Occlusal Splint versus Botulinum Toxin Type A in the Management of Jaw Muscle Pain

Objectives: This equivalence randomized controlled trial (RCT) evaluated and compared the effectiveness of an occlusal splint (OS) versus Botulinum toxin type A (BTX‑A) injections in reducing jaw‑muscle pain in adult patients with probable sleep bruxism. Methods: A total of 358 adults (≥ 18 years) with clinically diagnosed jaw‑muscle pain and probable sleep bruxism were randomized (OS: n = 176; BTX‑A: n = 182). The primary outcome measure was pain reduction using the Graded Chronic Pain Scale (GCPS v2.0). Secondary outcomes included mandibular range of motion (pain‑free opening, unassisted and assisted maximal opening, protrusion, laterotrusion), pain distribution among masticatory muscles, Jaw Functional Limitation Scale–20 (JFLS‑20), Oral Behaviors Checklist (OBC), and Oral Health Impact Profile‑14 (OHIP‑14). Outcome assessors were blinded. Multilevel mixed‑effects regression models were applied. Results: Both interventions induced significant reductions in GCPS scores at 3, 6 and 12 months (p < 0.001); no significant differences were found between groups (p = 0.632). The OS arm displayed modestly superior improvements in functional parameters such as maximum mouth opening and JFLS‑20 scores. In the BTX‑A arm, 72.5 % (n = 132) of participants reported mild transient chewing discomfort in the first week. Conclusion: Both OS and BTX‑A effectively reduce jaw‑muscle pain, improve oral health‑related quality of life (OHRQoL), and enhance masticatory‑functional outcomes in probable sleep bruxism patients. The occlusal splint demonstrated slight advantages in some functional outcomes and fewer initial discomforts. Clinical significance: In clinical practice, occlusal splints, being non‑invasive and reversible, may serve as first‑line therapy for bruxism‑associated jaw‑muscle pain, while BTX‑A is appropriate for cases with severe muscular hyperactivity or poor compliance with splint use.