Original article Detecting direct inferior alveolar nerve – Third molar contact and canal decorticalization by cone-beam computed tomography to predict postoperative sensory impairment P. Bozkurt a, *, C. Go ¨ ru ¨ rgo ¨z b a Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Ankara University, Ankara, Turkey b Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara, Turkey 1. Introduction Injury to the inferior alveolar nerve (IAN) is one of the most undesirable complications encountered during third molar (M3) surgeries [1]. Patients may experience prolonged (< 1%) or transient (8%) neurosensory deficits that can interfere with speech, chewing, and social interactions, all of which affect quality of life [2,3]. A detailed radiological evaluation is vital to understanding the IAN-M3 relationship and preparing a surgical plan. Ortho- pantomography (OPT) has been most commonly used for this purpose, although the tendency in recent years has been toward making further radiological evaluations due to technological advances [1,2,4,5]. During the last few years, cone-beam computed tomography (CBCT) has been highly accepted in the dentomaxillofacial field. It enables the exploration of multiple planes with sub-millimetric resolution. It provides reliable and accurate information about the anatomy of the region and the IAN-M3 relationship and is currently the primary choice for planning complicated M3 surgeries [1,5,6]. Various anatomical determinants detected from CBCT images have been reported as risk factors for postoperative neurosensory deficits, including direct IAN-M3 contact and interruption of the mandibular canal border (decorticalization) [1,4]. Accurate deter- J Stomatol Oral Maxillofac Surg xxx (2019) xxx–xxx Abbreviations: CBCT, Cone-Beam Computed Tomography; IAN, Inferior Alveolar Nerve; IOPAR, Intra Oral Periapical Radiography; M3, Third Molar, OPT, Orthopantomography. * Corresponding author at: Ankara U ¨ niversitesi, Dis ¸ Hekimlig ˘i Faku ¨ ltesi, Ag ˘ız Dis ¸ ve C ¸ene Cerrahisi ABD, Emniyet Mahallesi, I ˙ ncitas ¸ Sokak Yenimahalle, Ankara, Turkey. E-mail address: poyzanbozkurt@hotmail.com (P. Bozkurt). A R T I C L E I N F O Article history: Received 19 April 2019 Accepted 8 July 2019 Keywords: Third molar tooth Nerve injury Inferior alveolar nerve Cone-beam computed tomography Anatomy A B S T R A C T Background: Injury to the inferior alveolar nerve (IAN) is a severe complication of third molar (M3) surgeries that may interfere with speech, chewing, and social interactions, all of which affect quality of life. Factors such as direct IAN-M3 contact and interruption of the mandibular canal border (decorticalization) diagnosed from cone-beam computed tomography (CBCT) images have been reported as risk factors, although their relation to postoperative sensory impairment is controversial. The purpose of this study was to assess the association between postoperative nerve injury and direct contact between IAN and M3 or canal decorticalization defined with CBCT. Materials and methods: Seventy-five patients with at least one M3 tooth (total of 126 teeth) in direct contact with the IAN were included in the study. All associations were confirmed with CBCT. Nerve injuries after surgery were confirmed and follow-ups were made with information given by patients, light touch, and pinprick tests. The relationship between sensory impairment and direct contact between IAN and M3 or canal decorticalization on CBCT images was statistically assessed. Results: One M3 extraction (0.8%) presented with postoperative permanent sensory impairment. No correlation between nerve injury and direct contact with the IAN or canal decorticalization on CBCT could be established. Conclusion: There is no association between nerve injury and direct IAN-M3 contact or canal decorticalization. Although orthopantomography is commonly used to plan M3 surgeries, consideration of CBCT as a viable alternative is warranted.  C 2019 Elsevier Masson SAS. All rights reserved. G Model JORMAS-719; No. of Pages 5 Please cite this article in press as: Bozkurt P, Go ¨ ru ¨ rgo ¨z C. Detecting direct inferior alveolar nerve – Third molar contact and canal decorticalization by cone-beam computed tomography to predict postoperative sensory impairment. J Stomatol Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.jormas.2019.07.004 Available online at ScienceDirect www.sciencedirect.com https://doi.org/10.1016/j.jormas.2019.07.004 2468-7855/  C 2019 Elsevier Masson SAS. All rights reserved.