[Biomechanical study of rigid internal fixation for mandibular angle fracture].
OBJECTIVE
To develop a functional biomechanical mandibular model, and to observe the stress distribution of angle-fractured mandible under different rigid internal fixation (RIF) methods.


METHODS
A biomechanical model of mandible was built which include the simulative temporal-mandibular joint (TMJ) and was under mechanical loads of masseter, temporalis, medial pterygoid and lateral pterygoid. The different stress pattern was measured by strain gauges. Under the standard mandibular angle fracture, bilateral molar biting and four pairs of muscles loading, the strains were compared to evaluate the stability of one-or two-miniplate fixation.


RESULTS
The fixation of miniplate in the lateral oblique line can recover the main stress on the non-fracture side, but it was broken in the fracture side. The tension increased in the lower border of mandibular angle.


CONCLUSIONS
Through the biomechanical study based on the functional mandibular model, only one miniplate fixation in lateral oblique line for mandible angle fracture was insufficient buttressing of the segments, while the additional miniplate in the lower margin can recover the stress pattern and provide more stability.
Wang
Hang
H
Key Laboratory of Oral Biomedical Engineering, Ministry of Education, Sichuan University, Chengdu 610041, China.
Chen
Meng-Shi
MS
Tang
Wei
W
Tian
Wei-Dong
WD
D001696:Biomechanical Phenomena; D001860:Bone Plates; D005593:Fracture Fixation, Internal; D006801:Humans; D008334:Mandible; D008337:Mandibular Fractures; D008406:Masseter Muscle; D008963:Molar