History of N.D. - ICCMO.IT

PROFESSIONAL EDUCATION FOR DENTISTS
THE GENESIS OF NEUROMUSCULAR DENTISTRY

In 1967, Dr. Bernard Jankelson introduced the term Neuromuscular Dentistry to the dental profession. The masticatory system is a three-dimensional structure composed of teeth, temporomandibular joints (TMJs), and muscles. Without muscle activity, this system remains static and non-functional. Neuromuscular dentistry views the masticatory system as a dynamic apparatus governed by universal anatomical and physiological principles.

At the time, however, dentists lacked the tools and protocols necessary to objectively evaluate masticatory muscle function or dysfunction—or to predictably restore muscles to optimal function. Despite widespread consensus that approximately 90% of temporomandibular disorders (TMDs) are myogenous in origin, the dental field operated primarily in a two-dimensional realm, focusing on teeth and joints. It wasn't until new measurement technologies were developed that the essential muscle component could be quantitatively evaluated. Neuromuscular dentistry ushered in a three-dimensional approach—one that includes muscles as a central element.

The story of neuromuscular dentistry begins with a lesser-known chapter in Dr. Bernard Jankelson’s life. Known affectionately as “Dr. J” by his peers, his interest in neuromuscular medicine began in the early 1940s when his wife, Cherub, developed symptoms of a neuromuscular disorder—muscle weakness, vertigo, visual disturbances, and other non-specific signs. Dr. Jankelson embarked on a global search for answers, eventually connecting with Dr. Jonez, a physician at St. Joseph Hospital in Tacoma, who diagnosed Cherub with what we now know as multiple sclerosis.

With no known treatment available, Drs. Jonez and Jankelson theorized that the issue stemmed from degenerative changes in the myelin sheath that impaired electrical conduction in nerves. They hypothesized that since myelin consumes high levels of oxygen, increasing oxygen delivery to nerve tissue might slow degeneration. Dr. Jankelson pursued this theory alongside physicians and physiologists at the University of Washington and University of Oregon. Whether through treatment, luck, or love, Cherub went on to live a full and happy life until the age of 86.

This early foray into neuromuscular research laid the foundation for a major breakthrough in the 1960s, when Dr. Jankelson collaborated with renowned muscle physiologist Dr. H.H. Dixon at the University of Oregon. Together, they explored how low-frequency transcutaneous electrical nerve stimulation (TENS) could change muscle resting states and metabolism—a breakthrough that aligned dentistry with modern medical technology.

Dixon established the electrical parameters, and Jankelson devised a way to stimulate the Trigeminal (V) and Facial (VII) cranial nerves through the coronoid notch. This was the first time dentists had the technology to directly alter masticatory muscle states to aid in diagnosis and treatment.

In 1970, Dr. Jankelson brought together a team of former Boeing and biomedical engineers to develop jaw-tracking instrumentation. In 1974, the first clinical jaw-tracking device was introduced, using a small magnet placed on the lower incisors to track jaw movement in three dimensions and provide objective data for diagnosing occlusal-mandibular dysfunction.

To further advance diagnosis, technology to monitor masticatory muscle activity in both resting and functional states became essential. In 1979, surface electromyography (sEMG)—a technique that records muscle action potentials—became available to clinicians. By 1987, real-time sEMG was integrated into computerized jaw tracking systems, allowing for a more accurate correlation between jaw position and muscle activity.

Thanks to Dr. Jankelson’s foresight and determination, neuromuscular dentistry now applies scientific principles and advanced technology to treat patients suffering from TMDs, complex restorative needs, edentulism, and orthodontic challenges. Treating occlusion as a dynamic, three-dimensional biological system allows for diagnoses and treatment outcomes previously unattainable.

Neuromuscular Dentistry relies on scientifically validated biomedical instruments to objectively assess physiological aspects of jaw function. It adheres to universal cellular, anatomical, and physiological principles—paralleling the scientific foundation of other medical disciplines.

Key tenets include:

Neuromuscular treatment protocols begin with reversible therapies. Only after the patient reaches a symptom-free, stable state—maintained for at least three months—should Phase II, irreversible restoration, be considered.

One common finding in TMD patients is posterior hypo-occlusion, or insufficient posterior support. This is initially corrected with a reversible oral appliance. Long-term restoration follows only after verifying, through objective measures and patient feedback, that the patient is stable and pain-free—aligning with ADA guidelines for TMD care.

Historically labeled "TMJ" or "TMJD," temporomandibular disorders are now understood to involve not just the joints but also the muscles, occlusion, and nervous system. These are functional disorders caused by imbalance in the intricate relationship between the jaw, skull, muscles, and nerves.

The stomatognathic system—comprising teeth, muscles, joints, and the nervous system—is intricately linked to the entire musculoskeletal system. Dysfunction in one part often affects others, while proper posture, airway health, and functional harmony promote systemic balance.

Although various occlusal philosophies exist, ICCMO endorses the neuromuscular approach. This physiological philosophy emphasizes aligning dental occlusion with balanced muscle function. Its application extends across complex restorative dentistry, orthodontics, and more.

Neuromuscular dentistry offers hope to TMD sufferers who have found little relief from conventional treatments. By integrating orthopedic principles with dynamic functional analysis, clinicians can now achieve more predictable outcomes.

Modern computerized diagnostics—tracking mandibular movement, TMJ sounds, muscle function, and occlusion—provide data-driven insights beyond subjective patient reports or clinical guesses.

Recognizing musculoskeletal indicators and interpreting patient symptoms allows for accurate diagnosis in both pain management and occlusal reconstruction. The initial stabilization phase involves identifying the physiologic rest position and establishing a stable therapeutic occlusion through fixed or removable orthotic appliances.

By eliminating harmful proprioceptive stimuli and objectively measuring muscle and postural responses, dentists can reduce strain on the trigeminal system—enhancing long-term health and function.

The importance of a physiologic, neuromuscularly balanced occlusion cannot be overstated in the effective treatment of TMD. With the aid of advanced diagnostics, proven principles, and a patient-centered approach, neuromuscular dentistry continues to elevate the standard of care in modern dental practice.