Unintended changes to the occlusion following the provision of night guards.

A review of the literature on night guards left questions unanswered about the risk and possible causes of occlusal derangement linked to night guard design and use. Cases are presented where night guard use resulted in anterior open bite and associated occlusal derangement. The aetiology of the occlusal changes observed is discussed. It is concluded that adverse occlusal effects linked to the use of night guards may be found to be more common than anticipated from existing literature. Patient follow-up is essential to monitor the use and effects of night guards, and regardless of appliance type, unintended occlusal changes may result. The use and effects of partial coverage appliances require very careful monitoring. Suggestions are provided for information and written instructions to be given to patients provided with night guards and removable orthodontic retainers.