Article
Orthopedics
W. Wu, A. L. Bryant, R. S. Hinman, K. L. Bennell, B. R. Metcalf, M. Hall, P. K. Campbell, K. L. Paterson
Summary: Medial and lateral knee contact forces (KCFs) differ across grades of radiographic knee osteoarthritis (OA) severity, but are not associated with knee pain severity. Medial KCFs during early and middle stance are higher in participants with moderate and severe OA compared to mild OA. In contrast, lateral KCFs are higher in mild OA during middle to late stance. The external loading component (KAM) of medial KCF during middle to late stance is greater in participants with moderate and severe OA, while the internal (muscle) component is greater in participants with moderate and severe OA during early stance. There are no associations between medial KCF and knee pain in any radiographic OA grade.
OSTEOARTHRITIS AND CARTILAGE
(2022)
Article
Chemistry, Physical
Hisham Sabbagh, Sebastian Marcus Heger, Thomas Stocker, Uwe Baumert, Andrea Wichelhaus, Lea Hoffmann
Summary: This study investigated the suitability of manually fabricated setups for aligner therapy in terms of tooth movement precision. The results showed that manually fabricated setups could only be made with limited precision and were accompanied by unwanted movements in other planes. Therefore, manually fabricated setups are not suitable for aligner therapy.
Article
Engineering, Biomedical
Harsimrat Kaur, Tsolmonbaatar Khurelbaatar, James Mah, Giseon Heo, Paul W. Major, Dan L. Romanyk
Summary: The primary objective of this study was to investigate the impact of material selection and tooth position on orthodontic aligner biomechanics. The study found that different materials exerted varying forces and moments on the teeth, and the thermoforming process had an effect on the mechanical properties of certain polymers. These findings highlight the importance of evaluating material properties after thermoforming for clinical application.
JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS
(2023)
Article
Dentistry, Oral Surgery & Medicine
Paulo Eduardo Damasceno Melo, Jessica Rico Bocato, Ana Claudia de Castro Ferreira Conti, Karen Regina Siqueira de Souza, Thais Maria Freire Fernandes, Marcio Rodrigues de Almeida, Paula Vanessa Pedron Oltramari
Summary: The study evaluated the effects of orthodontic treatment with aligners and conventional fixed appliances on speech production. Changes in speech production were observed at the start of treatment in patients with aligners, but both groups reported significant speech difficulties immediately after appliance insertion. Over time, speech production improved in both groups.
ANGLE ORTHODONTIST
(2021)
Article
Engineering, Biomedical
Tarek M. Elshazly, Damiano Salvatori, Hanaa Elattar, Christoph Bourauel, Ludger Keilig
Summary: This numerical study investigated the influence of the geometry and extension of orthodontic aligner edges, as well as the aligner thickness, on force transmission to a specific tooth. The results showed that the design of the trimming line, edge extension, and aligner thickness significantly affect the magnitude of the resultant force and the distribution of normal contact force. A straight extended trimming design exhibited better force distribution and may lead to improved clinical outcomes.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2023)
Article
Engineering, Biomedical
Tarek M. Elshazly, Diva Nang, Bijan Golkhani, Hanaa Elattar, Ludger Keilig, Christoph Bourauel
Summary: The aim of this study was to investigate the effects of artificial aging by thermocycling and mechanical loading on force/torque delivery by thermoplastic orthodontic aligners. Ten thermoformed aligners made of ZenduraTM thermoplastic polyurethane sheets were aged in deionized water for two weeks using either thermocycling alone or both thermocycling and mechanical loading. The force/torque delivered by the aligners on a plastic model's upper second premolar was measured before aging and after different periods of aging. The results showed that while pure thermocycling had no significant effect on force decay, both thermocycling and mechanical loading resulted in a significant decrease in force/torque after 2 days of aging, which was no longer significant after 14 days of aging. Therefore, the mechanical loading of aligners has a greater impact on force/torque generation than pure thermocycling.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2023)
Article
Dentistry, Oral Surgery & Medicine
Tarek M. Elshazly, Ludger Keilig, Damiano Salvatori, Philippe Chavanne, Mostafa Aldesoki, Christoph Bourauel
Summary: This study investigated how the stress distribution and forces transmitted from orthodontic aligners to the tooth surface are affected by the geometry and extension of the trimming line. The results showed that the straight extended design of the trimming line exhibited more uniform force transfer and stress distribution across the tooth surface compared to other designs. This finding is clinically relevant and could have a significant impact on the outcome of orthodontic aligner treatment.
