Perception Of Differences In Lip Profile Between 2-D And 3-D, Andrew Hansen

Theses and Dissertations

Past studies evaluating the esthetics of orthodontic treatment have been done using 2-D images. New 3-D imaging offers an improved, real-life representation of a subject. The purpose of this study was to determine how laypeople perceived differences in lip position (flat versus ideal lip fullness) in 2-D compared to 3-D.

3dMD images of 8 Caucasian subjects were adjusted to an ideal and flat lip position in 3-D and then in 2-D from the profile view. 2 surveys were created with paired ideal and flat images on the screen, either in 2-D or 3-D, and evaluators were asked to choose which …

Twitter Analysis Of The Orthodontic Patient Experience With Braces Versus Invisalign, Daniel A. Noll

Theses and Dissertations

The purpose of this study was to examine the orthodontic patient experience with braces compared to Invisalign^® by means of a large-scale Twitter sentiment analysis. A custom data collection program was created to collect tweets containing the words “braces” or “Invisalign.” A hierarchal Naïve Bayes sentiment classifier was developed to sort the tweets into one of five categories: positive, negative, neutral, advertisement, or not applicable. Among the 419,363 tweets applicable to orthodontics collected, users posted significantly more positive tweets (61%) than negative tweets (39%) (p-value = ^® tweets (p-value=0.4189). In conclusion, Twitter users express more positive than negative sentiment …

Perception Of Profile Appearance As Judged By Peers Using 3d Video Imaging, Megan G. Schuler

Theses and Dissertations

The purpose of this study was to investigate the social perceptions of subjects with differing lip position and facial convexity in three dimensions. A 3dMD camera (3dMD, Atlanta, GA) was used to capture 3D images of 9 subjects’ faces. The images were altered to have ideal lip position and ideal convexity, ideal lip position and Class II convexity, Class II lip position and ideal convexity, and Class II lip position and Class II convexity. 400 laypersons rated their perceptions of the subjects’ athletic ability, popularity, leadership, and intelligence on a VAS scale. Subjects with ideal lip position relative to the …

Comparison Of Treatment Management Between Orthodontists And General Practitioners Performing Clear Aligner Therapy, Alexandra D. Best

Theses and Dissertations

The purpose of this study was to investigate differences in case confidence, treatment management, and Invisalign® expertise between orthodontists and general dentists. A survey was mailed to 1,000 randomly selected orthodontists and general dentists, respectively, who are Invisalign® providers, and results were analyzed. The results indicated that orthodontists treated significantly more Invisalign® cases and received more Invisalign® training than general dentists (P

Tooth Size Ratio In Orthodontic Patients With Varied Sagittal Skeletal Patterns; A Cbct Study, James Barra

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: Maxillomandibular tooth size ratio (TSR) is an important aspect in achieving a satisfactory orthodontic outcome. The purpose of this study is to compare TSR among orthodontically treated patients with different skeletal anteroposterior (AP) patterns. Methods and Materials: The post-treatment (T2) cone beam computed tomograms (CBCTs) of patients treated orthodontically without extraction and finished with canine and molar class I occlusion were evaluated. The subjects were categorized into class I, class II and class III skeletal pattern by analyzing A point-Nasion-B point (ANB) at T2. Overbite (OB), overjet (OJ), TSR for canine to canine (TSR3-3) and molar to molar (TSR6-6), …

The Effect Of Scan Settings On The Identification Of Tooth Socket Lamina Dura Surface: A Cbct Study, Erick Carlucci

Loma Linda University Electronic Theses, Dissertations & Projects

Aim: Cone-beam computed tomography (CBCT) is becoming a common adjunct in orthodontic diagnosis and treatment, however several questions remain about the impact of surrounding anatomical structures and varying scan settings on the ability to delineate buccal bone and overall diagnostic quality of images produced. The aim of this study was to determine if adjacent structures with similar radiodensity and variable scan settings (field of view and voxel size) significantly impact the ability to accurately identify the tooth socket facial lamina dura, facial bone surface, facial bone margin, as well as the facial bone thickness measurement. Materials & Methods: CBCT scans …

Tooth Length Measurements On 3t Mr Images: A Retrospective Study, Kevin G. Murray

