Orthodontics and Orthodontology Commons^™

The Influence Of Cbct-Derived 3d-Printed Models On Endodontic Microsurgical Treatment Planning And Confidence Of The Operator, Shreyas Oza, Johnah C. Galicia

Orthodontics and Endodontics Theses

Aims Use of 3D printed models in Endodontics has been gaining popularity since the technology to create them became more affordable. Currently, there are no studies that evaluate the influence of 3D models on endodontic surgical treatment planning and on operator confidence. Therefore, aims of this study were to: (i) Determine whether the availability of a 3D printed analogue can influence treatment-planning and operator confidence; and, (ii) Assess which factors of operator confidence are influenced, if any.

Materials and Methods Endodontists were asked to analyze a pre-selected CBCT scan of an endodontic surgical case and to answer a questionnaire that …

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 …

An Evaluation Of The Frankfort Mandibular Plane Angle Bisector (Fmab) Wits Appraisal In The Assessment Of Anteroposterior Jaw Relationships, Natalie Swoboda

Electronic Thesis and Dissertation Repository

An accurate anteroposterior measurement of jaw relationships is essential in orthodontic diagnosis and treatment planning. The purpose of this longitudinal study was to establish a new cephalometric Wits appraisal using a bisector of the mandibular plane angle, named the Frankfort Mandibular Plane Angle Bisector (FMAB). The FMAB was used to assess the sagittal jaw relationship in a sample of Class I individuals, and compare this measurement to the ANB angle and the Wits appraisal using the Maxillomandibular Bisector (MMB).

The data were collected from pre-treatment (T0), immediate post-treatment (T1) and two year post-retention (T2) lateral cephalograms of 61 male and …

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 …

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. …

Observer Reliability Of Cephalometric Landmark Identification On 3-D Mr Images, Michael S. Pollack

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Cephalometric analysis is a cornerstone of orthodontic diagnosis, yet much information is lost when 3-dimensional structures are assessed with 2-dimensional methods. CBCT offers 3-dimensional imaging but at the cost of higher levels of ionizing radiation. Magnetic resonance imaging provides 3-dimensional imaging without ionizing radiation and additionally imparts visualization of soft tissue structures. Prior to employing MR images for cephalometric analysis, reliability of landmark identification must be assessed. The purpose of this study was to evaluate intra- and interobserver reliability in 3-dimensional landmark identification using MR images.

Materials and Methods: Fifteen cranial MR images (3.0 T, MP-RAGE) from subjects between …

Effects Of Functional Appliances On The Tmj And Mandibular Length Of Skeletal Class Ii Patients: A Cone Beam Computed Tomography Study, David C. Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Functional appliances have been efficiently used in the treatment of Class II malocclusions caused by retrognathic mandibles. Cone beam computed tomography has enabled us to make more accurate linear measurements by eliminating superimposition of other structures and to analyze skeletal anatomic detail in all three planes of space. This retrospective study evaluated the osseous changes in the temporomandibular joint (TMJ) and length of the mandible in skeletal Class II malocclusion patients treated with the fixed functional appliances and compared measurements with Class I malocclusion patients treated with orthodontic mechanics that did not alter skeletal relationships.

Materials and Methods: Twelve …

Buccal Bone Changes Following Rapid Maxillary Expansion (Rmf), Long-Term Results, Elena S. Iacob

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to use Cone Beam Computed Tomography (CBCT) images to quantitatively evaluate buccal bone changes of maxillary first premolar (P1), second premolar (P2) and first molar (M1) shortly after Rapid Maxillary Expansion (RME) and at the end of orthodontic treatment, as well as to evaluate the variables that may be associated with the short-term and long-term changes. Forty-seven consecutive patients (25 males and 22 females) with a mean age of 14.5years and who required RME as part of their orthodontic treatment and had pre-RME (T1) and post-RME (T2) CBCT images available were used for the …

