Orthodontics and Orthodontology Commons^™

The Effect Of Orthodontic Treatment On Sagittal Root Position Of The Maxillary Central Incisor, Jeremy Haines

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Sagittal root position (SRP) of maxillary incisors is an important factor in implant treatment planning. Kan et al defined four classes of SRP in an effort to aid implant placement treatment planning and these SRP classifications represent a novel approach to describing bone changes around the maxillary incisors. The effect of orthodontic tooth movement, specifically changes in inclination, on SRP is of interest in potentially facilitating immediate implant placement. Purpose: The purpose of this study was to use Cone Beam Computed Tomography (CBCT) to evaluate the adaptation of alveolar bone around the maxillary incisors as a result of orthodontic …

A Cbct Study Of Pharyngeal Airway Changes Due To Fixed Functional Appliances, Scott T. Peterson

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this retrospective study, using head and neck Cone-Beam Computed Tomography (CBCT) images, was to measure and compare volumetric, area, and linear changes of the pharyngeal airway space in patients treated with a MARA or Herbst Class II correction appliances. Materials and Methods: Twenty-six patients treated with a MARA (mean age 13.2), nine with a Herbst (mean age 12.12) , and a control group twenty-five orthodontically treated class I patients (mean age 13.11). T1 and T2 CBCT images were measured and compared between the three groups for area, length, and width measurements along the velo-, oro-, and …

Ricketts Analysis Using Conventional And Dolphintm Generated Cbct Lateral Cephs, Yeganeh Parhizkar Jewell

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The aim of this study was to evaluate the difference between Ricketts analysis measurements made on Sirona Orthophos XG Plus (Sirona Dental Systems, Charlotte,NC) lateral cephalograms, and DolphinTM generated perspective and orthogonal lateral cephalograms from CBCT (NewTom 5G; QR srl, Verona, Italy). Materials and Methods: A Sirona digital lateral cephalogram and DophinTM synthesized CBCT lateral cephalograms of a radiographic phantom in orthogonal and perspective projections were created. Horizontal and vertical measurements were made in multiple planes on the radiographic phantom to compare each imaging modality. Twenty-five lateral cephalometric radiographs were selected retrospectively from the records of patients of …

Comparison Of Two Methods Of Transpalatal Arch And Lingual Arch Activation, Taoran Zhang

Loma Linda University Electronic Theses, Dissertations & Projects

The TPA and LA can be activated with two methods: the “shape-driven method” where the appliance is made to match the final tooth position and the “force-driven method” where the appliance is made to make sure the force system delivered by it at the beginning is consistent with the planned tooth movement. This study compared the two methods in vitro quantitatively with typodont teeth and multi-axis force torque transducers in all three dimensions. Results: In the TPA first order activation, with comparable Fy (force on Y axis) reading, the shape-driven activation group had a significantly higher Mx (moment on X …

An Evaluation Of Root Length Change Measurements Using Intraoral Scan And Panoramic Radiographs, Elijah C. Wang

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: This study was intended to evaluate the accuracy of using panoramic radiographs to measure root length change over the course of orthodontic treatment, using intraoral scans of crowns, and a mathematical model to account for distortions in the radiographs. The study additionally evaluated whether a best-fit equation could be created from the calculated data to minimize differences to the measurements of root resorption made on CBCT scans. Materials and Methods: Twenty-one patients were selected who had comprehensive orthodontic treatment, and all teeth in the upper right quadrant were evaluated in this study. T1 and T2 CBCT images were compared …

Correlation Of Tooth Length Measurements Made On Cbct And 3t Mr Images, Andrew Scott Taylor

Loma Linda University Electronic Theses, Dissertations & Projects

Objective. This study compared tooth length measurements made on cone beam computed tomography (CBCT) scans and 3-Tesla (3T) magnetic resonance (MR) scans performed with and without an alginate bite registration surrounding the crowns of the teeth. Materials and Methods. One CBCT scan, one MR scan with alginate bite registration, and one MR scan without bite registration were performed on 12 subjects. The alginate bite registration was used to provide a proton-rich material to surround proton-poor teeth in an attempt to improve visualization of teeth. DICOM formatted images from each of the three scans for each subject were oriented in all …

The Effect Of Orthodontic Appliances On The Evaluation Of The Professionalism And Esthetics Of An Adult Employee, Laura Hanson Vaccariello

Master's Theses (2009 -)

This study explored the influence of fixed and removable orthodontic appliances on participants’ ratings of the job performance, intelligence, and attractiveness of an adult female. Ninety-four adult subjects were recruited from the Graduate School of Management at Marquette University. Each subject received an identical employee performance review with an attached photograph of a female employee. The smile of the photo was manipulated to represent one of four conditions: no orthodontic appliance, a metal orthodontic appliance, a ceramic orthodontic appliance, or a clear aligner. Subjects then rated the employee on three continuous Likert scales. Ratings of job performance, intelligence, and attractiveness …

