Orthodontics and Orthodontology 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, …

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 …

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 …

Orthodontic Mini-Implant Failure: Assessing The Relationship To Bone Quality Using Qcbct, Joshua Schneider

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the cortical bone thickness (mm), cortical bone density (HU), and trabecular bone density (HU) of mini-implants sites in both the maxilla and mandible using QCBCT to determine if they had any effect on mini-implant failure rate. Patient characteristics (age, gender, facial type), mini-implant characteristics (date of placement, manufacturer, length, and diameter), and the mini-implant site (region) were also evaluated. One hundred and six mini-implants in 50 consecutive patients with complete patient records, CBCT information, and T1 radiographs were included in the study. Thirty-four of the 106 mini-implants were considered "failures" resulting in …

Cephalometric Analysis Using Magnetic Resonance Imaging, Wade A. Williams

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to determine if T1-weighted 3D magnetic resonance images performed at 3.0 Tesla could be used to conduct routine orthodontic cephalometric analysis.

Methods: Three cranial imaging methods were compared using sixteen non-growing subjects (10 male and 6 female) who were not claustrophobic, did not have any metallic restorations on the distal of first molars, had no medical implants and the female subjects were not pregnant. Sagittal cranial images were produced by three methods: (1) a digital lateral cephalometric (LC) radiograph (Orthophos XG Plus, Sirona^TM, Bensheim, Germany), (2) a 12-inch FOV cone beam …

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 …

Condylar Remodeling After Distraction Osteogenesis And Bilateral Sagittal Split Osteotomy, Robert Barker Hoffman

Loma Linda University Electronic Theses, Dissertations & Projects

The present pilot study is a histological evaluation of mandibular condyles taken from minipigs that underwent either traditional mandibular advancement (bilateral sagittal split osteotomy), or a distraction osteogenesis procedure to advance the mandible. One pig received a bilateral sagittal split osteotomy with an immediate mandibular advancement of 14 mm, while another pig underwent distraction osteogenesis consisting of a gradual advancement of 2 mm per day to advance the mandible the same distance. The control animal received no surgery.

In the present study, the mandibular condyles of the three pigs (2 control, 2 bilateral sagittal split osteotomy, and 2 distraction osteogenesis) …

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 …

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 …

A Bond Strength Comparison Of Led And Halogen Light Curing Units, John Richard Kavanagh

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this research was to compare the tensile bond strength of orthodontic flat based buttons bonded to bovine teeth with four commercial light-emitting diode (LED) curing lights and one conventional quartz tungsten halogen (QTH) curing light.

The dental market has recently been introduced to a number of commercially available light-emitting diode (LED) curing lights. Tensile bond strength was evaluated for LED curing lights (Rembrandt® Allegro^TM, Den-Mat Corp, Santa Maria, CA), (LEDemetron, Kerr/Demetron Corp, Danbury, Conn), (Ortholux LED, 3M^TMESPE^TM, St. Paul, MN),and (FLASH-lite 1001, Discus Dental, Culver City, CA) are compared with one …

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 Extension Of Euclidean Distance Matrix Analysis Applied To Craniofacial Growth Prediction, Mark K. Batesole

Loma Linda University Electronic Theses, Dissertations & Projects

This study is [sic] introduces a new extension of Euclidean Distance Matrix Analysis (EDMA) as applied to growth prediction analysis. Using EDMA eliminates the presupposition of a set growth pattern, which is introduced by traditional superimposition techniques. When EDMA is extended to analyze prediction methodologies, using a non-age-matched growth sample, some shortcomings become evident. These involve bootstrapping techniques, relative difference in growth, and absence of clinical, real world measure. To overcome these issues, a statistical approach using the Wilcoxen signed rank test, absolute difference in growth, and a new method to evaluate the error in a prediction methodology's landmark identification …

A Pilot Study Testing A Proprietary Sealant For Plaque Reduction, Jennifer Rowland

Loma Linda University Electronic Theses, Dissertations & Projects

Enamel demineralization due to increased plaque accumulation is a well-recognized problem associated with fixed orthodontic appliances. The purpose of this study was to evaluate the efficacy of a proprietary product to be marketed by 3M Unitek for the reduction of plaque accumulation and thereby reduce enamel demineralization.