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this study was to determine if MRI can be used to accurately measure tooth lengths. Methods: MRI tooth length measurements were compared with “actual tooth lengths” as measured on CBCT scans. Twenty three subjects received two scans (one CBCT and one MRI). Tooth length was measured and compared between the resultant images. Intraclass correlations were used for statistical analysis. Results: Tooth length measurements made on MRI scans showed moderate to almost perfect agreement with tooth length measurements made on CBCT scans. Higher levels of agreement were present in the maxillary arch compared to the mandibular arch. …

Treatment Outcomes Of Patients With Unilateral Class Ii Malocclusions: A Cbct Study, Brent Leggett

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purposes of this study were to determine the prevalence of Class II (Cl II) subdivision patients, to quantify the change in TMJ complex, and mandibular length after treatment was accomplished. Materials and Methods: Records of consecutive patients who sought orthodontic treatment at Loma Linda University (LLU) were screened. Only patients with dental Cl II subdivision that had completed treatment with pre- (T1) and post-treatment (T2) cone beam computed tomograms (CBCTs) available were evaluated for changes in the TMJ complex position related to Foramen Rotundum (TMJ-FR), joint spaces and mandibular length (condylion to genial tubercles). Comparisons were made between …

Morphological Changes In Alveolar Bone Following Orthodontic Space Closure, Ninette Hacopian

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Changes occurring in anterior alveolar bone following orthodontic tooth movement are controversial. Some research has shown that orthodontic tooth movement results in the adaptation of cortical bone; others have shown that it results in dehiscence and fenestrations.

Purpose: The purpose of this study was to evaluate the alveolar bone changes around maxillary anterior teeth following orthodontic space closure.

Materials and Methods: Cone beam computed tomograms (CBCTs) of non-growing patients who received orthodontic treatment with bilateral maxillary premolar extraction were evaluated. Only patients with at least 5 degrees of changes in maxillary incisor (U1) to palatal plane angle were included …

Prevalence And Rationale Of Orthodontic Extractions At Loma Linda University, Teresa T. Tran

Loma Linda University Electronic Theses, Dissertations & Projects

Aim: The purpose of this study was to determine the prevalence of orthodontic extraction cases and the rationale for the decision-making. Materials & Methods: The records of consecutive patients who had completed orthodontic treatment at Graduate Orthodontic Clinic, Loma Linda University School of Dentistry, between January 2010 and December 2014 were reviewed for prevalence of orthodontic extractions. Cone beam computed tomograms (CBCTs) of patients, that had extraction(s) prescribed as part of orthodontic treatment, were analyzed dentally and skeletally. Patients were then categorized according to the degree of crowding in each dental arch. A one-way ANOVA (Kruskal-Wallis) test and …

Changes In Composite Toxicity Following Exposure To Pulp Capping Materials, Audra Long

Master's Theses (2009 -)

Introduction: Direct pulp capping involves placing a material over the exposed pulp in order to maintain its vitality. For decades, calcium hydroxide (CH) has served as the gold standard for this purpose, but its toxicity to the pulp may negatively impact treatment outcomes. Mineral Trioxide Aggregate (MTA) has become a popular alternative based partly on its excellent biocompatibility. Pulp-capped teeth are often restored with highly toxic composite materials, but the pulp capping material’s ability to alter these toxic effects has never been investigated. The purpose of this in vitro study is to determine the effects of Dycal, a CH-based cement, …

The Direct Effect Of Low-Magnitude High-Frequency Mechanical Vibration On Osteoclast Formation From Raw267.4 Monocytes, Maxwell Antonio Abraham

Master's Theses (2009 -)

Low-magnitude high-frequency (LMHF) mechanical vibration has been demonstrated to enhance bone formation possibly through inhibition of osteoclastogenesis of bone. Earlier research has demonstrated osteoclast formation from RAW264.7 monocytes was inhibited by a chewing cycle mimicking vibration through inhibition of dendritic cell-specific transmembrane protein (DC-STAMP). We hypothesize that application of LMHF mechanical vibration directly inhibits osteoclast formation from RAW264.7 monocytes in a frequency dependent manner. RAW264.7 monocytes (ATCC) were cultured in alpha minimal essential medium (MEM) with 10% fetal bovine serum (FBS ) and 1% Pen/Strep at 37°C and 5% CO2. The cells were seeded at a density of 2000 cells/well …

Influence Of Fluoride And Stress On The Electrochemical Properties Of Nickel-Titanium Coils, Ashley Barnes

Master's Theses (2009 -)