The Effects Of Mechanical Vibration On Human Chondrocytes In Vitro, Bradley J. Gauthier

Master's Theses (2009 -)

Introduction: Inflammation is the biological basis of temporomandibular joint disorders (TMD), when severe it can lead to osteoarthritis. One of the physical therapies used to manage this condition is mechanical vibration, as has been used in medicine for many years as a non-pharmacological therapy. Recently an FDA approved dental device called AcceleDent has been introduced to increase the rate of tooth movement and decrease pain. As the device-generated vibration transmits to the TMJ, it is important for us to investigate whether mechanical vibration influences TMJ on its biologic basis – chondrocytes under normal and inflammatory conditions. Materials and Methods: Human …

Mechanical Properties Of Copper-Nickel-Titanium Archwires, Margaret Amelia Rosen

Master's Theses (2009 -)

Introduction: The initial phase of orthodontic therapy relies on flexible wires, usually composed of a nickel-titanium alloy, to apply a substantially constant load during tooth movement. Copper has been added to nickel-titanium archwires, resulting in an alloy with potential clinical advantages such as a lower stress hysteresis. Many orthodontic companies claim that their copper-nickel-titanium manufacturing process allows for the production of more consistent transition temperatures in the wires, allowing the orthodontist to customize treatment to various patients based on the force level needed. There are currently many manufacturers of these wires, creating a wide range of copper-nickel-titanium archwires from which …

Thermal Properties Of Copper Nickel-Titanium Orthodontic Archwires, Joshua Gilbert

Master's Theses (2009 -)

Introduction: Copper Nickel-Titanium (CuNiTi) is a relatively new composition of Nickel-Titanium (NiTi) archwires that was originally patented in 1991 as part of the Ormco line of wires. The patent has now recently expired and many other orthodontic companies are making their own CuNiTi wires. Advertisement claims have focused on the laboratory benefits of adding Copper (Cu) to the NiTi, however few independent laboratory testings have been conducted on these new wires to verify claims. The purpose of this study was to conduct thermal analysis of CuNiTi for all currently available wires in two Austenite Finish (Af) variants and two commonly …

The Effect Of Mechanical Vibration On Human Pdl Cell Differentiation And Response To Inflammation, Megan Desroches

Master's Theses (2009 -)

Low magnitude mechanical vibration is a therapeutic adjunct being investigated to alter bone remodeling and inflammation in areas such as osteoporosis, bone fracture healing, and muscle soreness after exercise. In orthodontics a device named AcceleDent has been marketed that claims to increase the rate of tooth movement and decrease pain. However evidence for these claims is lacking. In this study we looked at two potential cellular mechanisms for these claims: periodontal ligament (PDL) cell differentiation and inflammation under an orthodontic model of strain (IL-1β). Increased PDL cell differentiation into osteogenic cells could be an avenue of increasing orthodontic tooth movement. …

Comparison Of Treatment Management Between Orthodontists And General Practitioners Performing Clear Aligner Therapy, Alexandra D. Best

Theses and Dissertations

The purpose of this study was to investigate differences in case confidence, treatment management, and Invisalign® expertise between orthodontists and general dentists. A survey was mailed to 1,000 randomly selected orthodontists and general dentists, respectively, who are Invisalign® providers, and results were analyzed. The results indicated that orthodontists treated significantly more Invisalign® cases and received more Invisalign® training than general dentists (P

Perception Of Profile Appearance As Judged By Peers Using 3d Video Imaging, Megan G. Schuler

Theses and Dissertations

The purpose of this study was to investigate the social perceptions of subjects with differing lip position and facial convexity in three dimensions. A 3dMD camera (3dMD, Atlanta, GA) was used to capture 3D images of 9 subjects’ faces. The images were altered to have ideal lip position and ideal convexity, ideal lip position and Class II convexity, Class II lip position and ideal convexity, and Class II lip position and Class II convexity. 400 laypersons rated their perceptions of the subjects’ athletic ability, popularity, leadership, and intelligence on a VAS scale. Subjects with ideal lip position relative to the …

Twitter Analysis Of The Orthodontic Patient Experience With Braces Versus Invisalign, Daniel A. Noll

Theses and Dissertations

The purpose of this study was to examine the orthodontic patient experience with braces compared to Invisalign^® by means of a large-scale Twitter sentiment analysis. A custom data collection program was created to collect tweets containing the words “braces” or “Invisalign.” A hierarchal Naïve Bayes sentiment classifier was developed to sort the tweets into one of five categories: positive, negative, neutral, advertisement, or not applicable. Among the 419,363 tweets applicable to orthodontics collected, users posted significantly more positive tweets (61%) than negative tweets (39%) (p-value = ^® tweets (p-value=0.4189). In conclusion, Twitter users express more positive than negative sentiment …

Perception Of Differences In Lip Profile Between 2-D And 3-D, Andrew Hansen

Theses and Dissertations

Past studies evaluating the esthetics of orthodontic treatment have been done using 2-D images. New 3-D imaging offers an improved, real-life representation of a subject. The purpose of this study was to determine how laypeople perceived differences in lip position (flat versus ideal lip fullness) in 2-D compared to 3-D.

