Orthodontics and Orthodontology Commons^™

Facial Type Analysis Comparison Between Mri, Cbct, And Lateral Cephalometrics, Matthew A. Sanders

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Single Cephalometric measurements are comparable between Cone Beam Computed Tomography (CBCT), Magnetic Resonance Imaging (MRl) and Conventional Lateral Cephalometric (LC) imaging methods. This study evaluated the agreement between the three imaging methods in facial type analysis (using a composite of 5 cephalometric measures).

Methods and Materials: Twenty-two subjects participated in this study. Cranial images were generated via three modalities: LC, CBCT and MRl. Cephalometric landmarks were identified on the three images per subject and a facial type analysis performed. An equally weighted facial type calculation composed of 5 cephalometric measurements (facial axis, facial depth, mandibular plane, lower face height, …

Work Of Fracture In Ceramic Bracket Bonding Systems, Tye A. Roylance

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Work of fracture (WOE) is a method of analysis of the toughness or resilience of a bracket bonding system. It is an indication of a bracket bonding systems ability to withstand forces in the mouth below the force at which failure occurs. Work of fracture gives an indication of how much abuse the bracket/bonding system can withstand and still maintain an adequate adhesion to the tooth surface. This analysis incorporates shear bond strength and displacement and is determined in part by the elasticity and resilience of the specimen being studied.

Materials and Methods: One hundred and eighty bovine teeth …

Effects Of Orthodontic Treatment On Social Perceptions, Sherry A. Caraveo

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this study was to record first impressions elicited by photographs of orthodontic patients before and after treatment to test the hypothesis that after treatment patients will elicit a more positive first impression.

Methods and Materials: Before (Tl) and After (T2) photographs of six orthodontic patients equally divided by gender and standardized for background facial attractiveness were selected. Three different malocclusions were represented: 1) Class 1 crowded, 2) Class 11 div 1, and 3) Class 111. 108 college students rated each photographed patient on three attributes: physical attractiveness, intelligence and social desirability. Participants recorded their responses on …

Creating Prediction Models For Obstructive Sleep Apnea Based On Gender, Jeffrey Hwang

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Obstructive sleep apnea (OSA) is a common chronic disorder that is characterized by repetitive episodes of airflow cessation or reduction occurring during sleep as a result of partial or complete upper airway obstruction. These recurrent events have a tremendous impact on the cardiovascular system with a multitude of dangerous consequences. Numerous studies have been conducted determining etiological risk factors for OSA including anatomical predictors which have been observed with multiple imaging techniques. Cone beam computed tomography (CBCT) is a low-radiation mode of imaging that can be used to accurately identify anatomical landmarks and measure craniofacial relationships and airway dimensions. …

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 …

Correlating The Slope Of The Vomer With Cephalometric Vectors Of Facial Growth, Ryan Michael Pulfer

Loma Linda University Electronic Theses, Dissertations & Projects

It is important for orthodontists to have a basic understanding of the growth and development of the face. Scott's nasal septal cartilage theory proposes that the cartilage of the nasal septum proliferates along the anterior slope of the vomer bone by interstitial growth, simultaneously pulling and displacing the maxilla downward and forward. It is therefore logical to conclude that the vector of nasomaxillary growth has a geometric correlation with the anterior slope of the vomer bone.

There are no published studies comparing either the anterior or posterior slope of the vomer with any lateral cephalometric landmarks, the vectors of nasomaxillary …

Dentoskeletal And Soft Tissue Treatment Effects Of Two Different Methods For Treating Class Ii Malocclusions., Madhur Upadhyay

Master's Theses

Objectives: Moderate to severe Class II malocclusions can not only cause esthetic and functional problems but can also lead to psychological problems of varying intensity depending on the amount of anterior-posterior discrepancy and its interaction with the related soft tissue structures. Although there are several methods of treating such malocclusions (extractions,distalization,functional appliances etc), the final goal is always to provide acceptable esthetics and stability. The purpose of this clinical-cephalometric study was to examine the dentoskeletal and soft tissue treatment effects of maxillary anterior teeth retraction with mini-implant (MI) anchorage in young adults having Class II Division I malocclusion undergoing extraction …

Perception Of Soft Tissue Laser Use In Orthodontic Practice: A Survey Of Orthodontists, Periodontists, And General Dentists, Brandon Burke

