliance On The Glenoid Fossa, David A. Bennion

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this pilot study was to evaluate the initial effects of the Herbst appliance and determine through the use of common cephalometric radiographs that were optically enhanced and then digitally reproduced, if fossa migration is taking place. Fourteen, (6 male, 8 female), growing patients were treated by the same clinician for the correction of a Class II malocclusion using a modified Herbst appliance. Pretreatment (T₁) standard lateral cephalometric radiographs and post Herbst treatment (T_H) optically enhanced lateral cephalometric radiographs were taken. All radiographs were digitally captured and reproduced so 6 linear and 1 area …

Treatment Effects Of The Edgewise Bioprogressive Herbst Appliance, Bernard C. Chang

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of the Edgewise Bioprogressive Herbst appliance, as described by Dr. Terry Dischinger, was investigated on 24 Class II, Division 1 malocclusions. Mean pretreatment age of this sample was 11.2 months. All patients were treated by Dischinger with a Bioprogressive Herbst appliance. Lateral cephalographs taken before, after Herbst appliance therapy, and after edgewise treatment were traced, then digitized into Quick Ceph™. Measurements were computed by the computer software. The following results were found: 1) Average treatment time was 9 months. 2) An overcorrected Class I relationship was achieved. 3) Class II malocclusion was corrected by 4.5 mm skeletal alteration …

The Accuracy Of Computer Video Imaging Prediction : Just Prior To Surgical Mandibular Advancement/Genioplasty Orthognathic Cases, Jason T. Chiakowsky

Loma Linda University Electronic Theses, Dissertations & Projects

The accuracy of the computer video imaging treatment prediction was investigated using Quick Ceph Image.™ Thirty one surgical mandibular advancement/genioplasty orthognathic cases were examined to determine if the soft tissue profile prediction was representative of the actual result. All patients were over the age of 18. Lateral cephalographs and slides were taken immediately pre-surgically, and six months post-surgically. The slides were duplicated into 4X6 photographs. The cephalographs were digitized and the photographs captured by video on the Quick Ceph Image software program. A line drawing and computer video image treatment prediction were generated using the actual surgical change that had …

Mandibular Asymmetry In Unilateral Class Ii Malocclusion : A Cephalometric Study, Raed Z. Moussa

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to evaluate skeletal and dental asymmetry in unilateral class II malocclusion. A study group of 25 unilateral subdivision patients was compared to 25 class I malocclusion patients serving as the control group. Submento-vertical and frontal radiographs were used for the evaluation. Symmetry was evaluated by comparing measurements between right and left sides for both groups and matching the middle points with the midsagittal axis. Statistical paired and simple t-test were used to evaluate the difference between the two sides for both groups. The measurements showed no significant skeletal and dental asymmetries except for three …

The Rotations Of Maxillary Molars, Mandibular Molars, And Maxillary First Premolars In Acceptable Occlusions, G. Kristian Hansen

Loma Linda University Electronic Theses, Dissertations & Projects

The rotation of the maxillary molars is considered important in the orthodontic treatment of malocclusions. In this study a computer analysis program was developed to examine the rotations of maxillary molars, mandibular molars, and maxillary first premolars in casts of permanent dentitions with acceptable occlusions. Ninety three sets of untreated "acceptable occlusion" models from the collection of the Foundation for Orthodontic Research (FOR) were scanned on a flat bed scanner at 600 dots per inch (dpi). The images were analyzed using custom software on a computer. Measurements were made by relating maxillary first permanent molars to the midline, the archform, …

The Effects Of Rapid Palatal Expansion Therapy On The Periodontal Tissues Of The Central Incisors, Richard Gutierrez

Loma Linda University Electronic Theses, Dissertations & Projects

The periodontal structures around the maxillary central incisors in thirty-nine post-orthodontically treated patients, twenty-five of these patients had experienced Rapid Palatal Expansion (RPE), were examined to determine the periodontal consequences associated with two ways of managing the resultant diastema. In fourteen patients the diastema closure was assisted by elastomeric chain and in eleven patients the diastema closure was not assisted. Fourteen non-RPE orthodontically treated patients served as controls. Height of attached gingiva, gingival sulcus depth, attachment level, and alveolar bone level were recorded. One examiner, using calibrated techniques, performed all the measurements. The RPE groups and the control group all …

A Pilot Study Comparing The Forces Applied : Using A Chin Cup And Three Types Of Protraction Headgear, Daniel Miles Beisiegel

Loma Linda University Electronic Theses, Dissertations & Projects

A pilot study comparing force distributions of a chin cup, the Great Lakes reverse pull headgear (RPHG), Ormco's adjustable dynamic RPHG, and Grummons RPHG was done. A skull from a 69 year old female which demonstrated a Class III malocclusion was used to perform the tests of force. Forces applied to and generated on the skull were measured using a water-filled balloon system. This method was tested and found to be reliable and accurate.

