Abstract

This paper documents three practical techniques which make caring for children and special needs patients so much easier that the author calls them “Magic Bullets”. The first involves using a Broxodent electric toothbrush as a source of vibration for stimulating pressure receptors in the periodontal ligament and bone while at the same time providing counter-stimulation in the hand in order to reduce the perception of injection discomfort. The second is the use of a reduction handpiece that allows burs to rotate at speeds as slow as 1 revolution per second. This allows excavation of dentinal caries with no or a minimum of discomfort when counter stimulation is used in the hand. The use of a kit with this handpiece and a Broxodent electric toothbrush has resulted in many children who would otherwise need “one complete treatment” under a general anaesthetic being treated in the dental clinic without sedation. The third is the use of an acrylic finger-cot worn under the glove on the third or fourth finger of either or both hands. This allows the mouth to be examined in patients who might otherwise need heavy sedation or a general anaesthetic just to examine their teeth.

Introduction

For most of my dental career I have been caring for people with special needs, and in what follows I would like to offer three techniques that one can arm oneself with to make some very difficult situations so much easier to manage. Hence the title of my presentation.

Magic Bullet No.1

Strange as it may seem, the first is a non-threatening domestic gadget – an electric toothbrush. The Broxodent Klassic is a mains-powered motorised toothbrush which oscillates at 50 or 60 cycles per second (depending on the country one is in), which is simply the frequency of AC current. It provides a source of intense vibration which is almost universally interpreted by people as being pleasant. It is easily placed in a hand or the mouth, and is safe in a wet environment. As well, the heads are autoclavable, and don’t break when suddenly bitten on as they might be with cerebral palsy children or head injury patients. More importantly, biting on the brush does not stop the vibration or wreck the motor unit.

Previously I have presented papers on the use of a Broxodent toothbrush to provide counter-stimulation to stop pathological chewing in a semi-conscious man when his pharynx was suctioned, as well as its use in the desensitisation of a severely tactile defensive child so that he accepted regular dental care.

Today I want to offer a very simple technique that makes local anaesthesia much more pleasant because it is almost imperceptible. Among children with severe developmental delay I had noticed that reaction to touch in the mouth was reduced if a Broxodent toothbrush was put in their hands and switched on. It also stopped children with severe developmental delay from flicking their heads from side to side when the face was touched. A number of the adults I saw who had developmental delay were referred to me because they refused to have local anaesthetic for their dental treatment, especially inferior dental clocks and anterior injections. By using the technique I am about to show you they accepted local anaesthesia without sedation, and have been treated like this since then. But first some background.

The “Gate-control” theory of Melzack and Wall (1965) postulates that stimulation of larger diameter fibres (e.g. using appropriate pressure or vibration) can close the neural “gate” so that the central perception of itch and pain is reduced. They note (p976) that, “The stimulation of a single tooth results in the eventual activation of no less than five distinct brain-stem pathways.” Two of these pathways go on to consciousness in the sensory cortex, and the other three go on to the thalamic reticular formation and limbic system – in other words to the emotional control centre of the brain.

Since more than a third of the cells in the cerebral cortex are devoted to sensory inputs from the mouth (Barr 1979), it follows that dentists work in one of the most sensitive areas of the body. Furthermore, it also helps to explain why it may only take one traumatic experience at the dentist to produce an on-going anxiety or even phobia about dental care. Furthermore, since a third of the cells in the sensory cortex are devoted to the hand, especially the palm and thumb, it also helps to explain the effectiveness of holding a source of vibration in the hand as a counterstimulation when touching the mouth and teeth.

Vibration has been used to reduce the perception of itch (Melzack and Shecter, 1965); raise the pain threshold (Ekblom et. al. 1982; Pantaleo et. al. 1986; Sherer et. al. 1986); for successful relief of acute or chronic pain using vibration with moderate pressure for about 20-30 minutes with frequencies between 50 and 200 cycles per second (Lundeberg et. al. 1984, 1988); for relief of pain of dental origin whether pulpal, periodontal, or post-surgical (Ottoson 1981); and for the relief of chronic intractable orofacial pain (Lundeberg et al 1983).

Interestingly, recent research (Guieu et al 1994) has shown that the analgesic effects observed during the application of vibration and the pain relief which sometimes persists for several hours afterwards is not related to the release of endogenous opioids.

