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Zhou T, Gan Z, Zhang H, Liu Z, Pu Y, Rong M. A novel technique to harvest bone autografts with mild local hyperthermia and enhanced osteogenic bone quality: a preclinical study in dogs. BMC Oral Health 2023; 23:838. [PMID: 37936153 PMCID: PMC10631188 DOI: 10.1186/s12903-023-03611-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 11/02/2023] [Indexed: 11/09/2023] Open
Abstract
BACKGROUND Guided bone regeneration (GBR) involves collecting bone autografts with high bio-quality and efficiency. The current non-irrigated low-speed drilling has been limited for broader application in bone autograft harvest due to its low efficiency, inability to conduct buccal cortical perforation, and dependence on simultaneous implant placement. Increasing the drilling speed helps improve the efficiency but may incur thermal-mechanical bone damage. Most studies have addressed thermal reactions during bone drilling on non-vital models, which is irrelevant to clinical scenarios. Little has been known about bone's in vivo thermal profiles under non-irrigated higher-speed drilling and its influences on the resulting bone chips. AIM A novel technique for bone harvest and cortical perforation via in-situ non-irrigated higher-speed drilling was proposed and investigated for the first time. METHODS The third mandible premolars of eight beagles were extracted and healed for three months. Sixteen partial edentulous sites (left and right) were randomized into four groups for bone autograft harvest without irrigation: chisel, 50 rpm drilling, 500 rpm drilling, and 1000 rpm drilling. Bone chips were harvested on the buccal plates of the missing tooth. An infrared camera and an implantable thermocouple collaboratively monitored in vivo real-time bone temperature at the drilling sites. In vitro performances of cells from bone chips, including cell number, viability, proliferation, migration, ALP activity, in vitro mineralization, mRNA transcriptional level of osteogenic genes and heat shock protein 70 (HSP-70), and HSP-70 expression at the protein level were also studied. RESULTS 500 rpm produced mild local hyperthermia with a 2-6 °C temperature rise both on the cortical surface and inside the cortical bone. It also held comparable or enhanced cell performances such as cell number, viability, proliferation, migration, ALP activity, in vitro mineralization, and osteogenic genes expression. CONCLUSIONS In-situ non-irrigated higher-speed drilling at 500 rpm using a screw drill is versatile, efficient, and thermal friendly and improves the bio-quality of bone chips. Our novel technique holds clinical translational potential in GBR application.
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Affiliation(s)
- Tengfei Zhou
- Department of Periodontology and Oral Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, 510280, China
| | - Zekun Gan
- Department of Periodontology and Oral Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, 510280, China
| | - Hanfei Zhang
- Stomatological Hospital, Southern Medical University, Guangzhou, 510280, China
| | - Ziyi Liu
- Stomatological Hospital, Southern Medical University, Guangzhou, 510280, China
| | - Yiping Pu
- Department of Oral Surgery, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200001, China.
| | - Mingdeng Rong
- Department of Periodontology and Oral Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, 510280, China.
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Li S, Tanner A, Romanos G, Delgado-Ruiz R. Heat Accumulation in Implant Inter-Osteotomy Areas-An Experimental In Vitro Study. Biomedicines 2022; 11:biomedicines11010009. [PMID: 36672516 PMCID: PMC9855973 DOI: 10.3390/biomedicines11010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/26/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
To examine the influence of the distance between adjacent implant osteotomies on heat accumulation in the inter-osteotomy area, two experimental groups with 15 pairs of osteotomies in Type II polyurethane blocks were compared: 7 mm inter-osteotomy separations (Group A, n = 15) and 14 mm inter-osteotomy separations (Group B, n = 15). An infrared thermographic analysis of thermal changes in the inter-osteotomy area was completed. A one-way analysis of variance (ANOVA) and Fisher post-test were used to determine group differences. Higher temperatures were recorded in Group A at the coronal and middle levels compared to the apical level in both groups. The temperature reached max temperatures at T80s and T100s. In Group A, the threshold for thermal necrosis was exceeded. Meanwhile, Group B did not reach the threshold for thermal necrosis. Preparing adjacent implant osteotomies in dense bone with a 7 mm separation between their centers increases the temperature in the inter-osteotomy area, exceeding the threshold for bone thermal necrosis; meanwhile, increasing the distance between osteotomies reduces the thermal accumulation and the risk for thermal necrosis.
