Mandibular asymmetry often requires orthognathic surgery, and postsurgical relapse remains a concern. The masseter muscle may influence stability, but most studies have emphasized volumetric rather than qualitative changes. This prospective study evaluated 24 patients with mandibular asymmetry using ultrasonography preoperatively and at 1, 3, and 6 months after surgery. The parameters measured were thickness, stiffness ratio, echo intensity, and blood flow. The results showed significant postoperative adaptations. Masseter echo intensity increased markedly at 1 month (p < 0.001), peaked at 3 months (p = 0.042), and decreased toward baseline at 6 months (p < 0.001). Blood flow increased significantly from T1 to T2 (p < 0.001). Bite force dropped transiently at 1 month (p < 0.001) but recovered by 6 months (p < 0.001). At baseline, BMI correlated with echo intensity (r = 0.724, p < 0.001) and grip strength correlated with bite force (r = 0.705, p < 0.001). The stiffness ratio difference (contraction–rest) correlated with bite force (right: r = 0.629; left: r = 0.690). Relapse occurred in 25% of patients and correlated only with preoperative deviation and not ultrasound indices. Conclusions: Ultrasonography revealed meaningful qualitative muscle changes during recovery, though these were not strong predictors of relapse. Ultrasound remains a reliable, noninvasive tool for monitoring postoperative adaptation.

Accurate, standardized dental model measurements remain labor-intensive and difficult to scale in orthodontics. This technical development study aimed to develop and preliminarily evaluate a semiautomated three-dimensional (3D) dental cast measurement system using standardized measurement templates (patent pending). The workflow integrates robotic handling of models, X-ray CT acquisition of volumetric data, optional intraoral-scan polygonal data (e.g., STL), template generation from 3D data, and orthodontist-guided landmark placement, after which dedicated software retrieves 3D coordinates and performs automated measurements and visualization. The system was demonstrated on four standard models scanned by X-ray CT. It produced automated aggregation of measurements and 3D visual outputs, and enabled calculation of conventional indices as well as template-based metrics such as palatal volume and cusp height variation. This semiautomated approach combines mechanical efficiency with expert oversight, providing a standardized alternative to manual measurement and a foundation for broader applications in orthodontic, prosthodontic, and forensic contexts.