Theses and Dissertations

Recently, soft tissue lasers have been introduced into orthodontic practice to perform procedures that were traditionally referred to other dental professionals. The purpose of this study was to compare the attitudes of orthodontists, periodontists, and general dentists regarding the use of soft tissue lasers by orthodontists. The ultimate goal was to facilitate communication among dental professionals and improve the care of orthodontic patients requiring management of soft tissues. A survey was developed to evaluate and compare the current opinions of orthodontists (n=330), periodontists (n=171), and general dentists (n=77) regarding orthodontists’ use of soft tissue lasers. When compared to orthodontists and …

Efficacy Of Orthodontic Bonding Agents In Preventing Demineralization Around Brackets, Morris Poole

Theses and Dissertations

Enamel demineralization is a concern in orthodontic patients with poor oral hygiene. To curtail this problem, amorphous calcium phosphate (ACP) containing adhesives have been developed. The purpose of this in vitro study was to evaluate the cariostatic potential of an ACP containing orthodontic bonding agent adjacent to brackets. Sixty human molars were randomly distributed into: ACP adhesive, resin modified glass ionomer cement (RMGIC), and conventional composite resin groups (N=20 each). Brackets were bonded following the manufacturer’s instructions. Tooth enamel through a 2mm window around the brackets was cycled in demineralization (6 hrs) and remineralization (18 hrs) solutions. After 14 days, …

Self-Ligating Vs. Conventional Brackets As Perceived By Orthodontists, Chase Prettyman

Theses and Dissertations

Introduction: Within the past decade, significant developments, new designs, and numerous proposed advantages of self-ligating (SL) brackets have caused them to gain great popularity among practicing orthodontists. The purpose of this study was to determine if there are significant clinical differences between SL and conventional brackets on orthodontic treatment as perceived by practicing orthodontists, and more specifically, if the proposed advantages of SL brackets are evident in clinical practice. Methods: A survey was developed to evaluate how SL brackets compare to conventional brackets when perceived by practicing orthodontists (n=430). The initial series of questions focused on individual practitioner characteristics and …

Lip Profile Preferences Of Asian Americans, Hung Quoc Lu

Theses and Dissertations

The aim of this study was to evaluate how Asians, non-Asians, and orthodontists in America view esthetic soft tissue Asian lip profiles. The null hypothesis was that there was no difference in the perception of lip profile esthetics of Asian patients between Asian laypersons, non-Asians laypersons, and orthodontists. A survey was constructed using the profile photographs of one adult male and one adult female Asian American patient taken from the VCU Orthodontics Clinic records. Using Dolphin Imaging 3D, the original photographs were digitally altered. The lips in each photograph were moved in increments forward and backwards to produce 5 images …

A Survey Of Treatment Characteristics In A University-Based Graduate Orthodontic Program, A. Brian Anderson

Theses and Dissertations (ETD)

While there are a few national surveys on malocclusion in the U.S., few reports characterize actual orthodontic patients and their treatments. The purpose of this study was to describe the patients and their treatment at a university based orthodontic department, namely the University of Tennessee Health Science Center, Memphis. The goals of this study are: (1) to research patient demographics, dental and skeletal relationships and treatment variables; (2) to test for temporal trends in these patients and their treatment across a 26 year interval from 1980 to 2005; and (3) to assess the correlations among patient demographics, dental and skeletal …

Long-Term Changes In The Dental Occlusion Of Subjects Treated Orthodontically, Kenneth Cooper Dyer Iv

Theses and Dissertations (ETD)

A major challenge in orthodontics is to provide a treatment result that remains stable after appliances are removed. Orthodontic treatment can move teeth from their neutral positions, which increases potential for future relapse. The literature from the University of Washington, Seattle, shows that relapse is pervasive and of considerable magnitude (Little RM. Stability and relapse of mandibular anterior alignment: University of Washington studies. Semin Orthod 1999;5:191-204). The intent of this study was to quantify the posttreatment dental changes that occurred over approximately a quarter-century in a cohort of women who had received comprehensive orthodontic treatment as teenagers. Dental casts of …

Modulation Of Rankl And Osteoprotegerin In Adolescents Using Orthodontic Forces, Nathan Reed Hamman

Theses and Dissertations (ETD)

Orthodontic tooth movement is mediated by interactions between PDL cells and those of the alveolus. One protein--the receptor activator nuclear factor kappa B ligand (RANKL)--is critical for osteoclastogenesis, and osteoprotegerin (OPG) is a decoy ligand that competitively inhibits RANKL. A higher RANKL/OPG ratio is associated with areas of bone resorption, while a lower ratio occurs in areas of bone deposition and homeostasis. There has been almost no clinical study of RANKL and OPG expression in patients undergoing orthodontic tooth movement.