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Affiliation(s)
- Shanlin Li
- School of Dental Medicine, Stony Brook University, Stony Brook, New York, NY 11794, USA
| | - Adam Tanner
- School of Dental Medicine, Stony Brook University, Stony Brook, New York, NY 11794, USA
| | - Georgios Romanos
- Department of Periodontology, School of Dental Medicine, Stony Brook University, Stony Brook, New York, NY 11794, USA
| | - Rafael Delgado-Ruiz
- Department of Prosthodontics and Digital Technology, School of Dental Medicine, Stony Brook University, Stony Brook, New York, NY 11794, USA
- Correspondence:
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Metallic Implants Used in Lumbar Interbody Fusion. MATERIALS 2022; 15:ma15103650. [PMID: 35629676 PMCID: PMC9146470 DOI: 10.3390/ma15103650] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/12/2022] [Accepted: 05/13/2022] [Indexed: 02/07/2023]
Abstract
Over the last decade, pedicle fixation systems have evolved and modifications in spinal fusion techniques have been developed to increase fusion rates and improve clinical outcomes after lumbar interbody fusion (LIF). Regarding materials used for screw and rod manufacturing, metals, especially titanium alloys, are the most popular resources. In the case of pedicle screws, that biomaterial can be also doped with hydroxyapatite, CaP, ECM, or tantalum. Other materials used for rod fabrication include cobalt-chromium alloys and nitinol (nickel-titanium alloy). In terms of mechanical properties, the ideal implant used in LIF should have high tensile and fatigue strength, Young's modulus similar to that of the bone, and should be 100% resistant to corrosion to avoid mechanical failures. On the other hand, a comprehensive understanding of cellular and molecular pathways is essential to identify preferable characteristics of implanted biomaterial to obtain fusion and avoid implant loosening. Implanted material elicits a biological response driven by immune cells at the site of insertion. These reactions are subdivided into innate (primary cellular response with no previous exposure) and adaptive (a specific type of reaction induced after earlier exposure to the antigen) and are responsible for wound healing, fusion, and also adverse reactions, i.e., hypersensitivity. The main purposes of this literature review are to summarize the physical and mechanical properties of metal alloys used for spinal instrumentation in LIF which include fatigue strength, Young's modulus, and corrosion resistance. Moreover, we also focused on describing biological response after their implantation into the human body. Our review paper is mainly focused on titanium, cobalt-chromium, nickel-titanium (nitinol), and stainless steel alloys.
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The role of operating variables in improving the performance of skull base grinding. Neurosurg Rev 2022; 45:2431-2440. [PMID: 35258695 DOI: 10.1007/s10143-022-01736-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/30/2021] [Accepted: 01/06/2022] [Indexed: 10/18/2022]
Abstract
Control of the thermal and physical damage during skull base grinding is of great importance. We assess the effects of bur material (3 materials), angle of the bur (10 angles), bur diameter (10 diameters), gas coolant (4 coolants), and grinding time (10 times) to evaluate the role of operating variables in thermal and physical damage during skull bone grinding. After validation of finite element analysis (FEA) results with experimental data, the temperature in the grinding site and axial force are calculated using FEA. The use of a diamond bur leads to at least 24.48 and 12.9% reduction in thermal and physical damage, respectively. A change in angle of the bur from 0º to 90º leads to a 19.76-31.62 times increment in axial force. An increase in bur diameter from 1 to 5.5 mm led to 10.78-14.36% and 23.43-43.90% increase in maximum temperature and axial force, respectively. However, a bur diameter between 2.5 and 4 mm could provide enough grinding force with less thermal damage. Skull base grinding with dry (D) and normal saline (NS) coolants was always accompanied with thermal damage. The results of maximum and duration of temperature, axial force, and surface defect evaluation show CO2 coolants (especially internal CO2 coolant) are the best options to decrease thermal damage. The equations of temperature and axial force were estimated by regression analysis. This may be used as a guideline for neurosurgeons to control damage during skull base grinding and can also be helpful for the programming of robot-assisted skull grinding during surgery.
