[Experimental study on the biomechanical stability of different internal fixators for use in the mandible].
BACKGROUND
Comparative studies of different forms of osteosynthesis require that biomechanical and biological criteria be observed. The conditions in experimental studies should be as close as possible to the in vivo situation. The aim of our study was to develop a fracture model that would allow determination of the micromovements in the gap tissue following different forms of internal fixation in fractured human mandibles.


METHODS
Micromovements in the gap tissue of five human mandibles treated with different osteosynthetic systems (DCP, EDCP, Miniplates, 3-D systems) following osteotomy or fracture in the region of the corpus and median region were investigated by means of strain gauges. By fitting the human mandibles in plaster according to a method of our own it was possible to create fractures at predictable and comparable localizations.


RESULTS
Our investigations show that the micromovements in the gap tissue of osteotomied and fractured mandibles are different and not dependent on the form of osteosynthesis applied. Physiological micromovements in the gap tissue were found under strain for all osteosynthetic systems used in fractured and congruently reset mandibles.


CONCLUSIONS
Our fracture and osteosynthesis model allows the quantitative determination of micromovements in the gap tissue and shows the importance of ideal realignment, which has a decisive influence on micromovements in the gap tissue.
Piffkò
J
J
Klinik und Poliklinik für Mund-, Kiefer- und Gesichtschirurgie, Universität Münster. piffko@uni-muenster.de
Homann
Ch
Ch
Schuon
R
R
Joos
U
U
Meyer
U
U
D001696:Biomechanical Phenomena; D001732:Bite Force; D001860:Bone Plates; D001863:Bone Screws; D019544:Equipment Failure Analysis; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D008334:Mandible / Q000503:physiopathology; D008337:Mandibular Fractures / Q000503:physiopathology / Q000601:surgery*; D008953:Models, Anatomic