The aim of this study was to examine the effects of fluoride and stress on the electrochemical properties of nickel-titanium coils. Forty Dentsply GAC NiTi coils were divided into four groups of ten and individually tested. Twenty coils were placed in a solution of artificial saliva, where ten of the twenty were compressed and the other ten were not stressed. The other twenty coils were placed in a 1500 ppm NaF solution, where ten were compressed and ten were not. The coils were connected to a computer driven potentiostat and three tests were conducted: open circuit potential monitoring for 2 …

Influence Of Fluoride And Stress On The Mechanical Properties Of Nickel-Titanium Coils, Jennifer Ann Fehrman Roloff

Master's Theses (2009 -)

Objective: The objective of this study was to determine the influence of fluoride and stress on the mechanical properties of nickel-titanium open coil springs. Materials and Methods: Sentalloy nickel-titanium open coil springs (15 mm length) were divided into five groups. A control group was tested mechanically in as-received condition. The other four experimental groups were exposed to artificial saliva (Fusayama-Meyer solution) at 37oC for 12 weeks in a 2x2 factorial design with fluoride exposure and stress (compression) as the two factors. Those springs which were under compression were held at 5 mm in length for the entirety of the testing …

Mechanical Properties And Patient Perceptions Of Commonly Used Clear Aligner Systems As-Received And After Clinical Use, Lauren Evan Montoure Teske

Master's Theses (2009 -)

Background/Objectives: This study aimed to investigate the viscoelastic properties of two clear aligner systems, Invisalign (Align Technology, Inc, Santa Clara, CA, USA) and Simpli5 (Allesee Orthodontic Appliances, Sturtevant, WI, USA), and determine if there was a difference after use. A survey assessed patients’ perceptions of the aligner material and post-treatment satisfaction. Materials/Methods: Mandibular aligners were collected from two patients after 2-3 weeks of use (n=6). Duplicate, unused aligners were obtained for each patient (n=6). Dynamic mechanical analysis (DMA) characterized the viscoelastic properties of the materials. Three tests were done on separate specimens: frequency scan (0.1-10 Hz under 25 μm displacement …

Thermomechanical Characterization Of Variable Force Niti Orthodontic Archwires, Anjali Sudershan Krishan Mehta

Master's Theses (2009 -)

ABSTRACT THERMOMECHANICAL CHARACTERIZATION OF VARIABLE FORCE NITI ORTHODONTIC ARCHWIRES Anjali Mehta, BDS MDS Marquette University, 2015 Introduction: Nickel-Titanium (NiTi) archwires, due to their properties of superelasticity and shape memory, have been extensively used in orthodontic mechanotherapy. However, one of the shortcomings of these wires is that they deliver constant forces across the entire arch. The amount of force needed to move a tooth is a function of the surface area of the tooth and its supporting bone; and is lesser for single rooted anterior teeth compared to larger molars. The introduction of heat treatment of NiTi wires and the influence …

Crown Size Comparisons In Patients With Unilateral Palatally Displaced Canines, Joseph Eliason, Steven J. Lindauer

Theses and Dissertations

Abstract

CROWN SIZE COMPARISONS IN PATIENTS WITH PALATALLY DISPLACED CANINES

By Joseph L. Eliason, D.D.S.

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University.

Virginia Commonwealth University, 2015

Thesis Director: Steven J. Lindauer, D.M.D., M.Dent.Sc.

Professor and Chair, Department of Orthodontics

There has been significant debate over the past decades regarding the etiology of palatally displaced canines. Theorized risk factors include agenesis or malformation of the lateral incisors, incisor retroclination, transverse deficiency, or genetic predisposition. The purpose of this study is to compare the linear and volumetric …

Esthetic Preferences Of Maxillary Incisor Labiolingual Inclination Across Races, Elvi M. Barcoma

Theses and Dissertations

Abstract

ESTHETIC PREFERENCES FOR MAXILLARY INCISOR LABIOLINGUAL INCLINATION ACROSS RACES

by Elvi Marie Barcoma, D.D.S.

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University

Virginia Commonwealth University, 2015

Major Director: Bhavna Shroff, D.M.D., M.Dent.Sc, Program Director, Orthodontics

Objective: To determine if people of different racial backgrounds prefer different amounts of

maxillary incisor labiolingual inclination from a smiling profile view.

