LAUSR

BACKGROUND Orthognathic surgery has been performed with increasing frequency for the treatment of severe malocclusion, yet the postsurgical neuromuscular recovery of patients has been inadequately studied. OBJECTIVE To investigate the effect of short-term and simple jaw motor training on accuracy and precision of jaw motor control in patients following orthodontic treatment and orthognathic surgery. METHODS Twenty patients who had completed preoperative orthodontics, 20 patients who had undergone bimaxillary orthognathic surgery, and 20 age-and-gender-matched healthy controls participated in the study. Participants were asked to perform 10 continuous jaw opening and finger lifting movements before and after a 30-minute motor training session. The variability in the amplitude of these simple movements was expressed as percentage in relation to the target position (accuracy - Daccu ) and as coefficient of variation (precision - CVprec ) in order to describe the motor performance. Furthermore, the changes in amplitude before and after training were measured in percentage. RESULTS Daccu and CVprec of simple jaw and finger movements significantly decreased after motor training (P ≤ 0.018) in all groups. The relative changes in finger movements were higher than jaw movements (P < 0.001) but with no differences amongst the groups (P ≥ 0.247). CONCLUSION Both accuracy and precision of simple jaw and finger movements improved after short-term motor training in all three groups, demonstrating the inherent potential for optimization of novel motor tasks. Finger movements improved more than jaw movements but with no differences between groups, suggesting that changes in occlusion and craniofacial morphology are not associated with impaired neuroplasticity or physiological adaptability of jaw motor function.