Orthodontics and Orthodontology Commons^™

Evaluation Of Apical, Coronal And Occlusal Form Diffrences With Conventional Orthodontic Treatment, Tamar Sardarian

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Cone-beam computed tomography (CBCT) can be used to accurately identify dental landmarks in order to detect changes in dental arch forms. Purpose: The objective of this study was to determine how apical, coronal and occlusal arch forms change following orthodontic treatment with fixed appliances and to establish a base for future studies. Material and Methods: Maxillary and mandibular apical, coronal and occlusal landmarks of 27 subjects were selected on their respective CBCT images at two time points: pre-orthodontic treatment (T1) and post-orthodontic treatment (T2). Comparisons were made between the two time points to evaluate how each arch form changed …

Mechanical Evaluation Of Mandibular Defects Restored With Rhbmp-2: A Finite Element Model, Jelson Yalung

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The utilization of recombinant human Bone Morphogenetic Protein-2 (rh- BMP2) to form new bone has been shown to be a promising alternative to autogenous bone grafts. Understanding the biomechanical properties of rhBMP-2 restored mandibular defects would provide useful knowledge in the future success of orthopedic and dental treatment in patients who have had restoration of mandibular defects with rhBMP-2. The aim of the study was to evaluate and compare the biomechanical characteristics of rhBMP-2 regenerated bone in mandibular defects using 2 different concentrations of rhBMP-2 with a given carrier in non-human primates Material and Methods: Critical-sized defects (approximately 2.5 …

Influence Of Outdoor Air Quality On Maxillofacial Growth And Development, Ryan Rudd

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Mild to moderate deviations from normal facial types can significantly change orthodontic treatment modalities. Studies linking ambient air pollution with respiratory problems, as well as craniofacial morphology with respiratory problems are well established.1-19 In this study we aimed to determine if there was a correlation between ambient air pollution and maxillofacial growth and development. We also wanted to determine if further research should be done in this area, and if so how can the study be improved. Materials and Methods: We selected Santa Maria, CA and Upland, CA as sample areas due to their significant differences in air quality. …

Profile Attractiveness In Borderline Class Iii Surgical/Orthodontic Cases, Melina Adamian

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: This study evaluated differences between laypersons and orthodontists in rating facial attractiveness in borderline class III surgical/orthodontic cases. The purpose was to determine whether orthognathic surgery or camouflage is a better alternative for observable esthetic improvement in borderline Class III surgical/orthodontic patients. This study will aid the orthodontist in recommending treatment options to enhance profile attractiveness of borderline Class III surgical/orthodontic patients. Materials and Methods: Thirty profile images of treated borderline class III surgical/orthodontic cases were selected. Fifteen of the profile images were of cases that had been treated by orthodontics alone, and fifteen images were of cases that …

Cone-Beam Computed Tomography And Orthodontics: Awareness Assessment, Warren D. Libby

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this study was to evaluate a specific orthodontic community's knowledge and understanding of Cone-Beam Computed Tomography (CBCT) technology as well as awareness of the implications of CBCT use, including risk assessment, radiation dose estimation, diagnostic utility, and issues of informed consent. It is incumbent on the profession to understand how practitioners view this technology as it gains popularity and ease of use. Materials and Methods: A 21-question survey with 13 additional demographic questions was distributed to several different populations affiliated with Loma Linda University School of Dentistry: 1) undergraduate dental students, 2) students in specialty programs …

Sleeping Tongue Posture And Its Relationship To Craniofacial Morphology, Brent J. Tingey

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: There exists good consensus in the literature supporting the notion that resting tongue posture is an important factor in dental arch development and maintenance as well as airway control. What has yet to be quantitatively measured is the duration of time that a subconscious, resting tongue posture is maintained and whether such posture differs among various craniofacial morphologies. Quantifiable measurements might allow for prediction of tongue-posture-related problems specific to certain facial types. Purpose: The objective of this study was to record sleeping tongue posture over time in 27 subjects and to compare findings with craniofacial morphology determined by cephalometric …

Accuracy Of Unsegmented Cbct In Mesial-Distal Tooth Measurements, Todd Wesslen

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Cone-beam computed tomography (CBCT) scans may be used to measure mesial-distal (MD) tooth width for orthodontic diagnosis and treatment planning. Purpose: The objective of this study was to determine if MD tooth measurements from unsegemented CBCT scans in the axial, sagittal, and coronal planes or from a panoramic reconstruction correlate and agree with respective measurements made on study models. Material and Methods: Using stone models of 30 subjects, reference MD tooth measurements were made using digital calipers. From CBCT scans, five different methods of measuring MD width were used and compared to the reference: (1) points chosen from orthogonal …

Effects Of Orthodontic Treatment On Social Perceptions, Sherry A. Caraveo

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this study was to record first impressions elicited by photographs of orthodontic patients before and after treatment to test the hypothesis that after treatment patients will elicit a more positive first impression.

