An in vitro evaluation of miniplate fixation techniques for fractures of the atrophic edentulous mandible.

This study was undertaken to evaluate the biomechanical stability of various miniplate fixation techniques in varying degrees of atrophy and to determine optimal fixation techniques for fractures of the atrophic edentulous mandible. A total of 78 bovine ribs were randomly divided into 13 groups of six each; one non-atrophic group and twelve atrophic groups. Each one of the 13 sets of six ribs was formed based on the vertical dimension (40, 20, 15 or 10 mm) and osteotomized. The segments so produced were then reduced and fixed using various miniplate fixation techniques. The stability of various miniplate fixations in ribs showing varying degrees of atrophy (10, 15 and 20 mm) was compared with that of one miniplate fixation in non-atrophic ribs (40 mm), used as a standard. Atrophic groups utilizing single miniplate were significantly less stable than the non-atrophic group, whereas atrophic groups fitted with double miniplates, such as two 4-hole or two 6-hole miniplates, were significantly more stable than the non-atrophic group. The two miniplate fixation technique is recommended for the provision of adequate fracture site stability when open reduction is indicated in cases of atrophic edentulous mandibular fractures.