Sixty four bovine teeth were divided equally into an untreated control group and a group treated with the proprietary sealant product. Both groups were subsequently immersed in a Streptococcus mutans culture. Plaque deposits from each group were removed, suspended in trypticase soy broth, serially diluted, and plated on trypticase soy agar at 1, …

A Cephalometric Study Of The Class Ii Correction Effects Of The Eureka Spring, Ernest L. Stromeyer

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of the Eureka Spring appliance, was investigated on 37 consecutively treated, non compliant, bilateral Class II malocclusions, requiring at least 3 mm or more of additional molar correction. The mean pretreatment age of this sample was 13.9 years. All patients were treated by a single clinician utilizing the Eureka Spring. Lateral cephalographs were taken at start of orthodontic treatment (T1), at insertion of Eureka Springs (T2), and at removal of the Eureka Springs (T3). The average treatment interval between T2 and T3 was 4 months. Class II correction occurred almost entirely by dentoalveolar movement, 33% in the maxilla …

A New Soft Tissue Analysis : To Establish Facial Esthetic Norms In Young Adult Females, Anne Béress

Loma Linda University Electronic Theses, Dissertations & Projects

Two hundred and fifty-five articles, books, and masters theses were reviewed for the most frequently applied soft tissue measurements in the literature in order to develop a new soft tissue analysis computer program that includes established soft tissue measurements and the newly developed globe analysis. A meta analysis of 20 normal occlusion studies, was performed to obtain mean values and standard deviations to form a large sample size. Inclusion criteria for articles in the meta analysis were normal occlusion, no orthodontic treatment, pleasing faces, statement on age, race, and lip position of the population. For the lateral view, angular and …

Mandibular Asymmetry In Unilateral Class Ii Malocclusion : A Cephalometric Study, Raed Z. Moussa

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to evaluate skeletal and dental asymmetry in unilateral class II malocclusion. A study group of 25 unilateral subdivision patients was compared to 25 class I malocclusion patients serving as the control group. Submento-vertical and frontal radiographs were used for the evaluation. Symmetry was evaluated by comparing measurements between right and left sides for both groups and matching the middle points with the midsagittal axis. Statistical paired and simple t-test were used to evaluate the difference between the two sides for both groups. The measurements showed no significant skeletal and dental asymmetries except for three …

Space Closure Efficiency With Modified Ceramic Brackets : A Comparative Study, Kirk A. Specht

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine if the rate of extraction site closure was determined by the type of ceramic bracket used. A new ceramic bracket with a metal archwire slot was compared with a conventional ceramic bracket. Twenty patients were randomly assigned the metal slot ceramic bracket and conventional ceramic to one half of their maxillary arch respectively. The distribution was even left and right.

Retraction was started and completed on an 0.016" stainless steel round continuous archwire. One hundred gram sentalloy springs provided a uniform retraction force and were reactivated every four weeks to maintain a …

Long-Term Posttreatment Upper Incisor Inclination : Relative To Facial Axis Angulation As A Measure For Incisor Placement, David Lawrence Sparks

Loma Linda University Electronic Theses, Dissertations & Projects

This study was designed to determine whether upper central incisor inclination approximated the facial axis, long-term, posttreatment, regardless of the initial malocclusion or immediate posttreatment incisor inclination. Lateral head films at pretreatment, immediate posttreatment and long-term posttreatment were traced and evaluated. The sample was divided into facial type. Angle classification and treatment type (extraction vs. non-extraction). Statistical analyses included means, standard deviations, confidence intervals, population t tests and chi-square tabulations.

