Orthodontics and Orthodontology Commons^™

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 …

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 …

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 …

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 …

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 …

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) …

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 …

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 …

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 …

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 …

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 …

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, …

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 …

Mandibular Repositioning With Frankel Appliance Therapy, Clark E. Schneekluth

Loma Linda University Electronic Theses, Dissertations & Projects

A sample of twelve Frankel appliance (FR-2) treated patients, in the mixed dentition stage, were selectively chosen by an orthodontist based on the Class II correction and evaluated from before treatment and end of treatment laminagraphic and lateral cephalometric radiographs. The average treatment period was 22 months (1 yr. 10 mos.). The average pre-treatment age was 9.5 years with a range from 8 to 11 years old, while the average post-treatment age was 11.3 years with a range of 10 to 13 years.

Frankel appliance therapy was the only form of mechanics used in this study.

The before treatment lateral …

Treatment Of Persistent Open-Bite Malocclusions With Interarch Elastic Fixation, Kent L. Phillips

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to investigate the changes in the facial complex after treatment of persistent anterior open-bites with Dr. R. M. Ricketts' "squeeze treatment." This treatment method requires heavy elastic fixation for one month in conjunction with placement of T-loop arches.

Twelve open-bite patients were selected for the study. Quantative[sic] measurements from lateral cephalometric and laminagraphs of the temporomandibular joint were also evaluated. Qualitative observations were obtained from the periapical radiographs, models, and photos.

Tooth extrusion occurred in varying amounts followed by alveolar crest and apical repair.

Statistical significance was shown in the correction of incisor overbite, …

A Cephalometric Evaluation Of The Dentofacial Changes Effected With Non-Extraction Treatment Utilizing Class Ii Intermaxillary Elastics, Sing Autrapiromsook

Loma Linda University Electronic Theses, Dissertations & Projects

The effects of Class II intermaxillary elastics were studied by means of serial cephalometric records on 24 Class II malocclusions. All of the cases were non-extraction and no headgear was employed. Lateral cephalometric radiographs were taken prior to, and immediately following, the removal of the elastics. The amount of normal, growth adjustments was considered in all measurements. Molar movement and anatomical plane changes were analyzed statistically. The Student t-test were used to evaluate the significant changes.

The following conclusions are based upon a statistical analysis of the observed changes:

1. The maxillary first molars did not move distally with respect to …

A Study Of Treatment And Cephalometric Variables In Relation To Facial Axis Change During Treatment In A Dolichofacial Sample, Laurence A. Seifert

Loma Linda University Electronic Theses, Dissertations & Projects

The change in the facial axis in a sample of fifth-three dolichofacial patients, was compared with a number of pretreatment cephalometric variables. A number of treatment variables were also compared with the amount of facial axis change that occurred during orthodontic treatment.

The cephalometric variables measured were:

1. Facial axis
2. Upper face height (maxillary height)
3. Lower face height
4. Posterior face height
5. Mandibular arc
6. Palatal-mandibular plane
7. Palatal-occlusal plane
8. Occlusal-mandibular plane
9. Overbite
10. Upper first molar to palatal plane
11. Lower first molar to mandibular plane
12. Lower incisor to mandibular plane
13. Incisal edge of lower incisor to mandibular plane
14. Xi point to occlusal plane

Treatment …

A Cephalometric Study Of Mandibulo-Facial Disostosis In Monozygotic Twins Using Computerized Methods, Lyn M. Lamberton

Loma Linda University Electronic Theses, Dissertations & Projects

An investigation using computerized cephalometrics has been conducted to consider the cephalometric factors responsible for the characteristic appearance evident in individuals afflicted with Mandibulo-Facial Dysostosis. A pair of Negro monozygotic affected twins were studied using the other 10 non-affected members of the family as a control to minimize the environmental and hereditary factors. The Rocky Mountain Data System was utilized to analyze the lateral and frontal cephalometric radiographs of each individual using Ricketts Analysis and the data were subjected to statistical tests to determine the factors contributory to the syndrome. Age and size were considered and adjustments were made to …

A Clinical Comparison Of Six Orthodontic Techniques, Erik H. Madsen

Loma Linda University Electronic Theses, Dissertations & Projects

Controversy exists concerning the relative superiority of various orthodontic techniques because of the difficulties encountered in making comparative clinical studies of these techniques which are scientific and statistically meaningful. The purpose of this study was to clinically compare six different orthodontic techniques which are currently being taught, relative to a number of criteria, and to do it in a scientifically significant manner.

In order to eliminate as many of the irrelevant variables as possible, the patients were required to pass a relatively stringent screening to participate. Among other things, the patients had to have first molars in Class I relation …

A Comparative Roentgenographic Cephalometric Study Of The Facial Profile Of Orthodontic Patients Treated At Loma Linda University With Winners Of The "Smiles Of The Year" Contest, Romeo I. Stoll

Loma Linda University Electronic Theses, Dissertations & Projects

The "Smiles of the Year" winners and patients treated at Loma Linda University by the extraction or non-extraction approach were compared by linear and angular variables of skeletal, dental and soft tissue components. These findings were analyzed statistically to determine significant differences in the profile and detect the relationship between the integument and hard structures.

The following conclusions were drawn from this investigation to reflect the trend of treatment at Loma Linda University.

1. After treatment the patients had less skeletal convexity, but were more convexity than established standards.
2. The incisors of the patients treated by the extraction approach were less …

Masseter Muscle Position Relative To Skeletal Open Bite And Skeletal Closed Bite, Alonzo David Proctor

Loma Linda University Electronic Theses, Dissertations & Projects

Modification of cephalometric roentgenographic procedures provided a means to identify the anterior borders of the right and left masseter muscles and relate them to surrounding dentoskeletal elements. Attachment of short, stiff, wires to the cheeks in a position superficial to the anterior borders of the muscles, subsequent to palpation and prior to exposure of the roentgenographic film, was the procedure used. The bi-lateral images projected on the film were averaged and traced along with dentoskeletal elements including those associated with skeletal type. This line representing the anterior border of the musculature was used to assess muscle position in the vertical …

An Anthropometric Study Of The Face And Dentition Of The Pima Indian Population At The Stewart Indian School, Carson City, Nevada, Wilmonte Lee Penner

Loma Linda University Electronic Theses, Dissertations & Projects

Study casts and cephalograms were obtained on 18 female and 21 male Pima Indian students from the Stewart Indian Boarding School, Carson City, Nevada. Dentitional characteristics were assessed both clinically and by study casts. Cranio-facial analyses were performed by utilizing the skeletal and denture pattern variables suggested by the Downs and Riedel cephalometric analyses.

The purpose of this study was two-fold: (1) to determine the extent to which the Pima conforms to the Mongoloid master pattern, and (2) to test whether or not significant differences exist between the Pima and other Mongoloid groups which would allow discrimination.

The results of …