The purpose of this study was to quantify changes in the levels of RANKL and of OPG in response to …

Longitudinal Cephalometric Changes Of Orthodontic Patients Evaluated Long-Term, Lisa Ku

Theses and Dissertations (ETD)

Posttreatment changes are further complicated by the slow continued growth that occurs after treatment into adulthood. The purpose of this study was to examine long term posttreatment changes. The lateral cephalograms of 51 Caucasian females treated in the standard Edgewise practice of one private practitioner in Cookeville, TN were examined to investigate changes in the cranial base, nasomaxillary complex, mandible, interach relationships, dental relationships, and the soft tissue integumental profile that occured an average of 23 years posttreatment. Two tailed t-tests (α = 0.05) were run to see whether the posttreatment changes was statistically significantly different from zero. Craniofacial growth …

Cephalometric Evaluation Of Mara Therapy In The Treatment Of Class Ii Malocclusions, Tiffany Rachelle Mcclaran

Theses and Dissertations (ETD)

The effectiveness of functional appliances is a debatable topic in the orthodontic literature, primarily because the benefits have not been consistently reproduced among clinical studies. The present study was a retrospective cephalometric analysis of patients with Class II, division 1 malocclusions at the start of treatment. There were 51 children treated by a single clinician with a MARA in combination with Edgewise appliances. The comparison group consisted of subjects treated with fixed Edgewise appliances only from the University of Tennessee, Department of Orthodontics. Subjects in the two treatment groups were matched on a one-to-one basis for sex and for five …

The Effect Of Recombinant Human Bone Morphogenetic Protein-2 On The Osseointegration Of Temporary Anchorage Devices, Eden E. Cruz

Master's Theses

Titanium has been widely used for dental implants, and in particular, roughened titanium surfaces have provided a means for increasing bone apposition and strengthening the implant-to-bone interface. Finding a way to further increase osseointegration is important because there is a significant clinical benefit to patients if a stable anchor can be established instead of anchoring orthodontic hardware to the molars. In this study, the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on the ability of temporary anchorage devices (TADs) to osseointegrate was investigated. The temporary anchorage devices (TADs) used in this study were manufactured from commercially pure titanium and …

Osseointegration Of Temporary Anchorage Devices Using Recombinant Human Bone Morphogenetic Protein-2, Erin E. Cruz

Master's Theses

Over the past 5 years, the use of titanium implants as temporary anchorage devices (TADs) has become an important tool in clinical orthodontic practices. The use of TADs have provided orthodontists a way of moving teeth against fixed objects rather than against the surrounding teeth, which tend to counteract desired motion. At present, viable attachment of TADs involves direct insertion through gingival tissue and piercing of the bone. Surface modifications such as sandblasted and acid-etched treatment or bone morphogenetic protein surface treatment, however, can be applied to the TADs to promote enhanced osseointegration, thereby allowing the TADs to serve as …

Vertical Facial And Dental Arch Dimensional Changes In Extraction Vs. Non-Extraction Orthodontic Treatment, Meena Kumari, Mubassar Fida

Section of Dental-Oral Maxillofacial Surgery

OBJECTIVE: To compare the vertical facial and dental arch dimensional changes occurring with extraction and nonextraction orthodontic treatments.

STUDY DESIGN: Cross-sectional comparative study.

PLACE AND DURATION OF STUDY: The Aga Khan University Hospital, Karachi during the period 2003 to 2005.

METHODOLOGY: Data were collected using records of patients who visited the study setting during the study period. Pre- and post-treatment lateral cephalographs and study casts of 81 orthodontic patients (41=non-extraction and 40=premolar extractions) were taken. Variables used for evaluating vertical dimension were Frankfort mandibular plane angle (FMA), facial height (N-Me), facial height ratio (N-ANS/ANS-Me), soft tissue facial height (G' to …