The results revealed that the upper central incisor did not approximate the facial axis after a minimum of 7 years posttreatment. This failed to support the use of the facial …

A Non-Human Primate Model For Evaluating A Fenestration Corticotomy Technique, Philip G. M. Khng

Loma Linda University Electronic Theses, Dissertations & Projects

A study model has been designed to evaluate the effectiveness of a new fenestration corticotomy procedure in two non-human primates Macaca fasicularis.

The objective of this study was to evaluate the efficacy of a new conservative corticotomy procedure to facilitate dental translation using fenestrations. This pilot study compared treatment and control quadrants of each individual animal's maxilla and mandible with both having the same retraction appliance and force on the 2nd premolar following extraction of the 1st molars. The null hypothesis stated that there was no significant statistical difference between the new conservative corticotomy procedure (fenestrations) when compared with …

Soft Tissue Changes Of The Upper Lip Following Isolated Le Fort I Osteotomies, Kendall E. James

Loma Linda University Electronic Theses, Dissertations & Projects

Pre-operative (T-1) and post-operative (T-3) radiographs were obtained and traced for fifty-one non-growing patients who had undergone isolated Le Fort I osteotomies. These tracings were then digitized with the results arranged in a data file and subjected to statistical analysis. The purpose of this study was to establish ratios for certain hard to soft tissue movements that could be used to aid the clinician in post-surgical soft tissue profile prediction. The results showed that even though a large sample was used, individual patient variability remained high particularly in the horizontal directions. Most ratios found in this study were consistent with …

Condylar Angulations As Related To Submental-Vertex Radiographs, Jady L. Chiakowsky

Loma Linda University Electronic Theses, Dissertations & Projects

Pretreatment submental-vertex radiographs were obtained for 637 adolescent patients (307 males, 330 females) who had presented themselves for orthodontic treatment. The purpose of this study was to: (1) determine the relationship between condylar angulations and depth of cut with the variables: age, sex, and race, and (2) establish normative values for the categories studied. The results indicated that no significant differences existed between the condylar angulations for the variables measured. However, significant differences did exist between the depth of cut for the variables measured and there was significant interaction between age and race with respect to the depth of cut. …

The Accuracy Of Sonographic Imaging (Dolphintm Digigraph) And Standard Lateral Cephalometric Radiographs : A Comparative Study, Michael D. Teichman

Loma Linda University Electronic Theses, Dissertations & Projects

Radiation due to x-ray exposure is a concern, and the development of the Dolphin™ DigiGraph represents an attempt to limit this exposure. The purpose of this paper was to compare measurements (using Ricketts analysis) obtained from conventional radiographic cephalometric tracings with those obtained by computerized digitizing with the DigiGraph. Forty-six patients from the Loma Linda University School of Dentistry graduate orthodontic clinic were digitized, and the results were compared to the x-ray tracings of these patients. The results showed that seven of the twenty-one variables examined exhibited a statistical similarity between the two methods (DigiGraph and x-ray tracing). An examination …

The Fracture Strength Of Ceramic Brackets : An Update And Comparison, Christian P. Manley

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to compare the fracture strength of ceramic brackets which are currently on the market with ceramic brackets tested in a previous study at Loma Linda. Fracture strengths of standard edgewise ceramic brackets vs. pre-torqued ceramic brackets and bicuspid ceramic brackets vs. central incisor ceramic brackets were also compared.