In 1983 Lundeberg, Ottosen, and others from the Karolinska Institute in Sweden reported that pain reduction was greatest if the source of vibration was applied within the area directly affected by pain, and when the firmness of application stimulated the underlying bone. (p556) They noted, “… if this area was located in the region corresponding to the area innervated by the right second trigeminal branch, little or no effect was obtained if stimulation was applied in the area of the first or third branch or contralaterally.”

They also reported that several lines of evidence suggested that the pain-alleviating effect observed in their study was not a result of placebo effects. Thus pain reduction was only observed when the stimulation was applied in the painful region (Lundeberg et al 1983).

The question that occurred to me was whether stimulating the pressure receptors in the periodontal ligament and bone at the time of injecting while at the same time providing for counterstimulation in the hand would make a difference to how people perceived the local anaesthetic. In practical terms I found it did.

Topical anaesthetic, warmed solution, slow injection technique are assumed as givens. All the time the patient is also holding the brush with one hand. There are three basic ways that vibration is applied to the mouth:-

1. The patient bites on a vibrating toothbrush head so that the tooth immediately above the injection site is stimulated. The brush head is angled or comes across from the other side of the mouth so that the operator’s vision is not blocked.(vestibular, interdental, and intra-ligamentary injections)

2. The patient bites on a vibrating Broxodent motor unit wrapped in a plastic sleeve (Palatal injections) Usually it is more effective to infiltrate through the interdental papilla applying the brush head as in 1. above. I have found this is the least effective way to use the Broxodent.

3. The patient pushes a vibrating Broxodent motor unit firmly against the lower border of mandible for inferior dental blocks on the same side as the injection. The vibration should be felt by the operator when palpating the fossa prior to injection.

Magic Bullet No. 2

In the school dental service we provide a kit to therapists who want to treat young children who may be frightened of local anaesthetic.

The kit consists of a Broxodent electric toothbrush and the second “magic bullet”, an ultra-slow handpiece with a 7.4:1 reducing shank and a 10:1 reducing head. This rotates as slow as one rev per second or 60 – 200 revs per minute. This allows excavation of caries with no or minimum discomfort with a new or tungsten carbide (TC) bur. Lighter pressure can be applied than with hand excavators which may create osmotic changes under carious dentine which are painful. It is equivalent to an upbeat Atraumatic Restorative Technique (ART) technique. It is perceived as non-threatening and preferred to faster “low-speed” handpieces and is used in conjunction with a switched-on Broxodent electric toothbrush in the hand as a counter-stimulation. I set the Kavo 181M Airmotors used by the School Dental Service to the lowest quarter of the speed range. I use this technique for excavating root caries, and for excavating carious lesions on young children who have a fear of needles and whom anaesthetists may be very reluctant to give general anaesthesia to unless their condition is already life-threatening.

Sam was such a child. He had had 4 open heart operations, is on long term anticoagulants, and had had a CVA as a result of a hospital registrar not adjusting his anticoagulants when he had oral antibiotics. As a result of this incident, his mother was very suspicious of professionals and still felt angry about what had happened when I met them both. Sam was a 4 year old child frightened of all people in hospital settings, and had a particular fear of needles. Unfortunately, he also had an early childhood caries (ECC) pattern of decay with mostly upper teeth affected (Tinanoff 1998). Unbeknown to me, Mum took this video of Sam in the waiting room at his very last appointment for dental treatment. I had introduced the ultra-slow handpiece to him as Mr Bump a character from the Mr Men series of children’s books (Hargreaves 1971). “What’s Peter going to do?” his mother asked as she videoed. Sam had this to say: “He’s going to drill my teeth! Mr…..Mr Bump! He goes flip-flop, flip-flop all over my teeth.” He showed no fear, and regarded me as his friend who lived down the corridor in the dental surgery.

One of the experienced dental therapists in our service who uses the ultra-slow kit regularly comments: “I estimate that in the first six months of this year I would have treated 10-12 children who otherwise would have needed a general anaesthetic. I use it every week and regard it as indispensable now.”

Magic Bullet No. 3

The third “Magic Bullet” is an acrylic finger cot that I referred to in passing last year (Dennison et al In Press).

