TY - JOUR
T1 - Changes in load distribution after unilateral condylar fracture
T2 - A finite element model study
AU - Helmer, Loreine M.L.
AU - Klop, Cornelis
AU - Lobbezoo, Frank
AU - Lange, Jan de
AU - Koolstra, Jan Harm
AU - Dubois, Leander
N1 - Funding Information: This work was supported by the Strasbourg Osteosynthesis Research Group, Tuttlingen, Germany (grant number AOCMFS-19–05H). The organization had no involvement in the study design, collection and interpretation of data, writing of the manuscript, or decision to submit the manuscript for publication. Publisher Copyright: © 2023 The Authors
PY - 2023/11/1
Y1 - 2023/11/1
N2 - Objective: Premature dental contact on the fractured side and a contralateral open bite are signs of a unilaterally fractured condyle of the temporomandibular joint (TMJ). The lateral pterygoid muscle pulls the condyle inwards, causing angulation of the fractured part and shortening of the ramus. This imbalance after fracture might change the load in both TMJs and consequently induce remodeling. The present study aimed to calculate this change in load. It is hypothesized to decrease on the fractured side and increase on the non-fractured side. Design: For these calculations, a finite element model (FEM) was used. In the FEM, shortening of the ramus varied from 2 mm to 16 mm; angulation, from 6.25° to 50°. Results: After fracture, load on the non-fractured side increased, but only at maximal mouth opening (MMO). Simultaneously, load on the fractured side decreased, at both timepoints, i.e., MMO and closed mouth. When comparing all simulations at those time points, i.e., from 2 mm and 6.25° to 16 mm and 50°, the load in the fractured condyle declines steadily. However, for both timepoints, a threshold stands out around 6 mm shortening and 18.75° angulation: visualization of the fractured condyle showed, apart from load on the condylar head, a second point of load more medial in the TMJ which was most evident in the 6 mm – 18.75° simulation. Conclusions: These findings could implicate that the balance between both TMJs is more difficult to restore after a fracture with more than 6 mm shortening and more than 18.75° angulation.
AB - Objective: Premature dental contact on the fractured side and a contralateral open bite are signs of a unilaterally fractured condyle of the temporomandibular joint (TMJ). The lateral pterygoid muscle pulls the condyle inwards, causing angulation of the fractured part and shortening of the ramus. This imbalance after fracture might change the load in both TMJs and consequently induce remodeling. The present study aimed to calculate this change in load. It is hypothesized to decrease on the fractured side and increase on the non-fractured side. Design: For these calculations, a finite element model (FEM) was used. In the FEM, shortening of the ramus varied from 2 mm to 16 mm; angulation, from 6.25° to 50°. Results: After fracture, load on the non-fractured side increased, but only at maximal mouth opening (MMO). Simultaneously, load on the fractured side decreased, at both timepoints, i.e., MMO and closed mouth. When comparing all simulations at those time points, i.e., from 2 mm and 6.25° to 16 mm and 50°, the load in the fractured condyle declines steadily. However, for both timepoints, a threshold stands out around 6 mm shortening and 18.75° angulation: visualization of the fractured condyle showed, apart from load on the condylar head, a second point of load more medial in the TMJ which was most evident in the 6 mm – 18.75° simulation. Conclusions: These findings could implicate that the balance between both TMJs is more difficult to restore after a fracture with more than 6 mm shortening and more than 18.75° angulation.
KW - Condylar fracture
KW - Conservative treatment
KW - Finite element model
KW - Indications
KW - Load
KW - Resorption
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U2 - https://doi.org/10.1016/j.archoralbio.2023.105791
DO - https://doi.org/10.1016/j.archoralbio.2023.105791
M3 - Article
C2 - 37598527
SN - 0003-9969
VL - 155
SP - 1
EP - 6
JO - Archives of Oral Biology
JF - Archives of Oral Biology
M1 - 105791
ER -