A total of 160 Polycrystalline brackets, 8 categories in groups if 20, were tested for fracture strength. Each bracket was tested using the same testing model that was used in the previous study at Loma Linda. The brackets were tested by torquing a wire within the …

A Modified Nance Unilateral Molar Distalizer, Tracy J. Reiner

Loma Linda University Electronic Theses, Dissertations & Projects

This clinical study evaluated a modified Nance appliance designed by the author to distalize molars unilaterally for Class II correction. This fixed appliance did not rely upon extraoral traction or intraoral elastics. Twelve unilateral Class II patients aged 13 to 17 were treated nonextraction with the appliance. Pretreatment and posttreatment photographs were taken of the palatal soft tissue and did not reveal any untoward changes as a result of the Nance acrylic button. All molars were corrected to an Angle's Class I relationship. Molar correction was evaluated visually and molar distalization was measured using an acrylic jig fitted to the …

Feasibility Of An Extraoral Method For Predicting Manibular Incisor Relapse, Mark J. Saylor

Loma Linda University Electronic Theses, Dissertations & Projects

The author undertook to develop an extraoral model for predicting mandibular incisor relapse similar to the model described by Harvey and Sheldon Peck. Whereas the Peck and Peck method involves intraoral measurements, the method described in this paper relied on the taking of measurements from the patient's pre-treatment plaster models. Two hundred and sixty teeth were measured both orally and on plaster casts, and several statistical tests were performed to isolate any differences between the intraoral and extraoral methods. The principal difference was identified as the faciolingual measurement of the incisor, due to the height of contour often being subgingival …

Facial Typing Methods : A Comparative Study, James A. Grabow

Loma Linda University Electronic Theses, Dissertations & Projects

Facial typing methods are used to determine to which of three basic facial pattern categories an individual patient belongs. These three categories are mesofacial, brachyfacial, and dolichofacial. It is important to establish the correct facial type because the reaction to treatment mechanics and the stability of the denture is dependent upon the analysis of the facial patterns. The purpose of this paper was to show a comparative study of facial typing classification methods used on 100 patients (47 boys and 53 girls). The eight different methods used were as follows: Bioprogressive, Ricketts LLU1, LLU2, QuickCeph™, Jarabak, Facial-Mandibular Index, and Steiner. …

The Incidence And Magnitude Of Tooth-Size Discrepancies In Caucasians, Blacks And Hispanics, Dana R. Shaltry

Loma Linda University Electronic Theses, Dissertations & Projects

The present investigation utilized the Bolton Analysis to determine the incidence and magnitude of tooth-size discrepancy in a sample of 227 orthodontic patients. Sliding calipers were used to measure the mesiodistal width of the permanent dentition on pretreatment study models of 120 Caucasian, 51 Black, and 56 Hispanic patients. The overall and anterior ratios were analyzed and the frequency and magnitude of excess maxillary and mandibular tooth structure was determined. Each racial group demonstrated a significant incidence of tooth-size discrepancy in the maxillary and mandibular arches of a magnitude (> 0.5mm) which would require some form of correction. In addition, …

Amount Of Root Shortening Related To Type Of Fixed Appliance : A Comparison Of The 0.018" And 0.022" Bracket Slot, Thomas L. Thompson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine if a different incidence and severity of maxillary incisor apical root resorption occurs in cases treated with the 0.018 inch versus 0.022 inch slot in standard edgewise mechanics. A consecutively treated sample of 240 patients (98 boys and 142 girls), with a mean age of 13.4 years from the orthodontic clinic at Loma Linda University were studied. 120 of the cases were treated using 0.018" bracket slot with standard edgewise mechanics and 120 were treated using 0.022" non-torqued full banded standard edgewise mechanics. 60 of the cases in each of the above …

Third Molar Eruption Prediction, Michael L. Jacobsen

Loma Linda University Electronic Theses, Dissertations & Projects

The diagnosis and treatment of third molars has often been cited as a special problem to the orthodontist. If the prognosis of third molars could be determined, orthodontic treatment could progress on a more positive basis.

This study was designed to provide a method of deciding whether developing third molars will erupt or become impacted.

Records from 130 orthodontically treated cases of Dr. Fredsall⁸ were studied. Several factors were evaluated and measured using the patients' cephalometric radiographs.

The actual fate of the third molars were recorded in the hope it could be used to predict what to expect from …