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Liu P, Xiao JX, Zhao C, Li X, Sun G, Yang F, Wang X. Factors Associated With the Accuracy of Depth Gauge Measurements. Front Surg 2022; 8:774682. [PMID: 35096957 PMCID: PMC8793061 DOI: 10.3389/fsurg.2021.774682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 12/20/2021] [Indexed: 11/13/2022] Open
Abstract
Background: It is important to select appropriate screws in orthopedic surgeries, as excessively long or too short a screw may results failure of the surgeries. This study explored factors that affect the accuracy of measurements in terms of the experience of the surgeons, passage of drilled holes and different depth gauges.Methods: Holes were drilled into fresh porcine femurs with skin in three passages, straight drilling through the metaphysis, straight drilling through the diaphysis, and angled drilling through the diaphysis. Surgeons with different surgical experiences measured the holes with the same depth gauge and using a vernier caliper as gold standard. The length of selected screws, and the time each surgeon spent were recorded. The measurement accuracy was compared based on the experiences of the surgeons and the passage of drilled holes. Further, parameters of depth gauges and 12-mm cortical bone screws from five different manufacturers were measured.Results: A total of 13 surgeons participated in 585 measurements in this study, and each surgeon completed 45 measurements. For the surgeons in the senior, intermediate, and junior groups, the average time spent in measurements was 689, 833, and 785 s with an accuracy of 57.0, 42.2, and 31.5%, respectively. The accuracy and measurement efficiency were significantly different among the groups of surgeons (P < 0.001). The accuracy of measurements was 45.1% for straight metaphyseal drilling, 43.6% for straight diaphyseal drilling, and 33.3% for angled diaphyseal drilling (P = 0.036). Parameters of depth gauges and screws varied among different manufacturers.Conclusion: Both observer factor and objective factors could affect the accuracy of depth gauge measurement. Increased surgeon's experience was associated with improvements in the accuracy rate and measurement efficiency of drilled holes based on the depth gauge. The accuracy rate varied with hole passages, being the lowest for angled drilled holes.
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Affiliation(s)
- Pengcheng Liu
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Joanna Xi Xiao
- School of Clinical Medicine, The National University of Ireland Galway, Galway, Ireland
| | - Chen Zhao
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaodong Li
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Guantong Sun
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fei Yang
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoqing Wang
- Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- *Correspondence: Xiaoqing Wang
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Can M, Koluaçik S, Bahçe E, Gokce H, Tecellioglu FS. Investigation of thermal damage in bone drilling: Hybrid processing method and pathological evaluation of existing methods. J Mech Behav Biomed Mater 2021; 126:105030. [PMID: 34915360 DOI: 10.1016/j.jmbbm.2021.105030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/28/2021] [Accepted: 12/06/2021] [Indexed: 11/30/2022]
Abstract
In this study, a hybrid processing method using saline and cryogen cooler is proposed to keep the temperature below the threshold level during bone drilling. Drilling experiments were performed dry, saline, cryogen and, hybrid (saline + cryogen). At the end of the experiment, tool wear, the effect of the methods on the temperature, and the pathological evaluation of the thermal damage were investigated. The advantageous methods for bone drilling were proposed as a hybrid, saline, cryogenic and dry machining, respectively. In addition, it was observed that when cryogen was applied directly to the cutting area, it caused damage to the cell wall structure by the formation of ice crystals in the bone matrix. For this reason, it was recommended to be applied to the body of the cutting tool and it was found that cryogen flow rate has a significant effect on tool wear.
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Affiliation(s)
- Murat Can
- Department of Orthopedics and Traumatology, Malatya Training and Research Hospital, 44090, Malatya, Turkey
| | - Serdar Koluaçik
- Department of Orthopedics and Traumatology, Malatya Training and Research Hospital, 44090, Malatya, Turkey
| | - Erkan Bahçe
- Department of Mechanical Engineering, Inonu University, 44210, Malatya, Turkey.