I usually wear it under my glove on 3rd finger of either or both hands. Sometimes I use ones made for the 4th finger. The finger-cot still enables me to use the finger and thumb in hand which the patient is biting on. It has the big advantage of not dislodging when mouth opens, or the patient moves the jaws protrusively. They are easily bagged and put through an autoclave after use. It is particularly useful if an adult has developmental delay and the mouth cannot be easily examined.

Jessica, not her real name, was just such a child. She was booked for a general anaesthetic just to examine her mouth. With her mother’s cooperation I had a really good look around her mouth using the Broxodent for counter stimulation, using an acrylic finger cot, and a fibre-optic light source. She needed no treatment, not even a scale. I have used this with to provide restorative dental care to cerebral palsy children, head injury patients, and people such as Bev who has terminal primary progressive multiple sclerosis. All of these groups tend to clamp their teeth together with fearsome force.

The acrylic finger-cot is made of light-cured methacrylate baseplate which is moulded around tightly fitting glove on finger (usually third). Initially it is cured in an ultraviolet light box (the finger is removed when the finger cot has cured enough not to deform). Then the finger cot is completely cured in a pressure pot, bagged and autoclaved. Autoclaving also removes any residual traces of methacrylate monomer. So far the finger cots have not collapsed, but I have felt them flexing sometimes!

Summary

I summary, the three items mentioned here tend to be used in my practice again and again.

There would be loud protests if the first two were unavailable within the School Dental Service. The therapists were naturally sceptical at first. Now all who have used it would like their own kit. The down side is the relatively high expense of the handpieces – around $600-$800NZ. As for the humble methyl methacrylate finger cots – without them I would be unable to do many examinations on special needs patients without heavy sedation or general anaesthesia. And in a hospital costs for this start around $600 for theatre.

Because their effectiveness far exceeds their humble appearance, I have called them three “Magic Bullets”.

References

Barr M.L.: The Human Nervous System – an anatomic viewpoint New York; Harper and Row, 1979. (3rd Edition)

Dennison PJ and Walton-Jones A: The use of a neoprene “thumb-sock” to prevent trauma in a thumb-sucking child with intractable epilepsy: A case report Spec Care in Dentistry (In Press)

Ekblom A., and Hansson P.: Effects of vibratory stimulation on pain threshold of the human tooth. Acta Physiol Scand 114: 600-604, 1982.

Guieu R., Tardy-Gervet M.F., and Giraud P.: Met-enkephalin and beta-endorphin are not involved in the analgesic action of transcutaneous vibratory stimulation Pain 48: 83-88, 1992.

Hargreaves R: Mr Bump London: Thurman Publishing Ltd. 1971.

Lundeberg T., Nordemar R., and Ottoson D.: Pain alleviation by vibratory stimulation.Pain 20: 25-44, 1984.

Lundeberg T., Abrahamsson P., Bondesson L., and Haker E.:Effect of vibratory stimulation on experimental and clinical pain.

Scand. J. Rehab. Med. 20: 149-159, 1988.

Lundeberg T., Ottoson D., Hakansson S., and Meyerson B.A.:Vibratory stimulation for the control of intractable chronic orofacial pain. Advances in Pain Research and Therapy 5: 555-561, 1983.

Melzack R., and Wall P.D.:Pain mechanisms: a new theory.Science 150: 971-979, 1965.

Ottoson D., Ekblom A., and Hansson P.:Vibratory stimulation for the relief of pain of dental origin. Pain 10: 37-45, 1981.

Pantaleo T., Duranti R., and Bellini F.:Effects of vibratory stimulation on muscular pain threshold and blink response in human subjects. Pain 24: 239-250, 1986.

Sherer C.L., Clelland J.A., O’Sullivan P., Doleys D.M., and Canan B.:The effect of two sites of high frequency vibration on cutaneous pain threshold. Pain 25: 133-138, 1986.

Tinanoff N (Editor): Proceedings: Conference on early childhood caries. Bethesda, maryland, USA October 1997. Community Dent Oral Epidemiol 26: Supplement No. 1, 1998.

Peter Dennison
Specialist in Community Dentistry
e-mail: peter.dennison@hvh.co.nz

Ph: 00-64-4-570-0293
Fax 00-64-4-570-4456