General endotracheal tube anesthesia (GETA) is administered for mentally retarded patients that need dental rehabilitation. GETA is done, in all patients, with routine monitoring of electrocardiography, blood pressure recording, pulse oximetry and end-tidal capnography. These measurements are also used indirectly to determine the depth of anesthesia and the anesthetic is titrated to prevent awareness during surgery and any subsequent recall

(1). In addition, a recently introduced functional electroencephalography (EEG)-based awareness monitor directly analyzes the brain wave pattern during anesthetic delivery and aids the anesthesiologist in maintaining the ideal depth of anesthesia. The EEG based monitor serves to prevent awareness and recall due to light anesthesia or prolonged recovery following deep anesthesia (2). This instrument, named the Bispectral Index Scale (BIS) monitor, is non-invasive and is approved by the Food & Drug Administration. However, the BIS monitor is not being used routinely during the anesthetic management of mentally retarded patients due to a belief that such monitoring would be inaccurate in this cohort of patients (3). This assumption lacks scientific validation. Our trial will investigate the usefulness of BIS monitoring in mentally retarded patients and document any correlation between the severity of mental retardation and BIS scoring during various phases of anesthesia, such as awake status and sedation prior to anesthesia, induction and maintenance of anesthesia, and emergence and recovery from anesthesia. The anesthetic protocol will be standardized and the anesthetic management will not deviate from routine practice. The adjuvant therapies for infection prophylaxis and pain control will be administered in the usual fashion.