Objective: Aim of this study was to investigate the forces and moments during segmented intrusion of a mandibular canine using Cantilever-Intrusion-Springs (CIS).
Methods: Three different CIS modifications were investigated using a robotic biomechanical simulation system: unmodified CIS (#1, control), CIS with a lingual directed 6° toe-in bend (#2), and CIS with an additional 20° twist bend (#3). Tooth movement was simulated by the apparative robotic stand, controlled by a force-control algorithm, recording the acting forces and moments with a force-torque sensor. Statistical analysis was performed using Shapiro-Wilk, Kolmogorov-Smirnov, Kruskal-Wallis ANOVA and post hoc tests with Bonferroni correction (α = 0.05).
Results: The initial intrusive force, which was uniformly generated by a 35° Tip-Back bend, decreased significantly (p < 0.05) from 0.31 N in group (#1) to 0.28 N in group (#3). Vestibular crown tipping reduced significantly (p < 0.05) from 2.11° in group (#1) and 1.72° in group (#2) to 0.05° in group (#3). Matching to that the direction of orovestibular force significantly (p < 0.05) shifted from 0.15 N to vestibular in group (#1) to 0.51 N to oral in group (#3) and the orovestibular tipping moment decreased also significantly (p < 0.05) from 4.63 Nmm to vestibular in group (#1) to 3.56 Nmm in group (#2) and reversed to 1.20 Nmm to oral in group (#3). Apart from that the orovestibular displacement changed significantly (p < 0.05) from 0.66 mm in buccal direction in group (#1) to 0.29 mm orally in group (#2) and 1.49 mm in oral direction as well in group (#3).
Significance: None of the modifications studied achieved pure mandibular canine intrusion without collateral effects. The significant lingual displacement caused by modification (#3) is, not least from an aesthetic perspective, considered much more severe than a slight tipping of the canine. Consequently, modification (#2) can be recommended for clinical application based on the biomechanical findings.
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http://dx.doi.org/10.1016/j.jmbbm.2024.106720 | DOI Listing |
Medicina (Kaunas)
December 2024
Department of Cariology, Endodontics and Oral Pathology, School of Dental Medicine, University of Medicine and Pharmacy Iuliu Hatieganu, Str. Motilor 33, 400001 Cluj-Napoca, Romania.
: Most orthodontic forces are absorbed-dissipated before reaching the dental pulp and its neuro-vascular bundle (NVB); however, no data are available about their amounts. The objective of this study was to assess the amount of orthodontic force that reaches the dental pulp and its NVB during orthodontic movements in a healthy periodontium. : This study involved the second lower premolars of nine patients and 180 numerical simulations.
View Article and Find Full Text PDFJ Clin Med
December 2024
Department of Oral Rehabilitation, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400029 Cluj-Napoca, Romania.
: Eccentric bruxism is a complex parafunctional activity that involves grinding of teeth and occurs more frequently during sleep. This study aimed to assess differences in condylar parameters (sagittal condylar inclination -SCI and Bennett angle -BA) and mandibular and condylar kinematics during functional and parafunctional movements in bruxers and non-bruxers and to assess a digital method for quantifying eccentric bruxism using an optical jaw tracking system (Modjaw). : The study group included subjects diagnosed with eccentric bruxism according to validated clinical diagnostic criteria.
View Article and Find Full Text PDFDiagnostics (Basel)
December 2024
Department of Orthodontics, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania.
The finite element method (FEM) is an advanced numerical technique that can be applied in orthodontics to study tooth movements, stresses, and deformations that occur during orthodontic treatment. It is also useful for simulating and visualizing the biomechanical behavior of teeth, tissues, and orthodontic appliances in various clinical scenarios. The objective of this research was to analyze the mechanical behavior of teeth, tissues, and orthodontic appliances in various clinical scenarios.
View Article and Find Full Text PDFThe shoulder joint complex is prone to musculoskeletal issues, such as rotator cuff-related pain, which affect two-thirds of adults and often result in suboptimal treatment outcomes. Current musculoskeletal models used to understand shoulder biomechanics are limited by challenges in personalization, inaccuracies in predicting joint and muscle loads, and an inability to simulate anatomically accurate motions. To address these deficiencies, we developed a novel, personalized modeling framework capable of calibrating subject-specific joint centers and functional axes for the shoulder complex.
View Article and Find Full Text PDFAsian Spine J
December 2024
Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA.
Study Design: This study employed a patient-specific finite element model.
Purpose: To quantify the effect of anterior and posterior surgical approaches on adjacent segment biomechanics of the patient-specific spine and spinal cord.
Overview Of Literature: Adjacent segment degeneration (ASD) is a well-documented complication following cervical fusion, typically resulting from accelerated osteoligamentous deterioration and subsequent symptomatic neural compression.
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