Feasibility of a Clinical Trial on Physiotherapy and Mouthguards for Bruxism Using Posture and EMG Analysis

Participant recruitment was conducted at USJ dental clinics with support from the occlusal department and private clinic following patient consultations. Screening for bruxism involved a clinical examination and the DC/TMD questionnaire. Ethical approval was granted by the Saint Joseph University of Beirut (approval number USJ-2023-200), and informed consent was obtained from all participants.

Electromyographic (EMG) assessments were carried out by the principal investigator using a portable EMG machine (KM560). Electrodes were placed bilaterally on the masseter muscles. Participants were instructed to bite in maximum intercuspation six times for five seconds each, with rest intervals in between. The device recorded muscle activity during both contraction and relaxation phases to evaluate bruxism-related muscle function.

Forward head posture was analyzed through photogrammetry. Markers were placed at the tragus of the ear and the C7 vertebra. Lateral photographs were taken, and the craniovertebral angle was measured using image analysis software to assess postural alignment.

The physiotherapy protocol consisted of a six-week home program performed daily. It included awareness of the mandibular rest position, relaxation techniques, diaphragmatic breathing, self-massage of the masseter and temporalis muscles, stretching, coordination, and resistance exercises. Participants recorded and submitted daily videos via Teams or WhatsApp to ensure compliance.

Custom mouthguards were fabricated by the researcher. Dental impressions were taken using alginate (Hydrogum 5®), and casts were made. Mouthguards were then vacuum-formed using thermoplastic material (3A MEDES®), followed by trimming and polishing to ensure a comfortable fit.

Inclusion criteria

• Age between 18 and 65 years
• Confirmed diagnosis of bruxism by a qualified member of the occlusion unit department
• No history of temporomandibular disorders or other craniofacial pain conditions
• No history of neurological or psychiatric disorders
• No current use of medications that affect muscle tone or sleep

Exclusion criteria

• - The presence of any systemic or neuromuscular disorder affecting the jaw muscles or posture.
• Use of medications, substances, or drugs that may affect jaw muscle activity, such as muscle relaxants or stimulants.
• Lifestyle: sleep disorder, anxiety
• Presence of any oral pathology or dental prostheses that may interfere with the use of a mouthguard.
• Inability to tolerate the EMG electrodes or posture angle analysis.
• Patient who has recently undergone physiotherapy