18 research outputs found
Crown size comparisons in patients with unilateral palatally displaced canines
Abstract
CROWN SIZE COMPARISONS IN PATIENTS WITH PALATALLY DISPLACED CANINES
By Joseph L. Eliason, D.D.S.
A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University.
Virginia Commonwealth University, 2015
Thesis Director: Steven J. Lindauer, D.M.D., M.Dent.Sc.
Professor and Chair, Department of Orthodontics
There has been significant debate over the past decades regarding the etiology of palatally displaced canines. Theorized risk factors include agenesis or malformation of the lateral incisors, incisor retroclination, transverse deficiency, or genetic predisposition. The purpose of this study is to compare the linear and volumetric measurements of canines and lateral incisors to determine how tooth size relates to canine impaction. Cone-beam CT images for 40 patients with unilateral palatally displaced canines were utilized to measure the linear dimensions and total crown volume of canines and lateral incisors and to compare those teeth on the impaction side with their isomers on the non-impaction side. Results showed that unilateral palatally impacted maxillary canine crowns were slightly, but statistically significantly wider and larger in volume than their non-impacted isomers. Lateral incisor crowns adjacent to impacted canines were significantly shorter than those adjacent to non-impacted canines
Restoring Lateral Incisors and Orthodontic Treatment: Perceptions among General Dentists and Othodontists
The purpose of this study was to identify and compare preferences and perceptions of orthodontists and general dentists when restoring peg-shaped lateral incisors. The investigation sought to summarize these preferences with regard to treatment planning, tooth preparation and interdisciplinary communication. A pair of mailed and electronic surveys was distributed to 1,500 general dentists and orthodontists, respectively. The results indicated that general dentists perceived that general dentists held the primary decision-making responsibility, while orthodontists disagreed (P\u3c0.0001). Orthodontists prioritized the treatment goals of Class I canine relationship and overbite/overjet more significantly than general dentists, whom valued tooth proportions more highly (P\u3c0.0001). General dentists reported receiving significantly less input than orthodontists report seeking (P\u3c0.0001).The consensus of both groups showed that the tooth should be positioned centered mesiodistally and guided by the gingival margins incisogingivally. Both groups agree that orthodontists must improve communication to improve treatment results
Predicting Interest in Orthodontic Aligners: A Google Trends Data Analysis
Aligners are an example of how advances in dentistry can develop from innovative combinations of 3D technologies in imaging, planning and printing to provide new treatment modalities. With increasing demand for esthetic orthodontic treatment, aligners have grown in popularity because they are esthetically more pleasing and less obstructive to oral hygiene and other oral functions compared to fixed orthodontic appliances. To observe and estimate aligner treatment interest among Google Search users, Google Trends data were obtained and analyzed for the search term, “Invisalign”. A prediction of interest for the year 2022 for three European Union countries with the highest GDP was developed. “Invisalign” was chosen to represent all orthodontic aligners as the most searched term in Google Trends for aligners. This is the first study to predict interest in the query “Invisalign” in a Google search engine. The Prophet algorithm, which depends on advanced statistical analysis methods, positions itself as an automatic prediction procedure and was used to predict Google Trends data. Seasonality modeling was based on the standard Fourier series to provide a flexible model of periodic effects. The results predict an increase in “Invisalign” in Google Trends queries in the coming year, increasing by around 6%, 9% and 13% by the end of 2022 compared to 2021 for France, Italy and Germany, respectively. Forecasting allows practitioners to plan for growing demand for particular treatments, consider taking continuing education, specifically, aligner certification courses, or introduce modern scanning technology into offices. The oral health community can use similar prediction tools and methods to remain alert to future changes in patient demand to improve the responses of professional organizations as a whole, work more effectively with governments if needed, and provide better coordination of care for patients
Upper Lip Asymmetry During Smiling: An Analysis Using Three-Dimensional Images
Objective:The aim of this study was to use three-dimensional images to determine the presence of upper lip asymmetry at rest and during smiling in a group of individuals with no history of orthodontics or facial cosmetic surgery.MethodsStandardized three-dimensional frontal resting and smiling images of 54 volunteers were analyzed using the 3dMDvultus software (3dMD, Atlanta, GA). Measurements were made from the soft tissue nasion, ipsilateral ala, subnasale, and menton to the right and left commissures of the lip. A 2.5 mm or greater difference between the right and left sides was defined as an asymmetry. The agreement on the presence or absence of asymmetry between the subjects’ states of rest and smiling was determined by the McNemar’s chi-squared test. Statistical significance was defined as p<0.05.Results:Menton was the most stable facial landmark to evaluate the upper lip symmetry at rest and during smiling (p=0.002). Using menton as a landmark, only one of the 54 subjects showed asymmetry while resting, but 12 (22%) showed asymmetry when smiling.Conclusion:As part of treatment planning for orthodontics or orthognathic surgery, patients should be evaluated for the upper lip symmetry during resting and smiling. The presence of asymmetry during smiling is a significant clinical problem that needs to be recognized so that patients can be informed about the effect it can have on the final esthetic result
