This study is intended to compare the skeleton stability of bioabsorbable and titanium systems after orthognathic surgery in mandibular prognathism patients.

A Retrospective study of 28 mandibular prognathism patients who underwent BSSRO setback surgery at Chulalongkorn University. Both titanium and the bioabsorbable group would take lateral cephalometrics immediately postoperative in 1-week(T0), 3(T1), 6(T2), and 12(T3) months. These radiographs were analyzed with Dolphin imaging programTM. The vertical, horizontal, and angular indices were measured. To compare immediately postoperative and follow-up periods within the group, the Friedman difference was used, and the Man-Whitney U test was used between the two groups.

The measurements within the group presented no statistically significant differences. But this study showed that at T0-T1, there was a statistically significant difference between the two groups in the mean of Me in horizontal linear measurement. T0-T2 found differences between Me in both horizontal and vertical linear measurements, and the difference between ANB. The differences between B-point, Pog, and Me in vertical linear measurements at T0-T3 were also reported.

The significant difference values were within the normal range which indicated that using the bioabsorbable system could be well maintained as well as the titanium system.

The second operation for removing titanium plate and screw after conventional orthognathic surgery may leads patient discomforts. While a resorbable system might be the role change if the stability is place on the same level.