Journal of Peking University (Health Sciences) ›› 2021, Vol. 53 ›› Issue (5): 983-989. doi: 10.19723/j.issn.1671-167X.2021.05.029

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Three-dimensional finite element analysis of traumatic mechanism of mandibular symphyseal fracture combined with bilateral intracapsular condylar fractures

ZHOU Wei1,AN Jin-gang1,(),RONG Qi-guo2,(),ZHANG Yi1   

  1. 1. Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology & National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing 100081, China
    2. Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China
  • Received:2019-10-14 Online:2021-10-18 Published:2021-10-11
  • Contact: Jin-gang AN,Qi-guo RONG E-mail:anjingang@126.com;qrong@pku.edu.cn

Abstract:

Objective: To analyze the biomechanical mechanism of mandibular symphyseal fracture combined with bilateral intracapsular condylar fractures using finite element analysis (FEA). Methods: Maxillofacial CT scans and temporomandibular joint (TMJ) MRI were performed on a young male with normal mandible, no wisdom teeth and no history of TMJ diseases. The three-dimensional finite element model of mandible was established by Mimics and ANSYS based on the CT and MRI data. The stress distributions of mandible with different angles of traumatic loads applied on the symphyseal region were analyzed. Besides, two models with or without disc, two working conditions in occlusal or non-occlusal status were established, respectively, and the differences of stress distribution between them were compared. Results: A three-dimensional finite element model of mandible including TMJ was established successfully with the geometry and mechanical properties to reproduce a normal mandibular structure. Following a blow to the mandibular symphysis with different angles, stress concentration areas were mainly located at condyle, anterior border of ramus and symphyseal region under all conditions. The maximum equivalent stress always appeared on condylar articular surface. As the angle between the external force and the horizontal plane gradually increased from 0° to 60°, the stress on the mandible gradually concentrated to symphysis and bilateral condyle. However, when the angle between the external force and the horizontal plane exceeded 60°, the stress tended to disperse to other parts of the mandible. Compared with the condition without simulating the disc, the stress distribution of articular surface and condylar neck decreased significantly when the disc was present. Compared with non-occlusal status, the stress on the mandible in occlusal status mainly distributed on the occlusal surface, and no stress concentration was found in other parts of the mandible. Conclusion: When the direction of external force is 60° from the horizontal plane, the stress distribution mainly concentrates on symphyseal region and bilateral condylar surface, which explains the occurrence of symphyseal fracture and intracapsular condylar fracture. The stress distribution of condyle (including articular surface and condylar neck) decreases significantly in the presence of arti-cular disc and in stable occlusal status when mandibular symphysis is under traumatic force.

Key words: Symphyseal fracture, Intracapsular condylar fracture, Mandible, Finite element analysis

CLC Number: 

  • R782.6

Figure 1

Three-dimensional finite element model of mandible including TMJ (arrow indicates disc)"

Table 1

Mechanical properties of mandible based on HU from the CT image"

Gray value/HU Density/(kg/m3) Young modulus/(MPa) Poisson ratio
226.0-510.5 451.32 2 209.07 0.3
510.5-795.0 711.92 4 124.77
795.0-1 079.5 972.52 6 324.00
1 079.5-1 364.0 1 232.67 8 750.40
1 364.0-1 648.5 1 493.73 11 384.68
1 648.5-1 933.0 1 754.33 14 190.63
1 933.0-2 217.5 2 014.93 17 155.61
2 217.5-2 502.0 2 275.53 20 266.26
2 502.0-2 786.5 2 536.13 23 511.80
2 786.5-3 071.0 2 796.74 26 883.29

Table 2

Mechanical properties of masticatory muscles"

Muscle Cross sectional area/cm2 Number of elements, n Young modulus/MPa Poisson ratio
Masseter 6.80 28 19 0.3
Medial pterygoid 4.37 18 19
Lateral pterygoid 2.39 9 19
Anterior temporal 4.12 17 19
Posterior temporal 4.12 17 19

Figure 2

A load of magnitude 500 N was applied to mandibular symphysis The angles between load and horizontal plane: F1, 0°; F2, 30°; F3, 45°; F4, 60°; F5, 75°."

Figure 3

Equivalent stress distribution on mandible under different conditions The angles between load and horizontal plane: A, 0°; B, 30°; C, 45°; D, 60°; E, 75°."

Table 3

Maximum equivalent stress of mandible under different conditions"

Angle between load and horizontal plane/(°) Symphysis/MPa Anterior border of ramus/MPa Condylar articular surface/MPa
0 25.2 67.4 174.6
30 24.5 43.5 137.3
45 21.1 23.0 64.8
60 19.8 7.3 56.3
75 16.4 17.9 54.6

Figure 4

Equivalent stress distribution on condylar articular surface under different conditions The angles between load and horizontal plane: A, 0°; B, 30°; C, 45°; D, 60°; E, 75°"

Figure 5

Equivalent stress distribution of two models under the same condition A, model without disc; B, model with disc."

Figure 6

Equivalent stress distribution of two models under the same condition A, non-occlusal status; B, occlusal status."

