Analytical, Diagnostic and Therapeutic Techniques and Equipment Commons^™

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 …

Using Cone Beam Computed Tomography To Identify A Prediction Model For Obstructive Sleep Apnea, Jodi Parker

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Obstructive Sleep Apnea (OSA) patients have increased risk of morbidity and mortality. Early diagnosis may reduce morbidity and mortality. Prediction of OSA from imaging may help to identify OSA patients earlier in life. CBCT can be used for OSA diagnostic imaging due to its three-dimensional (3D) visualization of the upper airway and craniofacial complex. Magnification associated with conventional 2D radiography is eliminated with CBCT, and radiation to the patient is significantly less than previous modalities used to measure craniofacial & airway measurements associated with OSA. During a CBCT scan, the patient's image is taken supine, rather than the upright …

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 …

Immediate Provionalization Of Single Threaded Oxidized Implants On Maxillary Premolars Healed Sites: One-Year Study, Kiyotaka Umezu

Loma Linda University Electronic Theses, Dissertations & Projects

Osseointegrated endosseous implants have been widely used and become a predictable treatment option for completely and partially edentulous patients. The viability and predictability of this treatment modality have been supported with the high success rates in numerous studies. Clinical guideline requires a healing period of 3 to 6 months without functional loading to achieve osseointegration with machine surface implants. Therefore, numerous studies on immediately loaded implants have been conducted in an attempt to minimize or eliminate this healing period. The purpose of this study was to evaluate the success rate of the immediately provisionalized oxidized-surface implants in healed sites supporting …

Comparison Of Microleakage In Three Sealant Placement Protocols Vs. The Enamel Loc System, Audrey T. Sheu

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To evaluate sealant microleakage using four different application techniques.

METHODS: The four application techniques evaluated were acid etch only, Adper L-Pop bonding, Optibond bonding, and Enamel Loc One-Step Sealant. Sixty-four extracted third molar teeth were assigned on one of four application techniques (n=16) and Clinpro sealants applied according to the manufacturer's instructions. The teeth were thermocycled for 500 cycles, dyed, and embedded in resin. The samples were then sectioned and evaluated for microleakage on the buccal and lingual surfaces. Statistical methods employed to analyze the data were the Kruskal-Willis rank test and the Mann-Whitney U test.

RESULTS: No significant …

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 …

Comparison Of Laser And Phosphoric Acid Etching On Sealant Shear Bond Strength, Seth David Latimer

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare the effect of traditional phosphoric acid etching with Er,Cr:YSGG laser enamel etching on the shear bond strength of sealant material.

METHODS: Extracted healthy third molars were mounted in acrylic exposing the flattest surface available. Three groups of twenty teeth were used to evaluate traditional acid etching with 37% phosphoric acid as a control group as well as two different laser settings. The sealant material was attached using specialized jigs and then subjected to shear bond strength testing utilizing the ultradent method (MTS machine). Statistical methods employed were the Kruskal-Wallis rank test and the Mann-Whitney U test.

RESULTS: …

Reproducibility Of Two Non-Consecutive Scans Using A Newtom 3g; In Vitro Model, Hyoung Jin Park

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The aim of this study was to evaluate the reproducibility of mineral density measurement expressed in Hounsfield Units (HU) using a phantom device with known mineral densities and the NewTom 3G Cone Beam Computerized Tomography (CBCT).

Materials and Methods: A phantom device made of 21 HA cylindrical disks with known densities was fabricated. The phantom was scanned in 6, 9, and 12 inch fields of view using a NewTom 3G CBCT. The scans were repeated at non-consecutive sessions. Volumetric data in each of the scans were formatted to DICOM images. HU values of the regions of interest were retrieved …

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 …

Bone Morphogenic Protein Induced Repair Of The Premaxillary Cleft, Rick J. Rawson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to evaluate the bony augmentation of premaxillary clefts in humans using recombinant bone morphogenic protein (rhBMP-2) in a collagen sponge carrier. 12 patients with unilateral cleft alveolar ridges were evaluated pre- and 4 months postoperatively. 10 patients were repaired with rhBMP-2 while two others were grafted with anterior iliac crest particulate marrow cancellous bone (PMCB). Computed tomographic studies were used to evaluate preoperative alveolar cleft volumes, postoperative bone bridge volumes, and pre/post operative volume ratios.

A pre/post operative volume ratio for patients repaired with rhBMP-2 ranged from 24.1% to 90.6% with a mean of …

Influence Of Keratinized Mucosa, Bone Dimensions On Mucosal Recession And Bone Loss, Jeanette Keng Ling Chua

Loma Linda University Electronic Theses, Dissertations & Projects

Background: To accomplish successful esthetic outcome, it would be an advantage if some pre-implant placement conditions could be identified which would predict soft and hard tissue outcomes post-implant placement. This study was designed to evaluate the influence of 1) height of mid-buccal keratinized mucosa at implant surgery and 2) thickness of mid-buccal bone after osteotomy on the amounts of mid-buccal mucosal recession and bone loss during the first year after implant treatment. This report presents the initial 3-month follow-up.