Repeated measurements of force were recorded for each of the areas of stress (forehead, cheeks, chin, and condyles, as well as the posterior and superior portions …

An In Vitro Quantitative Evaluation And Comparison Of A Custom And A Popular Stock Orthodontic Appliance, Richard Scott Anderw Schalo

Loma Linda University Electronic Theses, Dissertations & Projects

An in vitro performance evaluation and comparison of a patient individualized appliance (Elan, Ormco Corporation, Glendora, California) and a Roth prescription appliance ("A"- Company, San Diego, California) was made using the Ideal Tooth Relationship Index (ITRI).

The sample consisted of 19 duplicated sets of models for a total sample of 38. For each pair of models one set was bonded with an Elan appliance and a duplicated set was bonded with a Roth appliance. Bracket placement followed the manufacturers recommendations. The bracketed teeth from these models were sectioned out individually and the appliances allowed to fully express themselves on full …

Load Deformation Test Of Mini Twin Metal Brackets : A Comparative Study, Karl D. Peach

Loma Linda University Electronic Theses, Dissertations & Projects

The trend toward more esthetic brackets has led to smaller brackets being used by orthodontists. The purpose of this study was to determine the force required to deform these smaller brackets and calculate the stress in the metal by using a torsional wire bending force. Ten types of brackets were tested and the results analyzed to determine how bracket geometry, manufacturing method, or material selection affected the strength of brackets. Results showed a significant difference between manufacturing methods, material used, and bracket geometry. Brackets made of 17-4 PH SS and 303 SS withstood higher stress than 316 SS, and all …

An Assessment Of Three Different Forms Of Sterlization And Clinical Usage On Various Orthodontic Pin And Ligature Cutters : A Pilot Study, Warren L. Creed

Loma Linda University Electronic Theses, Dissertations & Projects

With an awareness of cross infection in dentistry and of AIDS (acquired immune deficiency syndrome), sterilization in the dental office has been brought to the public's attention by the news media. Much work has been done on which sterilization methods are acceptable but little has been written about the effects of sterilization procedures on the instruments themselves. In this study, 36 pin and ligature cutters were sterilized 250 cycles using three different methods of sterilization following the guidelines given by the Center for Disease Control (CDC). The cutters were examined for changes in lateral hinge movement, visual appearance and ordinal …

The Fracture Strength Of Ceramic Brackets : An Update And Comparison, Christian P. Manley

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to compare the fracture strength of ceramic brackets which are currently on the market with ceramic brackets tested in a previous study at Loma Linda. Fracture strengths of standard edgewise ceramic brackets vs. pre-torqued ceramic brackets and bicuspid ceramic brackets vs. central incisor ceramic brackets were also compared.

A total of 160 Polycrystalline brackets, 8 categories in groups if 20, were tested for fracture strength. Each bracket was tested using the same testing model that was used in the previous study at Loma Linda. The brackets were tested by torquing a wire within the …

The Accuracy Of Sonographic Imaging (Dolphintm Digigraph) And Standard Lateral Cephalometric Radiographs : A Comparative Study, Michael D. Teichman

Loma Linda University Electronic Theses, Dissertations & Projects

Radiation due to x-ray exposure is a concern, and the development of the Dolphin™ DigiGraph represents an attempt to limit this exposure. The purpose of this paper was to compare measurements (using Ricketts analysis) obtained from conventional radiographic cephalometric tracings with those obtained by computerized digitizing with the DigiGraph. Forty-six patients from the Loma Linda University School of Dentistry graduate orthodontic clinic were digitized, and the results were compared to the x-ray tracings of these patients. The results showed that seven of the twenty-one variables examined exhibited a statistical similarity between the two methods (DigiGraph and x-ray tracing). An examination …

The Use Of Corrected Occlusal X-Ray For Determination Of Ald : A Comparative Study, Merlin D. Ekvall

Loma Linda University Electronic Theses, Dissertations & Projects

In this study arch length discrepancy or ALD was studied in 50 untreated patients. The measurements obtained from Hilgers' corrected occlusal x-ray using his Occlusal Paralleling Instrument or O.P.I, were compared with those derived by four conventional methods, - "Eye balling," digital caliper determination, conventional mandibular x-ray, and the Rocky Mountain Data Systems computer analysis (31 cases). When using the OPI, results give a higher negative ALD as it takes into consideration the space required to level a curve of Spee.

Measurements were made by the author and 3 faculty members using the above methods. Statistical analysis of the means …

The Long Term Stability Of The Dental Arches Following Rapid Palatal Expansion, Robert C. Stockdale

Loma Linda University Electronic Theses, Dissertations & Projects

The rapid palatal expander is an appliance which has been used to laterally expand the maxillary dental arch, with subsequent mandibular dental arch expansion.

The purpose of this study was to evaluate and quantify long term post treatment changes in the length and width of both dental arches following rapid palatal expansion.

Plaster models from eleven patients treated with rapid palatal expansion were obtained seven or more years after treatment. The dental arches were intact anterior to the first molars and no retreatment had taken place.

