THE INFLUENCES OF TWO SAGITTAL SPLIT OSTEOTOMY TECHNIQUES ON THE IN VITRO BIOMECHANICAL STABILITY OF TITANIUM PLATES

Abstract

The purpose of this study was to examine the influence of two different sagital split osteotomy techniques on the biomechanical stability of titanium plates used for mandibular advancement. 40 sheep mandible were cleaned of soft tissues to expose bone surface. Sagital split osteotomies were performed by either one of the techniques proposed by Obwegeser-Trauner (OT) or Obwegeser-Dal Pont (OD).Mandibular advancement of 5 mm was done using a surgical stent. One or two parallel mini plates with 4 holes in conjunction with four 5mm screws were used to fixate bone segments. All specimens were placed in a cervohydrolic testing unit and gradually increasing vertical force loads were applied above the molar teeth. The mean and standard deviations of the displacement values at each force level were compared with Mann-Whitney U test using % 95 confidence interval. There were significant differences between OT and OD groups as well as according to the number plates (p < 0.05). The use of double plating was found to generally increase overall stability and in OD specimens with two plates, these values were greater than other groups (p < 0.05). The stability of single plated OT specimens were observed to decrease with increasing force loads (p < 0.05). Within the limits of this experimental study, it can be suggested that the use of double plating has positive effects on the fixation of osteotomy sites in both techniques. However, although the application of single plate may be sufficient on the stability of OD, double plating would be more effective in OT osteotomy.