Dentistry Commons^™

Dental And Buccal Bone Stability After Rapid Maxillary Expansion And Fixed Orthodontic Treatment, Allison Milliner

Loma Linda University Electronic Theses, Dissertations & Projects

The objective of this study was to quantitatively evaluate, via CBCT, the dental and osseous effects of patients who had completed comprehensive orthodontic treatment with rapid maxillary expansion (RME) in conjunction with Ricketts prescription brackets. Thirty consecutive patients (16 males, 14 females; mean age = 13.9  1.9 years) who required RME as part of their orthodontic treatment and had pre-RME (T1), post-RME (T2) and final orthodontic (T3) CBCT images were included in the study. Thirteen patients had 2-banded, while 17 had 4-banded appliances. Measurements of interdental distance (ID), interdental angle (IA), buccal bone thickness (BBT) and buccal marginal bone …

Evaluation Of Apical, Coronal And Occlusal Form Diffrences With Conventional Orthodontic Treatment, Tamar Sardarian

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Cone-beam computed tomography (CBCT) can be used to accurately identify dental landmarks in order to detect changes in dental arch forms. Purpose: The objective of this study was to determine how apical, coronal and occlusal arch forms change following orthodontic treatment with fixed appliances and to establish a base for future studies. Material and Methods: Maxillary and mandibular apical, coronal and occlusal landmarks of 27 subjects were selected on their respective CBCT images at two time points: pre-orthodontic treatment (T1) and post-orthodontic treatment (T2). Comparisons were made between the two time points to evaluate how each arch form changed …

Effect Of Time On Gypsum-Impression Material Compatibility, John Boram Won

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the compatibility of dental gypsum with three recently introduced irreversible hydrocolloid (alginate) alternatives. The test materials were Alginot® (Kerr™), Position Penta Quick® (3M ESPE™) and Silgimix® (Sultan Dental™). The irreversible hydrocolloid impression material, Jeltrate Plus antimicrobial® (Dentsply Caulk™) served as the control. Materials and Methods: Testing of materials was conducted in accordance with ANSI/ADA Specification No. 18 for Alginate Impression Materials. Statistical Analysis: The 3-Way ANOVA test was used to analyze measurements between different time points at a significance level of (p < 0.05) Outcome: It was found that there was greater compatibility between gypsum and the alternative materials over time than the traditional irreversible hydrocolloid material that was tested. A statistically significant amount of surface change/incompatibility was found over time with the combination of the dental gypsum products and the control impression material (Jeltrate Plus antimicrobial®).

Mechanical Evaluation Of Mandibular Defects Restored With Rhbmp-2: A Finite Element Model, Jelson Yalung

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The utilization of recombinant human Bone Morphogenetic Protein-2 (rh- BMP2) to form new bone has been shown to be a promising alternative to autogenous bone grafts. Understanding the biomechanical properties of rhBMP-2 restored mandibular defects would provide useful knowledge in the future success of orthopedic and dental treatment in patients who have had restoration of mandibular defects with rhBMP-2. The aim of the study was to evaluate and compare the biomechanical characteristics of rhBMP-2 regenerated bone in mandibular defects using 2 different concentrations of rhBMP-2 with a given carrier in non-human primates Material and Methods: Critical-sized defects (approximately 2.5 …

Influence Of Outdoor Air Quality On Maxillofacial Growth And Development, Ryan Rudd

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Mild to moderate deviations from normal facial types can significantly change orthodontic treatment modalities. Studies linking ambient air pollution with respiratory problems, as well as craniofacial morphology with respiratory problems are well established.1-19 In this study we aimed to determine if there was a correlation between ambient air pollution and maxillofacial growth and development. We also wanted to determine if further research should be done in this area, and if so how can the study be improved. Materials and Methods: We selected Santa Maria, CA and Upland, CA as sample areas due to their significant differences in air quality. …

Identification Of The Mandibular Nerve With Cbct Using A Nerve Marking Tool Or Not, Myung Soo Choi

