Effectiveness of early active mandibular exercise in early recovery of mandibular movement and quality of life after orthognathic surgery: a single-centre randomised clinical trial.

Abstract

This study aimed to evaluate the effectiveness of early active mandibular exercise (AME) to address mouth-opening limitation following orthognathic surgery in patients with skeletal Class III malocclusion. This was a single-centre, randomised, controlled, and double-blinded experimental study. In 44 subjects, the experimental group (n = 21) performed AME 10 times daily and were asked to self-assess the degree of opening by counting the number of tongue depressors they could fit in, whereas the control group (n = 23) performed only basic finger exercises. Efficacy was assessed by the range of mandibular movement in four directions (maximum opening, and right lateral, left lateral, and anterior movements), and pain was assessed using a visual analogue scale. Opening-related quality of life (QoL) was assessed using a questionnaire. All variables were measured immediately (T0), and at one week (T1), two weeks (T2), four weeks (T3), and 12 weeks (T4) after the removal of intermaxillary fixation. Statistical analyses were performed using the Mann-Whitney U, Friedman, and chi-squared tests. The experimental group demonstrated earlier recovery of mandibular range of motion in all directions compared with the control group during T0-T1 (p < 0.05). The control group gradually recovered from T0-T4. At T1 the opening recovery rate was 56-68% in the experimental group and 18-39% in the control group. Pain scores were significantly lower in the experimental group than in the control group at T1 (p < 0.05). The experimental group also showed an earlier positive response to all daily living activities at T3 compared with T4 in the control group. AME not only effectively recovers mouth-opening limitation after orthognathic surgery, but also promotes early improvements in range of motion and pain scores. Furthermore, it is an effective intervention to facilitate an early return to the opening-related activities of daily living.