Detection Of Simulated Apical Root Resorption Using Three Cone Beam Ct Machines, Marcus Paulson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine orthodontists' ability to discriminate small differences of simulated apical root resorption (SARR) on extracted teeth, using the output from three cone beam computed tomography (CBCT) machines. Twenty-four unrestored maxillary anterior teeth exhibiting normal morphology, were collected. The teeth were scanned by three CBCT machines: 1) the NewTom 3G (AFP imaging, USA), 2) the iCAT (Imaging Sciences, USA) 3) and the MicroCAT II (Siemens Medical, USA). Using a sandblaster the apical portion of each tooth was reduced in 0.5 mm increments up to a total reduction of 1.5 mm. Each root modification was …

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 …

Accuracy Of The Newtom 3g™ In Measuring The Angle Of The Articular Eminence, Rehana Khan

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the accuracy of the Newtom 3G™ in determining the angulation of the articular eminence. The benefits of conducting this study were to provide additional uses for the standard records that are taken for the purposes of orthodontic treatment, as well as evaluate the Newtom 3G™ for accuracy in measuring the anatomy of the glenoid fossa. This study required 20 participants that volunteered to allow their records to be used. Records evaluated were the Newtom 3G™, impressions, and wax check bite registrations. The wax record was taken using the 'forced bite' technique to …

Magnification In Images Produced By Five Popular Digital Lateral Cephalometric Machines, Gretchen Marie Schnepper

Loma Linda University Electronic Theses, Dissertations & Projects

Modern digital lateral cephalometric images are produced by machines that vary in a number of critical features such as: 1) machine geometry, 2) movement (or lack of movement) of the x-ray source, 3) movement (or lack of movement) or x-ray detectors, 4) cephalostat geometry and 5) digital data manipulations by proprietary software. The purpose of this study was to evaluate the magnification characteristics of images produced by five commercial digital lateral cephalometric machines. These digital image magnification characteristics were then compared with images produced by an analog cephalometric machine. The two goals of this study were to: 1) measure the …

De-Bonding 4 Brands Of Ceramic Brackets With The Waterlase Er,Cr;Ysgg Laser, Carter A. Lane

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine if the Biolase Waterlase Er,Cr:YSGG laser could be used as a safe and effective tool to de-bond four currently available orthodontic ceramic brackets. Changes in interpulpal temperature, enamel surface conditions and the amount of time the laser was activated to debond (sic) the ceramic brackets were evaluated. Forty human maxillary premolars were divided into four groups of ten. Prior to direct bonding, all extracted teeth were impressed and duplicated in Araldite epoxy resin as the control surface. Identical techniques were used to bond 10 ceramic brackets from each manufacturer. Three of the …

Cbct Panoramic Images Vs. Traditional Panoramic Radiographs, Sunny Young Hutchinson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this research was to compare the accuracy of angular measurements of the panoramic image of the Newtom 9000™ Cone Beam Computed Tomography (CBCT) with the Sirona™ Orthophos panoramic unit. The study was separated into three parts: phantom study, patient study, and archform study. The phantom study used fabricated phantom typodonts to compare angular measurements between the Newtom 9000™ panoramic image and the Sirona™ panoramic radiograph. Accuracies of the measurements were then determined by comparing the values to the actual phantom typodont. No marked differences in angular measurements were recorded for the phantom typodont using either of the …

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 …

Cone Beam Ct And Digital Radiography. A Comparative Study Of P/A Cephalometrics., Michael John Erickson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine if Rickett's posterio-anterior (P/A) cephalogram measurements could be obtained from Cone Beam Computerized Tomographic (CBCT) images taken on the NewTom QR-DVT 9000™.

Fifteen frontal cephalometric radiographs were chosen for good image quality, with no regard for patient age or gender. Each cephalogram was traced three times by the same operator using ZeroBase™ software. Landmarks were located and measured according to the Rickett's frontal analysis technique. Methods were devised for obtaining analogous measurements using CBCT images on the same group of patients.

