Browsing by Subject "Orthodontics"
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Item A Comparative Study of the Fatigue Resistance of Four Orthodontic Alloys(1983) Kamisugi, Curtis N.This investigation was designed to compare the fatigue resistance of four orthodontic alloys and to determine whether their surface characteristics had any influence on their fatigue lives. Stainless steel, Blue Elgiloy, TMA, and Nitinol were evaluated using a round (.018") and a rectangular (.016" x .022") size of each type of alloy. Fifty specimens of each size were tested, making the total sample size 400. The wire samples were evaluated using a cantilever bend test in which each specimen was stressed cyclically at the defection of .625 inch in either direction. All of the wires were evaluated in their untreated condition, with the exception of Blue Elgiloy, which was heat-treated prior to testing at 900° Fahrenheit for seven minutes in a burnout furnace. One specimen from each group was viewed under the scanning electron microscope to evaluate its surface structure and each alloy presented a unique microstructure. Stainless steel was relatively smooth. Blue Elgiloy was slightly rougher in appearance, Nitinol appeared dimply and crater-like, and TMA looked eroded or striated. It was suspected that the alloys which had a rough surface would be less resistant to fatigue. On the other hand, due to the differences in modulus of elasticity of each alloy, the amount of stress applied to the different materials varied accordingly and the effect of surface roughness on fatigue resistance was not great enough to overcome the effect of stress. Since TMA and Nitinol had relatively low moduli of elasticity, they were subjected to less stress and were thus more fatigue-resistant than either stainless steel or Blue Elgiloy. Nitinol sustained the most cycles to fracture in both the round and rectangular samples. In the round sample, TMA had the next best fatigue life, and stainless steel and Blue Elgiloy had comparable fatigue lives. With the rectangular samples, there were no significant differences between TMA, stainless steel, and Blue Elgiloy. Therefore, although Nitinol and TMA cost more than stainless steel or Elgiloy, their high flexibility, large working ranges, and favorable fatigue properties make them attractive substitutes for the conventional stainless steel or Elgiloy wires. TMA and Nitinol provide a new dimension in controlling the magnitude of forces used for tooth movement, and Burstone40 has stated that "the variable-modulus concept gives the orthodontist one more tool in the efficient design and use of his appliance."Item A machine learning model for orthodontic extraction/non-extraction decision in a racially and ethnically diverse patient population(Elsevier, 2023-09) Mason, Taylor; Kelly, Kynnedy M.; Eckert, George; Dean, Jeffrey A.; Dundar, M. Murat; Turkkahraman, Hakan; Orthodontics and Oral Facial Genetics, School of DentistryIntroduction The purpose of the present study was to create a machine learning (ML) algorithm with the ability to predict the extraction/non-extraction decision in a racially and ethnically diverse sample. Methods Data was gathered from the records of 393 patients (200 non-extraction and 193 extraction) from a racially and ethnically diverse population. Four ML models (logistic regression [LR], random forest [RF], support vector machine [SVM], and neural network [NN]) were trained on a training set (70% of samples) and then tested on the remaining samples (30%). The accuracy and precision of the ML model predictions were calculated using the area under the curve (AUC) of the receiver operating characteristics (ROC) curve. The proportion of correct extraction/non-extraction decisions was also calculated. Results The LR, SVM, and NN models performed best, with an AUC of the ROC of 91.0%, 92.5%, and 92.3%, respectively. The overall proportion of correct decisions was 82%, 76%, 83%, and 81% for the LR, RF, SVM, and NN models, respectively. The features found to be most helpful to the ML algorithms in making their decisions were maxillary crowding/spacing, L1-NB (mm), U1-NA (mm), PFH:AFH, and SN-MP(̊), although many other features contributed significantly. Conclusions ML models can predict the extraction decision in a racially and ethnically diverse patient population with a high degree of accuracy and precision. Crowding, sagittal, and vertical characteristics all featured prominently in the hierarchy of components most influential to the ML decision-making process.Item A Novel Machine Learning Model for Predicting Orthodontic Treatment Duration(MDPI, 2023-08-23) Volovic, James; Badirl, Sarkhan; Ahmad, Sunna; Leavit, Landon; Mason, Taylor; Bhamidipalli, Surya Sruthi; Eckert, George; Albright, David; Turkkahraman, Hakan; Orthodontics and Oral Facial Genetics, School of DentistryIn the field of orthodontics, providing patients with accurate treatment time estimates is of utmost importance. As orthodontic practices continue to evolve and embrace new advancements, incorporating machine learning (ML) methods becomes increasingly valuable in improving orthodontic diagnosis and treatment planning. This study aimed to develop a novel ML model capable of predicting the orthodontic treatment duration based on essential pre-treatment variables. Patients who completed comprehensive orthodontic treatment at the Indiana University School of Dentistry were included in this retrospective study. Fifty-seven pre-treatment variables were collected and used to train and test nine different ML models. The performance of each model was assessed using descriptive statistics, intraclass correlation coefficients, and one-way analysis of variance tests. Random Forest, Lasso, and Elastic Net were found to be the most