Postoperative inferior alveolar nerve paresthesia and impacted third molar distance to the mandibular canal

The goals of this study were to assess the incidence of inferior alveolar nerve (IAN) paresthesia after impacted lower third molars extraction and to observe the distance between them and the mandibular canal (MC) cortical using cone beam computed tomography (CBCT). For this study, 29 patients with both impacted lower third molars (totaling 58 teeth) were selected. They initially underwent clinical examination and evaluation of preoperative sensory condition according to standard protocol for nerve injury. Subsequently, they underwent CBCT and third molar extraction at the Oral and Maxillofacial Surgery Residency Program from the Western Paraná State University. On the seventh postoperative day, they were submitted again to the sensory analysis protocol to check for IAN paresthesia. In CBCT, the distance between the MC cortical bone and the tooth was determined by the arithmetic mean of the closest measurement of these two structures in each of the tomography three sections (axial, coronal and sagittal). There was one paresthesia case (1.72%) and regarding the CBCT, 57 third molars were in close contact with the MC. It was concluded that CBCT played an important role in surgical planning and it is believed that its use contributed to the considerably low IAN paresthesia rate.