Design of Experiments and Sample Surveys 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, …

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 …

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 …

The Comparative Radiopacity Between Primary And Permanent Teeth, Robert C. Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This in vitro study compared the radiopacity between human primary and permanent enamel and dentin. It also compared the radiopacity between human anterior and posterior teeth.

Methods: Extracted primary and permanent teeth were used in this study. One mm enamel and one mm dentin slices were cut from each extracted tooth. Radiographs were taken of each enamel and dentin specimen 1 mm in thickness along with an aluminum step-wedge using procedures specified in International Standards Organization (ISO) 4049:2000. A densitometer was used to measure the Optical Density (OD) of the radiographs of the specimen and the accompanying aluminum step-wedge. …

Salivary Characteristics In 3 And 4 Year-Old Children With And Without Visible Caries, Gloria Yañez

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare salivary characteristics in 3 and 4 year-old Head Start children with and without visible caries.

METHODS: This case-control study was performed on 84 healthy 3 and 4 year-old Head Start children. After consent and inclusion criteria were met, each child was screened and assigned to one of two test groups based on their caries status. Group 1 consisted of children with no visible evidence of caries, although non-visible caries may have been present. Group II consisted of children with visible evidence demonstrating three or more carious lesions. Each child's unstimulated and stimulated whole saliva samples were collected …

The Effect Of Calcium Hydroxide Pastes On Root Dentin Fracture Resistance, Kurt W. Sturz

Loma Linda University Electronic Theses, Dissertations & Projects

Calcium hydroxide is a common intracanal medicament used in the treatment of immature teeth that have been subjected to trauma or decay prior to root canal therapy. The effect of calcium hydroxide on immature root dentin is important. One area of concern is the effect that calcium hydroxide has on the fracture resistance of an immature tooth. It is the aim of this study to compare the effect of four different commercially available calcium hydroxide pastes on the fracture resistance of bovine teeth. Seventy-five freshly extracted, intact bovine incisors were prepared according to a modified Haapasalo and Orstavik technique. Each …

Comparing The Use Of A Manual And A Power Toothbrush By 3-To-4 Year-Old Children, Lorena Delgado Salcedo

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare the ability of three-to four-year-old children in performing toothbrushing with manual versus battery-powered toothbrushes with and without oral hygiene instructions.

METHODS: This study was a randomized, controlled, examiner-blind, 4-period crossover design performed on 50 healthy children, ages 3 to 4 years old. Children were assigned either a manual or power toothbrush at visit one and alternated between the two types of toothbrushes each week, for four weeks. Plaque was scored before and after brushing using the Greene and Vermillion -Simplified Oral Hygiene Index. ^18,19 At their last two visits of the study, the children received brushing instructions …

Clinical Effectiveness Of A Subperiosteal Anchorage Device, Monica Anne Witte

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this pilot study was to evaluate the clinical efficacy of a subperiosteal anchorage device, the palatal OnPlant™, during orthodontic retraction of protruding anterior teeth in cases requiring maxillary premolar extraction. Seven subjects (5 female, 2 male), ages 13 to 55, were selected for the study. The OnPlant was surgically placed in the mid-palatal region through a well-defined subperiosteal tunnel. Following the manufacturer recommended osseointegration period of four months, the OnPlant was uncovered and attached to the first molars by means of a transpalatal bar. Standard orthodontic treatment then commenced to retract the anterior teeth after the first …

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 …

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 …

Measurement Of Blood Flow In Reflected Muco-Gingival Tissue Flaps In Cats : Using The Radiolabeled Microsphere Method, Gary T. Wuchenrich

Loma Linda University Electronic Theses, Dissertations & Projects

Blood flow to the maxilla and mandible may vary due to differences in vascular supply and in physiologic, metabolic and pathologic conditions. In general it is accepted that oral tissues have an abundant blood supply; however, there is little information quantifying blood flow to these regions. In this study, the maxillary tissues were chosen to measure the blood flow in attached and reflected gingival tissue in adult cats using the radiolabeled microsphere method.

Sixteen cats with permanent dentition, clean mouths, and without inflamed gingiva upon visual inspection were used and divided into two groups. Group 1 consisted of six cats …

Reproducibility Of Periodontal Probing, Su-Fang Wang

Loma Linda University Electronic Theses, Dissertations & Projects

This study evaluated reproducibility of periodontal probing by conventional manual and automated force-controlled electronic probes. A total of 1206 sites (6 sites per tooth including maxillary and mandibular incisor/canine, premolar, and molar sites) in 15 patients with history of moderate or advanced chronic periodontal disease were examined. Probings included probing pocket depths (PD), as well as probing attachment levels (PAL) from a reference stent. Measurements were recorded to the nearest 0.5 mm with both methods. Patients were examined twice, 7 to 10 days apart. At each visit, all sites were probed first with the conventional probe and then with the …