Relationship Between Masticatory Muscle Function and Bite Force : Morphological an Physiological Implications
An interview with Steven J. Lindauer
There are so many compliments to Dr. Steven Lindauer that is hard for one to figure where to start from… Well, travelling backwards in time, all the way to the year 2000, I went to Virginia to study English at Virginia Commonwealth University (VCU), in Richmond, Virginia, USA. During my daily walks to the English school, I used to pass by the School of Dentistry, where the Department of Orthodontics was. That was the place where my very first “contact” with the VCU happened. In 2015, 15 years later, I had the pleasure to go back to the VCU and spend two days with Dr. Steven Lindauer. I have to confess that I was anxious and nervous to get to know not only the Chair of the Department, but also the Editor-in-chief of “The Angle Orthodontist”. Since the very first moment I could experience how incredibly positive and pro-active the environment within the Department was. Staff members, Residents and Faculty members used to work very gladly and in perfect synergy. After a quick chat with the residents, I heard from them: “Dr. Lindauer is an unprecedented human being! Besides a brilliant Professor, Researcher and Administrator, he is like a father to all of us!” Besides this touching testimony, I also heard flattering compliments from workmates to the great friend, leader and partner Dr. Lindauer was. Here goes some food for thought, though. Unfortunately, the leader is often compelled to resort to unpopular measures in order to enforce compliance. Dr Lindauer is the living proof that a boss, a leader, can be a light, humble, friendly and highly charismatic human being. In 2016, I was given a second chance to enjoy Dr. Lindauer’s company when he visited Brazil as a guest lecturer in Salvador, at the Federal University of Bahia and the Brazilian Association of Orthodontics (Bahia Chapter). I noticed, once again, that besides an excellent lecturer and careful clinician, he mastered orthodontic mechanics very proficiently. And needless to say at length about his brilliance ahead of “The Angle Orthodontist”... It didn’t take me long to realize that his virtues by far exceeded the boundaries of the professional domain. Despite his utterly busy schedule, he is still able to dedicate time to his parents, taking them to trips around the world. Interestingly, at every international trip, he always remembers his puppies (Memphis, Baxter and Kingston - in memoriam), taking sightseeing pictures to immediately Photoshop them into. Having done the well deserved introductions to our distinguished interviewee, I would like to offer righteous acknowledgements to the colleagues Jorge Faber, David Turpin, Bhavna Shroff and David Normando, for having accepted the invitation to take part in this interview. I also would like to offer my heartfelt thanks to Dental Press for having entrusted me with the honor to conduct this project. I wish all readers as delightful and rich of an experience when going through this interview as it’s been the scientific path that brought us all here in the first place. No doubts, you stand in face of a life dedicated to Orthodontics. (Andre Wilson Machado, interview coordinator
Design and Performance of the Vegetation Canopy Lidar (VCL) Laser Transmitter
The Vegetation Canopy Lidar (VCL) laser is a Nd:YAG Q-switched, diode side-pumped, zig-zag slab design producing 10 ns, 15 mJ pulses at 1064 nm. It employs an unstable resonator as well as a graded reflectivity output coupler with a Gaussian reflectivity profile. In order to conserve power, a conductively cooled design is employed and is designed to operate over a range of 25 C without active thermal control. The laser is an oscillator-only design and equipped with an 15X beam expander to limit the output divergence to less than 60 microrad. Thermal lensing compensation in the side-pumped slab was performed with different treatments of the x and y portions of the z-directed beam. Performance data as a function of temperature are given
Compact, Passively Q-Switched Nd:YAG Laser for the MESSENGER Mission to the Planet Mercury
A compact, passively Q-switched Nd:YAG laser has been developed for the Mercury Laser Altimeter (MLA) instrument which is an instrument on the MESSENGER mission to the planet Mercury. The laser achieves 5.4 percent efficiency with a near diffraction limited beam. It has passed all space flight environmental tests at system, instrument, and satellite integration. The laser design draws on a heritage of previous laser altimetry missions, specifically ISESAT and Mars Global Surveyor; but incorporates thermal management features unique to the requirements of an orbit of the planet Mercury