Orthodontics and Orthodontology Commons^™

Force Comparison Of Rotational Tooth Movements For Loop-Design And Traditional Aligners, Robert Olsen

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction

This study aimed to evaluate the force (F) and torque (Tq) exerted on a rotated canine and molar tooth by two different aligner systems. An ArchForm loop clear aligner (AFL) was compared to a traditional clear aligner (T) with the force (F) and torque (Tq) compared. A reduction in F and Tq with AFL aligners could possibly decrease the incidence of Orthodontic Root Resorption (ORR), while also creating more effective forces for tooth movement.

Materials and Methods

Two types of T aligners varying by material thickness were compared to two types of AFL aligners varying by loop width. All …

Maxillary Central Incisor Rr In Hispanic And Non-Hispanic White Patients With Rme, Madison Healy

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Apical root resorption is one of the most common adverse effects of orthodontic treatment. Forces used during orthodontic tooth movement can cause permanent loss of apical surfaces of teeth and although most reported cases of root resorption are asymptomatic, the process is irreversible and often unpredictable. Thus, it is of clinical interest to investigate which patients may be at greatest risk.

Purpose: This study utilized Cone Beam Computed Tomography (CBCT) to evaluate whether rapid maxillary expansion (RME) in Hispanic patients increased the severity of orthodontically induced apical root resorption.

Materials and Methods: Pre-treatment (T1) and post-treatment …

Evaluating The Treatment Effectiveness And Efficiency Of The Df2 Protocol Using Invisalign® For Treatment Of Class Ii Malocclusion: A Retrospective Comparison Study, Bryan J. Otis

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This retrospective study evaluated the treatment effectiveness and efficiency of the DF2 protocol for correction of class II malocclusions in comparison to conventional protocol using Invisalign®.

Materials and Methods: Clinical and cephalometric data of patients that were treated for class II malocclusion between July 30, 2014 and July 22, 2021 were reviewed and selected. The selected patients were matched for age, sex, and treatment complexity and divided into two groups: Group 1 (G1) —DF2 protocol and Group 2 (G2)—conventional class II Invisalign®. Clinical variables to represent the skeletal and dentoalveolar changes during treatment were assessed using pre-treatment (T1) …

A Comparison Of The Area Of The Internal Nasal Valve In Cbct And Mri, Chantelle Ghiam

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study compared the agreement between whole head Cone-Beam Computed Tomography (CBCT) and 3T Magnetic Resonance Imaging (MRI) methods to assess the cross-sectional area of the internal nasal valve.

Methods: Thirteen human subjects (mean age 15y11m) were used in this study. All scans were preformed [sic] within two weeks of one another. CBCT images were made with an 18x16 inch field of view, exposure time of 5.4 s, and resolution of 0.3x0.3x0.3 mm. 3T MR images were captured as contiguous sagittal images of the whole head with a T1-weighted 3D imaging sequence (Magnetization Prepared Rapid Acquisition by …

Attitudes And Understanding Of Orthodontic Treatment Using Comic Vs. Text Format, Darron Miya

Loma Linda University Electronic Theses, Dissertations & Projects

Objectives: To examine adolescent patient attitudes and understanding of basic orthodontic treatment information presented in either comic book format or plain text.

Methods: This study involved subjects undergoing orthodontic treatment at the Loma Linda University Graduate Orthodontic Clinic. Subjects were randomly assigned to two groups: Group 1 subjects received an orthodontic comic book to read, while Group 2 subjects received a plain text information sheet containing the same pertinent information as Group 1. All subjects completed an identical survey regarding the material they read. Statistical analysis consisted of a chi-square test at α = 0.05 to determine potential …

Ratio Of Rme Appliance Expansion To Increase In Arch Perimeter Using Cbct Imaging, Evan Agnetta

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study measured CBCT images to determine if a consistent ratio exists between the quantifiable number of millimeters a cemented rapid palatal expansion appliance is opened and the subsequent increase in the arch perimeter obtained due to lateral expansion of the arch.

Methods: The following measurements: arch perimeter, arch width at first molars, first bicuspids, appliance length, as well as arch depth; were taken from CBCT images of patients who had completed RME therapy. These were obtained both before and after maxillary palatal expansion therapy using a fixed rapid palatal expander. Correlations were calculated for each of …

Measurements Of The Pharyngeal Airway Using Whole Head 3t Mri And Cbct, Victoria Geren

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study compared pharyngeal airway measurements (volume, linear, area) made using whole head Cone-Beam Computed Tomography (CBCT) and 3T Magnetic Resonance Imaging (MRI) methods.

