What is neuromuscular dentistry?

What is Neuromuscular Dentistry?

Neuromuscular dentistry is a dental approach that evaluates and treats the relationship between jaw position, occlusion (bite), and the neuromuscular function of the masticatory muscles, temporomandibular joint (TMJ), and their connections to the autonomic nervous system and overall body posture. 1, 2

Core Principles

Neuromuscular dentistry operates on the premise that optimal dental occlusion must account for the physiological resting position of the jaw muscles and their neurological control, rather than simply aligning teeth based on anatomical landmarks alone. 1, 3

• The field recognizes that the masticatory apparatus has intimate anatomical and functional relationships with the cranium, cervico-scapular muscular system, and autonomic nervous system. 1, 3
• Disorders in dental occlusion can manifest as temporomandibular disorders (TMD), headaches, neck pain, postural dysfunction, and even affect cerebral fluid circulation and gaze stabilization. 1, 3
• The sphenopalatine ganglion (SPG) plays an integral role in orofacial pain pathophysiology, supplying direct parasympathetic innervation to the trigeminal and facial nerves. 2

Diagnostic Methods

Surface electromyography (sEMG) is the primary diagnostic tool used to assess jaw muscle function and establish whether occlusion is neuromuscularly balanced. 4

• Normal reference values for healthy young adults with ideal occlusion show sEMG activity of 1.01-3.57 µV at rest, 3.50-10.85 µV during swallowing, and 41.04-86.59 µV during mastication in the temporalis and masseter muscles. 4
• During clenching, values reach 230.08-243.55 µV for the anterior temporalis and masseter muscles. 4
• Asymmetry indices, activity indices, and torque indices are calculated to identify muscular imbalances that may indicate occlusal disease. 4
• Mandibular kinematics are measured, including lateral excursion (7.54 mm), protrusive movement (8.44 mm), and maximum opening (37.38 mm) in healthy subjects. 4

Treatment Modalities

Ultra-low frequency transcutaneous electrical nerve stimulation (ULF-TENS) is employed to relax masticatory musculature and provide neuromodulation to the autonomic nervous system. 2

• ULF-TENS acts on the limbic system and hypothalamic-pituitary-adrenal (H-P-A) axis to address psychological and stress-related components of TMD. 2
• The technique directly affects the autonomic component of the trigeminal nerve involved in headaches, migraines, and myofascial disorders. 2
• Neuromuscular electrical stimulation (NMES) can be applied to manage dysphagia and TMD by targeting specific muscle groups. 5

Clinical Applications

Neuromuscular dentistry addresses multiple conditions beyond traditional dental concerns:

• Temporomandibular disorders (TMD): Caused by malocclusion, bruxism, stress, or trauma, affecting mastication, teeth, supporting structures, and quality of life. 1, 5
• Orofacial pain syndromes: Including trigeminal autonomic cephalalgias, jaw pain, sinus pain, and eye pain mediated through the SPG. 2
• Postural dysfunction: Due to the biomechanical interrelationship between occlusion and the cervico-scapular system. 1, 3
• Oro-pharyngeal dysphagia: Difficulty swallowing that can be addressed through NMES-based therapeutic regimens. 5

Critical Diagnostic Signs

Patients may present with occlusal disease manifesting as sensitive teeth, tired facial muscles upon waking, TMJ pain following dental restoration or extraction, headaches, or neck pain. 1

• The intimate relation of the masticatory apparatus with cranial and cervico-scapular systems means disorders in one system affect the others. 1
• Very few dentists can accurately diagnose occlusal disease, and many who do resort to overly aggressive treatment modalities. 1

Interdisciplinary Necessity

The neuromuscular approach requires extensive cooperation between dentists and physicians across multiple specialties. 3

• The influence of dental occlusion and TMJ status on general health necessitates collaboration with orthopedics, neurology, physical therapy, and speech-language pathology. 5, 3
• Many theoretical aspects of interdisciplinary relationships remain insufficiently examined, leaving practical consequences unclear and requiring further research. 3

Common Pitfalls

• Prioritizing esthetics over occlusion: While esthetic demands should not be undermined, occlusion/bite must be given prime importance in any dental treatment plan. 1
• Failure to recognize systemic manifestations: Occlusal problems can present as headaches, postural issues, or cervical pain rather than obvious dental symptoms. 1, 3
• Lack of evidence-based protocols: Many treatment regimens for TMD and related conditions lack proper evidence-based literature support, requiring caution in application. 5