Methods and Materials: Before (Tl) and After (T2) photographs of six orthodontic patients equally divided by gender and standardized for background facial attractiveness were selected. Three different malocclusions were represented: 1) Class 1 crowded, 2) Class 11 div 1, and 3) Class 111. 108 college students rated each photographed patient on three attributes: physical attractiveness, intelligence and social desirability. Participants recorded their responses on …

Cephalometric Analysis Using Magnetic Resonance Imaging, Wade A. Williams

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to determine if T1-weighted 3D magnetic resonance images performed at 3.0 Tesla could be used to conduct routine orthodontic cephalometric analysis.

Methods: Three cranial imaging methods were compared using sixteen non-growing subjects (10 male and 6 female) who were not claustrophobic, did not have any metallic restorations on the distal of first molars, had no medical implants and the female subjects were not pregnant. Sagittal cranial images were produced by three methods: (1) a digital lateral cephalometric (LC) radiograph (Orthophos XG Plus, Sirona^TM, Bensheim, Germany), (2) a 12-inch FOV cone beam …

Precision Of Temporary Anchorage Device Placement With 2d Vs. 3d Diagnostic Tools And Surgical Guides, Howard Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Current methods of temporary anchorage device (TAD) planning and placement are performed by radiographic analysis in a two-dimensional plane that lends itself to inaccuracy secondary to variations in the angle from which the radiograph is taken, as well as the magnification of the radiographic image, resulting in an increased likelihood of placement errors. The purpose of this study was to compare a three-dimensional (3D) TAD planning and placement technique to a traditional two-dimensional (2D) technique. In the 2D group, periapical radiographs and pre-fabricated wire guides were used for planning and placement of TADs on five plastic models. For the 3D …

Influence Of Mandibular Fixed Retainers On Diagnostic Quality Of Cranial Mri, Norman E. Carter

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the diagnostic quality of MR images taken on subjects with different types of orthodontic lingual retainers in place. The study provides guidelines and recommendations for use of lingual retainer materials in those patients who are or may potentially undergo routine magnetic resonance imaging. Ten subjects had impressions taken and models made for retainer tray fabrication. Removable trays with each lingual retainer material incorporated in them were fabricated from the models. Subjects underwent scans with each of the five test trays in place. T1 sagittal (T1), T2 axial (T2), gradient echo (GRE), and …

Variability In Selecting Lateral Cephalometric Landmarks In Two Cbct Image Modes, Dana Nguyen

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to determine the variability of lateral cephalometric landmark selection in two cone beam computed tomography (CBCT) lateral cephalometric simulations: 1) a mean projection image (MPI) and 2) a serial sagittal slice image (SSSI).

Methods: A MPI is a two-dimensional (2D) image obtained from the NewTom 3G^TM CBCT that resembles the conventional lateral cephalogram. A SSSI is a 2D image also obtained from CBCT data, but is created by superimposing a series of selected thin sagittal slices containing the required cephalometric landmarks. This study compared the Ricketts and Steiner analysis of the MPI …

Prevalence Of Degenerative Joint Disease In A Pre-Orthodontic Adolescent Sample, Marie Mansour

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this research was to determine a prevalence of degenerative joint disease in our pre-orthodontic adolescent patients age ten through seventeen. The prevalence was assessed according to gender. Severity of DJD was established for each patient and a "red flag" for diagnosis was identified. The purpose was also to establish norms for joint space for patients with and without degenerative joint disease. Correlations to distal condyle position and angle classification were described. 123 consecutive patients, 77 female and 46 male T1 NewTom records were reviewed. Severity of DJD was classified according to none, mild, moderate, and severe. Sagittal …

Measured Effects Of Rapid Palatal Expansion On Nasal Cavity Volume Utilizing Cbct, Jon Neal Robinson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate and predict the expected changes that occur in the nasal cavity volume following rapid palatal expansion. Eighteen subjects (11 female, 7 male), ages 9 to 18, requiring rapid palatal expansion in conjunction with comprehensive orthodontic treatment, were selected for the study. Rapid palatal expansion was accomplished using the standard, banded hyrax appliance. Three-dimensional cone beam computed tomograms using the NewTom 9000™ were acquired before and after expansion. Serial coronal slices of the nasal cavity were made using the QV9000™ software program. The resultant serial images were imported into 3-D Doctor™ for analysis …