[1] 武付花, 黄迪炎, 郭振国, 等. 三维有限元分析下颌骨不同部位受力髁突的力学应变 [J]. 中国组织工程研究, 2015, 19(29):4667-4671.
[2] Gallas-Torreira M, Fernandez JR. A three-dimensional computer model of the human mandible in two simulated standard trauma situations [J]. J Craniomaxillofac Surg, 2004, 32(5):303-307.
doi: 10.1016/j.jcms.2004.04.008
[3] 徐晓峰, 苏佳楠, 代杰文, 等. 颏部骨折合并双侧髁突囊内骨折3种不同治疗方式的三维有限元分析 [J]. 中国口腔颌面外科杂志, 2016, 14(5):409-412.
[4] Liu YF, Wang R, Baur DA, et al. A finite element analysis of the stress distribution to the mandible from impact forces with various orientations of third molars [J]. J Zhejiang Univ Sci B, 2018, 19(1):38-48.
doi: 10.1631/jzus.B1600552
[5] Loukota RA, Neff A, Rasse M. Nomenclature/classification of fractures of the mandibular condylar head [J]. Br J Oral Maxillofac Surg, 2010, 48(6):477-478.
doi: 10.1016/j.bjoms.2009.08.036 pmid: 19896755
[6] Antic S, Vukicevic AM, Milasinovic M, et al. Impact of the lower third molar presence and position on the fragility of mandibular angle and condyle: A Three-dimensional finite element study [J]. J Craniomaxillofac Surg, 2015, 43(6):870-878.
doi: 10.1016/j.jcms.2015.03.025
[7] Thresher RW, Saito GE. The stress analysis of human teeth [J]. J Biomech, 1973, 6(5):443-449.
pmid: 4748494
[8] Arne W, Wolfgang K, Kurt S, et al. A 3-dimensional finite-element analysis investigating the biomechanical behavior of the mandible and plate osteosynjournal in cases of fractures of the condylar process [J]. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2002, 94(6):678-686.
doi: 10.1067/moe.2002.126451
[9] Rho JY, Hobatho MC, Ashman RB. Relations of mechanical properties to density and CT numbers in human bone [J]. Med Eng Phys, 1995, 17(5):347-355.
pmid: 7670694
[10] Wang R, Liu Y, Wang JH, et al. Effect of interfragmentary gap on the mechanical behavior of mandibular angle fracture with three fixation designs: A finite element analysis [J]. J Plast Reconstr Aesthet Surg, 2017, 70(3):360-369.
doi: 10.1016/j.bjps.2016.10.026
[11] Chaudhry H, Bukiet B, Anderson EZ, et al. Muscle strength and stiffness in resistance exercise: Force transmission in tissues [J]. J Bodyw Mov Ther, 2017, 21(3):517-522.
doi: S1360-8592(16)30128-0 pmid: 28750958
[12] Weijs WA, Hillen B. Relationship between the physiological cross-section of the human jaw muscles and their cross-sectional area in computer tomograms [J]. Acta Anat, 1984, 121(1):31-35.
doi: 10.1159/000145938
[13] Bezerra TP, Silva Junior FI, Scarparo HC, et al. Do erupted third molars weaken the mandibular angle after trauma to the chin region? A 3D finite element study [J]. Int J Oral Maxillofac Surg, 2013, 42(4):474-480.
doi: 10.1016/j.ijom.2012.10.009
[14] Santos LS, Rossi AC, Freire AR, et al. Finite-element analysis of 3 situations of trauma in the human edentulous mandible [J]. J Oral Maxillofac Surg, 2015, 73(4):683-691.
doi: 10.1016/j.joms.2014.10.014
[15] Stringhini DJ, Sommerfeld R, Uetanabaro LC, et al. Resistance and stress finite element analysis of different types of fixation for mandibular orthognathic surgery [J]. Braz Dent J, 2016, 27(3):284-291.
doi: 10.1590/0103-6440201600336 pmid: 27224561
[16] Bujtar P, Sandor GK, Bojtos A, et al. Finite element analysis of the human mandible at 3 different stages of life [J]. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2010, 110(3):301-309.
doi: 10.1016/j.tripleo.2010.01.025
[17] Sun M, Yang J, Zhou R, et al. Mechanical analysis on individualized finite element of temporal-mandibular joint under overlarge jaw opening status [J]. Int J Clin Exp Med, 2015, 8(6):9046.
[18] Cheng HY, Peng PW, Lin YJ, et al. Stress analysis during jaw movement based on vivo computed tomography images from patients with temporomandibular disorders [J]. Int J Oral Maxillofac Surg, 2013, 42(3):386-392.
doi: 10.1016/j.ijom.2012.07.005
[19] Chen S, Zhang Y, An JG, et al. Width-controlling fixation of symphyseal/parasymphyseal fractures associated with bilateral condylar fractures with 22.0 mm miniplates: A retrospective investigation of 45 cases [J]. J Oral Maxillofac Surg, 2016, 74(2):315-327.
doi: 10.1016/j.joms.2015.09.030
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