Collecting a verbal history
Sir, — We read the paper 'Introductory notes regarding a European Medical Risk Related History questionnaire (EMMRH) designed for use in dental practice' (British Dental Journal1998; 185: 445–448) with concern. The authors state that this self-administered health questionnaire 'would make dental treatment safer' and 'would be an effective method of history taking for the dentist'. These claims are given added credibility by their inclusion in the 'Practice' section of the Journal.
The research-based evidence would strongly suggest that self-administered health questionnaires alone cannot be trusted to yield accurate medical histories. Brady and Martinoff found that 32% of patients did not answer self-administered health questionnaires correctly.1 They stated that 'It cannot be assumed that dental patients provide valid health history information on the written self-administered health questionnaire'. Scully and Boyle found that a self-administered health questionnaire missed 32 out of 291 (11%) relevant medical histories.2 The validity of the European Medical Risk Related History questionnaire has been tested twice by groups which included one of the authors of the recent BDJ paper. In the first of these studies 7 out of 48 relevant medical histories (15%) were missed by the questionnaire.3 In the second, 14 out of 101 relevant medical histories (14%) were missed.4
As these questionnaires were tested on patients attending dental hospitals, the results may actually understate the problem. These patients, many of whom were attending oral medicine and oral surgery clinics, may have been more conscious of their health problems than patients attending a general dental practice. Our own experience suggests that self-administered health questionnaires in general dental practice miss 25% of relevant medical histories.5 A number of the patients whom we surveyed failed to provide essential significant information because they could not see the relevance of their conditions to the dentist.
The most valid method for assessment of relevant medical history is the structured verbal interview. The researchers who tested the validity of the European Medical Risk Related History questionnaire3, 4 described the verbal interview as the 'gold standard'.
The message for the readers of the BDJ must be that the best method for determining patients' medical status is careful verbal history. Self-administered health questionnaires, though possibly useful as an adjunct and as an aide memoire to patients, are insufficiently reliable for routine use and expose the patient to hazard and the dentist to possible medico-legal action.
M Fenlon
London
B McCartan
Dublin
The authors respond:We regret that the paper suggested to Doctors Fenlon and McCartan that a perfect medical history patient operated questionnaire was formulated or that the clinician's judgement should be superseded by such a procedure. If such an interpretation could be construed from reading our paper, we thank the writers for providing the opportunity to clarify any possible ambiguity. We appreciate that European dentists are currently not trained sufficiently in medicine to compete with the verbal history taken by an experienced physician. Neither are they given the financial resources to allow time for a proper medical history. In such a situation, a patient-administered questionnaire is surely safer than asking 'are you in good health?' which is the only method employed in some instances.
Regarding the methodological notes, we emphasise that aiming at an instrument that not only could, but would be used in general dental practice, practical considerations were as important to us as methodological. We understand that patients administration is less reliable than dentists, GPs or physicians filling in the form, but this is not feasible within existing health care and remuneration systems. We believe that the growing awareness in patients of physical health will improve the questionnaire's ability to reveal relevant medical data. The paper by de Jong et al referred to has been updated by the validity study recently undertaken. Secondly, de Jong showed that 7 out of 1782 questions were answered incorrectly (0.39%). Our Belgian partner published results in 1997 showing 1.6% of incorrect answers. Research published in the Netherlands Dental Journal (1998) and an article accepted by Preventive Medicine show that the Dutch version of the EMRRH is to be preferred to a Dutch general dental practitioner taking a verbal history. Finally, the EMRRH does not only record medical data, but also provides preventive measures, making it more effective in preventing medical calamities than other available instruments aimed at 'just' providing medical information.
Sign of the times
Sir, — Further to C H Walker's letter (British Dental Journal1999; 186: 104), I would like to submit my nomination for the BDJ Book of Records! In the 'Most unusual case of a traumatised upper central incisor' category, I saw a little girl some years ago who had fractured her tooth while biting her toe-nails.
R Evans
Abingdon
Carpal tunnel syndrome
Sir, — I was interested to read in the letters page (British Dental Journal1999; 186: 105), about your reader seemingly surprised to have carpal tunnel syndrome and warning younger dentists. All dental personnel should be aware of the potential problem.
Dental hygienists seem particularly vulnerable and Dental Health, the journal of the association, has carried articles in recent years alerting members to the syndrome — vol 28, no 4 and vol 31 no 5.
Some manufacturers of instruments are alert to carpal tunnel and gradually instruments are being made 'fatter', which is a start.
C Clitter
Camberley
Overcoming failed local anaesthesia
Sir, — I was very interested to read the paper ' How to overcome failed local anaesthesia' by J G Meechan (British Dental Journal1999; 186: 15–20). It is indeed a very well written article offering practical advice to general dental practitioners in the approach to overcoming local anaesthetic failure. However, I feel that the section on 'Barriers to anaesthetic diffusion' of the article deserves comment.
The first molar region in the adult maxilla has always presented with problems of anaesthesia due to the thick zygomatic buttress in this region, which prevents passage of the anaesthetic to the dental apices. The author's answer to this problem is to inject mesial and distal to the first molar away from the buttress (as the first molar can obtain supply from both posterior and middle superior alveolar nerves, a posterior alveolar nerve block may be unsuccessful).