Evaluation Of Alveolar And Soft Tissue Changes After Muscular Release Surgery In Patients Undergoing Fixed Orthodontic Therapy, Virginia Bernal

Loma Linda University Electronic Theses, Dissertations & Projects

This study compared pre-treatment to post-treatment changes in patients undergoing fixed orthodontic therapy who have had muscular release surgery. The alveolar and soft tissue changes in the mandible of 128 subjects from a private practice in Northern Italy (74 females and 54 males) were analyzed. In addition, comparisons were made of changes related to age, gender, facial type, and movement of the lower incisor. Lateral cephalograms were analyzed before and after treatment for skeletal, esthetic, and dentoalveolar changes. Photographs were used to assess changes in the soft tissue of the lower anterior region at pretreatment (Tl) versus post-treatment (T2). The …

Post-Treatment Evaluation Of Isometric Function Of The Elevator Muscles, Margaret Barbara Kowalczyk

Loma Linda University Electronic Theses, Dissertations & Projects

This study mainly examined neuromuscular function, occlusal index, and centric relation-centric occlusion (CR-CO) discrepancy of 23 orthodontically treated patients. Phase I, craniofacial anomalous, and orthognathnic surgery cases were excluded from the study. Record taking was done in 2 sessions: (1) at the time of deband and (2) 3-4 months later. Records taken at each session included facial and intraoral photographs, impressions, CR wax bites, a facebow, and surface EMG (sEMG) recordings.

For the sEMG recordings, electrodes were placed on the upper hyoid, masseter, and anterior temporalis muscles. Subjects were asked to perform numerous tests; these included baseline, clenching to test …

An In Vitro Study Of Plaque Deposition And Its Comparative Effect On Bond Strength, Debra L. Finch Cook

Loma Linda University Electronic Theses, Dissertations & Projects

Treatment with fixed orthodontic appliances can change the environment in the oral cavity by creating stagnant areas that facilitate bacterial colonization and substance retention. The purpose of this study was to examine in vitro plaque formation associated with bonded orthodontic appliances and how this could affect bonding strengths.

Ortho Concise and Transbond XT were the composite resin materials used in this study. Mandibular incisor metal brackets were bonded to bovine mandibular anterior teeth. Each composite resin was studied in two groups: plaque growth and without plaque growth, and their bond strengths were compared at time intervals of 3,45, and 180 …

A New Soft Tissue Analysis : To Establish Facial Esthetic Norms In Young Adult Females, Anne Béress

Loma Linda University Electronic Theses, Dissertations & Projects

Two hundred and fifty-five articles, books, and masters theses were reviewed for the most frequently applied soft tissue measurements in the literature in order to develop a new soft tissue analysis computer program that includes established soft tissue measurements and the newly developed globe analysis. A meta analysis of 20 normal occlusion studies, was performed to obtain mean values and standard deviations to form a large sample size. Inclusion criteria for articles in the meta analysis were normal occlusion, no orthodontic treatment, pleasing faces, statement on age, race, and lip position of the population. For the lateral view, angular and …

Facial Typing Methods : A Comparative Study, James A. Grabow

Loma Linda University Electronic Theses, Dissertations & Projects

Facial typing methods are used to determine to which of three basic facial pattern categories an individual patient belongs. These three categories are mesofacial, brachyfacial, and dolichofacial. It is important to establish the correct facial type because the reaction to treatment mechanics and the stability of the denture is dependent upon the analysis of the facial patterns. The purpose of this paper was to show a comparative study of facial typing classification methods used on 100 patients (47 boys and 53 girls). The eight different methods used were as follows: Bioprogressive, Ricketts LLU1, LLU2, QuickCeph™, Jarabak, Facial-Mandibular Index, and Steiner. …

An Anthropometric Study Of The Face And Dentition Of The Apache Indian Population At The Stewart Indian School, Garold D. Becker

Loma Linda University Electronic Theses, Dissertations & Projects

Cephalometric and dental morphology records were obtained from forty-three contemporary Apache Indian subjects (living at the Stewart Boarding School for Indians, Carson City, Nevada) to study the cranial, facial, skeletal and dentitional patterns and compare discriminately to other contemporary North American Indian groups: Pima, Papago, Mayo and Chamula. Materials on other Indian tribes considered were obtained from studies completed at Loma Linda University. The data obtained from dental morphology analysis of the Apache Indian subjects was com pared to the Mongoloid Master Pattern (1-4) as described by Moorrees (1957).

The contemporary Apache Indian conformed to the Mongoloid Master Pattern for …