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: In the field of implant dentistry, cone beam computed tomography can give clinicians valuable information regarding anatomic structures, bone quantity and quality. If the mandibular nerve is encroached during surgery, severe morbidity of the patient and medico-legal issues may result. Thus the importance of accurate determination of the position of mandibular canal cannot be overemphasized. Purpose: The aim of this study is to evaluate the difference in the position of the mandibular nerve determined, and marked by a radiology technician utilizing nerve marking tool and compared to the same measurement by a clinician not utilizing a nerve marking tool. …

Profile Attractiveness In Borderline Class Iii Surgical/Orthodontic Cases, Melina Adamian

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: This study evaluated differences between laypersons and orthodontists in rating facial attractiveness in borderline class III surgical/orthodontic cases. The purpose was to determine whether orthognathic surgery or camouflage is a better alternative for observable esthetic improvement in borderline Class III surgical/orthodontic patients. This study will aid the orthodontist in recommending treatment options to enhance profile attractiveness of borderline Class III surgical/orthodontic patients. Materials and Methods: Thirty profile images of treated borderline class III surgical/orthodontic cases were selected. Fifteen of the profile images were of cases that had been treated by orthodontics alone, and fifteen images were of cases that …

Cone-Beam Computed Tomography And Orthodontics: Awareness Assessment, Warren D. Libby

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this study was to evaluate a specific orthodontic community's knowledge and understanding of Cone-Beam Computed Tomography (CBCT) technology as well as awareness of the implications of CBCT use, including risk assessment, radiation dose estimation, diagnostic utility, and issues of informed consent. It is incumbent on the profession to understand how practitioners view this technology as it gains popularity and ease of use. Materials and Methods: A 21-question survey with 13 additional demographic questions was distributed to several different populations affiliated with Loma Linda University School of Dentistry: 1) undergraduate dental students, 2) students in specialty programs …

Sleeping Tongue Posture And Its Relationship To Craniofacial Morphology, Brent J. Tingey

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: There exists good consensus in the literature supporting the notion that resting tongue posture is an important factor in dental arch development and maintenance as well as airway control. What has yet to be quantitatively measured is the duration of time that a subconscious, resting tongue posture is maintained and whether such posture differs among various craniofacial morphologies. Quantifiable measurements might allow for prediction of tongue-posture-related problems specific to certain facial types. Purpose: The objective of this study was to record sleeping tongue posture over time in 27 subjects and to compare findings with craniofacial morphology determined by cephalometric …

Accuracy Of Unsegmented Cbct In Mesial-Distal Tooth Measurements, Todd Wesslen

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Cone-beam computed tomography (CBCT) scans may be used to measure mesial-distal (MD) tooth width for orthodontic diagnosis and treatment planning. Purpose: The objective of this study was to determine if MD tooth measurements from unsegemented CBCT scans in the axial, sagittal, and coronal planes or from a panoramic reconstruction correlate and agree with respective measurements made on study models. Material and Methods: Using stone models of 30 subjects, reference MD tooth measurements were made using digital calipers. From CBCT scans, five different methods of measuring MD width were used and compared to the reference: (1) points chosen from orthogonal …

Civic Attitude And Activity Of Loma Linda University Dental Graduates, Gregory W. Olson

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Dentistry is regarded as a profession and granted certain privileges, such as self-regulation. Associated with this status are stated and implied responsibilities which are widely debated. In recent years, dental professionalism seems to be on the decline. Evidence cited includes access-to-care issues and decreased public trust in dentists. In response, academia and professional organizations have developed curricula and statements intended to bolster professionalism. Meanwhile little is known about practicing dentists’ attitudes or participation in health-related civic matters. Objectives: This study seeks to examine the importance Loma Linda University (LLU) dental graduates place on public roles, their reported participation in …

The Influence Of Outdoor Air Quality On Vertical And Transverse Dental Dimensions, Vanessa Jenee Kaplan

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Ambient air pollution exposure is significantly associated with increased posterior crossbite tendency. Purpose: The objectives of this study were to assess whether there was an association between exposure to ambient air pollution and skeletal and dental measurements of vertical and transverse dimension among adolescents in a clinical cohort in Southern California, and to determine what methods may be best suited for use in future research. Materials and Methods: 179 subjects’ addresses were geocoded and ambient air pollution exposure was calculated based on the Environmental Protection Agency’s (EPA) air quality and emissions databases. Vertical and transverse measurements made from subjects’ …

The Association Between Body Mass Index And Dental Caries In Hispanic Elementary School Children, Mary Creske

Loma Linda University Electronic Theses, Dissertations & Projects

Background: Dental caries is the most common chronic disease of children ages 6 to 11. According to the U.S. Department of Health and Human Services, 41% of the children in this age group experience decay in their primary teeth. Since 1980 the number of overweight children ages 6 to 11 has doubled. Childhood obesity is currently the most prevalent nutritional condition of children in the U.S.

