In order to prevent post OGS mandibular hypomobility, implementation of a sound postoperative rehabilitation program is very important [82]. The incidence of mandibular hypomobility after IVRO is very low and recovery of MMO is known to be 90-98% of pre-operative opening. Aragon et al. [82] showed 90% of recovery in 13 patients, Storum and Bell [110] showed 98% of recovery on 24 patients, Boyd et al. [39] showed 98% of recov- ery in 9 patients, and Jung et al. [95] reported 91.3% of recovery in 187 patients within 6 month and 95.7% re- covery at 24 month after the procedure (Figure 5A). Pa- tients with MMO less than 40 mm showed 112.5 to 123.2% recovery after IVRO procedure (Figure 5B).