Orthodontics and Orthodontology Commons^™

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 …

Civic Attitude And Activity Of Loma Linda University Dental Graduates, Gregory W. Olson

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Dentistry is regarded as a profession and granted certain privileges, such as self-regulation. Associated with this status are stated and implied responsibilities which are widely debated. In recent years, dental professionalism seems to be on the decline. Evidence cited includes access-to-care issues and decreased public trust in dentists. In response, academia and professional organizations have developed curricula and statements intended to bolster professionalism. Meanwhile little is known about practicing dentists’ attitudes or participation in health-related civic matters. Objectives: This study seeks to examine the importance Loma Linda University (LLU) dental graduates place on public roles, their reported participation in …

The Influence Of Outdoor Air Quality On Vertical And Transverse Dental Dimensions, Vanessa Jenee Kaplan

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Ambient air pollution exposure is significantly associated with increased posterior crossbite tendency. Purpose: The objectives of this study were to assess whether there was an association between exposure to ambient air pollution and skeletal and dental measurements of vertical and transverse dimension among adolescents in a clinical cohort in Southern California, and to determine what methods may be best suited for use in future research. Materials and Methods: 179 subjects’ addresses were geocoded and ambient air pollution exposure was calculated based on the Environmental Protection Agency’s (EPA) air quality and emissions databases. Vertical and transverse measurements made from subjects’ …

Three-Dimensional Evaluation Of The Effect Of Maxillary Incisor Retraction On The Palatal Bone And Root Resorption, Jessica R. Lynch Dmd

Master's Theses

Introduction: The objective of this study was to compare pre-treatment and post-treatment cone-beam computed tomography images of patients to quantitatively evaluate the effect of orthodontically retracting maxillary incisors on the height and labiolingual thickness of labial and palatal alveolar bone and incisor apical root resorption. Methods: Maxillary central incisor apical root resorption, labial and palatal alveolar bone height, and labiolingual thickness were assessed on pre-treatment and post-treatment cone-beam computed tomography scans of 59 subjects (mean age, 13.00 years) with premolar extractions and 63 subjects (mean age, 13.40 years) who were treated with non-extraction therapy. Results: The mean incisor apical root …

Efficacy Of Temporary Fixed Retention Following Comprehensive Orthodontic Treatment, Mark J. Owens

Theses and Dissertations (ETD)

Instability of the occlusion is a common problem following orthodontic treatment. The purpose of the present research was to evaluate posttreatment relapse at long-term recall (> 10 years) in cases (A) treated with temporary fixed mandibular retention plus Hawley retainers compared to (B) a similar group retained with just removable retention (standard Hawley type retainers alone). Fixed retainers were removed after having been in place for about 2.5 years. Following this period, use of removable retention was left up to the discretion of the patient in both groups. Data consisted of orthodontic records of 166 American whites, all of whom …

Craniofacial Changes Following Nonextraction Orthodontic Treatment: A Long-Term Cephalometric Analysis, James Austin Rahaim

Theses and Dissertations (ETD)

Long-term posttreatment cephalometric changes from late adolescence into early adulthood were analyzed in this study. Lateral cephalometric radiographs from a sample of 30 Class II division 1 Caucasian females treated without extractions were evaluated at posttreatment (mean age = 15.9 years) and recall (mean age = 28.3 years). All of the subjects were treated in the private practice of a single, experienced practitioner. The cephalograms were examined to investigate changes in the cranial base, midface, maxilla, mandible, maxillomandibular relationships, dental relationships, and the soft tissue profile that occurred at an average of 12.4 years posttreatment. Descriptive and inferential statistics were …

The Long-Term Stability Of Class Ii Cases Treated In A Private Practice Using A Straightwire Appliance: A Dental Cast Analysis, Lina K. Kulkarni

Theses and Dissertations (ETD)

