Audit on the success rate of functional appliance treatment

Functional appliance treatment is a very useful treatment modality for modifying jaw growth and correcting non-harmonious jaw relationships. This often allows treatment to be carried out without having to resort to dental extractions, which is an obvious advantage. The appliances are however necessarily bulky and difficult to acclimatise to and the success rate of this treatment is therefore lower than average. This audit aimed to establish what proportion of patients managed to wear their functional appliances sufficiently to achieve the desired outcome.

Out of a sample of 400 consecutive patients starting treatment, 29 patients had been prescribed a Twin Block functional appliance. Failure was defined as the discontinuation of treatment or the modification of the treatment plan to include an alternative to the functional appliance before the desired overjet reduction had occurred. The overall success rate for functional appliance treatment was 80% in one practice and 68% in the other. These figures compare favourably with other studies.

We discussed possible reasons for the differences between the two practices and suggested ways of trying to improve the success rate further and these have now been implemented. We plan to repeat this audit soon and with a larger sample size to determine whether there has been any improvement.