| | - Hasan Gokce
- Department of Pathology, School of Medicine, Inonu University, 44210, Malatya, Turkey
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Gholampour S, Hassanalideh HH, Gholampour M, Frim D. Thermal and physical damage in skull base drilling using gas cooling modes: FEM simulation and experimental evaluation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 212:106463. [PMID: 34688175 DOI: 10.1016/j.cmpb.2021.106463] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 10/06/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Skull base drilling, as a high-risk process, is one of the most important techniques of skull base surgeries. METHODS The temperature, thrust force, and torque were calculated using finite element method (FEM) simulation under two conventional cooling models, and internal and external CO2 cooling modes at four rotational speeds (1000-4000 rpm). The temperatures at the bottom and on the surface of the drilling site were measured experimentally using a thermometer and a thermographic camera, respectively. The results were then compared with FEM results. RESULTS The efficiency rates of CO2 coolants in reducing the maximum temperature, thrust force, and torque were at least 5.0-11.2%, 16.5-33.8%, and 6.9-11.3% higher than conventional cooling modes, respectively. The experimental results indicated that, in contrast to the maximum temperature, temperature durability was 72.7-107.3% higher in the conventional cooling modes than the cooling modes with external CO2 coolant systems. The cracks and surface defects were less in the CO2 coolants than the other cooling modes. The maximum temperature after the second and third drillings increased by 17.7 and 26.8%, compared to the first drilling in the conventional cooling modes. On the other hand, the repeated drillings had no impact on the temperature in the CO2 cooling modes. CONCLUSION Skull base drilling with a rotational speed of 2000 rpm in the cooling mode of an external CO2 coolant, even for repeated drillings, can lead to a skull drilling process with minimum risk of drill bit breakage and thermal and physical damage.
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Affiliation(s)
- Seifollah Gholampour
- Department of Neurological Surgery, University of Chicago, 5841 S. Maryland Ave, Chicago, IL 60637, United States
| | | | | | - David Frim
- Department of Neurological Surgery, University of Chicago, 5841 S. Maryland Ave, Chicago, IL 60637, United States.
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Zhang J, Guan K, Zhang Z, Guan Y. In vitro evaluation of ultrafast laser drilling large-size holes on sheepshank bone. OPTICS EXPRESS 2020; 28:25528-25544. [PMID: 32907071 DOI: 10.1364/oe.396727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
Bone drilling has been widely used in medical surgeries such as repair and fixation in orthopedics. Traditional drilling method using drill-bits inevitably causes significant thermal and mechanical trauma in the adjacent bone tissues. This paper demonstrates the feasibility of femtosecond laser drilling in vitro large-size holes on the sheepshank bone with high efficiency and minimal collateral damage. A Yb:KGW femtosecond laser was utilized to drill millimeter-scale holes on the bone under different cooling conditions including gas- and water-assisted processes. Scanning electron microscopy, confocal laser scanning microscopy and infrared thermographic imaging system were used to investigate the residual debris, removal rate, bone temperature variation and hole morphology. Histological examination, Fourier transform infrared spectroscopy and Raman spectroscopy were employed to study thermal damage. Results show that a 4 mm hole with smooth and clean surface was successfully drilled on the bone, and the highest removal rate of 0.99 mm3/s was achieved, which was twenty times higher than the previous study of 0.05 mm3/s. Moreover, bone and bone marrow were distinguished by real-time monitoring system during laser drilling. This work demonstrates the potential for clinical applications using an ultrafast laser to produce crack-free large-size bone holes.
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Naghibzadeh M, Gholampour S, Naghibzadeh M, Sadeghian-Nodoushan F, Nikukar H. The effect of electromagnetic field on decreasing and increasing of the growth and proliferation rate of dermal fibroblast cell. Dermatol Ther 2020; 33:e13803. [PMID: 32526050 DOI: 10.1111/dth.13803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 04/06/2020] [Accepted: 06/06/2020] [Indexed: 11/29/2022]
Abstract
Maintaining the health of dermal fibroblast cells and controlling their growth and proliferation would directly affect the health of skin tissues. The present study encompassed three control and three experimental specimens, which were different in terms of the duration of exposure to electromagnetic field (EMF) and intensity. With a decrease in intensity from 2 to 1 mT during 24, 48, and 72 h after exposing the cells to EMF, the frequency of the sample fibroblast cells increased by 60.3%, 144.9%, and 90.1%, respectively. With an increase in intensity from 3 to 4 mT during 48 and 72 h of exposure to EMF, the frequencies of the sample fibroblast cells decreased by 6.8% and 86.7%, respectively. It seems to be possible to achieve the most desirable condition to help the restoration of wounds and skin lesions through decreasing the exposure intensity from 2 to 0.5 mT and increasing EMF exposure time from 24 to 72 h simultaneously and non-invasively. The most desirable approach to improve the treatment of skin cancers non-invasively is to increase the intensity from 3 to 5 mT and to enhance EMF exposure time from 48 to 72 h.
