Analysis of complications in fractures of the mandibular angle--a study with finite element computation and evaluation of data of 277 patients.
OBJECTIVE
The purpose of this study was to compute the load on different osteosynthesis plates in a simplified model using finite element analysis, and to find out whether miniplates were sufficiently stable for application at the mandibular angle.


METHODS
Data from 277 patients with 293 fractures of the mandibular angle have been evaluated.


METHODS
A computation model using finite elements was established in order to compute mechanical stress occurring in osteosynthesis plates used for fixation of fractures of the mandibular angle. In the second part of this study, the data from all in-patients treated for fracture of the mandibular angle were evaluated retrospectively. Age and sex of the patients, cause of fracture, state of dentition, type of therapy as well as complications were noted.


RESULTS
In those tests, both the 1.0 mm miniplate and the 2.3 mm module plate were sufficiently stable. The rate of major complications (requiring revisional surgery with general anaesthesia) amounted to approximately 17% in comminuted fractures, or in non-compliant patients in which primary stability with a single miniplate did not appear sufficient, so that other osteosynthesis methods were used in addition. This rate was considerably higher than that in simple mandibular fractures. Simple fractures of the mandibular angle were just treated with one miniplate following Champy's guidelines strictly. In these fractures the rate of major complications was only 2.3%.


CONCLUSIONS
In comminuted fractures and in non-compliant patients, the use of a stronger osteosynthesis material should be considered while in all other cases application of a single 1.0 mm miniplate was regarded as sufficient for fixation using open reduction.
Feller
Kay-Uwe
KU
Department of Maxillofacial Surgery, Carl Gustav Carus Medical School of University, Dresden, Germany.
Schneider
Matthias
M
Hlawitschka
Matthias
M
Pfeifer
Günter
G
Lauer
Günter
G
Eckelt
Uwe
U
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001860:Bone Plates / Q000009:adverse effects; D002102:Cadaver; D002648:Child; D003198:Computer Simulation; D004867:Equipment Design; D005260:Female; D020342:Finite Element Analysis; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000295:instrumentation*; D018460:Fractures, Comminuted / Q000601:surgery; D006801:Humans; D008297:Male; D008337:Mandibular Fractures / Q000601:surgery*; D008875:Middle Aged; D008954:Models, Biological; D011183:Postoperative Complications; D012086:Reoperation; D012189:Retrospective Studies; D013314:Stress, Mechanical; D016312:Treatment Refusal