Alternative approach to prevent inferior alveolar nerve injury in lower third molar surgery: A pilot study on coronectomy

BACKGROUND A serious complication of surgical removal of impacted lower third molars is inferior alveolar nerve (IAN) injury. Evaluation of radiographic factors to predict IAN injury using CT and panoramic radiography includes root morphology assessment, follicular sac size, mandibular bone density, inferior alveolar nerve and vessels, condition of the overlying tissues, relation of the impacted tooth with the body and ramus of the mandible and the adjacent teeth. This study was done to evaluate the radiological features of the impacted lower mandibular teeth and their relationship with IAN through panoramic radiography and CT and to assess the most predictable radiological criteria for inferior alveolar nerve injury in impacted third molar surgery. METHODS All the patients indicated for lower third molar extraction were included in the study and pre-operative conventional panoramic radiographs (Planmeca Proline PM 2002 CC, Helsinki, Finland) and CBCT (Kodak CBCT) were taken. Any post-operative nerve injuries detected were followed up after 15 days or 1 month. Fisher’s exact test was done to find the association between the outcome variable and explanatory variables. RESULTS Only 11.4 % (N = 4) of all participants had IAN injury following surgical disimpaction. All the participants with IAN injury showed narrowing of the canal on their preoperative panoramic radiographs and presence of nerve approximation with the tooth in cone beam computed tomography (CBCT) reports (P < 0.05). CONCLUSIONS A statistically significant association exists between IAN injury and nerve exposure, radiographic signs of nerve involvement for panoramic radiograph, level of third molar impaction, and nerve approximation in CBCT. KEY WORDS Inferior Alveolar Nerve Injury, Lower Third Molar Impaction, Panoramic Radiography, CBCT

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Coronectomy - A viable alternative to prevent inferior alveolar nerve injury

Journal of College of Medical Sciences-Nepal ◽

10.3126/jcmsn.v11i3.14055 ◽

2015 ◽

Vol 11 (3) ◽

pp. 1-5

Author(s):

Alok Sagtani ◽

Reshu Agrawal Sagtani ◽

Mehul Jaisani ◽

Leeza Pradhan

Keyword(s):

Nerve Injury ◽

Inferior Alveolar Nerve ◽

Third Molar ◽

Viable Alternative ◽

Third Molars ◽

Dry Socket ◽

Root Exposure ◽

Mandibular Third Molars ◽

Inferior Alveolar Nerve Injury

Background and Objectives: Coronectomy is a relatively new method to prevent the risk of Inferior Alveolar Nerve (IAN) injury during removal of lower third molars with limited scientific literature among Nepalese patients. Thus, a study was designed to evaluate coronectomy regarding its use, outcomes and complications.Materials and Methods: A descriptive study was conducted from December 2012 to December 2013 among patients attending Department of Oral and Maxillofacial Surgery, College of Dental Sciences, BP Koirala Institute of Health Sciences, Dharan, Nepal for removal of mandibular third molars. After reviewing the radiograph for proximity of third molar to the IAN, coronectomy was advised. A written informed consent was obtained from the patients and coronectomy was performed. Patients were recalled after one week. The outcome measures in the follow-up visit were primary healing, pain, infection, dry socket, root exposure and IAN injury. The prevalence of IAN proximity of lower third molars and incidence of complications were calculated.Results: A total 300 mandibular third molars were extracted in 278 patients during the study period. Out of 300 impacted mandibular third molar, 41 (13.7%) showed close proximity to inferior alveolar nerve . The incidence of complications and failed procedure was 7.4% among the patients who underwent coronectomy. During the follow up visit, persistent pain and root exposure was reported while other complications like inferior alveolar nerve injury, dry socket and infection was not experienced by the study patients.Conclusion: With a success rate of 92.6% among the 41 patients, coronectomy is a viable alternative to conventional total extraction for mandibular third molars who have a higher risk for damage to the inferior alveolar nerve.JCMS Nepal. 2015;11(3):1-5.

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