This study investigated the correlation between bone characteristics, the design of orthodontic mini-implants, the pull-out force, and primary stability. This experimental in vitro study has examined commercial orthodontic mini-implants of different sizes and designs, produced by two manufacturers: Tomas-pin SD (Dentaurum, Ispringen, Germany) and Perfect Anchor (Hubit, Seoul, Korea). The total number of 40 mini-implants were tested. There are two properties that are common to all tested implants—one is the material of which they are made (titanium alloy Ti-6Al-4V), and the other is the method of their insertion. The main difference between the mini-implants, which is why they have been selected as the subject of research in the first place, is reflected in their geometry or design. Regardless of the type of implant, the average pull-out forces were found to be higher for a cortical bone thickness (CBTC) of 0.62–0.67 mm on average, compared to the CBTC < 0.62 mm, where the measured force averages were found to be lower. The analysis of variance tested the impact of the mini-implant geometry on the pull-out force and proved that there is a statistically significant impact (p < 0.015) of all three analyzed geometric factors on the pull-out force of the implant. The design of the mini-implant affects its primary stability. The design of the mini-implant affects the pulling force. The bone quality at the implant insertion point is important for primary stability; thus, the increase in the cortical bone thickness increases the value of the pulling force significantly.
The main objective of this research is to establish a connection between orthodontic mini-implant design, pull-out force and primary stability by comparing two commercial mini-implants or temporary anchorage devices, Tomas®-pin and Perfect Anchor. Mini-implant geometric analysis and quantification of bone characteristics are performed, whereupon experimental in vitro pull-out test is conducted. With the use of the CATIA (Computer Aided Three-dimensional Interactive Application) CAD (Computer Aided Design)/CAM (Computer Aided Manufacturing)/CAE (Computer Aided Engineering) system, 3D (Three-dimensional) geometric models of mini-implants and bone segments are created. Afterwards, those same models are imported into Abaqus software, where finite element models are generated with a special focus on material properties, boundary conditions and interactions. FEM (Finite Element Method) analysis is used to simulate the pull-out test. Then, the results of the structural analysis are compared with the experimental results. The FEM analysis results contain information about maximum stresses on implant–bone system caused due to the pull-out force. It is determined that the core diameter of a screw thread and conicity are the main factors of the mini-implant design that have a direct impact on primary stability. Additionally, stresses generated on the Tomas®-pin model are lower than stresses on Perfect Anchor, even though Tomas®-pin endures greater pull-out forces, the implant system with implemented Tomas®-pin still represents a more stressed system due to the uniform distribution of stresses with bigger values.
10 May 2017 in South European Journal of Orthodontics and Dentofacial Research
Introduction: Various types of malocclusions present one of the most common dental problems of today’s population. Planning the implementation of orthodontic therapy, especially preventive and interceptive measures is one of many activities of public sector health, and it requires information regarding the prevalence of malocclusion in different parts of our country. Aim: The aim of this study was to determine the prevalence of malocclusion of preschool and school children in the city of Sarajevo. Materials and methods: This study was comprised of 373 children out of which 200 preschool and school children were included in the final sample according to the inclusion and exclusion criteria for participation. 100 children were five-year-olds with complete deciduous dentition, and 100 children were 14-year-olds with permanent dentition. The examined variables in the study were: dental status and existence of caries, overjet, depth of overbite, a presence of premature contacts, a presence of diastemas, crowding of teeth in the dental arch (for 14-year-olds) and rotation of teeth in the dental arch (for 14-year-olds). Results: The prevalence of malocclusion was 58% in the group of preschool children and 83% in the group of school children. Conclusion: Results of this study demonstrate a need for the implementation of preventive and interceptive orthodontic methods in primary health care, which would reduce the need for expensive and long term orthodontic therapy
1 January 2023 in Balkan Journal of Dental Medicine
Background/Aim: The objective of this research was to evaluate the level of oral hygiene, the prevalence of caries, and the condition of the soft tissues in children and adolescents referred for their first orthodontic examination. Material and Methods: The research was conducted at the Department of Orthodontics of Sarajevo University - at the Faculty of Dentistry with the Dental Clinical Center. A total of 300 patients with mixed and permanent dentition who were referred for their first orthodontic examination were included in the study. The patients were offered to sign a Letter of Informed Consent for this study. All patients were assigned a Decayed, Missing, and Filled Teeth (dmft/DMFT) index. Periodontal indices were evaluated on all first permanent molars and all permanent central incisors. The periodontal indices included the determination of PI,CI,GI, PBI. Results: The results were processed with the application of standard statistical methods, by using the SPSS computer program for statistical analyses (SPSS-Statistical Package for Social Sciences) Version 21.0. The results of this study show a high dmft and DMFT indices in patients referred for orthodontic examination. The dmft index value in the respondents with mixed dentition was 3.0 (1.0 - 6.0). The DMFT index value in the respondents with permanent dentition was 4.0 (0.0 - 6.0), while in the respondents with mixed dentition, it was 1.0 (0.0 - 3.0). Our research also shows that out of 300 patients referred to an orthodontist for their first orthodontic examination, 250 of them (83.33%) have demonstrated an increased value of the Plaque index. Conclusions: The results of this research should be peculiarly alarming for pedodontists and general dentists, cautioning them to implement caries prevention measures more intensively and make referrals to an orthodontist only in case of those patients who have been cured previously.
9 August 2023 in Engineering, Technology & Applied Science Research
This study performed a mechanical stability analysis for the impact of axial pressure on an Ultra X external unilateral fixation device applied to a tibia with an open fracture. The real construction of the fixation device was used to create a 3D geometric model using a Finite Element Method (FEM) model, which was made to perform structural analysis in the CATIA V5 (Computer Aided Three-dimensional Interactive Application) CAD/CAE system. Specific stresses and displacements were observed at points of interest using structural analysis. The focus was on the relative displacements of the proximal and distal bone segments in the fracture zone. These displacements were used to calculate the stiffnesses of the bone in the fracture zone and the fixation device itself. The results obtained provide the necessary information regarding the stability of the Ultra X fixation device.
Introduction: Impacted maxillary canines are among the most common orthodontic anomalies and often require comprehensive radiographic assessment for accurate diagnosis and treatment planning. The KPG index is a CBCT-based three-dimensional classification system used to evaluate the severity of canine impaction. Aim: To assess the association between the KPG index and angular parameters (α and θ angles) in impacted maxillary canines. Materials and Methods: This retrospective study included 30 patients with impacted maxillary canines treated at the Department and Clinic of Orthodontics, Faculty of Dental Medicine, University of Sarajevo. Cone-beam computed tomography (CBCT) scans and panoramic radiographs were analyzed. The KPG index was determined from CBCT images, while α and θ angles were measured on panoramic radiographs. Correlation analysis was performed to evaluate the relationship between the KPG index and angular parameters. Results: The mean KPG index was 13.17 ± 7.29, the mean α angle was 32.93 ± 21.34°, and the mean θ angle was 53.87 ± 19.91°. A statistically significant moderate positive correlation was found between the KPG index and α angle (rs = 0.635, p < 0.001). No statistically significant association was observed between the KPG index and θ angle (rs = −0.234, p = 0.206). Conclusion: The α angle showed a significant positive association with the KPG index and may represent a useful adjunctive parameter in the assessment of impacted maxillary canines. In contrast, the θ angle was not significantly associated with impaction severity. Although panoramic radiographs provide valuable diagnostic information, CBCT-based three-dimensional imaging remains the gold standard for evaluating impacted maxillary canines and supporting orthodontic treatment planning.