JOURNAL OF DENTISTRY
(2022)
Review
Dentistry, Oral Surgery & Medicine
Yassir A. Yassir, Sarah A. Nabbat, Grant T. McIntyre, David R. Bearn
Summary: The study evaluated the clinical effectiveness of clear aligner treatment (CAT). The findings showed that CAT is effective for mild to moderate malocclusions but less effective for severe cases or specific tooth movements. There were conflicting results regarding treatment duration, but CAT may lead to shorter treatment in mild to moderate cases. CAT had a higher risk of relapse but better periodontal health. The risk of root resorption tended to be lower with CAT.
CLINICAL ORAL INVESTIGATIONS
(2022)
Article
Dentistry, Oral Surgery & Medicine
Bernhard Wiechens, Phillipp Brockmeyer, Teresa Erfurth-Jach, Wolfram Hahn
Summary: The study evaluated the force delivered on an upper central incisor by removable thermoplastic appliances modified with Hilliard precision thermopliers. Results showed that higher activation degrees of the thermopliers resulted in greater forces being applied. Different-sized thermoformed protuberances altered the biomechanical parameters of the appliances, providing a potential option for treatment modification.
CLINICAL ORAL INVESTIGATIONS
(2022)
Article
Dentistry, Oral Surgery & Medicine
Maryam AlSeraidi, Ismaeel Hansa, Fadia Dhaval, Donald J. Ferguson, Nikhilesh R. Vaid
Summary: This study found that patients undergoing Aligner therapy reported the highest quality of life scores during orthodontic treatment, followed by lingual and vestibular groups.
PROGRESS IN ORTHODONTICS
(2021)
Article
Sport Sciences
Wenxing Zhou, Zhangqi Lai, Shiwei Mo, Lin Wang
Summary: This study found significant biomechanical effects of different overground surfaces on habitual non-rearfoot strikers, with synthetic rubber reducing joint loads.
JOURNAL OF SPORTS SCIENCES
(2021)
Review
Polymer Science
Kanket Kiatwarawut, Dinesh Rokaya, Irin Sirisoontorn
Summary: This study conducted a systematic review to compare the antimicrobial activity of various chemical disinfectants on orthodontic thermoplastic polymeric appliances. The findings showed that both over-the-counter orthodontic appliance cleaners and applied-chemical disinfectants were effective against bacteria, but no conclusive guidelines were found regarding the duration and frequency of usage.
Article
Dentistry, Oral Surgery & Medicine
Shou-Min Chen, Chun-Te Ho, Tsui-Hsein Huang, Chia-Tze Kao
Summary: The present study aimed to compare the force decay of invisible aligners for maxillary anterior teeth with different labial movements within a simulated oral environment. The results showed that larger labial movement resulted in higher force decay and longer immersion time in saliva led to increased force decay.
JOURNAL OF DENTAL SCIENCES
(2023)
Article
Multidisciplinary Sciences
Aseel Ghazwan, Chris Wilson, Cathy A. Holt, Gemma M. Whatling
Summary: This study investigated the variation in neuromuscular control mechanisms and joint biomechanics in different subject groups with knee osteoarthritis. The results showed that muscle strength and coordination could influence joint control and loading, potentially exacerbating joint destruction. The increase in lateral muscle co-contraction reflected the progression of osteoarthritis, while the increase in medial muscle co-activation could potentially differentiate between different types of arthritis.
Article
Dentistry, Oral Surgery & Medicine
Shou-Min Chen, Tsui-Hsein Huang, Chun-Te Ho, Chia-Tze Kao
Summary: This study compared the strength changes of three types of invisible aligner films immersed in different drinks. The results showed that, except for films with TPU ingredients, other films experienced strength decay after being soaked in solutions.