accurate, with a mean absolute error of 7.27 months in predicting treatment duration. Extraction decision, COVID, intermaxillary relationship, lower incisor position, and additional appliances were identified as important predictors of treatment duration. Overall, this study demonstrates the potential of ML in predicting orthodontic treatment duration using pre-treatment variables.Item A Cephalometric Study of the Mesio-Distal Axial Inclinations of the Teeth(1968) Burns, Richard D.Eighteen adult human skulls with "normal occlusion" were examined with oriented lateral, 15, 25, 45, 75, and 90 degree cephalograms from which the mesio-distal axial inclinations of the teeth were measured. This study indicates that a large variation of the mesio-distal axial inclinations of the teeth may occur and still have a "normal occlusion". The standard deviations varied from a maximum of 11.0 degrees for the maxillary third molar to a minimum of 3.4 degrees for the maxillary cuspid. Rotation of the midsagittal plane of the head with the film effected the measurements of the maxillary first molars and cuspids, and the mandibular bicuspids by producing divergence of their roots on the film image. No relationship was found between measurements of this sample and measurements of mandibular plane, A-B plane, Y-axis, facial angle, angle of convexity, Down's occlusal plane, lower incisor - A-Pg, and interincisal angle. A positive relationship was found between the measurements of this sample and the posterior one-half of nasal floor, posterior occlusal plane, and the labiolingual axial inclination of the lower incisor.Item Changes of the Nasolabial Angle Due to Orthodontic Treatment and Facial Growth(1987) Sessions, Jeffrey D.; Garner, LaForrest; Miller, James; Nelson, Charles; Shanks, James; Barton, PaulThis study addressed the quantitative changes of the Nasolabial angle, lip retraction and columellar changes due to treatment with concomitant growth. Sixty initial and final lateral headplates were examined on prepubertal children who underwent comprehensive orthodontic treatment. The angular changes in the Nasolabial angle (△NLA), Labial angle (△A) and Nasal angle (△B) were measured along with the horizontal (△H) and vertical (△V) linear changes of maxillary central incisor. Each of these five measurement changes was tested for the effects of extraction and gender. Correlations were drawn between the △NLA: △AH, △NLA: △V, NLA: △A, △NLA: △B, and △A: △H. Analysis of variance showed that extraction therapy exhibited a larger treatment change than non-extraction therapy for the NLA and upper lip, with the NLA increasing in magnitude and the Labial angle showing upper lip retraction. There was also a sex difference for the treatment change in the lower border of the nose. The only high correlation found was between the opening of the NLA and the retraction of the upper lip (NLA: △A gave r = -0.84). The other correlations were significant but low. These findings could aid in orthodontic treatment planning when changes in the upper lip and NLA will affect the facial esthetics.Item Comparative Tensile Strengths of Brackets Bonded to Porcelain with Orthodontic Adhesives and Porcelain Repair Systems(1986) Eustaquio, Robert I.; Garner, LaForrest D.; Barton, Paul; Hennon, David K.; Moore, B. Keith; Muñoz, Carlos; Shanks, James C.This study evaluated the feasibility of bonding brackets to porcelain for orthodontic purposes by measuring and comparing tensile strengths of five silane-based adhesive systems. Each adhesive system bonded mesh pad brackets to 10 glazed and 10 deglazed metal-ceramic crowns and the specimens were then thermocycled between 16 degrees and 56 degrees for 2500 cycles. Clinically relevant bond strengths, comparable to those of adhesives bonding brackets to enamel, were recorded for four of the systems compared. System l+ and Porcelain Primer had the highest mean values followed by Lee's Enamelite 500, then Vivadent's Silanit, Contact-Resin and Isopast, then 3M's Concise and Scotchprime. Most, if not all, failure sites for the four were at the bracket-resin interface. Two-way factorial analysis of variance demonstrated significant differences at P<.001 among the four adhesives but no contribution of surface effect, whether glazed or deglazed, was suggested statistically. Neuman-Keul sequential range tests showed significant differences between System l+ and the three other systems but no significant differences among the three were detected. Den-Mat's Ultrabond recorded extremely low tensile strength values and was of dubious clinical value. A t-test suggested that deglazing porcelain contributed no significant difference in strength compared with intact, glazed porcelain. All failure sites were at the porcelain-resin interface for this product. Since resin may remain bonded to porcelain following debonding, George Taub's diamond polishing paste and Shofu porcelain polishing wheels were compared as to their ability in restoring the porcelain to its original state. Because of the great adhesive bond of the resin to porcelain, craters, pits or tears may be created when resin is cleaned from porcelain with conventional scalers and pliers. The diamond paste gave a better restorative finish than the stones but the end result depended on the extent of original damage following cleaning. Orthodontists should take this point into account when considering bonding to porcelain crowns or veneers for esthetics sake where final risks may outweigh initial benefits. In a limited survey of 100 orthodontists responding to a questionnaire, 89% indicated that they have bonded or contemplated bonding to composite restored teeth, and 83% indicated that they have bonded or contemplated bonding to porcelain.Item COVID-19: What do we know?