3dMD images of 8 Caucasian subjects were adjusted to an ideal and flat lip position in 3-D and then in 2-D from the profile view. 2 surveys were created with paired ideal and flat images on the screen, either in 2-D or 3-D, and evaluators were asked to choose which …

Quality Of Life And Subjective Outcomes Following Maxillomandibular Advancement Surgery For The Treatment Of Obstructive Sleep Apnea, Andrew D. Emanuele

Electronic Thesis and Dissertation Repository

Objective: The aim of this study was to assess outcomes related to general quality of life, daytime sleepiness and functional sleep outcomes, functional outcomes of orthognathic surgery, and facial aesthetics in patients undergoing maxillomandibular advancement (MMA) surgery for the treatment of obstructive sleep apnea (OSA).

Materials and Methods: This was a cross-sectional self-report study. A questionnaire was constructed using questions drawn from previously validated questionnaires. The survey was distributed to 25 patients who underwent MMA surgery for the treatment of OSA at LHSC in London, Ontario by a single surgeon between 2002 and 2013.

Results: The survey results showed that …

Dexamethasone Regulates Gene Expression Induced By The Mechanosensitive P2x7 Receptor In Osteoblasts, Meena Na

Electronic Thesis and Dissertation Repository

Orthodontic tooth movement involves activation of osteoblasts and osteoclasts in response to mechanical forces. Extracellular nucleotides, released in response to mechanical stimuli, signal through P2 receptors in osteoblasts. P2X7 receptors are ATP-gated cation channels implicated in mechanotransduction in bone. Corticosteroids such as dexamethasone exhibit anti-inflammatory effects and their chronic use has been linked to serious side-effects such as osteoporosis. We investigated gene expression following P2X7 receptor activation with benzoylbenzoyl-ATP (P2X7 receptor agonist) in osteoblast precursor cells in the presence or absence of dexamethasone. We hypothesized that dexamethasone inhibits the ability of ATP to stimulate the expression of anabolic (bone forming) …

An Evaluation Of The Constructed Frankfort Mandibular Plane Angle Bisector (Cfmab) Wits' Appraisal In The Assessment Of Anteroposterior Jaw Relationships, Derek R. Tomson

Electronic Thesis and Dissertation Repository

For proper orthodontic diagnosis and treatment planning, an accurate measurement of the relationship of the maxilla to the mandible in the sagittal plane is required. The ANB measurement has long been the gold standard for explaining this association. The purpose of this longitudinal study was to evaluate three linear measurements of the maxillomandibular anteroposterior relationship and determine which one best correlates with ANB. The constructed Frankfort horizontal-mandibular plane angle bisector (cFMAB-Wits), maxillomandibular bisector (MMB-Wits), and Frankfort-mandibular plane angle bisector (FMAB-Wits) were measured using a Wits’-type analysis and compared to ANB.

Pre-treatment (TO), immediate post-treatment (T1), and two years post-retention (T2) …

Treatment Outcomes Of Patients With Unilateral Class Ii Malocclusions: A Cbct Study, Brent Leggett

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purposes of this study were to determine the prevalence of Class II (Cl II) subdivision patients, to quantify the change in TMJ complex, and mandibular length after treatment was accomplished. Materials and Methods: Records of consecutive patients who sought orthodontic treatment at Loma Linda University (LLU) were screened. Only patients with dental Cl II subdivision that had completed treatment with pre- (T1) and post-treatment (T2) cone beam computed tomograms (CBCTs) available were evaluated for changes in the TMJ complex position related to Foramen Rotundum (TMJ-FR), joint spaces and mandibular length (condylion to genial tubercles). Comparisons were made between …

Morphological Changes In Alveolar Bone Following Orthodontic Space Closure, Ninette Hacopian

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Changes occurring in anterior alveolar bone following orthodontic tooth movement are controversial. Some research has shown that orthodontic tooth movement results in the adaptation of cortical bone; others have shown that it results in dehiscence and fenestrations.

Purpose: The purpose of this study was to evaluate the alveolar bone changes around maxillary anterior teeth following orthodontic space closure.

Materials and Methods: Cone beam computed tomograms (CBCTs) of non-growing patients who received orthodontic treatment with bilateral maxillary premolar extraction were evaluated. Only patients with at least 5 degrees of changes in maxillary incisor (U1) to palatal plane angle were included …