Methods: Eleven subjects (mean age 15y11m) received whole head CBCT (NewTom5G, AFP Imaging, USA) and 3T MRI (Siemens Medical Solutions, DE). Each subject received both scans within a one-month period of time. CBCT images were made with an 18x16 inch field of view, exposure time of 5.4s, and resolution of 0.3x0.3x0.3mm. 3T MR images were captured as contiguous sagittal images of the whole head with a T1- weighted 3D imaging sequence (Magnetization Prepared …

Clinical Effects Of Oral Hygiene Instruction Via Texting In Orthodontic Patients, Jessica Liu

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This randomized controlled study quantitatively investigated whether providing oral hygiene instruction (OHI), through texting images and videos, affected oral hygiene status in orthodontic patients.

Materials and Methods: Sixty patients between 13-21 years of age, with visible plaque and used a smart phone, were recruited from the Graduate Orthodontic Clinic at Loma Linda University. Once recruited (T1), an initial survey was completed, MBI and OPI were recorded, and OHI was given. Subjects were randomly distributed into either a control or experimental group. The experimental group received OHI texts weekly, whereas the control group did not. After 3 months …

Accuracy Of Surface Area And Volume Measurements Of Teeth Determined From Cbct, Joseph Hourany

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study compared surface area and volume measurements made from 3D scans of physical teeth and segmented teeth taken from Cone-Beam Computed Tomography (CBCT) scans of a cadaver. Methods: A cadaver specimen was imaged by CBCT and all the teeth were subsequently extracted and cleaned of any tissue. Of all the extracted teeth, sixteen single-rooted teeth were included in this study. The extracted teeth were scanned with a 3M True Definition 3rd Generation intraoral scanner (3M, ESPE) to generate a stereolithography (STL) file to serve as the control for this study and their surface area and volume measurements as …

Comparison Of Maxillary Sinus Dimensions And Volumes On Cbct And 3t Mr Images, Cara Hodgson

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study compared the height, width, length, and volume of the maxillary sinus in Magnetic Resonance Imaging (MRI) and Cone-Beam Computed Tomography (CBCT).

Methods: Eleven human subjects participated in the study (mean age of 14y7m). One CBCT scan and one MRI scan were performed on each patient. CBCT images were captured with an 18 x16 inch field of view that covered the whole head. Contiguous sagittal MR images of the whole head were produced using a 3.0T imaging system with a T1-weighted 3D imaging sequence and isotropic resolution of 1.0 x1.0 x1.0 mm. Images were imported as …

Effect Of Centric Interference On Canine Tooth Wear, Andrey Gaiduchik

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The aim of this study was to determine the long term effect of a centric interference on canine tooth wear (CTW) and on centric occlusion (CO) and maximal intercuspation (MIP) variance. Materials and Methods: Thirty subjects, 11 males and 19 females, were selected based on inclusion and exclusion criteria. Changes in enamel volume were studied between the end of orthodontic treatment (T2) and at least seven years post treatment (T4). All models were scanned using a high resolution desktop scanner, (OrthoInsight 3D Scanner™, MotionView LLC). T4 models were articulated using a Panadent® Articulator and evaluated for dental interferences and …

Estimating Root Volumes By Limited Segmentation: A Volumetric Analysis Of Cbct And Micro-Ct Data, Theresa C. Baldwin

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The increased dimensional accuracy of images provided by cone beam computed tomography (CBCT) scans allows for more in-depth diagnosis and treatment planning. Expedient interpolation of segmented data that provides clinically acceptable results will encourage clinicians to frequently use CBCT images for clinical/radiographic evaluation. Some of these applications include, quantification of root resorption, determination of force required for specific tooth movements, and customized appliances. Purpose: The study had two purposes. The first was to compare the accuracy of digital tooth volumes acquired from CBCT to the gold standard, micro-computed tomography (micro-CT). The second was to determine the effect of axial …

Reliability And Accuracy Of A Novel Photogrammetric Orthodontic Monitoring System, Vahe Ohanesian

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This study quantitatively investigated the reliability and accuracy of Dental Monitoring’sTM proprietary orthodontic tracking system in comparison to an established reference. Materials and Methods: Intraoral scans (True Definition Scanner, 3MTM) and video scans (iPhone 7, AppleTM) were taken of 30 subjects undergoing comprehensive orthodontic treatment at Loma Linda University’s Graduate Orthodontic Clinic at T1 (initial) and T2 (3 months later). At each time point, an intraoral scan was taken by the operator followed by three video scans- two taken by the patient and one by the operator. Three linear and three angular measurements were analyzed using Dental Monitoring’sTM tracking …

Accuracy Of Cephalometric Analyses And Tooth Movements Of Conventional Vs Cbct-Generated Cephalograms, Thanh Khong Ng

