Conscious sedation is a minimally depressed level of consciousness that retains the patient's ability to maintain the airway continuously and to respond appropriately to physical stimulation and verbal command at any time, produced by a pharmacologic or nonpharmacologic method or a combination thereof. In dental anesthesia, a state of sedation in which the conscious patient is rendered free of fear, apprehension, and anxiety through the use of pharmacologic agents. Midazolam is a useful drug of benzodiazepine on minor operation of dentistry. The purpose of this study is to estimate the appropriate dosage protocol of midazolam to the patient receiving intravenous sedation at the department of oral and maxillofacial surgery.

Total subject was fifty-one patients and fifteen patients of this subject were decided to control group (Group I) that they were not received intravenous sedation. The experimental group was randomly subdivided into two groups and each of those groups was administrated to 0.05 mg/kg (Group II) and 0.08 mg/kg (Group III) each other. All patients of the subject were surveyed with postoperative one day questionaire to evaluate the level of sedation.

In view of antegrade amnesia,

1. Group II and III were statistically different compared to Group I, respectively.

2. Group II and III were not statistically different.

Apparent antegrade amnesia was found in both groups 0.05 mg/kg and 0.08 mg/kg intravenously administered. So we present the protocol of the department of oval and maxillofacial surgery, Kangnung National University Dental Hospital. But further studies concerning patient's age, body weight, and general condition will be carried out.