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Affiliation(s)
- Mehran Naghibzadeh
- Department of Biomedical Engineering, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Seifollah Gholampour
- Department of Biomedical Engineering, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Majid Naghibzadeh
- Medical Nanotechnology and Tissue Engineering Research Center, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Fatemeh Sadeghian-Nodoushan
- Medical Nanotechnology and Tissue Engineering Research Center, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.,Department of Tissue engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Habib Nikukar
- Medical Nanotechnology and Tissue Engineering Research Center, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
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Effect of Ambient Temperature Changes on Blood Flow in Anterior Cerebral Artery of Patients with Skull Prosthesis. World Neurosurg 2019; 135:e358-e365. [PMID: 31837495 DOI: 10.1016/j.wneu.2019.11.171] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/28/2019] [Accepted: 11/29/2019] [Indexed: 11/23/2022]
Abstract
BACKGROUND In many cases, an injury to the head leads to the replacement of a part of the skull with materials such as titanium and polyether ether ketone. METHODS Three-dimensional heads model of 15 healthy individuals and 13 patients were prepared. The models were simulated using thermal fluid structure interaction analysis to evaluate the effects of cold (5°C) and hot (55°C) temperatures of the skull on the conditions of blood flow in the anterior cerebral artery. RESULTS The results showed negligible changes (<3%) in wall shear stress (WSS) vessel and von Mises stress between the healthy individuals and patients both at 25°C and 55°C. However, at 5°C, the values of these 2 parameters in the patients were 2.1 and 2.5 times those in healthy individuals, respectively. The value of WSS in healthy individuals and the patients in cold temperature was 1.2 and 2.9 times those at normal temperature. The corresponding values for von Mises stress were 1.1 and 2.2, respectively. Accordingly, the stress changes between cold and hot ambient temperatures were found to be negligible in all samples. CONCLUSIONS The changes in stress were significant only for the patients when exposed to cold ambient temperature, and only in patients, exposure to a cold ambient temperature significantly increased the risks of vascular aneurysm and damage to the brain tissue surrounding the blood vessels. These risks were found to be negligible for both healthy individuals and patients when exposed to hot ambient temperature and also for healthy individuals exposed to cold ambient temperature.
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Gholampour S, Gholampour H, Khanmohammadi H. Finite element analysis of occlusal splint therapy in patients with bruxism. BMC Oral Health 2019; 19:205. [PMID: 31484524 PMCID: PMC6727492 DOI: 10.1186/s12903-019-0897-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 08/21/2019] [Indexed: 11/22/2022] Open
Abstract
Background Bruxism is among the habits considered generally as contributory factors for temporomandibular joint (TMJ) disorders and its etiology is still controversial. Methods Three-dimensional models of maxilla and mandible and teeth of 37 patients and 36 control subjects were created using in-vivo image data. The maximum values of stress and deformation were calculated in 21 patients six months after using a splint and compared with those in the initial conditions. Results The maximum stresses in the jaw bone and head of mandible were respectively 4.4 and 4.1 times higher in patients than in control subjects. Similar values for deformation were 5.8 and 4.9, respectively. The maximum stress in the jaw bone and head of mandible decreased six months after splint application by up to 71.0 and 72.8%, respectively. Similar values for the maximum deformation were 80.7 and 78.7%, respectively. Following the occlusal splint therapy, the approximation of maximum deformation to the relevant values in control subjects was about 2.6 times the approximation of maximum stress to the relevant values in control subjects. The maximum stress and maximum deformation occurred in all cases in the head of the mandible and the splint had the highest effectiveness in jaw bone adjacent to the molar teeth. Conclusions Splint acts as a stress relaxer and dissipates the extra stresses generated as well as the TMJ deformation and deviations due to bruxism. The splint also makes the bilateral and simultaneous loading possible and helps with the treatment of this disorder through regulation of bruxism by creating a biomechanical equilibrium between the physiological loading and the generated stress.
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Affiliation(s)
- Seifollah Gholampour
- Department of Biomedical Engineering, North Tehran Branch, Islamic Azad University, Tehran, Iran.
| | - Hanie Gholampour
- Department of Electrical and Computer Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Hamed Khanmohammadi
- Department of Biomedical Engineering, North Tehran Branch, Islamic Azad University, Tehran, Iran
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