Background Dental injury as a result of oroendotracheal intubation during general anesthesia is very common. We report our experiences of using mouthguard to prevent dental injury during intubation based on our protocol. Methods This retrospective study enrolled patients referred for preanesthetic evaluation, those patients with a history of any of the dental treatments to their anterior teeth listed on our fabrication protocol from January 1, 2009 to June 30, 2010. Results No cases of dental trauma during oroendotracheal intubation were reported among the 202 patients who used a protective device. 66% of the patients had risk factors for hard tissue damage aged 10-40 years. At the ages of 40-70 years, the incidence of risk group for periodontal damage was higher. Conclusions Preanesthetic consultation was effective for preventing dental injury, so preanesthetic questionnaire and proper dental consultation would be helpful.