Orthodontics and Orthodontology Commons^™

Investigate The Role Of Tgfβ3 In Regulating Irf6 And Δnp63 In Periderm Desquamation, Nam Ha

Theses & Dissertations

Introduction: Failure in palatal fusion during palate development results in cleft palate, one of the most common birth defects in the US. During the final phases of palatogenesis, the palatal periderm (a protective cell layer that prevents premature fusion and adhesion with oral epithelium) must be removed, also known as desquamation. This process is a prerequisite for establishing the midline seam in the fused palate. Previous studies have shown that transforming growth factor-β3 (TGFβ3) plays an irreplaceable role in palate development in mice. Our previously published mechanistic models outline the role of TGFβ3 and its downstream signaling cascade involving proteins …

Posterior Anatomic Limit For Mandibular Molar Distalization In Subjects With Different Growth Patterns, Genders, And Growth Status, Rehana Bashir

Theses & Dissertations

The objective of this study is to identify the anatomical limits for mandibular molar distalization, a technique frequently employed in orthodontics to address various malocclusions. Mandibular molar distalization plays a critical role in the management of crowding, and correction of the molar relationship.

It is imperative to assess the posterior anatomical space (PAS) in the mandibular retromolar area prior to distalization or uprighting the mandibular molars to avoid periodontal issues (dehiscence, orthodontically induced root resorption, and tooth mobility) and achieve successful treatment outcomes.

A clinical question that, however, isn't well understood is whether the amount of mandibular molar distalization is …

Development Of A Streptococcus Mutans Biofilm Model On A Typodont Platform To Investigate Its Dynamics In Orthodontics, Hibah Chughtai

Theses & Dissertations

Introduction: Biofilm formation plays a significant role in dental health, resulting in plaque accumulation, which can lead to caries and oral diseases. Streptococcus mutans (S. mutans) is a key bacterium involved in this process. The goal of this study was to establish a protocol for the development of an S. mutans biofilm on dental typodont teeth to analyze the effects of orthodontic brackets on biofilm formation. Understanding these dynamics is critical for developing strategies to mitigate biofilm accumulation during orthodontic treatment. Methods: S. mutans biofilms were cultivated under three conditions: 96-well tissue culture plates, S. mutans inoculated non-bracketed …

Machine Learning For Automated Cervical Vertebral Maturation Assessment On Lateral Cephalograms, Nuo Dong

Theses & Dissertations

Introduction: Skeletal maturation age is an important guide in growing adolescent patients to determine the proper time to start orthodontic treatment. The most practical and commonly used method to determine skeletal age in today’s clinical practice is the Cervical Vertebral Maturation (CVM) method [2]. Based on the morphology of the cervical vertebrae, six maturational stages can be determined – designated CS 1 to CS 6. The main drawback of this technique is the time required to determine CS number. Objective: In this research a machine learning (ML) algorithm to automatically determine CVM staging from the lateral cephalometric radiograph was developed. …

Biomechanics Of The Tip-Back Bend: An Analysis Of The Force System Via Translational Research, Lyndzie Brace

Theses & Dissertations

Purpose: The purpose of this study was to 1. experimentally (in vitro) quantify the force system acting on the molar and the incisor when a tip-back bend is placed on an auxiliary spring mounted on a base archwire and create a prediction model 2. to compare the type of tooth movement obtained from the prediction model (in-vitro) and the clinical outcome (in-vivo) data obtained from a previously conducted clinical trial. Methods: A computerized 3-dimensional (3D) orthodontic force tester (OFT) was used to quantify and compare the force systems generated from different combinations of tip-back bend archwires and base …

Three-Dimensional Analysis Of Condylar Displacement After Orthognathic Surgery In Patients With Facial Asymmetry, Teresa Bae

Theses & Dissertations

Facial asymmetry is apparent when there is a clinically significant variation between the two halves of the face. There can be varying degrees of facial asymmetry and mild asymmetry can be treated by orthodontics alone. For severe facial asymmetry a combination of orthodontics and orthognathic surgery may be necessary. The condyle must be in a stable position following surgery to have functional and structural stability and prevent relapse. This research proposal is to perform a retrospective CBCT study on the displacement of the condyle following orthognathic surgery in patients with facial asymmetry. The CBCTs were obtained from Taipei Veterans General …

Accuracy Of Interproximal Reduction In Commonly Used Operator Positions Using An Intraoral Scanner, Behnoush Bakhtiari

Theses & Dissertations

Introduction: The aim of this study was to determine operator’s best position when doing interproximal reduction. Also, to determine if these positions are ergonomically recommended.

Materials and methods: 54 sets of upper and lower models were scanned and 3D-printed. Air-rotor stripping was performed at different provider positions. Vertical and horizontal deviations were measured, and errors were recorded.

