Effect of the Occlusal Splint Therapy on Mandibular Condylar Position in Patients With Myofascial Pain and an Average Skeletal Growth Pattern: A CBCT-Based Randomized Controlled Trial

Introduction Myogenic temporomandibular disorders (M-TMDs) cause masticatory muscle pain and impaired mandibular function. This study evaluated the effect of occlusal splint therapy on mandibular condylar position in patients with M-TMDs using cone-beam computed tomography (CBCT). Materials and methods This is a two-arm, open-label randomized controlled trial, with an additional non-randomized external healthy control group. A total of 65 participants were included; 44 patients with M-TMDs were randomly allocated to group A, which received occlusal splint therapy combined with pharmacotherapy (n=22), or group B, which received pharmacotherapy alone (n=22). Group C comprised 21 healthy participants recruited as a non-randomized reference group without TMDs. An average skeletal growth pattern was confirmed using composite cephalometric analysis. Condylar positional parameters, including the condylar ratio (CR), sagittal condylar guidance angle (SCGA), and temporomandibular joint spaces, were evaluated using CBCT. Groups A and B were assessed at baseline and after three months, whereas group C underwent a single baseline CBCT assessment. Data were analyzed using the Shapiro-Wilk test, paired sample t-test, one-way analysis of variance, and Tukey's post hoc test. Results In group A, the right CR decreased significantly from 0.24 ± 0.10 at baseline to 0.11 ± 0.04 after three months (p<0.001). Significant within-group changes were also observed in the left CR (p=0.039), right SCGA (p=0.005), and left SCGA (p<0.001). Group A additionally demonstrated a greater reduction in pain intensity, increased maximum mouth opening, and significant changes in temporomandibular joint space measurements compared with group B. However, most post-treatment comparisons of CR and SCGA among the three groups were not statistically significant. Conclusion Three months of occlusal splint therapy combined with pharmacotherapy was associated with reduced pain, improved mouth opening, and short-term changes in CBCT-derived condylar positional parameters in patients with M-TMDs. These findings should be interpreted as positional adaptations rather than evidence of osseous condylar remodeling.