Measurements obtained using CBCT correlated well with those obtained using the …

Comparison Of Bracket Bond Strength By Total, Self-Etch And Laser Treatment, Kyo Sung Shawn Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Laser etching of enamel surfaces alters the physical and chemical characteristics of the enamel. These changes in characteristics enhance the bonding to enamel. The purpose of this study was to compare the shear and tensile bond strength of Er,Cr:YSGG hydrokinetic laser system (Biolase) with 37% phosphoric acid and self etching primer 30 minutes and 72 hours after bonding. Four different laser power output setting was observed: 1.5W, 2.0W, 2.5W, and 3.0W. Two hundred forty bovine teeth free of defect, caries, and dentin exposure were mounted in acrylic resin and divided into 24 groups of 10 teeth. Sixteen groups of 10 …

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 …

Synovial Fluid Hydrostatic Pressure In The Tmj After Mandibular Advancement In Sus Scrofa, Samuel A. Demirdji

Loma Linda University Electronic Theses, Dissertations & Projects

Mandibular advancement is performed in patients routinely by traditional bilateral sagittal split osteotomy (BSSO) or less commonly by distraction osteogenesis (DO). The influence of mandibular advancement on the temporomandibular joint (TMJ) is well recognized but not fully explored. This study involved the direct measurement of synovial fluid hydrostatic pressure (SFHP) in the TMJ after mandibular advancement by either BSSO or DO in two male mature minipigs, Sus scrofa. Titanium pressure transducers were inserted into the right superior temporomandibular joint spaces of the minipigs and the measurements were displayed on an AC/DC amplifier. The first minipig underwent BSSO, which involved immediate …

Comparative Methods Of Measurement To Evaluate Onplant Assisted Anchorage, Marc Reid Larson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to compare the two-dimensional cephalometric and the three-dimensional tomographic radiographic methods in their ability to assess anatomic measurements while using the Onplant anchoring device in anterior retraction cases.

The Onplant was surgically placed beneath the periosteum of the hard palate. After osseointegration the Onplant was then uncovered and attached to the first molars by means of a transpalatal bar. Conventional orthodontic treatment was then used to retract the anterior teeth after 1^st premolars were extracted.

To evaluate the movement of the Onplant, a three-dimensional measuring tool was needed. Seven different measurements were made …

Patient Satisfaction And Effectiveness Of A New Resin Used To Bumper Orthodontic Brackets, Timothy B. Elison

Loma Linda University Electronic Theses, Dissertations & Projects

Fear of pain is a key factor in discouraging patients from seeking orthodontic treatment, with many patients discontinuing treatment due to pain experienced in the early stages of treatment. Patients often complain of traumatized lips and buccal mucosa, which is usually caused by the brackets. Orthodontists try to minimize this pain and discomfort by using bumpering materials. Although wax is the most commonly used product, there are many bracket bumpering materials available.

The purpose of this study was to evaluate the clinical effectiveness and patient comfort/satisfaction of a new flowable resin, Ortho Shield, designed to protect the lips and …

Bond Strengths Of Three Orthodontic Adhesives For Direct And Indirect Bonding, Aaron Rondon

Loma Linda University Electronic Theses, Dissertations & Projects

The technique of bonding orthodontic brackets utilizing a transfer tray, otherwise known as indirect bonding, is a dichotomous subject. It allows for more accurate bracket placement and reduced chair time for the patient and doctor, yet its technique sensitivity can yield bracket failures at the time of tray removal. With the recent development of 3M's Sondhi Rapid Set, an adhesive specifically designed for orthodontic bonding, the purpose of this study was to compare this fairly new indirect adhesive with 3M's Transbond XT and Reliance's Rely-A-Bond.

Two hundred and seventy freshly extracted bovine teeth were mounted in acrylic resin and divided …

Fracture Properties Of Different Orthodontic Bonding Materials, Daryl Lynden Proctor

Loma Linda University Electronic Theses, Dissertations & Projects

Spontaneous debonding has proven a constant problem since the introduction of bonded orthodontic brackets in the early 1960's by Newman¹.

Components in classic bond strength testing are the bracket, the adhesive, the adhesive curing method, the type of teeth used, and the test method. These tests lead to extensive and compounding variables that make it difficult to evaluate the performance of any of the components individually.

