Orthodontics and Orthodontology Commons^™

A Study Of Crown And Root Angulation On Maxillary First And Second Bicuspids, Craig A. Chamberlain

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 in magnitude adjustments of an archwire. The purpose of this in vitro study was to examine the normal variations in crown angulation of individual maxillary bicuspids, in a simulated flat plane of occlusion, and how this relates to marginal ridge discrepancies. A second purpose of this study was to examine these same teeth for the angulations of the roots. Fifty maxillary first bicuspids and thirty eight second bicuspids from the Loma Linda University Dental School restorative dentistry department were, in a flat plane …

Soft Tissue Changes Of The Lower Lip Following Isolated Mandibular Advancement Osteotomies, Ronald Roy A. Simus

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the soft tissue changes that occur following isolated mandibular advancement surgery. A sample of 70 non-growing patients were examined by tracing pre and post-operative radiographs. Then various landmarks were chosen and hand measured to determine hard and soft tissue changes. Significant correlations were found for many of the horizontal and vertical tissue landmarks and weaker correlations for all other landmarks. The decrease in the interlabial gap and the angular changes in the lower lip reflect the direction of surgical movement. The data from this study supports previous studies of smaller sample sizes …

An Evaluation Of Surface Enamel Damage Following The Debonding Of Ceramic Brackets : A Follow-Up Study, C. Steven Edney

Loma Linda University Electronic Theses, Dissertations & Projects

Surface enamel damage was evaluated after debonding ceramic brackets on forty-four bicuspid teeth. These teeth had been previously bonded with two different types of ceramic brackets. One of the brackets utilized a mechanical base for retention and the other bracket utilized a polycarbonate base for retention. The brackets were bonded to the respective teeth for a total of seven to ten days. After debonding, the teeth were extracted and evaluated with a scanning electron microscope. A metal bracket SEM scan was used for a control. The study concluded that: 1) all brackets alter the surface enamel, 2) metal brackets cause …

Assessment Of The Accuracy Of Three Methods Of Computerized Growth Prediction Of The Soft Tissue Profile, In Untreated Individuals, Pat Diciccio

Loma Linda University Electronic Theses, Dissertations & Projects

This study was performed to determine the accuracy and reliability of the long range growth predictions for profile structures by three computer software systems (QuickCeph™ for Apple Macintosh™ systems. Rocky Mountain Data Systems™ for IBM™ mainframe systems, and Facial Print™ for IBM™ personal computers), on untreated individuals. The total sample consisted of 90 Caucasian children from the Burlington Growth Centre. These were subdivided into groups of 15 children in each of mesiofacial, dolichofacial, and brachyfacial growth types for both males and females, with Angle class I occlusions, normal overbite, and normal overjet. Points measured consisted of 14 skeletal and soft …

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 …

A Shear Bondstrength Evaluation Of Five Orthodontic Light-Cured Adhesives, Perry M. Unruh

Loma Linda University Electronic Theses, Dissertations & Projects

In this study, the shear bondstrengths of five commercially available orthodontic light-cured adhesives were evaluated with respect to two types of curing lights and various cure-times. A total of 160 Transcend brackets (mechanical retention) were utilized. The brackets were individually bonded to knurled stainless steel testing rings via the respective adhesives. Each bracket was sheared from the testing ring using an Instron machine. For each adhesive a 2, 5, 10, and 20 second cure-time, and an immediate, 5 minute, 20 minute, and 24 hour shear test time was employed. The adhesives were cured using high intensity and low intensity visible …

A Pilot Study On The Evaluation Of Short Term Effects Of Jasper Jumper Therapy, Eric D. Fraser

Loma Linda University Electronic Theses, Dissertations & Projects

Lateral cephalometric radiographs were obtained for ten patients treated with Jasper Jumper appliances from three locations. Pre and post-appliance measurements were compared to determine the cephalometric effects seen in this group of patients. All patients in this study exhibited mesofacial to brachyfacial growth patterns and were all of growing age. All patients were treated to Class I along the complete buccal segment. The results yielded the following conclusions: 1) the facial axis did not open and the lower face height did not increase significantly for this group of patients, 2) there is an intrusive effect delivered to the upper first …

New In Vivo And In Vitro Techniques For Quantification Of Lateral Force Levels That Cause Implants To Fail : A Progress Report On Monkey Research, V. Leroy Leggitt

Loma Linda University Electronic Theses, Dissertations & Projects

Two new techniques for quantification of forces generated by an expansion screw apparatus placed between pairs of cylindrical endosseous titanium implants are described, along with preliminary data gained from their use in Macaca rhesus monkeys. Strain gages were bonded to the expansion apparatus and were calibrated either directly by micro load cell, or indirectly by Instron Machine to reflect the applied force.

Immediate loads of up to 6 kilograms have been applied to the implants with no increase in mobility as verified by a Periotest device. No previous studies on the orthodontic uses of implants have evaluated in vivo forces …

An Evaluation Of Surface Enamel Damage Following The Debonding Of Ceramic Brackets : A Follow-Up Study, B. Scott Hood

Loma Linda University Electronic Theses, Dissertations & Projects

To evaluate surface enamel damage after debonding ceramic brackets using their manufacturer's recommended methods, sixty four bicuspid teeth were bonded with three different types of ceramic brackets and one type of metal bracket. All the brackets tested utilized mechanical retention only. The brackets were debonded in the mouth seven to ten days after bonding, extracted and evaluated with a scanning electron microscope. The study concluded that: 1) all brackets alter the surface enamel, 2) there is a significant difference in surface enamel damage between the metal bracket and the ceramic brackets utilizing a tensile debonding method, 3) there is no …

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. …

Predicting Post-Treatment Maxillary Lip Position : A Comparison Of Two Techniques, Kevin J. Andrews

Loma Linda University Electronic Theses, Dissertations & Projects

The objective of this study was to compare the "drape" technique as proposed by Economides with the Holdaway technique in predicting post-treatment maxillary lip position and to determine which method was more accurate. Pre and post-treatment lateral cephalograms were traced for ninety (Caucasian) cases equally divided by sex into three treatment groups: a) non-extraction with at least 4mm of upper incisor retraction, b) extraction of upper first bicuspids only, and c) extraction of all first bicuspids. VTO's were constructed as outlined by Economides (drape) and Holdaway for prediction of post-treatment maxillary lip position. The predicted lip positions were compared to …

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 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 …

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 …

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]