Materials and methods: Nine patients scheduled for surgical placement of a total of 11 single-staged implants, without adjacent teeth and planned …

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 …

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 …

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 …

Resonance Frequency Analysis As A Determinant Of Implant Initial Stability, Negar Tabandeh

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The clinicians' decision regarding immediate loading is largely determined by the assessment of initial stability of the dental implant. Computed tomographic assessment of recipient site bone quality, insertion resistance torque and post-insertion resonance frequency are currently the only objective methods of measurement establishing initial stability.

Purpose: A study was designed to measure resonance frequency of root form dental implants placed in cadaver jaws. The resonance frequency values were compared to previous subjective and objective data reported in prior studies in the series.

Materials and Methods: Resonance frequency measurements were secured using the Osstell ™ mentor unit on 4.0 X …

Comparison Of Different Methods Of Assessing Ridge Width Prior To Implant Placement, Lung-Cheng Chen

Loma Linda University Electronic Theses, Dissertations & Projects

The aim of this study was to compare the following 3 methods of assessing alveolar ridge dimensions prior to placement of dental implants: 1) ridge mapping measurement before surgical flap reflection using a caliper; 2) direct caliper measurement following surgical exposure of the bone, and 3) measurement using images from cone beam computerized tomography.

Sixteen subjects having 25 sites for planned implant placement or ridge augmentation were recruited. An acrylic stent was fabricated for each patient. The stent provided 3 buccal/lingual pairs of consistent measurement points for each implant site, located 4, 7 and 10 mm from the summit of …

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 …

Effect Of Anti-Tgfß1 And Pycnogenol® On Scar Formation In Rats, Pilseong Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Wound healing is a complex biologic process that involves chemotaxis and division of cells, neovascularization, synthesis of extracellular matrix proteins, and remodeling of the repaired tissues. Of equal importance is the restoration of normal tissue structure and function without scar formation. The aim of this study was to find out the clinical effects of anti-TGFß1 and Pycnogenol® on scarless wound healing on rat skin.

An acute incision wound model was used with 20 healthy rats. Four incisions were made on each rat's skin and 4 different variables were applied by local infiltration. The four variables were anti-TGFß1, Pycnogenol®, PBS, and …

Detection Of Bacteria To Dental Tissue By Low-Light Imaging, G-Hong Robert Hsu

Loma Linda University Electronic Theses, Dissertations & Projects

Bacteria have been shown to play an important role in the development of pulp and periradicular disease. The source of the infective bacteria is most often the oral cavity. Previous studies have detected bacteria in teeth that are structurally intact that seemingly have no communication intraorally. Anachoresis has been proposed as a mechanism for localizing circulating bacteria to such teeth. In several previous bacteriologic anachoresis studies, bacteria have been found to localize in inflamed dental tissues. The criticism most commonly associated with these investigations has been the potential contribution of contaminant bacteria resulting in false positive findings.

Low-light image analysis …

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 …

The Radiopacity Of 29 Resin Restorative Materials Compared To Enamel, Peter Lubisich Iv

Loma Linda University Electronic Theses, Dissertations & Projects

The radiodensity of a composite resin can greatly influence a clinician's ability to analyze a restoration for failure. The purpose of this study was to determine the relative radiopacities of 29 resin restorative materials compared to enamel, and to verify the comparable radiopacity between shades of 23 of the restorative composite resin materials. Composite resin discs measuring >5mm in diameter and 2 mm in thickness were made and polymerized. Radiographs were taken of the composite resin discs, which included an aluminum step wedge for calibration and a densitometer was used to measure the radiodensity of the composite resin samples. The …

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 …

Effects Of Mtad On Some Physical Properties Of Enamel And Dentin, Tanya Kristina Machnick

Loma Linda University Electronic Theses, Dissertations & Projects

Recently, a Mixture of Tetracycline, an Acid, and a Detergent (MTAD) has been advocated to remove smear layer and disinfect canals. The purpose of this study was to evaluate the effect of MTAD the flexural strength and modulus of elasticity of dentin as well as its effect on the bond strength to enamel and dentin. In Part I, dentin bars were randomly assigned to eight groups treated either with various concentrations of NaOCl (5.25%, 2.65%, 1.31%, 0.66%), 17% EDTA, MTAD, saline, or according to a clinical protocol with 1.3% NaOCl and then 5 min of MTAD. …