Maxillary and mandibular canine, premolar and molar arch width, arch length, arch circumference, and …

Evaluation Of Headgear Safety : A Comparative Study, William J. Pritchard

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the relative safety of headgear safety straps. Samples from five different safety headgear straps simulated orthopedic and orthodontic use and data were collected from a series of pulls on an Instron machine. The straps were compared by the distance the face bow traveled before the safety mechanism released, the force built into the face bow at safety release and the force required to remove the inner bow out of the molar tube. The conclusions are as follows: (1) the distance a face bow can travel from the molar tube and still be …

A Modified Nance Unilateral Molar Distalizer, Tracy J. Reiner

Loma Linda University Electronic Theses, Dissertations & Projects

This clinical study evaluated a modified Nance appliance designed by the author to distalize molars unilaterally for Class II correction. This fixed appliance did not rely upon extraoral traction or intraoral elastics. Twelve unilateral Class II patients aged 13 to 17 were treated nonextraction with the appliance. Pretreatment and posttreatment photographs were taken of the palatal soft tissue and did not reveal any untoward changes as a result of the Nance acrylic button. All molars were corrected to an Angle's Class I relationship. Molar correction was evaluated visually and molar distalization was measured using an acrylic jig fitted to the …

Feasibility Of An Extraoral Method For Predicting Manibular Incisor Relapse, Mark J. Saylor

Loma Linda University Electronic Theses, Dissertations & Projects

The author undertook to develop an extraoral model for predicting mandibular incisor relapse similar to the model described by Harvey and Sheldon Peck. Whereas the Peck and Peck method involves intraoral measurements, the method described in this paper relied on the taking of measurements from the patient's pre-treatment plaster models. Two hundred and sixty teeth were measured both orally and on plaster casts, and several statistical tests were performed to isolate any differences between the intraoral and extraoral methods. The principal difference was identified as the faciolingual measurement of the incisor, due to the height of contour often being subgingival …

A Non-Human Primate Model For Studying Corticotomy-Facilitated Orthodontic Tooth Movement, R. David Rynearson

Loma Linda University Electronic Theses, Dissertations & Projects

This study was undertaken to test the hypothesis that a corticotomised tooth moves as a tooth-bone unit when under orthodontic force. A non-human primate model was designed to test the hypothesis. The non-human primate selected was Macaca fasicularis. Three adult males with erupted third molars were chosen so that extrapolation could be made to the adult human. The methods employed included the following: 1) Each animal had one treatment quadrant and one control quadrant per arch; 2) Pre-op and post-op study models were made; 3) All 2nd premolars, 2nd molars, and 3rd molars were banded; 4) A full-thickness flap …

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 …

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 …

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 …

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 …

A Comparison Of Two Rapid Palatal Expansion Appliances And Their Effect On Palatal Cross-Sectional Area, William D. Scott

Loma Linda University Electronic Theses, Dissertations & Projects

Two rapid palatal expansion appliances, acrylic-free and acrylic-reinforced, were compared for their effect on the cross-sectional area of the palate. Two groups, twenty-five patients in each, were selected so that they would match as closely as possible with regards to age and sex distribution. The pre-treatment and post-treatment maxillary models were duplicated, and this duplicate model was then trimmed in a specific manner to allow the cross-sectional area between the first permanent molars to be compared. The results indicate that there is no difference, at the five percent level of significance, between these two appliances. It is concluded that the …

A Correlation Study Of Facial Soft Tissue Proportions (Golden Sections) And Cephalometric Measurements Of Golden Sections And The Eleven Factor Analysis, Russell Andrew Sutliff

Loma Linda University Electronic Theses, Dissertations & Projects

Frontal photographs on a total of one hundred and three individuals who had been treated by Dr. Ricketts, and had been involved in a prior study at Rocky Mountain Data Systems, were evaluated for facial proportions according to Ricketts application of Pythagoras' golden section. Seven facial proportions were analyzed from 1:1 retention phase frontal photographs. Forty individuals, made up of twenty-two females and eighteen males, 12.2 to 21.0 years of age, were selected and divided into two groups of twenty each, according to their soft tissue facial proportions. A range of acceptability for the facial proportions was derived. Proportions within …

The Effects Of Second Molar Extractions In Conjunction With Bionator Treatment, Mohammed Toufic Jeiroudi

Loma Linda University Electronic Theses, Dissertations & Projects

The intent of this paper is to evaluate the effects of second molar extractions in conjunction with Bionator treatments. Eighteen Orthodontic patients were used in this study. All had had second molars extracted. Lateral cephalometric radiographs were traced and used to evaluate the treatment. The average age at time of extraction was 13 years, 3 months. The average treatment time was 38.3 months.

There were some orthopedic changes. The convexity decreased significantly, the condyle axis increased more than expected in normal growth. Also, the lower facial height and facial axis both became more dolichotype (open).

The upper and lower incisors …