Informed consent in oral surgery: the value of written information.

OBJECTIVE To evaluate the efficacy of the written explanation given to patients when obtaining informed consent for oral surgery, taking the surgical extraction of the impacted mandibular third molar as the clinical model for this study. PATIENTS AND METHODS This study included 87 patients requiring surgical extraction of an impacted lower third molar. Residents of the Oral Surgery Department explained verbally and in writing 7 possible complications that could arise as a result of the operation, after which informed consent was obtained from the patient. These complications were as follows: altered sensation of the homolateral lower lip and chin; altered sensation of the tongue; swelling; trismus; pain; allergies; and infection. The patients completed a Corah anxiety test on the same day, as well as a preoperative questionnaire about their level of understanding of the informed consent. Seven days after the operation, the patients returned to have their stitches removed and for a postoperative interview. RESULTS A total of 87 patients participated in the study. Of these, 64% (n = 56) had understood the objective of the informed consent. All but 1 (1%) of the patients remembered having been informed of the possible risks before the operation. Changes in sensation of homolateral lower lip and chin (98%, n = 85) and of the tongue (86%, n = 75) were among the complications most recalled by the patients. Ninety-six percent of patients (n = 84) preferred to be informed preoperatively, and 71% (n = 61) described the signs and symptoms to be exactly as explained by the residents. CONCLUSIONS Patients do not remember the majority of the information they receive before giving informed consent. Paresthesia of the lower lip and chin on the operated side and of the tongue are among the most recalled complications. This may be due to the seriousness of this complication, to the effect it can have on the patients' daily life, and to the possibility that it may be irreversible.