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The aim of this study was to compare Ricketts and American Board of Orthodontics (ABO) cephalometric measurements and tooth movements from tracings between conventional lateral cephalograms (Sirona Orthophos XG Plus, Charlotte, NC) and CBCT-generated cephalograms (NewTom 5G; QR srl, Verona, Italy). Materials and Methods: Patients who had bilateral Angle’s class II molar were evaluated. Pre-treatment (T1) and post-treatment (T2) conventional lateral cephalograms (CLCs) and CBCT-generated lateral cephalograms (CBLCs) were traced in Quick Ceph Studio using Ricketts and ABO cephalometric analyses. Linear and angular cephalometric measurements from tracings were compared between the two radiographic modalities using one-sample Wilcoxon signed rank …

A Retrospective Cephalometric Growth Study Of Sagittal Airway In Skeletal Class Ii Patients, Sue V. Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The study retrospectively determined the average sagittal pharyngeal airway widths in Class II males and females between 7 to 16 years of age and changes in sagittal airway with increasing age. Additionally, this study determined whether average airway differs between gender at each age and compared the average airway widths in relation to increasing age between Class I and II patients. Materials and Methods: Longitudinal cephalograms were digitally traced for 38 untreated subjects (23 males, 15 females) from age 7 to 16 with skeletal and dental Class II patterns. These records were previously taken through growth studies conducted between …

Measuring A Sample Of Orthodontic Models/Panographs At Llusd Using The Cr-Eval, Jonathan Michael Drew

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: An index must be used to quantify the improvement in the position of teeth treated by orthodontics. The Cast-Radiograph Evaluation is the index used by the American Board of Orthodontics. The purpose of this study is to use this index to evaluate treatment outcomes in the graduate orthodontic clinic at Loma Linda University from 2012-2016. Materials and Methods: Patients included were comprehensively treated, debonded between 1/1/2012 and 12/31/2016, and under age 30. A total of 80 patients were randomly selected, with 16 coming from each year. The ABO DI was used to score the T1 models, and the CR-Eval …

Factors Associated With Orthodontically Induced Apical Root Resorption Of Maxillary Incisors, Brandon Malan

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Resorption of root apices is a ubiquitous occurrence in orthodontic treatment. Although most occurrence of resorption during orthodontic treatment is clinically inconsequential, a small percentage of patients have a severe amount of root structure that is lost. There are factors that are widely accepted as responsible for apical root resorption (RR), such as heavy compressive forces on the periodontal ligament (PDL). Unfortunately, it is still largely unpredictable if one patient will experience more root loss than what is considered normal. Thus, it is of clinical interest to further study what factors play a role in RR. Purpose: The purpose …

Comparison Of Tooth Length Measurements Made On Cbct And 3t Mr Images, Danielle A. Piano

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: The aim of this study is to compare tooth length measurements made on cone beam computed tomography (CBCT) scans and 3-Tesla (3T) magnetic resonance (MR) scans. Materials and Methods: One CBCT scan (NewTom5G, AFP Imaging, USA) and one 3T MR scan (Siemens Medical Solutions, DE) as performed on 12 subjects. CBCT images were captured with an 18x16 inch field of view that covered the whole head. Contiguous sagittal MR images of the whole head were produced in a 3.0T imaging system with a T1-weighted 3D imaging sequence (Magnetization Prepared Rapid Acquisition by Gradient Echo (MP-RAGE), TP/TE = 1950/2.26 ms) …

Prediction Of Root Form Using Crown Data: Mandibular Left First Premolar, Matthew E. Durschlag

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this study was to determine if a statistical shape model (SSM) of the lower left first premolar, consisting of both crown and root data, could adequately describe the root form from a surface scan consisting of only crown data. Secondly, it tested if there were any angles or measurements on the tooth crown that correlate with any aspects of root morphology. The average orthodontist practicing today or in the near future is likely to use or own a digital intraoral scanner in their office. Yet optical scans only allow visualization of the crowns of teeth and …

Effects Of Wire Material, Deflection, And Interbracket Distance On Burstone Bracket Geometry Force Systems, Skyler J. Liatti

Loma Linda University Electronic Theses, Dissertations & Projects

Objective. This paper aims to quantify the effect of wire material, dimension, and deflection on the most identifiable feature of the six-geometries: the moment dissociation point (force system with no moment on the lesser angled bracket), which may or may not occur at the classically defined geometry IV. Materials and Methods. A six-degree of freedom load cell was used to measure the force systems in different combinations of wire materials, wire dimensions, total angle of bracket, and interbracket distance. Brackets were progressively rotated through Burstone and Koenig’s six geometries and the moment on the right bracket was plotted against the …

A Retrospective Lateral Cephalometric Growth Study Of Sagittal Airway Changes, Grace H. Woo

