Dentistry Commons^™

Cephalometric Analysis Of Soft Tissue Profile Change Associated With Orthodontics And Orthognathic Surgery : A Long-Term Study, Douglas M. Brown

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the effect of combined orthodontic and orthognathic surgical treatment upon the soft tissue profile, and to determine the correlation between soft tissue response and the following variables: type of surgery, genioplasty, lip thickness, method of surgical site closure, interlabial distance and eversion of the lower lip. Preoperative and long-term postoperative lateral cephalograms were traced for 327 patients (231 females, 96 males) who had been treated with orthognathic surgery (108 Le Fort I, 109 mandibular sagittal split, 110 combined Le Fort I and mandibular sagittal split surgery). The results indicated that strong correlations …

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 …

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 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 …

Histomorphometric Analysis Of Primate Periodontal Tissues Following Corticotomy In Orthodontics, Wuiteng Koh

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the prevalence of specific cell types and structures at the active tooth movement site in corticotomized and non-corticotomized specimens obtained from a previous study, and to consider the hypothesis that corticotomy facilitated orthodontics is efficacious due to an inflammatory response rather than tooth-bone block movement. Specimens from 3 monkeys, each of which had a treatment and control quadrant in each arch, were sectioned, mounted on glass slides, and stained with Giemsa, haematoxylin, and Safranin stains. A histomorphometric analysis was performed with DataVoice™, a voice activated computer system which allowed for digitization of …

The Use Of Corrected Occlusal X-Ray For Determination Of Ald : A Comparative Study, Merlin D. Ekvall

Loma Linda University Electronic Theses, Dissertations & Projects

In this study arch length discrepancy or ALD was studied in 50 untreated patients. The measurements obtained from Hilgers' corrected occlusal x-ray using his Occlusal Paralleling Instrument or O.P.I, were compared with those derived by four conventional methods, - "Eye balling," digital caliper determination, conventional mandibular x-ray, and the Rocky Mountain Data Systems computer analysis (31 cases). When using the OPI, results give a higher negative ALD as it takes into consideration the space required to level a curve of Spee.

Measurements were made by the author and 3 faculty members using the above methods. Statistical analysis of the means …

The Impact Of Variations In Buccolingual Thickness Of Maxillary Anterior Dentition On First Order Arch Form Adjustments, Craig A. Andreiko

Loma Linda University Electronic Theses, Dissertations & Projects

Pre-adjusted bracket systems offer the clinician the convenience of working with both fewer in number and smaller magnitude adjustments in the archwire. The purpose of this study was to examine the normal variations in the thickness of the six maxillary anterior teeth and how this relates to anticipated first order bends in the archwire. A second purpose was to examine these same teeth for bilateral symmetry.

Thirty casts from the Loma Linda University completed treatment files were examined with respect to variations in the thicknesses of the crowns at the level of the archwire plane. From these, the mean difference …

Concentration Of Leukotrienes B4 And C4 In Human Periradicular Lesions, Elisabetta Cotti

Loma Linda University Electronic Theses, Dissertations & Projects

The 5-lipoxygenase metabolites of arachidonic acid such as leukotrienes (LT) B₄ and C₄, are potent mediators of inflammation. The purpose of this investigation was to determine the concentrations of LTB₄ and LTC₄ in human periradicular lesions. Specimens from asymptomatic and symptomatic patients were obtained and immediately frozen in liquid nitrogen. Periradicular tissues from unerupted third molars as well as chronically inflamed gingival tissues were also obtained, frozen and were used as negative and positive controls respectively. The concentrations of LTB₄ and LTC₄ were determined by the reverse phase high pressure liquid chromatography. Representative …

The Long Term Stability Of The Dental Arches Following Rapid Palatal Expansion, Robert C. Stockdale

Loma Linda University Electronic Theses, Dissertations & Projects

The rapid palatal expander is an appliance which has been used to laterally expand the maxillary dental arch, with subsequent mandibular dental arch expansion.

The purpose of this study was to evaluate and quantify long term post treatment changes in the length and width of both dental arches following rapid palatal expansion.

Plaster models from eleven patients treated with rapid palatal expansion were obtained seven or more years after treatment. The dental arches were intact anterior to the first molars and no retreatment had taken place.

Maxillary and mandibular canine, premolar and molar arch width, arch length, arch circumference, and …

Correlation Of Condylar Angulation To Occlusion, Facial Type, Age, And Sex, Perry A. Stevenson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the correlation between the condylar angulation and the following variables: occlusion, facial type, depth of cut, overbite, overjet, interincisal angle, age, and sex. Pretreatment lateral cephalograms, submental vertex radiographs and study models were obtained for 114 patients (66 females, 48 males) with a mean age of 16 who were considered to have normal, asymptomatic temporomandibular joints. The results indicated that no significant correlation existed between the condylar angulation and the variables measured. Therefore, there is no method of predicting the condylar angulation by occlusion characteristics, facial type, age, or sex.