Materials and Methods: An electronic survey was created with smiling profile images of an African-American female and a White female with varying degrees of maxillary incisor labiolingual inclination. …

In-Vitro Assessment Of A Novel Bracket's Effect On Resistance To Sliding, James Blackburn

Theses and Dissertations

Friction, binding and notching are the factors that contribute to resistance to sliding during orthodontic tooth movement. However, most attempts at reducing resistance aim only to reduce the archwire/ligature friction. In this study, a novel bracket with a unique design aimed to reduce all three components of resistance to sliding. Four types of brackets (passive and active self-ligating, traditionally ligated and the novel bracket, (n=5, each) were tested at 0, 2, 4, 6, and 8ᵒ of tip on a 0.019 x 0.025”archwire. The resistance to sliding values were recorded. At 0ᵒ, the passive self-ligating and novel bracket showed reduced resistance …

Restoring Lateral Incisors And Orthodontic Treatment: Perceptions Among General Dentists And Othodontists, Matthew A. Sandretti, Bhavna Shroff, Steven J. Lindauer, Al M. Best

Theses and Dissertations

The purpose of this study was to identify and compare preferences and perceptions of orthodontists and general dentists when restoring peg-shaped lateral incisors. The investigation sought to summarize these preferences with regard to treatment planning, tooth preparation and interdisciplinary communication. A pair of mailed and electronic surveys was distributed to 1,500 general dentists and orthodontists, respectively. The results indicated that general dentists perceived that general dentists held the primary decision-making responsibility, while orthodontists disagreed (P<0.0001). Orthodontists prioritized the treatment goals of Class I canine relationship and overbite/overjet more significantly than general dentists, whom valued tooth proportions more highly (P<0.0001). General dentists reported receiving significantly less input than orthodontists report seeking (P<0.0001).The consensus of both groups showed that the tooth should be positioned centered mesiodistally and guided by the gingival margins incisogingivally. Both groups agree that orthodontists must improve communication to improve treatment results.

Skeletal Changes After Rapid Maxillary Expansion And Fixed Orthodontic Treatment: A Cbct Study, Chandler Ho

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this study was to use cone-beam computed tomography to quantitatively evaluate the skeletal effects of rapid maxillary expansion and orthodontic treatment, with a specific interest in evaluating whether the skeletal changes achieved by RME will maintain throughout orthodontic treatment. Methods: Thirty consecutive patients (16 boys, 14 girls; mean age, 13.9 ± 1.8 years) who required RME with Hyrax appliances as part of their comprehensive orthodontic treatment were studied. Measurements before and after RME, and after orthodontic treatment, of palatal and buccal maxillary widths, palatal alveolar angle, nasal width, nasal floor width, and maxillary sinus width at …

Copper, Aluminum And Nickel: A New Monocrystalline Orthodontic Alloy, Mark Wierenga

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: This study was designed to evaluate, via tensile and bend testing, the mechanical properties of a newly-developed monocrystalline orthodontic archwire comprised of a blend of copper, aluminum, and nickel (CuAlNi). Methods: The sample was comprised of three shape memory alloys; CuAlNi, copper nickel titanium (CuNiTi), and nickel titanium (NiTi); from various orthodontic manufacturers in both 0.018” round and 0.019” x 0.025” rectangular dimensions. Additional data was gathered for similarly sized stainless steel and beta-titanium archwires as a point of reference for drawing conclusions about the relative properties of the archwires. Measurements of loading and unloading forces were recorded in …

The Effect Of Tooth Presence On Identification Of Tooth Socket Lamina Dura Surface: A Cbct Study, Morse Stonecypher

Loma Linda University Electronic Theses, Dissertations & Projects

Aim: The accuracy in identifying anatomical landmarks on CBCT images can be affected by the presence of surrounding anatomical structures with similar radiodensity. The purpose of this study was to evaluate the effect of the presence of tooth structure on the accuracy in identifying the lamina dura surface, facial bone surface, facial and lingual bone margins, socket apex, as well as in facial bone thickness measurement. Materials & Methods: Three fresh cadaver heads were scanned using a NewTom 5G CBCT at 0.100 mm voxel size at three time-points: before extraction (T1), after extraction and reinsertion (T2), and after tooth removal …

Cbct Evaluation Of Morphological Changes To Alveolar Bone Due To Orthodontic Tooth Movement, Jeremy M. Hoff

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The mandibular process is the anatomic factor that limits the orthodontic movement of the mandibular incisors, and awareness of this structural limitation may reduce the risk of potential damage to tooth roots and alveolar bone. A decision regarding the correct placement of the lower incisors will be largely determined by the amount of adaptation possible within the alveolar bone. Purpose: The purpose of this study was to use Cone Beam Computed Tomography (CBCT) to evaluate the adaptation of alveolar bone around the mandibular anterior teeth before and after orthodontic tooth movement. Methods: This study compared changes in area (mm2) …

Cbct And Cephalometric Analysis Of The Tmj Complex After Treatment Using A Mara Appliance, Melissa Danette Shotell

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The mandibular anterior repositioning appliance (MARATM) is a fixed appliance intended for the correction of class II malocclusion. Many advocate the use of the MARA appliance to minimize patient non-compliance with treatment; however, little information is known as to the skeletal changes in the temporomandibular complex. The purpose of this study is to investigate the changes in the temporomandibular complex using both cephalometric and cone beam computerized tomography.