Purpose: The purpose of this observational study was to determine if there is an association between childhood dental caries and childhood obesity. The study also explored the effects of diet and other covariates.

Method: …

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 …

Comparison Of Non-Surgical And Surgical Endodontic Retreatment: A Systematic Review, Robert Corr

Loma Linda University Electronic Theses, Dissertations & Projects

Primary root canal therapy has been shown to be a predictable procedure with a high degree of success ^1-4, however failures can occur after treatment. Treatment options for the preservation of teeth that have had previous endodontic treatment but demonstrate persistent disease include non-surgical (orthograde) or surgical (retrograde) endodontic retreatment, assuming the tooth is restorable, periodontally sound, and the patient desires to retain the tooth. The purpose of this study was to conduct a systematic review of the current available evidence to compare the clinical and radiographic outcomes of nonsurgical with those of surgical endodontic retreatment. Methodology began with …

Correlating The Slope Of The Vomer With Cephalometric Vectors Of Facial Growth, Ryan Michael Pulfer

Loma Linda University Electronic Theses, Dissertations & Projects

It is important for orthodontists to have a basic understanding of the growth and development of the face. Scott's nasal septal cartilage theory proposes that the cartilage of the nasal septum proliferates along the anterior slope of the vomer bone by interstitial growth, simultaneously pulling and displacing the maxilla downward and forward. It is therefore logical to conclude that the vector of nasomaxillary growth has a geometric correlation with the anterior slope of the vomer bone.

There are no published studies comparing either the anterior or posterior slope of the vomer with any lateral cephalometric landmarks, the vectors of nasomaxillary …

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. …

Microct Study Of Critical-Sized Defects Restored With A New Rhbmp-2 Carrier, Joanne S. Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Regenerating bone in critical-sized maxillofacial osseous defects remains a challenge. The utilization of recombinant human bone morphogenetic protein-2 (rhBMP-2) to form new bone has been shown to be a promising alternative to autogenous bone grafts, and the development of a carrier matrix to effectively deliver the rhBMP-2 has been identified as the critical factor necessary for the successful clinical application of rhBMP-2. The objective of this study was to perform a microCT analysis to examine the density of reconstructed bone using different rhBMP-2 carriers in critical-sized defects.

Material and Methods: Critical-sized defects (approximately 2.5 cm) were created in the …

Effects Of Orthodontic Treatment On Social Perceptions, Sherry A. Caraveo

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this study was to record first impressions elicited by photographs of orthodontic patients before and after treatment to test the hypothesis that after treatment patients will elicit a more positive first impression.

Methods and Materials: Before (Tl) and After (T2) photographs of six orthodontic patients equally divided by gender and standardized for background facial attractiveness were selected. Three different malocclusions were represented: 1) Class 1 crowded, 2) Class 11 div 1, and 3) Class 111. 108 college students rated each photographed patient on three attributes: physical attractiveness, intelligence and social desirability. Participants recorded their responses on …

Immediate Tooth Replacement With Subepithelial Connective Tissue Graft Using Platform Switching Implants, Seunghwan Chung

Loma Linda University Electronic Theses, Dissertations & Projects

This case series evaluated the facial gingival stability following immediate tooth replacement in conjunction with subepithelial connective tissue graft in the esthetic zone. Implant success rate and peri-implant tissue response were also reported.

