Predictive value of ultrasound elastography for functional outcomes after orthognathic surgery

This study aimed to evaluate the utility of ultrasound elastography for assessing postoperative recovery of the masseter muscle, and its potential role in predicting functional outcomes in patients undergoing orthognathic surgery. Fifteen patients with dentofacial deformities (30 masseter muscles) underwent ultrasound strain elastography at rest, during mouth opening, and during clenching, at four time points: preoperatively, and at seven days, one month, and three months postoperatively. Strain values (SVs), cross-sectional muscle area, and maximal mouth opening (MMO) were measured. Statistical analyses included Friedman and Wilcoxon signed-rank tests, with correlations assessed using Pearson's or Spearman's coefficients, as appropriate. SVs significantly decreased at seven days postoperatively and recovered to baseline by one month, remaining stable at three months. The cross-sectional area increased significantly at seven days and one month in the rest and mouth opening conditions, returning to baseline at three months, while no significant changes were observed during clenching. Significant positive correlations were observed between SVs and muscle area at rest and during mouth opening. In addition, higher preoperative SVs were associated with greater postoperative improvement in MMO. Ultrasound elastography provides objective, non-invasive information on postoperative changes in the masseter muscle. This modality may serve as a useful tool for predicting functional recovery after orthognathic surgery in patients with dentofacial deformities.