Materials and Methods: The initial and final treatment cone beam computerized tomography (CBCT) scans of 5 patients treated with the MARA appliance were collected from the Loma Linda University Orthodontics Clinic. …

Efficacy Of The Flosspro Flosser Versus Finger Flossing In Orthodontic Patients, Sharareh S. Sabet

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The maintenance of good oral hygiene among orthodontic patients is a challenge. The purpose of this study was to compare the oral hygiene habits, gingival health, and preference of orthodontic patients when using a floss aid compared to conventional finger flossing with a floss threader. Methods: Thirty-four adolescent and young adult patients with fixed orthodontic appliances and poor oral hygiene were enrolled from the Loma Linda University Graduate Orthodontic Clinic. This was a single blind crossover study. The patients were randomly assigned to one of two treatment groups (floss aid or finger floss) in phase I. After prophylaxis, subjects …

Microstructure And Mechanical Properties Of Nickel-Free And Nickel-Containing Stainless Steel Orthodontic Wires, Amanda Olejniczak

Master's Theses (2009 -)

Introduction: In orthodontics, contact dermatitis caused by nickel allergy should be of concern with the number of nickel-containing appliances and wires used. Stainless steel archwires are commonly used throughout orthodontic treatment. With the release of nickel from these wires, some manufacturers have turned to nickel-free stainless steel alternatives. The goal of this research was to compare nickel-free stainless steel with traditional stainless steel archwires with regard to mechanical properties and microstructure. Materials and Methods: Nickel-free stainless steel and regular stainless steel archwires from four companies were included. Five random samples of each wire, vertically mounted in fast-set acrylic, were indented …

Dimensional Changes Of Facial Soft Tissue Associated With Rapid Palatal Expansion, Peter Charles Longo

Master's Theses (2009 -)

Introduction: Orthodontic treatment demands excellent outcomes in both function and esthetics. Despite the popularity of rapid palatal expansion in orthodontic treatment, few studies have examined its consequences on facial soft tissue using direct anthropometric measurements. The primary goal of this study was to determine facial soft tissue changes immediately following rapid palatal expansion. Materials and Methods: Twenty-eight patients (age range, 8-17 years) attending Marquette Dental School Orthodontic Post-Graduate Clinic were enrolled in the study. Facial soft tissue measurements were taken with digital calipers at two separate time points (T0: initial exam and T1: thirty days following expansion); measurements were recorded …

Composition, Phase Structure, And Corrosion Of Nickel-Free And Nickel-Containing Stainless Steel Orthodontic Wires, Amrita Rakalla

Master's Theses (2009 -)

Stainless steel wires have long been used in orthodontics. The austenitic stainless steel used in orthodontics contains approximately 18 wt% chromium and 8 wt% nickel. Nickel improves the corrosion resistance and helps maintain the austenite structure of stainless steel. Nickel is the most allergenic metal and is the most common metal associated with contact dermatitis in orthodontics. Nickel-free wires have been developed, and it was the goal of this study to compare nickel-free and nickel-containing stainless steel orthodontic wires to determine and compare their composition, phase structure, and corrosion properties. For each test, nickel-free and conventional stainless steel wires were …

An Investigation Into The Bonding Properties Of New Generation Ceramic Brackets As Compared To A Stainless Steel Bracket, Ami Inoue

Master's Theses (2009 -)

Introduction: More patients are seeking esthetic alternatives for their orthodontic treatment options, which has led to increased use of ceramic brackets in recent years. These brackets were marketed before independent scientific research was completed. Many of the early ceramic brackets used a silane coupling agent to allow for a chemical bond between the bracket and the adhesive resin. Early reports from clinicians of increased bond strengths and iatrogenic tooth damage after bracket removal were common. Manufacturers have made changes to their base designs, relying more on mechanical retention for bond strength. The goal of this study was to test the …