The purpose of this study was to compare several contemporary orthodontic bonding adhesives by testing the physical and mechanical characteristics of the adhesives alone. Material properties compared were sonic and tensile measurements …

Optimum Bonding Time Of Four Different Curing Lights, Nathan Don Cotten

Loma Linda University Electronic Theses, Dissertations & Projects

With the development of new high-intensity curing lights, the time required to bond orthodontic brackets is steadily decreasing. The objective of this study was to determine the optimum curing time for bonding orthodontic brackets using four different visible curing lights (Standard Optilux 501, High Intensity Optilux 501 with Turbo Tip, Virtuoso Plasma Arc, and ESPE LED light). This study also tested the new generation of light emitting diode (LED) lights to determine if they can be used for bonding orthodontic brackets. Three hundred freshly extracted bovine teeth were mounted in acrylic resin and divided into 20 groups of 15 teeth …

An Evaluation Of The Short And Long Term Effects Of Quad Helix Expansion, Sonja F. Finnie

Loma Linda University Electronic Theses, Dissertations & Projects

This study was conducted to examine, retrospectively, orthodontic and orthopedic changes resulting from quad helix expansion therapy in mixed and permanent dentition stages. Twenty-one subjects with an average age of 10.2 years who experienced an expansion of at least 3 mm with the quad helix appliance were selected for this study. The subjects were evaluated according to facial type and age for both short and long-term stability. Plaster dental casts and posteroanterior (frontal) radiographs were evaluated at the beginning of treatment (T1), at the completion of Phase 1 or full treatment (T2), and approximately two years following the completion of …

Failure Mode Of An Orthodontic Resin Alone And With Bonded Brackets, Marc Cody Dunn

Loma Linda University Electronic Theses, Dissertations & Projects

Since the introduction of bonded orthodontic brackets in the early 1960's spontaneous debonding has been a constant nemesis. Most attempts to avoid this problem by orthodontic manufactures have focused on "bond strength" issue. Whether they chose to address the materials, the bracket base or both, the common method used to evaluate improvements entailed the use of just one testing apparatus: a static universal testing machine such as the Instron.

Metal, ceramic and plastic bonded brackets were tested with the traditional shear/peel method as well as a new high strain rate impact test. The resin itself was also evaluated for physical …

Clinical Debonding Simulation Study Of One Metal And Two Ceramic Brackets, Hyunsup Shim

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to compare two mechanical debonding methods on ceramic brackets (TP MXi and 3M Clarity) and a metal bracket (GAC OmniArch) with four different bonding materials (light-cured, one-step chemical-cured, two-step chemical-cured, and Fuji GIC) in clinical simulation, where the diametral force was applied on the handle of the pliers. The effectiveness of mechanical debonding technique was determined by evaluating the following variables: the amount of force required to debond the bracket, the amount of residual adhesive remaining on the enamel surface, the frequency of unexpected bracket failure, and the prevalence of visible enamel damage. The …

Establishing Norms For A Mexican Group Using Ricketts, Steiner And Arnett Analyses, Mauricio Gonzalez Balut

Loma Linda University Electronic Theses, Dissertations & Projects

Most existing cephalometric analyses are based on norms for the Caucasian population. Therefore, they cannot be properly applied for Mexican or Hispanic patients. Ethnic variations in the normal positions of the maxilla and mandible influence and alter the diagnosis and treatment plan for each of the different type of malocclusions. Previous studies have addressed the difference between the Caucasian norms and the Hispanic norms, this indicates the variety of their skeletal, dental and facial features.

It is the purpose of this study to establish specific cephalometric standards for the native Mexican group, using the Steiner and Ricketts analyses along with …

A Pilot Study On The Short Term Effects Of The Herbst Appliance On The Glenoid Fossa, David A. Bennion

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this pilot study was to evaluate the initial effects of the Herbst appliance and determine through the use of common cephalometric radiographs that were optically enhanced and then digitally reproduced, if fossa migration is taking place. Fourteen, (6 male, 8 female), growing patients were treated by the same clinician for the correction of a Class II malocclusion using a modified Herbst appliance. Pretreatment (T₁) standard lateral cephalometric radiographs and post Herbst treatment (T_H) optically enhanced lateral cephalometric radiographs were taken. All radiographs were digitally captured and reproduced so 6 linear and 1 area …