Comparison of the long-term skeletal stability between a biodegradable and a titanium fixation system following BSSO advancement - a cohort study based on a multicenter randomised controlled trial.

Biodegradable fixation systems could reduce or eliminate the problems associated with removal of titanium plates. A multicenter randomised controlled trial (RCT) was performed in the Netherlands from December 2006-July 2009, and originally 230 injured and orthognathic patients were included. The patients were randomly assigned to either a titanium control group (KLS Martin) or to a biodegradable test group (Inion CPS). The aim of the present study was to compare the long-term skeletal stability of advancement bilateral sagittal split osteotomies (BSSO) of a biodegradable system and a titanium system. Only patients from the original RCT who were at least 18 years old and who had a BSSO advancement osteotomy were included. Those who had simultaneous Le Fort I osteotomy or genioplasty were excluded. Analysis of skeletal stability was made by digital tracing of lateral cephalograms. Long-term skeletal stability in BSSO advancement did not differ significantly between patients treated with biodegradable plates and screws and those treated with titanium plates and screws. Given the comparable amount of relapse, the general use of Inion CPS in the treatment of BSSO advancement should not be discouraged. On the basis of other properties a total picture of the clinical use can be obtained; the short-term stability, the intraoperative switches, the number of plates removed and cost-effectiveness. Trial registration of original RCT: http://www.controlled-trials.com; ISRCTN 44212338.