Anton Sklavos1, Seth Delpachitra2, Tom Jaunay3, Ricky Kumar4, Arun Chandu5. 1. Senior Resident, Department of Oral and Maxillofacial Surgery, Royal Dental Hospital Melbourne, Carlton, VIC; and Senior Resident, Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Vic, Australia. Electronic address: anton.sklavos@unimelb.edu.au. 2. Senior Registrar, Department of Oral and Maxillofacial Surgery, Royal Dental Hospital Melbourne, Carlton, VIC. 3. Consultant Surgeon, Department of Oral and Maxillofacial Surgery, Royal Dental Hospital Melbourne, Carlton, VIC. 4. Head of Unit, Department of Oral and Maxillofacial Surgery, Royal Dental Hospital Melbourne, Carlton, VIC. 5. Consultant Surgeon and Associate Professor, Department of Oral and Maxillofacial Surgery, Royal Dental Hospital Melbourne, Carlton, Victoria, Australia; Consultant Surgeon and Associate Professor, Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia; and Consultant Surgeon and Associate Professor, School of Dentistry & Health Sciences Charles Sturt University Orange, NSW, Australia.
Abstract
PURPOSE: Cone-beam computed tomography (CBCT) offers the advantage of a 3-dimensional representation of the anatomic relationship of the mandibular third molar tooth and the inferior alveolar canal (IAC), as compared to a panoramic radiograph. We hypothesized that a novel method of categorizing the degrees of compression of the IAC were reliable predictors for postoperative nerve injuries. METHODS: We conducted a retrospective analysis of the outcomes in third molar surgery for patients who obtained a CBCT scan in additional to a plain film radiograph over a 12 months period and underwent surgical removal of their mandibular third molars; 257 consecutive patients were identified, and 416 mandibular third molars were surgically removed. RESULTS: Patients who had severe compression of the inferior alveolar canal (IAC) on CBCT imaging had a significantly increased risk of a postoperative IAN injury (P = .0068, OR = 3.47, 95% CI: 1.40 to 8.54) and accounted for 52.17% of all IAN injuries. Ninety-one percent of all cases of postoperative nerve injury occurred in female patients. The mean age of patients with a postoperative IAN injury (30.2 years) was significantly higher than those without injury 26.0 years; (P = .016, 95%CI: 25.11 to 33.80) CONCLUSIONS: In addition to patient factors, assessment of the degree of compression on a preoperative CBCT image is a useful tool for predicting outcomes in mandibular third molar surgery. In cases of severe compression of the IAC, patients are at a significantly increased risk of postoperative IAN injury.
PURPOSE: Cone-beam computed tomography (CBCT) offers the advantage of a 3-dimensional representation of the anatomic relationship of the mandibular third molar tooth and the inferior alveolar canal (IAC), as compared to a panoramic radiograph. We hypothesized that a novel method of categorizing the degrees of compression of the IAC were reliable predictors for postoperative nerve injuries. METHODS: We conducted a retrospective analysis of the outcomes in third molar surgery for patients who obtained a CBCT scan in additional to a plain film radiograph over a 12 months period and underwent surgical removal of their mandibular third molars; 257 consecutive patients were identified, and 416 mandibular third molars were surgically removed. RESULTS:Patients who had severe compression of the inferior alveolar canal (IAC) on CBCT imaging had a significantly increased risk of a postoperative IAN injury (P = .0068, OR = 3.47, 95% CI: 1.40 to 8.54) and accounted for 52.17% of all IAN injuries. Ninety-one percent of all cases of postoperative nerve injury occurred in female patients. The mean age of patients with a postoperative IAN injury (30.2 years) was significantly higher than those without injury 26.0 years; (P = .016, 95%CI: 25.11 to 33.80) CONCLUSIONS: In addition to patient factors, assessment of the degree of compression on a preoperative CBCT image is a useful tool for predicting outcomes in mandibular third molar surgery. In cases of severe compression of the IAC, patients are at a significantly increased risk of postoperative IAN injury.