Bio-Jva from Bio-Research remains a very important tool for all practices to use. At my practice 90% of patients are scanned with JVA for their TMJ health, says Dr. Sanjay Arora.
Joint Vibrational Analyser (JVA) – A very simple principle:
The global positioning system (GPS) has revolutionized the way people travel, whether it is by air, water or land. This system precisely directs users to their geographic destinations. Today, dentists have a similar advantage, the opportunity for clinical predictability as a result of the advancements in diagnostic and restorative technology.
Bio-JVA (Joint Vibration Analysis) is based on simple principles of motion and friction: When smooth surfaces glide against each other – muffled soft sounds are produced. If these surfaces become rough, then friction and vibration are created.
JVA records
BioJVA Fast and Accurate
Understanding TMJ function is vital anytime you are changing the vertical, lateral or A/P position of the mandible. Common treatments that change mandibular position such as TMD treatment, Orthodontics, Prosthodontics, Reconstruction and Sleep Dentistry can all from JVA testing.
How it works?
Human joints have surfaces which rub together in function. Smooth, well lubricated surfaces in a proper biomechanical relationship produce little friction and little vibration. But surface changes, such as those caused by degeneration, tears or displacements of the disk, generally produce friction and vibration. Different disorders can produce different vibration patterns or “signatures”. PC-assisted digital vibration analysis helps identify these patterns and helps you distinguish among various TM disorders.
Computer-assisted digital vibration analysis, recorded by accelero- meters rather than a microphone (sonography), identifies these patterns more accurately and predictably to distinguish among various TMD’s.
BioJVA/JT-3D
The wavelet transform view provides a 3D visualization of the marked episodes and the recorded frictional energy being generated during the episode for easy interpretation and patient explanation of the diagnosis.
JVA Interpretation
Physics and Engineering Perspective
Only two types of vibrations exist in the TMJ, one with resonance related to movement of the disk and the other randomized or a combination of the two. A physical body tends to vibrate at its resonant frequency and the other vibrations are the result of movement against rough surface.
In jaw joint, there is a condyle disc assembly. The disc displaces and reduces causing a resonant frequency of about 60-100 Hz. Joint is surrounded by soft tissue, this soft tissue absorbs the vibration and because of soft tissue, these vibrations are damped (do not last very long). A unilateral disc displacement with reduction (DDR) alters the normal pathways of the condyles on both sides, meaning on the normal side too. This can lead to roughening of the cartilage even on the normal side.
Longer vibrations occur with degeneration in the joint. If friction increases in the joint, it means there has been cartilage damage. During the progression of disease the vibration amplitude increases. When there is no reduction and the perforation of disc or the retrodiscal tissue takes place, bone rubs against bone and causes the increase in vibration amplitude. But when bone becomes smooth, there is comparatively less noise or the vibration amplitude is reduced. Thus, the cycle of the noise spectrum in the progressive disease in the joint will be from a quiet joint (normal), to a noisy joint (disk displacement with reduction), to very noisy (with perforation) , to less noisy (increasing chronicity) and back to quiet (end stage of the disease). This cycle follows Piper’s classification of events from Stage I to Stage V with TMJ internal derangements.
Disc Displacement
Biomechanical Stand Point
When the jaw joint is excessively loaded by the system, which generally is through the teeth, the disc will tend to balance out or equalize the imbalance of applied forces by displacing. In this way the temporomandibular joint adapts by partial or complete disc displacement. It’s simple that imbalanced forces applied to the disc will cause displacement. If the joint forces are equalized by disc displacement, the patient adapts to that condition and there is no further progression of disease. However, if a partial or complete disc displacement does not balance the forces, the disease progresses to the next stage.
The disc displaces and remains displaced in some cases, causing the posterior attached tissue come over the condyle and causes pain since this retrodiscal tissue has extensive innervation and is vascular. Ultimately, this retrodiscal tissue becomes scar tissue and may act as pseudo disc. Then, usually the patient gradually regains a near normal range of motion (good adaptation). In other patients with disc displacement without reduction, the retro-discal tissue is destroyed and the condyle rubs against the eminence (poor adaptation). This type of patient progresses into arthritis.
A vascular necrosis of head of condyle can occur due to disc displacement without reduction by impinging the blood supply. This necrosis may be bilateral or unilateral and is seen as a collapse of the condylar head without erosion of the overlying cartilage. If it occurs in young age, it is even more detrimental as it can affect the normal growth and development of the masticatory system.
JVA records a stable condition as a reference in real time to determine the condition of the jaw in the future. It can determine if a vibration occurs first on the left or on the right and which side is a bigger event. JVA can determine how much of a vibration from one joint is being transferred to the other joint. This allows JVA to determine if there is anterior disc displacement with reduction, anterior medial disc displacement with reduction or a medial disc displacement with reduction. This is done by calculating the percentage of vibration transfer to the opposite joint. If the transfer to the other joint is below
33%, it’s an anterior disc displacement with reduction. Similarly, if the amount of transfer is between 33 to 66%, its an antero-medial disc displacement with reduction. For transfer of more than 66% of the vibration to the other joint means medial disc displacement with reduction.
When clinically evaluating a unilateral medial disc displacement with reduction by palpation, the vibration feels the same for both the sides because it is the same. When listening with a stethoscope, the vibrations sound the same too for the same reason. The human ear with its limitations cannot detect a difference of less than 3 decibels (a 50% increase in amplitude). Thus, even the patient will report that the vibration is occurring on the side that his or her ear is most sensitive. With a medial disc displacement with reduction we can’t palpate the difference, hear any difference or rely on the patient to tell us which side is reducing. So, JVA can tell us things which even our senses cannot.
Computer Shot of JVA