Results: In LA, there was no statistically significant difference between vertical deviations in P7 and 11, however, they were both superior to P9. In LL, P11 leads to significantly lower vertical deviation than P7 and 9. In LR, P9 and 11 were superior …

Aerosols In Orthodontics: Characterization Of Particle Size And Travel Distance, Donte Jochum-Nesbitt

Theses & Dissertations

Introduction: Aerosol production is a key contributor to occupational risk and disease transmission in the dental clinic. These aerosols can host harmful pathogens, such as SARS-CoV-2. Considering the 2020 pandemic, researchers endeavored to bolster the existing body of literature related to disease transmission via aerosols and droplets to provide better recommendations for infection control. This investigation aims to support that mission by characterizing the risk to orthodontic professionals and patients based on aerosolized particle size and travel distance. Methods: The experimental protocol used in this study was validated through a smaller scale pilot study in 2021. High- and Low-risk orthodontic …

The Effect Of Orthodontic Treatment With Extraction On The Upper Airway Dimensions And Three-Dimensional Morphology: A Retrospective Study Using Cone-Beam Computed Tomography Technique, Ehsan Mostaghni

Theses & Dissertations

The purpose of this study was to evaluate the effect of orthodontic treatment with and without extractions of teeth on the upper airway dimension and morphology. Records of 40 consecutively treated patients who received orthodontic treatment with or without dental extractions were evaluated. Pre-and post-treatment volumes, minimum cross-sectional areas, and linear dimensions of oropharyngeal airways were quantified using InVivo Dental 6.0 (Anatomage, San Jose, CA). Additionally, pre and post CBCT images of the upper airways were superimposed on each other using voxel-based registration and fixed coordinate system using 3D Slicer 4.1.1 (www.Slicer.org) and ITK-SNAP (http://www.itksnap.org). While the …

Characterization Of Aerosols Produced By Common Orthodontic Procedures, Anna R. Schoettger

Theses & Dissertations

Introduction: Aerosols can harbor active viruses, including SARS-CoV-2, making it vital that clinical protocols implemented in the orthodontic office be based on which procedures produce aerosols. Research shows that various procedures in the field of orthodontics generate aerosols, however, there is a lack of consensus as to which procedures should be deemed aerosol-generating procedures (AGPs). The current study aimed to better understand aerosol production of various orthodontic procedures. Methods: Orthodontic procedures were performed in a closed-room dental operatory on acrylic teeth mounted onto a dental manikin. Procedures performed included: debonding, bonding, and repositioning of one bracket. Variations introduced included: high-speed …

Alignment Of Cervical Vertebrae And Reliability Of Cephalometric Measurements, Ece Agirgol

Theses & Dissertations

Cervical vertebrae are in close relationship with dentofacial structures due to their anatomical position. In previous studies, the inclination of cervical vertebrae was measured by mostly Nasion-Sella line as the reference plane to evaluate the relationship with dentofacial structures.

The aim of this study is to observe the correlation between cervical vertebrae inclination and lateral cephalometric measurements. 124 lateral cephalograms taken in Natural Head Position of subjects over 18 years of age were traced with Dolphin Imaging Software 11.95 Premium. Cervical vertebrae inclination was measured by using the lines passing from landmarks on second, third and forth cervical vertebrae. Correlation …

Inflammatory Cytokine Expression Of Immune Cells On Exposure To Invisalign® Material: An In Vitro Pilot Study, Alaina M. Allen

Theses & Dissertations

The purpose of this study is to characterize the inflammatory cytokines that are expressed in peripheral blood mononuclear cells (PBMCs) and THP-1 monocytes exposed to Invisalign^® aligner material in vitro. Invisalign^® material was ground into particles, soaked in artificial saliva, and the eluate was collected. Commercially available cryopreserved pooled and individual human PBMCs and THP-1 monocytes were cultured with Invisalign^® material eluate and positive (lipopolysaccharide) and negative controls. The supernatants were collected and used with a BioLegend LEGENDplex^™ multi-analyte flow assay, a sandwich enzyme-linked immunosorbent assay (ELISA), to identify the expression of TNF-α, IL-6, IL-8, IL-10, …

Stress Relaxation In Orthodontic Aligner Plastics; An In Vitro Comparison Study, Kristopher J. Keller

Theses & Dissertations

The purpose of this study was to ascertain if repeated stresses from extension cycling would result in accumulated damage in aligner materials and affect force delivery. A secondary goal was to identify potential differences in mechanical behavior present among orthodontic aligner polymers. Four thermoplastic polymers (Essix ACE, Taglus, Zendura, and Zendura FLX) were thermoformed, cut into strips, and extension cycled to 0.4 millimeters in a 37C water bath. Force decay, maximum and minimum force, and elastic modulus were measured during cycling. Additional samples were subjected to controlled tension until failure, allowing the measurement of yield strength, ultimate strength, and elastic …

Outcomes Of Unilateral Alveolar Clefts Grafted Using Recombinant Human Bone Morphogenetic Protein-2: A Retrospective Volumetric Analysis Using Cbct, Landon Robert Peterson

