This study compares three treatment approaches for adults with bruxism-related temporomandibular disorder symptoms: occlusal splint therapy, botulinum toxin type A injection, and combined medical-splint therapy. Participants were assigned to one of three non-randomized treatment arms according to clinical indication, symptom profile, shared decision-making, and patient preference. Symptom severity was assessed before treatment and after 3 months using the Fonseca Anamnestic Index. The primary purpose of the study was to compare the 3-month change in total Fonseca Anamnestic Index scores among the treatment arms. Selected symptom items and treatment-related adverse events were also evaluated during follow-up.

This is a prospective, non-randomized, open-label, controlled, parallel-arm clinical trial evaluating treatment outcomes in patients with bruxism-related temporomandibular disorder symptoms. A total of 60 adult participants were assigned to one of three treatment arms: occlusal splint therapy, botulinum toxin type A injection, or combined medical-splint therapy.

Participants in the occlusal splint arm received custom-made maxillary stabilization splints and were instructed to use the splints during sleep. Participants in the botulinum toxin type A arm received a single session of intramuscular injections into the masseter and temporalis muscles. Participants in the combined medical-splint arm received a maxillary stabilization splint together with a short-term pharmacological regimen for acute symptom control.

The Fonseca Anamnestic Index was administered at baseline and at the 3-month follow-up. The primary outcome was the change in total Fonseca Anamnestic Index score from baseline to 3 months. Secondary assessments included changes in selected Fonseca Anamnestic Index sub-item scores, changes in Fonseca Anamnestic Index severity categories, and monitoring of treatment-related adverse events. Because of the nature of the interventions, participants and clinicians were not blinded to treatment assignment.

Inclusion Criteria:

• Adults aged 18 years or older.
• Presence of bruxism-related temporomandibular disorder symptoms.
• Self-reported sleep or awake bruxism based on clenching or grinding awareness.
• Clinical signs compatible with bruxism, including dental attrition, cupped-out wear facets, or shiny occlusal surfaces.
• Absence of known systemic conditions that could interfere with treatment or outcome assessment.
• Ability to provide written informed consent.

Exclusion Criteria:

• Age younger than 18 years.
• Presence of systemic or neurological disorders.
• Uncontrolled psychiatric conditions.
• Infection or inflammatory lesions at the planned injection sites.
• History of maxillofacial surgery or severe trauma in the relevant orofacial region.
• Inability or unwillingness to provide written informed consent.

De-identified individual participant data underlying the results reported in this study may be made available from the corresponding author upon reasonable request. Data will be shared only after review of the scientific purpose of the request and, where appropriate, completion of a data sharing agreement.

De-identified individual participant data and available supporting information will be made available beginning 6 months after publication and will be available for 5 years.

De-identified individual participant data may be shared with qualified researchers for scientifically valid purposes upon reasonable request to the corresponding author. Requests will be reviewed by the study investigators, and data will be shared only after approval of the request and, where appropriate, completion of a data sharing agreement. Shared data will not include information that could directly identify participants.

No masking was performed because of the nature of the interventions. Participants and care providers were aware of the assigned treatment.