Effects of Orofascial Myofunctional Therapy and Cervical Stabilization Exercises on Temporomandibular Dysfunction

Temporomandibular disorders (TMDs) are among the most common musculoskeletal conditions affecting the craniofacial region and are characterized by pain, joint sounds, restricted movement, and functional limitations. Anterior disc displacement is one of the most frequently observed temporomandibular joint (TMJ) disorders and is classified as anterior disc displacement with reduction (ADDwR) or without reduction (ADDwoR). In ADDwR, the articular disc becomes displaced during mandibular movement but returns to its normal position during opening, commonly producing a clicking sound. Although disc displacement can occur in asymptomatic individuals, repeated episodes may interfere with normal joint mechanics, alter mandibular movement, and contribute to maladaptive muscular activity. In some patients, ADDwR may progress to disc displacement without reduction, resulting in limited mouth opening, restricted lateral movement, minimal condylar translation, and deviation of the mandible toward the affected side. TMDs have a multifactorial etiology involving trauma, parafunctional activities such as clenching and bruxism, emotional stress, anxiety, depression, sleep disturbances, abnormal muscle recruitment, occlusal characteristics, and disc or bony morphology. Epidemiological evidence indicates that TMDs are particularly common among adults aged 18-60 years, with a consistent female predominance. Individuals exposed to repetitive masticatory activities and high-stress occupations may also be at increased risk.

Normal orofacial function depends on coordinated activation of the jaw, tongue, lips, cheeks, palate, pharyngeal, and laryngeal muscles. Orofacial Myofunctional Therapy (OMT) consists of individualized oral and peri-oral exercises designed to retrain muscle function and improve the coordination of the stomatognathic system. OMT may promote appropriate tongue posture, nasal breathing, lip seal, swallowing, mastication, and jaw-muscle coordination. Although OMT has demonstrated benefits in several orofacial conditions, its specific role in TMD, particularly ADDwR, remains insufficiently explored. The TMJ also has a close anatomical and neurophysiological relationship with the cervical spine. Cervical muscles contribute to head stabilization during chewing, swallowing, speaking, and breathing, while convergence between trigeminal and cervical sensory pathways can facilitate pain referral between the neck and craniofacial region. Consequently, cervical postural abnormalities, instability, and impaired neuromuscular control may contribute to mandibular dysfunction and TMJ-related pain. Cervical stabilization exercises (CSE) may therefore complement OMT by improving deep cervical muscle activation, reducing excessive superficial muscle activity, and enhancing overall neuromuscular control.

Current research suggests that OMT may improve pain, oral function, muscle activity, and other functional outcomes; however, the evidence remains inconclusive because many studies involve heterogeneous TMD populations, small samples, methodological limitations, combined interventions, and potential placebo effects. Most previous research has also failed to focus specifically on joint-level characteristics such as disc position, reduction mechanics, and condylar-disc coordination. Therefore, a diagnostically precise investigation of patients with ADDwR is warranted. Examining OMT combined with cervical stabilization may provide a more comprehensive rehabilitation approach by addressing both local orofacial dysfunction and associated cervical impairments. Such an integrated intervention could improve mandibular function, muscle coordination, pain, and overall TMJ-related disability. Further high-quality research is therefore needed to establish the effectiveness of combined OMT and cervical stabilization specifically in patients with ADDwR and to guide evidence-based, outcome-oriented management of this common condition.