JOURNAL OF DENTAL SCIENCES
(2023)
Article
Health Care Sciences & Services
F. Elkholy, S. Schmidt, M. Amirkhani, F. Schmidt, B. G. Lapatki
JOURNAL OF HEALTHCARE ENGINEERING
(2019)
Article
Biophysics
Falko Schmidt, Bernd Georg Lapatki
JOURNAL OF BIOMECHANICS
(2019)
Article
Dentistry, Oral Surgery & Medicine
Konstantinos Naziris, Neltje E. Piro, Rudolf Jaeger, Falko Schmidt, Fayez Elkholy, Bernd G. Lapatki
JOURNAL OF OROFACIAL ORTHOPEDICS-FORTSCHRITTE DER KIEFERORTHOPADIE
(2019)
Article
Dentistry, Oral Surgery & Medicine
F. Elkholy, B. Mikhaiel, S. Repky, F. Schmidt, B. G. Lapatki
JOURNAL OF OROFACIAL ORTHOPEDICS-FORTSCHRITTE DER KIEFERORTHOPADIE
(2019)
Article
Biophysics
Rudolf Jaeger, Falko Schmidt, Kostas Naziris, Bernd G. Lapatki
Summary: This study investigates the impact of different bracket-wire contact configurations in a three-bracket setup using experimental and numerical methods, revealing significant changes in effective wire stiffness under different configurations, which have important implications for clinical therapy. By measuring the contact between orthodontic wires and brackets, the results of this research can help dentists better predict the mechanical behavior during teeth straightening procedures.
JOURNAL OF BIOMECHANICS
(2021)
Article
Dentistry, Oral Surgery & Medicine
Catrin Gerhart, Johanna Radeke, Fayez Elkholy, Elena Schramm, Bernd G. Lapatki
Summary: Digital orthodontics, particularly in diagnostics and therapy, has gained popularity in recent years. Intraoral scanning for creating digital jaw models is becoming more prevalent, allowing for accurate evaluation using sophisticated software tools. The availability of digital jaw models opens up new therapeutic possibilities and attractive applications for treatment simulations.
INFORMATIONEN AUS ORTHODONTIE UND KIEFERORTHOPAEDIE
(2021)
Article
Dentistry, Oral Surgery & Medicine
Johanna Radeke, Annike B. Vogel, Falko Schmidt, Fatih Kilic, Stefan Repky, Jan Beyersmann, Bernd G. Lapatki
Summary: This study evaluated deviations of full-arch intraoral scans from reference desktop scans in terms of translations and rotations of individual teeth, finding that deviations varied among different tooth positions.
CLINICAL ORAL INVESTIGATIONS
(2022)
Article
Dentistry, Oral Surgery & Medicine
Fayez Elkholy, Silva Schmidt, Falko Schmidt, Masoud Amirkhani, Bernd G. Lapatki
Summary: This study investigated the effect of different loading and unloading cycles on force delivery during orthodontic aligner therapy. The results showed a significant decrease in force after loading, and the decay in force differed among the different loading modes during the last two days of the loading periods.
JOURNAL OF OROFACIAL ORTHOPEDICS-FORTSCHRITTE DER KIEFERORTHOPADIE
(2023)
Article
Dentistry, Oral Surgery & Medicine
Falko Schmidt, Fatih Kilic, Catrin Verena Gerhart, Bernd Georg Lapatki
Summary: This study investigates the accuracy of a novel superimposition approach based on biomechanical principles for monitoring and simulating large orthodontic tooth movements (OTM). The results show that this approach allows accurate quantification of OTM even in challenging situations and enhances the value of digital setups for decision-making in orthodontic treatment planning.
JOURNAL OF OROFACIAL ORTHOPEDICS-FORTSCHRITTE DER KIEFERORTHOPADIE
(2022)
Article
Dentistry, Oral Surgery & Medicine
Fayez Elkholy, Sandra Wulf, Rudolf Jager, Falko Schmidt, Bernd G. Lapatki
Summary: This in vitro study aimed to determine the 3-dimensional force-moment systems applied to the 4 mandibular incisors and the deactivation behavior of the appliance by different configurations of the 3-piece intrusion mechanics. The study found that appliance configurations had no significant influence on the labial tipping moments, and the force reduction rate during simulated intrusion was 21% per mm.
AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS
(2023)
Article
Dentistry, Oral Surgery & Medicine
Fayez Elkholy, Sophia Weber, Stefan Repky, Rudolf Jaeger, Falko Schmidt, Bernd G. Lapatki
Summary: The purpose of this study was to determine the optimal modification geometry and foil thickness for generating the force-moment systems required for palatal root torque. The results showed that the crescent, capsular, and double-spherical modification geometries were effective in achieving the desired palatal root torque. The best results were obtained with a foil thickness of 0.75 mm and a modification depth of 1.5 mm for the crescent and capsular modification geometries.
CLINICAL ORAL INVESTIGATIONS
(2023)