However, a study of the posterior superior alveolar nerve block has been reported in which anaesthesia of all ipsilateral maxillary permanent molars was achieved without a supplementary local infiltration over the first molar.6 This was further re-evaluated by a documented series of cases.7
The regional nerve block described by Adatia (Dental Practit1968; 18: 321) is referred to as the maxillary molar nerve block instead of the posterior superior alveolar nerve block. It is widely taught at the Bristol University Open Learning Diploma course (BUOLD) to dentists studying oral surgery. This technique is quite simple to learn and has many advantages.
Adatia's maxillary nerve block is a relatively safe procedure, since it avoids the danger of haematoma formation associated with the conventional posterior superior alveolar nerve block technique. It achieves anaesthesia of all ipsilateral maxillary permanent molars without a need to give a supplemental infiltration over the mesio-buccal root of the first molar. Because of its ease, I use it routinely in my practice. A surprising finding is the incidental demonstration of anaesthesia of the premolars also.
I would be interested to hear comments from Mr Meechan regarding this. I would also be interested to hear about the experiences of other dental practitioners who may be using this technique.
A R Dhanji
Northolt
The author responds:I am grateful to Dr Dhanji for his kind comments on my recent article.8 He is not alone in his enthusiasm for the modification of the superior alveolar block technique described by Adatia.9 I know a number of practitioners champion this method. My opinion is that if it works for you, use it and inform your colleagues. I am sure there are a number of practitioners who have developed techniques which are effective and they should be encouraged to inform colleagues via the dental journals.
Some comment about the technique described in 1968 by Adatia is merited. The original method recommended the use of 26-gauge needles and noradrenaline-containing local anaesthetic solutions. Neither of these are routinely used or recommended in current UK practice. Finally, as Adatia notes, the method will not eliminate accessory pulpal supply from the greater palatine nerve, so occasionally palatal anaesthesia is needed to obtain satisfactory pain control in the pulp.
Saliva production
Sir, — During the late 1980s it was fashionable among ravers to wear a baby soother on a cord or chain around the neck. This originated in the use of 'dummies' to alleviate the dry mouth experienced by those who took Ecstasy.
The loss or reduction of buffering provided by saliva seems likely to be an important component in the type of tooth wear described in the letter by Murray and Wilson (British Dental Journal1998; 185: 264) and dental caries in those who resort to sugary drinks, which will have been observed by many general dental practitioners.
J P Murphy
Gravesend
Complete denture quality
Sir, — After reading Dr Hellyer' s letter (British Dental Journal1999; 186: 51), in which he expressed concern that the standard of prosthetic technology in the UK was poor, we read the letter's pages of subsequent copies of the BDJ with interest waiting for an outcry in protest. This did not come, so may we venture a defence ourselves?
The main support of Dr Hellyer's argument is a recent article by Kippax et al (British Dental Journal1998; 185: 189–133) in which technical work involving duplication of dentures was 'poorly produced' by a number of commercial laboratories (including one hospital laboratory — we hope it was not Sheffield) at prices ranging from £40–£75, 'with little understanding of the rationale behind the technique'. If the described work had been carried out at Sheffield Dental Hospital laboratory the charge would have been approximately £113, including the technician's salary, materials and laboratory overheads. That the work for the study had been carried out in commercial laboratories at such moderate prices makes you, to paraphrase Dr Johnson, not so much surprised that it is not done well, but surprised to find it done at all.
I suspect that Dr Kippax and his co-workers were also aware of this. Their research was perfectly objective, and after commenting on the quality of work their restrained conclusions were 'there is considerable scope for further training of technicians in this important technique'. A more general conclusion might be that conscientious GDPs and technicians have been trying to subsidise the production of complete dentures on the NHS for many years — to the complete satisfaction of our treasury paymasters.
D J Lamb
K Lee
Sheffield
Electronic dental discussion lists
Sir, — Further to the recent paper by Drs Muhumuza, Moles and Bedi, citing the use of 1% electronic mail by dental practitioners (British Dental Journal1999; 186: 131–133), dental teachers in dental schools, hospitals, community and general practice might be interested to learn of a new discussion list which has been launched by this dental school on the internet.
The new list is called 'dental-education' and is provided by Mailbase, a centrally-funded service located at Newcastle University which runs electronic discussion lists primarily for the UK academic community. However, the use of the dental-education list is not confined to academic staff, but is intended for all those involved or interested in dentistry and dental care education. It covers all levels of dental education (including dental auxiliaries) and provides a forum for discussion, exchange of ideas and information. Two other Mailbase lists which might be of interest to dental practitioners are 'dental-cal', a list dealing with computer aided learning and 'The use of IT in dentistry and dental-health', which deals with dental and oral health issues.
The mailbase list 'medical-education', which was established by one of us (MGB) three years ago, now has 307 members across the world and is used for a variety of purposes, including conference and meeting announcements, curriculum enquiries, and electronic research questionnaires. There are hundreds of other Mailbase discussion lists available to join which allow colleagues to talk with one another via electronic mail, to collaborate on projects, arrange meetings, or just to keep in touch.
More information is available about joining 'dental-education' and other Mailbase lists by using: http://www.mailbase.ac.ukldocs.
M G Brennan
M L Jones
Cardiff