Active Treatment Time And Incisor Root Resorption Of Malocclusions Treated With Corticotomy Facilitated Orthodontics Vs. Non-Corticotomy Treatment, Douglas F. Tetz

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the variables of treatment time and root resorption comparing subjects treated with corticotomy-facilitated orthodontics and controls treated by conventional methods. Twelve adult corticotomy subjects were utilized for the treatment time variable and seven of these subjects were utilized for the root resorption variable. These subjects were matched with non-corticotomized adult controls with regards to malocclusion, facial type, overbite, overjet and arch length deficiency. Average treatment time was found to be decreased by an average of 50% for those treated by corticotomy-facilitated orthodontics compared to non-corticotomy facilitated orthodontic care. Root resorption was significantly …

Molar And Incisor Changes With Wilson "Rapid Molar Distalization", D. Dween Muse

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]

Evaluation Of Headgear Safety : A Comparative Study, William J. Pritchard

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the relative safety of headgear safety straps. Samples from five different safety headgear straps simulated orthopedic and orthodontic use and data were collected from a series of pulls on an Instron machine. The straps were compared by the distance the face bow traveled before the safety mechanism released, the force built into the face bow at safety release and the force required to remove the inner bow out of the molar tube. The conclusions are as follows: (1) the distance a face bow can travel from the molar tube and still be …

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 …

The Stability Of Mandibular Bilateral Sagittal Split Osteotomy Advancements Using Rigid Skeletal Fixation, Michael E. Fox

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]

The Concentration Of Prostaglandin E2 In Periradicular Lesions, Steve N. Mcnicholas

Loma Linda University Electronic Theses, Dissertations & Projects

Prostaglandins (PG) have been implicated in pathogenesis of periapical lesions. The purpose of this study was to determine the concentrations of PGE₂ in human periapical lesions. Periapical specimens from patients with clinical signs and symptoms of chronic and acute apical periodontitis were obtained and immediately frozen in liquid nitrogen. Periradicular tissues from unerupted third molars were frozen and used as controls. The concentration of PGE₂ was determined by radioimmunoassay. Low levels of PGE₂ were found in the control tissues as compared to those detected in chronic and acute lesions. A significantly higher level of PGE₂ was …

The Effect Of An Anti-Osteoclastic Agent And A Collagen Sponge On Root Resorption Following Regenerative Periodontal Surgery In The Dog, Rudolf Hahn

Loma Linda University Electronic Theses, Dissertations & Projects

Previous studies indicate that root resorption is a frequent sequela to significant amounts of periodontal repair following experimental regenerative periodontal surgical procedures in animal models. To study if root resorption can be reduced or prevented, periodontal repair was evaluated in large horizontal circumferential defects in the dog in the absence of influence from the oral environment. Diphosphonate (Cl₂ MDP) applied topically to the root surfaces prior to wound closure as well as the use of a collagen sponge membrane (Helistat®) draped over the root surfaces and a control with no additional treatment after defect creation were the modalities employed. …

A Statistical Evaluation Of Class Iii Indicators In A Caucasian Population, Javier Canut

Loma Linda University Electronic Theses, Dissertations & Projects

In order to evaluate the significance of seven Class III indicators (molar relation, cranial deflection, ramus position, porion location, Xi to Pt Vertical, Xi to SNa Vertical and Xi-S-Na angle) seventy cases with a Class III malocclusion and excessive facial depth were selected from the files of the Loma Linda University Orthodontic Department, Loma Linda University Oral Surgery Department and Fundacion Jimenez Diaz Hospital Orthodontic Department (Madrid, Spain), and compared to a control group of seventy non-Class III cases.

Means and standard deviations of all variables were calculated and compared between the sample and control groups. Significant differences were determined …

Co-Cr Comparison Between Untreated & Treated Cl Ii Div 1 Cases, James W. Davis

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this retrospective study was to compare the COCR differences in pretreatment and posttreatment CI II Div I patients. Similar sample groups were chosen from patients of the graduate orthodontic clinic at Loma Linda University School of Dentistry.

Each patient's models were mounted on a Sam II articulator using a face bow transfer and a centric relation check bite. The COCR discrepancies in the anterior-posterior, superior-inferior, and side-shift dimensions were determined with the Mandibular Position Indicator.

Using t-test analyses, statistically significant differences were found between the pretreatment and posttreatment groups, with the posttreatment sample exhibiting a smaller CO-CR …

Load Deformation Test Of Metal Brackets : A Comparative Study, Luke K. Choi

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the effect material and design (slot torque degree and wing type) had on the force and stress to permanently deform metal brackets.