(Elsevier, 2020-09-21) Marshall, Steve; Duryea, Michael; Huang, Greg; Kadioglu, Onur; Mah, James; Palomo, Juan Martin; Rossouw, Emile; Stappert, Dina; Stewart, Kelton; Tufekci, Eser; Orthodontics and Oral Facial Genetics, School of DentistryCoronavirus disease 2019 (COVID-19) is a global pandemic caused by the pathogen severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).1 Preliminary assessments suggest the virus is highly transmittable and infectious,2, 3, 4, 5, 6, 7 with similarities in nosocomial and super-spreading events seen with severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) in 2003.8 Patients infected with SARS-CoV-2 display a wide range of host responses including no symptoms, mild nonrespiratory symptoms, severe respiratory illness, or organ dysfunction and death.1,5 The American Association of Orthodontists Council on Scientific Affairs was charged with examining the literature to determine the best evidence for questions pertaining to COVID-19 and its impact on the practice of orthodontics.Item Decoding Deep Learning applications for diagnosis and treatment planning(SciELO, 2023-01-06) Retrouvey, Jean-Marc; Conley, Richard Scott; Orthodontics and Oral Facial Genetics, School of DentistryIntroduction: Artificial Intelligence (AI), Machine Learning and Deep Learning are playing an increasingly significant role in the medical field in the 21st century. These recent technologies are based on the concept of creating machines that have the potential to function as a human brain. It necessitates the gathering of large quantity of data to be processed. Once processed with AI machines, these data have the potential to streamline and improve the capabilities of the medical field in diagnosis and treatment planning, as well as in the prediction and recognition of diseases. These concepts are new to Orthodontics and are currently limited to image processing and pattern recognition. Objective: This article exposes and describes the different methods by which orthodontics may benefit from a more widespread adoption of these technologies.Item Dental Professionals’ Perspective on Direct-To-Consumer Clear Aligners(2021-07-01) Stewart, Kelton; Hoagburg, Brian; Keith, Caleb; Janik, Robert; Albright, DavidBackground: Technology continues to drastically change the practice of orthodontics. One recent change includes direct-to-consumer (DTC) clear aligners, a model that omits a clinical exam by a licensed dentist and radiographic evaluation prior to initiating treatment. The purpose of this study was to collect quantitative data about dental professionals’ perspectives of the DTC treatment model. Materials and Methods: The Qualtrics-based survey was disseminated to dental professionals using several email lists. The survey included 26 questions, containing four domains: basic demographic information, perceptions of the direct-to-consumer clear aligner model, standards of orthodontic care, and patient experiences. Responses were summarized with descriptive statistics. Associations between respondent demographics and their perceptions about DTC clear aligner treatment and standards of orthodontic care were evaluated using Mantel- Haenszel Chi-squared tests. Results: There were 334 completed surveys, with 155 orthodontists (46.4%), 154 general dentists (46.1%), and 25 other dental specialties (7.5%) participants. More than 95% of respondents had a generally negative view of the DTC treatment model, with most respondents citing “suboptimal orthodontic care” and “misleading the public about orthodontic treatment” as the biggest influence in their view. Over 94% of respondents agreed that it is not within the standard of care to initiate orthodontic treatment without an in-person clinical exam or radiographs. Conclusion: Results suggest that dental professionals regard treatment rendered by DTC modalities not in the best interest of the public. Practical Implications: Dentists should be more active with educating patients about the impact of different dental treatment modalities.Item Diagnostic efficacy of novel cephalometric parameters for the assessment of vertical skeletal dysplasia(Tabriz University of Medical Sciences, 2022) Gandhi, Kaveri Kranti; Rai, Anshu; Periodontology, School of DentistryBackground. An accurate diagnosis of vertical skeletal abnormalities presents several challenges. Specific cephalometric parameters can be effectively used for this purpose; however, the diagnostic accuracy of these parameters has not been entirely ascertained. This study examines the effectiveness of two novel cephalometric parameters for diagnosing vertical dysplasia. Methods. In this retrospective study, orthodontic patients were distributed into three study groups: average growth (AGG), horizontal growth (HGG), and vertical growth (VGG). The efficacies of the sum of angles (maxillary, mandibular, and ramal) and the height ratio (lower anterior facial height [LAFH]/upper anterior facial height [UAFH]) in identifying different growth patterns were examined. Receiver operating characteristic (ROC) curves were employed to assess the diagnostic precision quantitatively. Results. A total of 150 patients were included and divided equally among the three study groups. The ramal and mandibular angles varied across AGG, HGG, and VGG; however, the maxillary angle and the sum of these three angles did not vary significantly. There was a substantial variance in LAHF, UAHF, and their ratio in the three groups. The height ratio had 88% and 92% sensitivity to diagnose VGG and HGG, with cut-off values of 46 and 34, respectively (P<0.001). Conclusion. Height ratio values varied considerably depending on the facial growth patterns, suggesting its efficacy as a diagnostic tool for skeletal dysplasia, with greater reliability for positive treatment outcomes.