Radiographic signs associated with inferior alveolar nerve damage following lower third molar extraction

Abstract

The aim was to carry out a literature review of preoperative radiographic signs in orthopantomography (OPG) and computed tomography (CT) related with the risk of inferior alveolar nerve damage during the surgical extraction of lower third molar (LTM). A search was made on PubMed for literature published between the years 2000 and 2009. In the reviewed literature, radiographic signs in the OPG that indicate a relationship between the LTM and the inferior alveolar canal are considered a risk factor for nerve damage. These signs are darkening and deflection of the root, and diversion and interruption in the white line of the canal. In the majority of these studies, the routine use of CT is not justified, and is only recommended when radiographic signs appear in the OPG that demonstrate a direct anatomical relationship between the LTM and the canal. In the CT, the absence of cortical bone in the canal implies a contact between the root of the LTM and the canal, and is related with the presence of some radiographic signs in the OPG. Some studies demonstrate that despite the absence of cortical bone, the risk of lesion or exposure of the nerve during the extraction of LTM was low.

Accuracy of Panoramic Radiograph in Assessment of the Relationship Between Mandibular Canal and Impacted Third Molars

“…Although panoramic images cannot provide three-dimensional information, numerous clinical studies [ 2 , 5 , 7 , 11 -13, 17 ] have been performed to determine panoramic findings suggestive of inferior alveolar nerve exposure or postoperative dysesthesia. In addition, many studies reported the panoramic findings that associated direct contact between inferior alveolar nerve and impacted third molar on computed tomography or cone-beam CT images [ 8 , 14 , 18 ].…”

“…Thus, it is important to evaluate the topographic relationship between the mandibular canal and impacted third molar preoperatively. There were reports [ 6 , 7 , 9 , 11 ] that showed the following 4 panoramic features were significantly associated with inferior alveolar nerve exposure following third molar extraction: interruption of mandibular canal, darkening of third molar root, diversion of mandibular canal and narrowing of third molar root. In addition, many studies reported that the interruption of mandibular canal was the most found panoramic feature that associated with direct contact between the two structures, which could be the risk of nerve injury and paraesthesia [ 2 , 6 , 8 , 12 ].…”

Correlation of panoramic radiographs and cone beam computed tomography in the assessment of a superimposed relationship between the mandibular canal and impacted third molars

“…In contrast, it has been shown that the darkening of the root can even present as the evidence of thinning of the lingual cortical plate without root grooves 12. The interruption of the cortical line of the canal on panoramic radiograph was related to the absence of cortical bone on computed tomography (CT) image 13. It has been reported that the absence of the cortical bone of the canal was closely related to the exposure of IAN 14…”

The Comparison of Anti-Inflammatory Effect in Two Methods of Topical Dexamethasone Injection and Topical Application of Ginger Aqua-Alcoholic Extract after Removing Mandibular Wisdom Teeth

“…In general, the most common problems after removing the wisdom tooth are complications such as pain, swelling, trismus, and the anesthetic of the lingual nerve, infection, etc. which occur due to the trauma to the tissue and the inflammation caused by it (3,4). Inflammation is the natural defense mechanism of the body to damage or cell death, which is characterized by redness, warmth, pain and swelling in the area (5).…”