Sir, your editorial of the above title appearing in the British Dental Journal1 raises intriguing questions regarding the current expansion of dental practice taking place in North America. Professional courses are being offered as 'continuing dental education' by university-affiliated dental schools in 'Neuromodulators: cosmetic treatment of the upper face and bruxism'.

These courses are essentially the art and science of eliminating or diminishing the facial wrinkles of ageing. By precise administration of neuromodulators Botox, Dysport and Xeomin, these drugs cause paralysis of facial wrinkling muscles by preventing the release of the neurotransmitter, acetylcholine, at the neuromuscular junction of striated muscle, which produces 'chemical denervation', resulting in temporary paralysis of the muscles.

The temporary nature of the paralysis, lasting from three to six months is due to the re-establishment of neuromuscular transmission by the growth of axonal sprouts at the neural end-plate region. These new axonal sprouts then begin to release acetylcholine, restoring muscular function. The consequent recurrence of the wrinkles then requires re-administration of the drugs at regular intervals, ensuring regular 'maintenance' of the wrinkle-free state.

The traditional role of dentists as 'operators of the teeth' is now being expanded into cosmeticians, to which your editorial has drawn attention.