Ten patients (6 males, 4 females), with a mean age of 52.1 (range = 22.7 to 67.1) years, underwent immediate implant placement and provisionalization with SCTG and were evaluated clinically and radiographically at pre-surgery (T0), immediately after immediate tooth replacement and SCTG (T1), 3-months (T2), 6-months (T3), and 12-months (T4) after surgery. Data was analyzed using the Wilcoxon Signed-Ranks Test and Friedman Test at the significance level …

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 …

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 …

The Influence Of Work Of Fracture On Six Orthodontic Bonding Systems, Tyler S. Pritchard

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Bonding is the primary method of attaching brackets to teeth in modem orthodontics. Thus, many studies have focused on the maximum shear bond strength values of orthodontic adhesives. In contrast, very little research has been performed considering the work of fracture of orthodontic bonding systems. Work of Fracture is defined as the area under the curve of a stress-strain graph. Previous shear bond strength studies measured the force necessary to produce bond failure. The purpose of this study was to measure the maximum shear force and displacement of six bonding systems and to calculate the work of fracture.

Materials …

Influence Of Stainless Steel Orthodontic Brackets On Magnetic Resonance Imaging, Christian James Hoybjerg

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Magnetic resonance imaging (MRI) machines provide 2D as well as 3D images that are excellent in contrasting soft-tissue in the maxillofacial region and are void of ionizing radiation. The drawbacks include the lack of depiction of cortical bony detail and image degradation caused by substances in the scanned area. Specifically, in the orthodontic field stainless steel brackets cause more distortion of MR images then any other bracket material. It is unknown what type of stainless steel alloy causes the most MRI distortion. The purpose of this study is to evaluate the degree of craniofacial MR distortion caused by various …

Effects Of Functional Appliances On Pharyngeal Airway Dimensions: A Cone Beam Computed Tomography Study, Melissa K. Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Functional appliances are intended to correct by incremental advancement of the mandible for correction of skeletal Class 11 relationships. Similar in design to functional appliances, mandibular advancing devices (MAD) are used for obstructive sleep apnea (OSA) patients as they increase the size of the airway by drawing the tongue and soft palate forwards, and thus maintain its patency during sleep. It has been shown that significant increases in airway dimensions and decreases in airway resistance were gained in OSA patients while evaluated with a MAD in place. This retrospective study evaluated volumetric, cross-sectional area and linear changes in the …

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 …

The Effect Of Auxiliary Preparation Elements On The Resistance Form Of Complete Metal Crowns, Mostafa Nazari

Loma Linda University Electronic Theses, Dissertations & Projects

This study measured the resistance to dislodgment of complete metal crowns when they were fabricated for tooth preparations lacking resistance form. These preparations were modified with four different auxiliary preparation features.

An Ivorine mandibular first molar was prepared on a milling machine with the following characteristics: 20 degrees of total occlusal convergence (TOC), 360 degrees shoulder finish line of 1.0 mm width, and axial wall of reduced height offering no geometric resistance form. The following tooth preparation modifications were studied:

1. Two proximal grooves (two lingually positioned grooves, one on the mesial and one on the distal surface) (design B) (Figures …

Effect Of Auxiliary Preparation Elements On Resistance Form Of Complete Crowns, Manuel H. Guevara

Loma Linda University Electronic Theses, Dissertations & Projects

This study compared the effectiveness of six different auxiliary preparation elements on the resistance to lateral dislodgment of complete crown preparation lacking resistance form.

An ivorine mandibular first molar was prepared with the following characteristics: 20° TOC, 360° shoulder finish line of 1.0 mm width and axial wall of reduced height offering no geometric resistance form (Group A: control). Preparation modifications were Group B: MD grooves, Group C: BL groves (sic), Group D: MDBL grooves, Group E: MD small boxes, Group F: MD large boxes and Group G: 8° TOC at the cervical 2 mm of the axial walls. Ten …

Immediate Loading Of Unsplinted Implants In The Anterior Mandible For Overdentures, Phillip Roe

Loma Linda University Electronic Theses, Dissertations & Projects

In this one-year prospective study, eight completely edentulous patients were selected from the Loma Linda University School of Dentistry (LLUSD) patient population to participate. There were five male and three female patients, between the ages of 58 and 82 (mean age of 69.1 years). All participants received new maxillary and mandibular complete dentures prior to implant placement. Two 4.0 mm x 13 mm threaded implants with a fluoride-modified, micro-roughened, titanium surface were placed mesial to each mandibular canine position. Locator abutments were connected and torqued to 25 Ncm and primary closure was achieved with a nonresorbable suture material. The Locator …