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This study retrospectively examined the average sagittal dimensions in the pharyngeal airway from skeletal and dental Class I males and females from 7 to 16 years of age utilizing longitudinal data from the American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection. The study evaluated whether average sagittal airway dimensions differed between males and females at each age, and whether the sagittal airway dimension changed with increasing age. Materials and Methods: Sagittal airway dimension based on identifiable anatomical landmarks were digitally traced and measured from the longitudinal lateral cephalograms of 30 females and 32 males from the AAOF Growth …

Ricketts Analysis Using Conventional And Dolphintm Generated Cbct Lateral Cephs, Yeganeh Parhizkar Jewell

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The aim of this study was to evaluate the difference between Ricketts analysis measurements made on Sirona Orthophos XG Plus (Sirona Dental Systems, Charlotte,NC) lateral cephalograms, and DolphinTM generated perspective and orthogonal lateral cephalograms from CBCT (NewTom 5G; QR srl, Verona, Italy). Materials and Methods: A Sirona digital lateral cephalogram and DophinTM synthesized CBCT lateral cephalograms of a radiographic phantom in orthogonal and perspective projections were created. Horizontal and vertical measurements were made in multiple planes on the radiographic phantom to compare each imaging modality. Twenty-five lateral cephalometric radiographs were selected retrospectively from the records of patients of …

Comparison Of Two Methods Of Transpalatal Arch And Lingual Arch Activation, Taoran Zhang

Loma Linda University Electronic Theses, Dissertations & Projects

The TPA and LA can be activated with two methods: the “shape-driven method” where the appliance is made to match the final tooth position and the “force-driven method” where the appliance is made to make sure the force system delivered by it at the beginning is consistent with the planned tooth movement. This study compared the two methods in vitro quantitatively with typodont teeth and multi-axis force torque transducers in all three dimensions. Results: In the TPA first order activation, with comparable Fy (force on Y axis) reading, the shape-driven activation group had a significantly higher Mx (moment on X …

The Effect Of Orthodontic Treatment On Sagittal Root Position Of The Maxillary Central Incisor, Jeremy Haines

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Sagittal root position (SRP) of maxillary incisors is an important factor in implant treatment planning. Kan et al defined four classes of SRP in an effort to aid implant placement treatment planning and these SRP classifications represent a novel approach to describing bone changes around the maxillary incisors. The effect of orthodontic tooth movement, specifically changes in inclination, on SRP is of interest in potentially facilitating immediate implant placement. Purpose: The purpose of this study was to use Cone Beam Computed Tomography (CBCT) to evaluate the adaptation of alveolar bone around the maxillary incisors as a result of orthodontic …

A Cbct Study Of Pharyngeal Airway Changes Due To Fixed Functional Appliances, Scott T. Peterson

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this retrospective study, using head and neck Cone-Beam Computed Tomography (CBCT) images, was to measure and compare volumetric, area, and linear changes of the pharyngeal airway space in patients treated with a MARA or Herbst Class II correction appliances. Materials and Methods: Twenty-six patients treated with a MARA (mean age 13.2), nine with a Herbst (mean age 12.12) , and a control group twenty-five orthodontically treated class I patients (mean age 13.11). T1 and T2 CBCT images were measured and compared between the three groups for area, length, and width measurements along the velo-, oro-, and …

An Evaluation Of Root Length Change Measurements Using Intraoral Scan And Panoramic Radiographs, Elijah C. Wang

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: This study was intended to evaluate the accuracy of using panoramic radiographs to measure root length change over the course of orthodontic treatment, using intraoral scans of crowns, and a mathematical model to account for distortions in the radiographs. The study additionally evaluated whether a best-fit equation could be created from the calculated data to minimize differences to the measurements of root resorption made on CBCT scans. Materials and Methods: Twenty-one patients were selected who had comprehensive orthodontic treatment, and all teeth in the upper right quadrant were evaluated in this study. T1 and T2 CBCT images were compared …

Correlation Of Tooth Length Measurements Made On Cbct And 3t Mr Images, Andrew Scott Taylor

Loma Linda University Electronic Theses, Dissertations & Projects

Objective. This study compared tooth length measurements made on cone beam computed tomography (CBCT) scans and 3-Tesla (3T) magnetic resonance (MR) scans performed with and without an alginate bite registration surrounding the crowns of the teeth. Materials and Methods. One CBCT scan, one MR scan with alginate bite registration, and one MR scan without bite registration were performed on 12 subjects. The alginate bite registration was used to provide a proton-rich material to surround proton-poor teeth in an attempt to improve visualization of teeth. DICOM formatted images from each of the three scans for each subject were oriented in all …

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 …

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 …