August 30, 2020
The dental profession involves a lot of treatment and laboratory procedures where an individual utilizes various motorized instruments that carry a certain frequency of vibrations. These vibrations are transmitted to the dentist or the dental technician's hand at a regular basis for prolonged hours owing to their profession. So can these vibrations be harmful in any way?
Vibrations from motorized dental equipment may or may not cause a damage to the dominant hand. But if they do cause a severe damage, then it leads to Hand-Arm Vibration Syndrome (HAVS). The prevalence of this syndrome is rare, even in the dental sector. But when it occurs, it can result in permanent damage.
HAVS is classified as an occupational condition. It is a challenging disorder for doctors as well, since there is no particular test to diagnose it. The only way to conclude that an individual is a victim of HAVS is by the method of exclusion. Several tests need to be conducted including a thorough history of occupation in order to single out Hand-Arm Vibration Syndrome.
Transmission of motorized vibrations to the dominant hand can cause damage to the nerves and the blood vessels of the hand. Vibration frequencies between 8 Hz to 300 Hz can adversely affect the fingers and the hand. Frequencies in this range causes the tips of the fingers turn white, which due to lack of blood supply. This is known as blanching. The extent of blanching is so much, that it gave HAVS a synonym - "Vibration induced White Fingers." When blood tries to flow back in those areas it causes a feeling of numbness in this region. Thus, tingling, numbness and blanching are the initial signs of HAVS. These episodes of numbness can range from 5 minutes to 30 minutes.
Even though these initial signs of Hand-Arm Vibration Syndrome do not seem too suggestive of a syndrome initially, it is important to note that HAVS can develop immediately or even decades later. Researchers are yet to confirm the particular onset of HAVS. The severity of this syndrome increases when the nerves of the hand get damaged. High frequency vibrations affect the nerves, initially causing loss of dexterity and later deteriorating the sensation of touch. The affected fingers if left untreated can lead to cell death and eventual gangrene.
There are reported cases of victims of HAVS developing a blockage in the arteries of the affected hand. Other comorbidities like a weak grasp, inflammation of the tendons, carpal tunnel syndrome, bone cysts, limited motion of the arms and painful sensations are commonly observed.
HAVS affects not only dentists but also electricians, welders, construction site workers and all those professions which utilize vibration producing motorized instruments. In dentistry, dental tools like hand pieces, hand-held burnisher, milling and grinding instruments are the commonly used high vibration producing equipment. In dentistry more than dentists, dental technicians are at a greater risk of developing HAVS.
In order to prevent the development of Hand-Arm Vibration Syndrome, it is important for these workers to take regular breaks while using those instruments. Moreover, the frequency of vibrations should be adjusted to a lower scale during prolonged work. It is also recommended for these workers to wear protective clothing on the hands. This is done to keep the hands warm, as cold environments can contribute to the numbness of the digits and the arm. Furthermore, these industries should always try to utilize alternative machineries to hand-held vibrational devices.
It is still in question whether HAVS can be reversed to a normal condition. Even if there are improvements, these take place at a slower pace over a long period of time. If the nerves are affected, the condition is irreversible. So how do healthcare professionals deal with HAVS?
The most commonly prescribed drug is Nifedipine. However, it is not a definitive treatment for HAVS. At times, a surgical approach may be aimed at. But such an approach does not cure the condition but only regresses its severity. It is advised that individuals with HAVS should immediately cease smoking. This is because smoking affects the blood flow and can further worsen the condition.
Hand-Arm Vibration Syndrome is a condition that was recognized in the late 1910s. Since then, any machinery utilizing motorized vibrations is given two values. One value which signals a time when the machine's vibration needs to be reduced (Exposure Action Value) and another value which standardizes a time for each machine after which it should not be used (Exposure Limit Value). Thus, these values, specific to each machinery, should be strictly followed by every occupation in order to prevent themselves from being a victim of HAVS.