Department of Oral and Maxillofacial Surgery, Amsterdam Academic Medical Centers and Academic Centre for Dentistry (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Department of Orofacial Pain and Dysfunction, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Head Face Med. 2023 Jul 8;19(1):27. doi: 10.1186/s13005-023-00370-5.
After a fracture of the condyle, the fractured ramus is often shortened, which causes premature dental contact on the fractured side and a contralateral open bite. The imbalance could change the load in the temporomandibular joints (TMJs). This change could lead to remodelling of the TMJs to compensate for the imbalance in the masticatory system. The load in the non-fractured condyle is expected to increase, and the load in the fractured condyle to decrease.
These changes cannot be measured in a clinical situation. Therefore a finite element model (FEM) of the masticatory system was used. In the FEM a fractured right condyle with shortening of the ramus was induced, which varied from 2 to 16 mm.
Results show that, with a larger shortening of the ramus, the load in the fractured condyle decreases and the load in the non-fractured condyle increases. In the fractured condyle during closed mouth a major descent in load, hence a cut-off point, was visible between a shortening of 6 mm and 8 mm.
In conclusion, the change of load could be associated with remodelling on both condyles due to shortening of the ramus.
The cut-off point implies that shortening over 6 mm could present more difficulty for the body to compensate.
髁突骨折后，骨折的升支通常会缩短，导致骨折侧的牙齿过早接触，并导致对侧开颌。这种不平衡会改变颞下颌关节（TMJ）的负荷。这种变化可能导致 TMJ 的重塑，以补偿咀嚼系统的不平衡。预计未骨折髁突的负荷会增加，而骨折髁突的负荷会减少。
这些变化在临床情况下无法测量。因此，使用了咀嚼系统的有限元模型（FEM）。在 FEM 中，诱导了右侧髁突骨折伴升支缩短，缩短范围从 2 毫米到 16 毫米不等。
结果表明，随着升支缩短的增加，骨折髁突的负荷减少，而非骨折髁突的负荷增加。在闭合时，在骨折侧髁突中，可见从 6 毫米到 8 毫米的缩短，负荷出现明显下降，即出现一个截止点。
总之，由于升支缩短，负荷的变化可能与两个髁突的重塑有关。
该截止点意味着超过 6 毫米的缩短可能会使身体更难补偿。
