[Should osteosynthesis plates in the area of the facial skull be removed again? Results of experimental and clinical studies].

We discuss the arguments dealing with removal of fixation devices and plates after osteosynthesis of facial bone fractures. As an experimental model for examining the soft tissue reaction to implants under standard conditions, an inguinal flap was prepared in 24 Wistar rats. Titanium mesh implants (10 x 8 x 0.3 mm) were then inserted into the flaps. Twelve implants were additionally bent to investigate histologically the influence of mechanical preparation on tissue reactions. Examination of all specimens was carried out with the technique of Donath and showed a thin capsule around the titanium implants but without any signs of infection. Around the bent areas of the implants there were minimal signs of local chronic inflammation without a capsule. Use of titanium microplates instead of miniplates in 89 patients with midfacial fractures diminished the rate of local complications. Based on our experimental and clinical results, indications for the different types of plates and the necessity for their later removal are discussed. Our present plates are only removed from the maxillary sinus wall and the alveolar ridge, after osteosynthesis in children, and in patients with local complications. If removal of the material is planned (because of the location), less expensive steel implants are used.