Sir, accurate and timely written correspondence between orthodontists and referring dentists is essential, particularly when requesting extractions. In keeping with NHS guidance1 these letters are now commonly copied to the patient or parent. This has a number of advantages including improving a patient's understanding of the care they are receiving and empowering young people to take more responsibility for their own health.1,2 However, a recent incident with a shared case has cautioned us to rethink whether this is always desirable.

We referred a 12-year-old boy with autism spectrum disorder from our community-based specialist paediatric dentistry service to our hospital orthodontic department. The orthodontist wrote back requesting extraction of primary canines. Waking early during the school holidays our patient was first downstairs to find the post on the doormat. On seeing his own name on a letter addressed to 'Parent of...' he opened and read it, promptly deciding to complete the requested extractions himself. Fortunately, his sister heard him in the garage and removed a hammer from his hand before it was too late. His parents were understandably shaken and concerned. He was known to be anxious about the proposed extractions but no one had anticipated this scenario.

It can be difficult to judge children's level of understanding, especially in those who display limited verbal communication in the dental setting. This may result in risk of either under- or over-estimating a child's anxiety and ability to cope with treatment, even in the hands of experienced dentists.3 Self-extraction or other oral self-injurious behaviour has been described before in children with autism4,5,6 but not to our knowledge as a manifestation of dental anxiety about proposed treatment nor prompted by a copy of clinical correspondence.

As NHS services come under increasing pressure to deliver efficiency savings, a one-size-fits-all policy on copying correspondence to the patient appears to be an attractive solution with patients' information needs at its heart. However, our experience reminds us that we must never lose sight of getting to know our patients as individuals so that, whenever possible, we can predict the likely effect of our communication and take care to word individual letters accordingly.7 Furthermore it has prompted us to remember that it is good practice to obtain patient or parental consent to receive copy letters.1,7