Sir, I read with interest B.Littler's letter 'Phantom Bite revisited' (BDJ 2005, 198: 149). Dr. Litter quite rightly states that we should focus on the cause, which is clenching and the lack of proprioceptive feedback.

A patient's perception of his bite is a result of the proprioception from his masticatory system. This involves receptors in the temporo mandibular joint, muscles of mastication and in the periodontal membrane. High filling, whiplash injury causing disc displacement in the temporo mandibular joint or trauma to any of the masticatory muscles can cause this. Usually the patient's ability to adapt resolves this matter, with or without a little help from his dentist. I have observed that the muscles of patients who have a parafunctional habit eg clenching/grinding of the teeth are “hypersensitive”. These can eventually, though not always lead to symptoms of TMD. These are the patients who may develop the phantom bite. The initiating cause may have been a visit to the dentist. Even keeping the mouth open for a long time can cause the “hypersensitive” muscles to go beyond the adaptability of the patient, and the phantom bite develops. If we can relax these sensitive muscles, the patient will start to accept his bite. Two case studies illustrate this phenomenon.

Patient A had a full upper denture made and found that when she wore this denture it caused her considerable facial pain and could not wear it for more than 30 minutes. Examination showed that the vertical dimension had been opened 7 mm beyond the resting vertical position. All the muscles of mastication were extremely tender.

Although the increased vertical dimension had improved the face aesthetically according to the Golden Proportion Rule, she felt that her bite wasn't right and her teeth didn't meet properly and this was causing all the facial pain.

I made her a pivot appliance causing the vertical to open by another 5mm. The patient was made aware of her clenching habits and taught by biofeedback to maintain a freeway space at all times. Within a month there was a dramatic improvement in her muscles. The patient found it difficult to be without her upper denture, and now no longer needs to wear the pivot appliance and her bite is no longer a problem.

Patient B, a patient with full dentition came in complaining of his bite being wrong and having difficulty in chewing and constantly biting his cheek and tongue.

Examination showed decreased lower facial height and very tender muscles of mastication. A pivot appliance was made, which initially made the symptoms worse, but gradually by controlling the clenching with biofeedback, and carefully monitoring the use of the pivot appliance, there was an improvement in the muscles of mastication. The patient no longer feels that his bite is wrong, his muscles look much more relaxed and his facial features look aesthetically more pleasing.

I hope these two cases illustrate the fact that we shouldn't readily refer patients for psychiatric treatment until all other methods have been tried. Biofeedback and pivot appliance give very good results.