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 …

The Role Of T Cells In The Pathogenesis Of Periapical Lesions, John B. Wallstrom

Loma Linda University Electronic Theses, Dissertations & Projects

The pulps of mandibular molars of 15 athymic and 15 conventional rats were surgically exposed and left open to their oral flora. Each group was divided into 3 subgroups of 5 animals each. The rats were sacrificed after their pulps were exposed for 2, 4, or 8 weeks. After fixing, decalcifying, and embedding, the specimens were sectioned and stained with H and E. They were then examined under a microscopic grid and quantified by percentages of surface areas of bone, connective tissue, bone marrow, intrabony spaces, periapical lesions, and numbers of osteoclasts. This was done using a DataVoice computerized data …

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 …

Orthodontic Information Systems : A Developmental Study, Gary D. Sheldon

Loma Linda University Electronic Theses, Dissertations & Projects

The intent of this study was to design and implement a computer-based orthodontic system providing an integrated information environment throughout the entire patient treatment process.

Total system integration was achieved by restructuring the entire information gathering process. A complete, evaluation of patient diagnosis and treatment evaluation procedures established five major information categories and a critical information list for proper patient management. Information organization was outlined to provide a logical progression in the information gathering process and patient chart forms were designed to implement this. Defining the computer system's performance identified three functions as follows: 1) entry and editing of individual …

Comparative In Vitro Studies On Bond Strength And Sealant Polymerization, Gerald E. Sievers

Loma Linda University Electronic Theses, Dissertations & Projects

A comparison of two orthodontic sealants and two adhesives was made. An experimental adhesive was tested (Unitek*) also an experimental sealant (Unitek**) was evaluated for its ability to polymerize into a thin film. An established adhesive and sealant system (Concise***) was compared with the above products.

The factors which were considered important to the study were: the strength of the bond formed; the working efficiency; the ability for these materials to bond to the lingual of teeth; and the value of using contralateral teeth when testing bond strength.

An Instron testing machine was used to record the shear strength of …

The Effect Of Periapical Inflammation On Cellular Cementum : A Scanning Electron Microscope Study, Gary S. Yonemoto

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to obtain information on the morphologic changes that occur in cellular cementum exposed to periapical inflammation.

Ten single rooted human teeth were collected. There were five specimens of normal cellular cementum and five specimens of diseased cellular cementum, which had been exposed to periapical inflammation. Each specimen was fractured longitudinally through the apical foramen, leaving the organic component intact. The cross-sectional morphology of cellular cementum was then examined using an ARM Model 1000 scanning electron microscope. Energy dispersive x-ray spectrometry was also conducted on samples representative of the two test groups.

A methodology was …

Methodology In Measurement Of Load Loss Or Gain In Orthodontic Wires : A Pilot Study, Merton S. Lacy

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this investigation was to develop methods and equipment to measure and record over any desired length of time the loss or gain in force of any material used in orthodontics that can produce a force upon an object. The material and the object being acted upon should not be disturbed while measuring that force.

Holding devices were designed and constructed in two basic forms. For intrusive and extrusive type forces, a load cell was fixed horizontally in such a position that an adjustable tube with a set screw to hold the wire could be rotated to cause …

Evaluation Of New Attachment Following Full Thickness Flap Procedure In Humans, Shaunda S. Steiner

Loma Linda University Electronic Theses, Dissertations & Projects

A study was made to investigate the biological possibility of obtaining new connective tissue attachment to periodontally diseased root surfaces following full thickness flap procedure. Reconstructive surgery was performed on seven teeth involved in advanced chronic periodontal disease. A mucoperiosteal flap was raised and the apical extent of existing subgingival calculus was marked with a notch made into the root just apical to the calculus. Following thorough instrumentation, sterile saline was applied to the root surface for five minutes, and the flap was repositioned and sutured. Four months later the teeth with attached periodontal tissues were removed and processed for …

Fatigue Properties Of Orthodontic Wire, Kirkland B. Reuer

Loma Linda University Electronic Theses, Dissertations & Projects

Fracture of orthodontic appliances can be a problem because of the time involved to replace and repair them. It has been shown that most failures have been a result of fatigue fracture, i.e., failure resulting from cyclic loading.

The purpose of this study was to determine what effect variation of the type of orthodontic wire and heat treatment had on fatigue resistance. A device was constructed to put a cyclic load on a piece of wire until fracture. Two types of cobalt-chromium alloy wire (Blue and Green Elgiloy from Rocky Mountain Orthodontics) and three types of stain less steel wire …

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 …

Evaluation Of A Precision Filing Test For Predicting Dental Technic Performance, Douglass Roberts

Loma Linda University Electronic Theses, Dissertations & Projects

A precision filing test involving the reduction of a steel cylinder to a perfect cube with the use of a hand file and bench vise was devised as a diagnostic tool for the early detection of freshman students having technic difficulties. The test was administered to 188 freshman dental students in three classes at Loma Linda University, School of Dentistry. Subjective and objective scores were then statistically compared with subsequent technic and clinic grades of the students. The simple linear correlations between the predictor test variable and criterion grades were statistically significant for one class and for the combined classes …

A Clinical Comparison Of The Effectiveness Of Two Intracanal Medicaments, Xp-7/Prednisolone And 1% Pcp/Prednisolone, In Reduction And Duration Of Post-Treatment Pain, Kenneth G. Whitnack

Loma Linda University Electronic Theses, Dissertations & Projects

This study was undertaken to determine which intracanal medication, 1% aqueous parachlorophenol with prednisolone or XP-7 with prednisolone was the most effective in reducing the severity and duration of post-treatment pain following initial, conventional endodontic therapy. The investigation was conducted by five endodontists in their private offices and utilized a double-blind technique.