Fourteen different types of metal brackets were tested and categorized into three categories. The three categories were: raw material composition, slot torque degree, and wing type. There were 5 types of raw materials (310SS, 316L, 303SE, 3038, and 17-4PH), 3 types of slot torque degree (0 degree, 7 degree, and 12 degree), and 4 types of wing design (mini twin, single, regular twin, and modified twin). All brackets were tested …

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. …

A Correlational Study Of Mandibular Rotation And Morphology Of The Mandible, Brian S. Noguchi

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]

A Study Of Deep Overbite Correction With Lingual Orthodontics, Randall K. Bennett

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of the present study was to cephalometrically evaluate the bite plane effect associated with deep overbite correction in cases treated exclusively with the Ormco-Kurz™ lingual orthodontic appliance, and to evaluate whether differences existed between dolichofacial and brachyfacial facial types. Variables involved in the bite plane effect; incisor intrusion and proclination, as well as molar extrusion and mandibular rotation were measured. Fifty-nine cases were evaluated by means of computer digitized tracings of pretreatment and posttreatment lateral cephalograms. Mandibular incisor proclination of 4.5 degrees, mandibular incisor intrusion of 2.3 mm, lower anterior facial height opening of 1.3 mm and maxillary …

Immunologic Mechanisms Involved With Human Endodontic Lesions, Sunita V. Prabhu

Loma Linda University Electronic Theses, Dissertations & Projects

Endodontic or root canal infection results in immunologic changes in periapical region, which causes the destruction of pulpal and periapical tissue. No definitive study has identified a specific organism or a group of organisms as a etiological agents. Past studies have indicated that immunoglobulin E play a significant role in the pathogenesis of periapical lesions. The presence of this factor suggests that some of the endodontic flare-ups may be IgE-mediated hypersensitivity reactions. Antibody levels of IgA have been quantitatively measured by ELISA and IgE by modified RAST assay, against eleven oral bacteria which are routinely isolated from such lesions. The …

Treatment Of Periodontal Furcation Defects, Michael Martin, Bernard Gantes

Loma Linda University Electronic Theses, Dissertations & Projects

[Note: Three parts in one.]

I. Review of the Literature and Description of a Regeneration Surgical Technique

This report provides an abbreviated review of the literature on treatment and prognosis of periodontal furcation lesions. In addition, it describes a surgical technique designed to accomplish bone regeneration in class II furcation defects, together with the rationale for the development of this procedure. Results of treatment of 30 defects with this technique are presented in a subsequent report (Gantes et al. 1987).

II. Bone Regeneration in Mandibular Class II Defects

A total of 30 mandibular, buccal class II furcation defects were treated …

The Effects Of Subcondylar Fracture On Mandibular Symmetry, Crystal Gregory-Anderson

Loma Linda University Electronic Theses, Dissertations & Projects

A sample of thirteen patients who had sustained subcondylar fractures were evaluated for mandibular asymmetry. They were compared with a set of age and sex matched control patients with no history of fracture. The comparison was done cephalometrically by analysis of posterior-anterior radiographs. The purpose of the study was to determine if there was an increase in mandibular asymmetry in the subcondylar fracture patients over the control patients and to determine the location of the change.

On each radiograph 53 measurements were taken; of these there were 17 sets of bilateral measurements. Each set of bilateral measurements was analyzed in …

The Fracture Strength Of Ceramic Brackets : A Comparative Study, Daniel A. Flores

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the effect of different surface conditions and different ligation methods on the fracture strength of ceramic brackets and the yield strength of metal brackets.

Ceramic brackets followed the Griffith model, which was used to interpret their fracture strength with respect to their surface condition. With surface damage (scratching), their fracture strength decreased, while metal brackets experienced work hardening and an increased yield strength. Undamaged single-crystal brackets had a higher fracture strength than undamaged polycrystalline brackets, but after scratching, their strength decreased to value near to that of polycrystalline brackets. The fracture strength …

Magnetic Resonance Imaging Of Oromandibular Limb Hypogenesis Syndrome (Olhs) : Type 1a Congenital Hypoglossia With Micrognathia, Edmond H. Henken

Loma Linda University Electronic Theses, Dissertations & Projects

An eighteen-year old female with Oromandibular Limb Hypogenesis Syndrome Type 1A was imaged with Magnetic Resonance in the sagittal, coronal, and transverse planes with the jaws closed. The intrinsic muscles of the tongue, genioglossus, geniohyoid, mylohyoid, medial and lateral pterygoid muscles were identified and compared with a control of the same age and sex. All the muscles in question were present. Combined with the intrinsic muscles of the tongue, the genioglossus were approximately one-half the size of the control in the sagittal plane. The geniohyoid of the OLHS subject was enlarged most probably due to the hyperactivity of the floor …

Electromagnetic Field Variations In The Activation Of Bone Cell Synthesis, Gary Ketcherside

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]