Achieving long-term stability after orthodontic treatment is a major challenge for orthodontists. The previous literature shows that relapse occurs at a considerable magnitude. The purpose of the present study was to determine the amount and type of long-term, posttreatment relapse that occurs in a homogeneous group of patients treated by a single experienced orthodontist in a private practice setting. Dental casts from a sample of 30 Class II division 1 Caucasian females treated without extractions were evaluated at pretreatment (mean age = 13.1 years), posttreatment (mean age = 15.9 years) and recall (mean age = 28.3 years) to determine the …

Frictional Resistance Of Aesthetic Orthodontic Arch Wires Compared To Traditional Arch Wires Before And After Toothbrush Abrasion, Stephen Yamodis, Jeremy Manuele, Adam Kessler, Brendan O'Toole, James Mah, Bob Martin

Festival of Communities: UG Symposium (Posters)

Our objective was to compare frictional resistance evident in aesthetic archwires to traditional (non-aesthetic) archwires. Methods: Archwires ligated with elasatics to fixed brackets were pulled through these brackets while frictional resistance (in lbf) was measured. Results: There were no confirmed significant differences between the frictional resistance of the aesthetic arch wires compared to the traditional non-coated wires for all wire sizes tested Conclusions: Our data suggests that a sacrifice of clinical performance with these aesthetic archwires as compared to traditional archwires is not likely

Friction Testing Of A New Ligature, Alison Mantel

Master's Theses (2009 -)

Objective: To determine if American Orthodontics' (AO) new, experimental ligature demonstrates less friction in vitro when compared to four other ligatures on the market.

Methods: Four brackets were mounted on a custom metal fixture allowing an 0.018-in stainless steel wire attached to an opposite fixture with one bracket to be passively centered in the bracket slot. The wire was ligated to the bracket using one of five types of ligatures including the low friction test ligatures (AO), conventional ligatures (AO), Sili–TiesTM, Silicone Infused Ties (GAC), Synergy® Low-Friction Ligatures (RMO), and SuperSlick ligatures (TP Orthodontics). Resistance to sliding was measured over …

Effect Of Bracket Width On The First-Order Toe-In Angle Of The Maxillary First Molar, Erin N. Brophey

MUSC Theses and Dissertations

Introduction: The first-order toe-in angle of the maxillary first molar is an important aspect of orthodontics and occlusion. Many variables contribute to the amount of distal offset expressed such as bracket slot dimensions, the amount of toe in angle built into the prescription of the bracket, bracket placement, bracket deformation, and tooth morphology. The purpose of this study is to mathematically predict the degree of first-order toe in angle loss with various archwire dimensions in various molar tube width preprogrammed brackets. Methods: Molar brackets from 3M Unitek, American Orthodontics™ (AO), Great American Orthodontics™ (GAC), Ormco™, Opal™, Rocky Mountain Orthodontics™ (RMO) …

Hydrolysis Of Amelogenin By Matrix Metalloprotease-20 Accelerates Mineralization In Vitro, Vuk Uskoković, Feroz Khan, Haichuan Liu, Halina Ewa Witkowska, Li Zhu, Wu Li, Stefan Habelitz

Pharmacy Faculty Articles and Research

In the following respects, tooth enamel is a unique tissue in the mammalian body: (a) it is the most mineralized and hardest tissue in it comprising up to 95 wt% of apatite; (b) its microstructure is dominated by parallel rods composed of bundles of 40 – 60 nm wide apatite crystals with aspect ratios reaching up to 1:10,000 and (c) not only does the protein matrix that gives rise to enamel guides the crystal growth, but it also conducts its own degradation and removal in parallel. Hence, when mimicking the process of amelogenesis in vitro, crystal growth has to …

Facial Type Analysis Comparison Between Mri, Cbct, And Lateral Cephalometrics, Matthew A. Sanders

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Single Cephalometric measurements are comparable between Cone Beam Computed Tomography (CBCT), Magnetic Resonance Imaging (MRl) and Conventional Lateral Cephalometric (LC) imaging methods. This study evaluated the agreement between the three imaging methods in facial type analysis (using a composite of 5 cephalometric measures).