Theses & Dissertations

Purpose of this study is to evaluate the success rates of secondary alveolar grafts using recombinant human bone morphogenetic protein with CBCT and to evaluate the effects of several variables on these outcomes. After our inclusion/exclusion criteria, records of 24 patients receiving secondary alveolar grafts at the University of Nebraska Medical Center were evaluated. Pre-graft and 6-month post-graft cleft volumes were measured using ITK-SNAP 3.8.0 software to determine a percent residual defect following surgery. Of the 24 patients, one was excluded as the graft surgery was deemed a failure. The patients’ gender, age, side of cleft, cleft side canine root …

Orthodontically Induced External Root Resorption In Extraction Versus Non-Extraction Treatment Modalities – A Retrospective Cone-Beam Computed Tomography (Cbct) Study, Jaykishan Patel

Theses & Dissertations

Purpose of this study was to evaluate orthodontically induced external apical root resorption using cone beam computed tomography in patients receiving orthodontic treatment with or without extractions. Records of 188 consecutively treated patients who received orthodontic treatment with or without extractions were evaluated. Pre-and post-treatment root lengths of maxillary incisors, volumes of maxillary central incisors, and apex displacement of either right or left maxillary central incisors were measured using Invivo 5.4 or ITK-SNAP 3.8.0 software. After adjusting for initial length, treatment duration, tooth, sex, race, bracket type, and malocclusion, maxillary incisor reduction of root length in extraction group was 0.37 …

The Effectiveness Of Resin-Modified Glass Ionomer Varnish In Preventing White Spot Lesions During Fixed Appliance Orthodontic Therapy: An In Vitro Study, Bradley Herman

Theses & Dissertations

The purpose of this investigation was to evaluate the efficacy of a glass ionomer varnish in preventing demineralization of enamel adjacent to and some distance away from an orthodontic bracket. Forty extracted human molars were divided into four different treatment groups (varnish in distilled water, varnish in acetic acid, enamel in acetic acid, and enamel in distilled water). Two 3 x 3 mm graphite windows were drawn on the tooth, one adjacent to the bracket and one 3 mm away from the first window, indicating the scanning area. Varnish was applied to the teeth in the varnish groups and all …

Effects Of Class Ii Correctors And Functional Appliances On The Periodontal Health Of The Mandibular Incisors – A Prospective Cone-Beam Computed Tomography (Cbct) Study, David C. Duevel

Theses & Dissertations

The purpose of this investigation was to evaluate the effects of Class II correctors and functional appliances on the dentoalveolar support of the mandibular incisors during orthodontic treatment. Twenty six patients who were treated with a Forsus^TM, Herbst, or MARA participated this study. Lateral cephalometric radiographs, limited field-of-view CBCTs, and periodontal measurements were collected both the day of appliance activation and day of appliance deactivation. Ten hard tissue measurements on all four mandibular incisors were collected at each time point on CBCT images. Bone thickness increased at 6 and 9 mm apical from the cementoenamel junction (CEJ) on …

Changes In The Transverse Dimension Of The Nasomaxillary Complex Following Rapid Palatal Expansion – A Post-Retention, Cbct Evaluation, Allison Schubert

Theses & Dissertations

Purpose: The purpose of this investigation was to evaluate the immediate and long-term effects of palatal expansion on the transverse dimension of the nasomaxillary complex.

Materials and Methods: Twenty-eight patients’ CBCTs were obtained at four time points: pre-expansion (T₁), post-expansion (T₂), pre-treatment (T₃), and middle or end of orthodontic treatment (T₄). The patients’ age, sex, cervical vertebral maturation stage, and the number of instructed expander turns were recorded. Measurements of the nasal floor, nasal passage, maxillary sinus, maxillary first molar mesiolingual cusp, maxillary first molar palatal cusp, maxillary first molar buccal cortical …

The Effect Of Mechanical Vibration On Pain And Rate Of Tooth Movement During Initial Orthodontic Alignment, Leslie Ellingson

Theses & Dissertations

Purpose: The purpose of this investigation was to evaluate the effect of mechanical vibration on pain experienced and rate of tooth movement (OTM) during the initial alignment phase of orthodontic treatment.

Materials and Methods: Participants were randomly allocated to control, low frequency or high frequency. An electric toothbrush was modified to provide high frequency vibration. A low frequency vibration device was acquired from a commercial vendor. Experimental groups applied vibration to the dentition for 20 minutes daily. All participants completed questionnaires using visual analog scales at five time points. Pain experience was measured in millimeters (mm) with the scale measuring …

Effects Of Flash-Free Technique On Plaque Retention, White Spot Lesions, And Bracket Failure: A Randomized Clinical Trial, Payam Ishani Afousi

Theses & Dissertations

A side effect of orthodontic treatment is the development of white spot lesions (WSLs). This thesis attempted to evaluate the effects of the use of APC™ Flash-Free (FF) and conventional adhesives in bonding of orthodontic brackets on plaque formation and retention, WSL development, and bracket failure in-vivo. This was accomplished by collecting plaque samples from around orthodontic appliances and analyzing them using ATP-driven bioluminescence; scanning enamel surfaces using the Canary System™ to evaluate WSL development, and counting the number of spontaneous debonding of brackets of the 4 maxillary incisors in the first 6 months of treatment. It was found …