Objective: Adverse events due to long-term use of night guards have not been sufficiently elucidated. We herein report a case of occlusal changes in a patient who underwent continuous regular observations for at least 14 years since starting to use a night guard and discuss the precautions in the management of night guard use.
Case: A 50-year-old female, with the chief complaints of clenching, tongue ache, abrupt awakening, etc.
Results: A night guard for the upper jaw was fabricated, and shrinkage of the interdental space in the maxillary anterior region and occlusal changes （open bite） were observed after 12 years and 6 months of its continuous intermittent use. A new night guard for the lower jaw was also fabricated because the patient wanted to continue using it even after the observation. The patient has been using these night guards without any major worsening.
Conclusion: Night guards intended to prevent tooth abrasion, root fracture, or tongue pain from sleep-related bruxism may lead to adverse events. As with oral appliances, the fabrication process requires adequate consideration as well as regular and quantitative management.