Methods and Materials: Twenty-two subjects participated in this study. Cranial images were generated via three modalities: LC, CBCT and MRl. Cephalometric landmarks were identified on the three images per subject and a facial type analysis performed. An equally weighted facial type calculation composed of 5 cephalometric measurements (facial axis, facial depth, mandibular plane, lower face height, …

Work Of Fracture In Ceramic Bracket Bonding Systems, Tye A. Roylance

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Work of fracture (WOE) is a method of analysis of the toughness or resilience of a bracket bonding system. It is an indication of a bracket bonding systems ability to withstand forces in the mouth below the force at which failure occurs. Work of fracture gives an indication of how much abuse the bracket/bonding system can withstand and still maintain an adequate adhesion to the tooth surface. This analysis incorporates shear bond strength and displacement and is determined in part by the elasticity and resilience of the specimen being studied.

Materials and Methods: One hundred and eighty bovine teeth …

Correlating The Slope Of The Vomer With Cephalometric Vectors Of Facial Growth, Ryan Michael Pulfer

Loma Linda University Electronic Theses, Dissertations & Projects

It is important for orthodontists to have a basic understanding of the growth and development of the face. Scott's nasal septal cartilage theory proposes that the cartilage of the nasal septum proliferates along the anterior slope of the vomer bone by interstitial growth, simultaneously pulling and displacing the maxilla downward and forward. It is therefore logical to conclude that the vector of nasomaxillary growth has a geometric correlation with the anterior slope of the vomer bone.

There are no published studies comparing either the anterior or posterior slope of the vomer with any lateral cephalometric landmarks, the vectors of nasomaxillary …

Creating Prediction Models For Obstructive Sleep Apnea Based On Gender, Jeffrey Hwang

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Obstructive sleep apnea (OSA) is a common chronic disorder that is characterized by repetitive episodes of airflow cessation or reduction occurring during sleep as a result of partial or complete upper airway obstruction. These recurrent events have a tremendous impact on the cardiovascular system with a multitude of dangerous consequences. Numerous studies have been conducted determining etiological risk factors for OSA including anatomical predictors which have been observed with multiple imaging techniques. Cone beam computed tomography (CBCT) is a low-radiation mode of imaging that can be used to accurately identify anatomical landmarks and measure craniofacial relationships and airway dimensions. …

Microct Study Of Critical-Sized Defects Restored With A New Rhbmp-2 Carrier, Joanne S. Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Regenerating bone in critical-sized maxillofacial osseous defects remains a challenge. The utilization of recombinant human bone morphogenetic protein-2 (rhBMP-2) to form new bone has been shown to be a promising alternative to autogenous bone grafts, and the development of a carrier matrix to effectively deliver the rhBMP-2 has been identified as the critical factor necessary for the successful clinical application of rhBMP-2. The objective of this study was to perform a microCT analysis to examine the density of reconstructed bone using different rhBMP-2 carriers in critical-sized defects.

Material and Methods: Critical-sized defects (approximately 2.5 cm) were created in the …

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 …

Dentoskeletal And Soft Tissue Treatment Effects Of Two Different Methods For Treating Class Ii Malocclusions., Madhur Upadhyay

Master's Theses

Objectives: Moderate to severe Class II malocclusions can not only cause esthetic and functional problems but can also lead to psychological problems of varying intensity depending on the amount of anterior-posterior discrepancy and its interaction with the related soft tissue structures. Although there are several methods of treating such malocclusions (extractions,distalization,functional appliances etc), the final goal is always to provide acceptable esthetics and stability. The purpose of this clinical-cephalometric study was to examine the dentoskeletal and soft tissue treatment effects of maxillary anterior teeth retraction with mini-implant (MI) anchorage in young adults having Class II Division I malocclusion undergoing extraction …