The postoperative reactions of 343 patients were examined statistically. It was shown that there was no statistically significant difference in the reduction or duration of post-treatment pain with either drug. Other factors such as sex, age, location of tooth and presence of a radiographic lesion were statistically significant …

Developing A Periodontal Screening Examination, Jeffrey R. Morgulis

Loma Linda University Electronic Theses, Dissertations & Projects

Periodontal disease is the primary cause of tooth loss in the adult, and therefore, early diagnosis of periodontal disease by the general practitioner is important in terms of prevention as well as treatment. The present study was designed to develop a periodontal screening examination which would fulfill the following requirements:

1. It should utilize precise and easily understood criteria.
2. It should take a short period of time.
3. It should enable the practitioner to accurately place patients into various disease categories.
4. It should enable the practitioner to easily and quickly relate these disease categories to treatment.

A "comprehensive" periodontal examination was performed …

The Effects Of A Topically Applied Anti-Inflammatory Agent On Root Resorption In The Replanted Teeth Of Canines, William L. Young

Loma Linda University Electronic Theses, Dissertations & Projects

Root resorption is a constant finding on the roots of replanted teeth. In this study it was suggested that root resorption is perhaps related to inflammation and that teeth incubated in an anti-inflammatory agent such as triamcinolone acetonide, a corticosteroid, before replantation would have less resorption. To investigate this hypothesis nineteen mature teeth in five mongrel dogs were extracted and replanted. Ten of the teeth were incubated for five minutes in the steroid and nine control teeth for the same period in a saline solution. Before euthanizing the animals at one, three, five, and seven weeks, a clinical evaluation of …

An In Vivo Perfusion Apparatus For Studies On Gingival Disease In The Albino Rat : Assessment By A Perfusion Of The Enzymes Collagenase And Hyaluronidase, James A. Smith

Loma Linda University Electronic Theses, Dissertations & Projects

This thesis describes an in vivo perfusion apparatus which can continuously deliver controlled quantities of solutions to localized, contralateral intraoral areas in albino rats. Three animals were per fused on the experimental area (the mesial sulcular area of the maxillary first molar) on one side with tap water and Trypan blue. Localization of the solution delivered and minimal histological changes due to the presence of the apparatus was demonstrated on these animals. Solutions of .5%, 1%, and 2% hyaluronidase and collagenase were perfused on the experimental areas of nine animals. When both enzymes were used, hyaluronidase always preceded collagenase in …

An Analysis Of Orthodontic Treatment Results Employing Class Ii Armstrong Adjustable Intermaxillary Springs, Michael E. Shumate

Loma Linda University Electronic Theses, Dissertations & Projects

A study of orthodontic treatment results employing Class II Armstrong Adjustable Intermaxillary Springs was made on twenty-eight randomly selected patients which were treated by Dr. Maclay Armstrong.

The skeletal and dental changes observed during treatment with the Class II springs was compared with those results observed when comparable type malocclusions were treated with Class II elastics. A list of changes which were observed during treatment with Class II elastics was compiled from the literature using individual studies published by Ricketts, Creekmore and Hanes.

The study was based on the findings observed in the initial and final cephalometric radiographs. A statistical …

The Effect Of Removing The Crevicular Epithelium Upon Canine Tooth Replantation, Leon A. Leonard

Loma Linda University Electronic Theses, Dissertations & Projects

The nature of epithelium and the remarkable facility with which it aggressively covers granulation tissue, suggests that removal of the sulcular epithelium surrounding the extraction wound of a tooth to be replanted could promote reattachment of the periodontal tissues at a more nearly ideal coronal level. To investigate this hypothesis twenty mature teeth in five mongrel dogs were experimentally replanted. One half of them were replanted in alveoli around which the crevicular epithelium had been removed, the remaining teeth without creviculoectomy acting as controls. Animals were euthanized at one, two, three, five, and sixteen weeks. After clinical evaluation of the …

Craniofacial Changes Resulting From Expansion Of The Midpalatal Suture In The Macaca Mulatta Monkey As Revealed By Roentgenographic Analysis, Raymond M. Sugiyama

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the effects of midpalatal suture separation on the craniofacial complex by quantitative roentgenographic analysis.

Ten female Macaca mulatta monkeys were randomly grouped for experimentation. Six animals were paired in groups for two months of treatment, four months of treatment followed by two months of post retention, and six months of treatment. The four remaining monkeys were paired and served as control animals for two and six month periods. Total activation of the expansion appliances in the treated animals was completed over a three week period.

The findings of this study were based …