Coronectomy: A Surgical Option for Impacted Third Molars in Close Proximity to the Inferior Alveolar Nerve-A 5-Year Follow-Up Study.

PURPOSE: The extraction of third molars is the most common surgical procedure performed in the oral cavity. Coronectomy is a surgical protocol to reduce the risk of neurologic lesions to the inferior alveolar nerve (IAN). We evaluated early (up to 1 month) and late (from 2 to 60 months) postoperative complications. MATERIALS AND METHODS: This prospective cohort study enrolled patients treated at the Unit of Oral and Maxillofacial Surgery, University of Bologna. The predictor variable was the time after coronectomy with up to 5 years' follow-up. To assess the rate of postoperative complications, the outcome variables were neurologic injuries, postoperative pain, swelling, fever, alveolitis, pulpitis, and root exposure. The success rate, need for a second surgical procedure, probing pocket depth, and bleeding on probing also were investigated. Univariate and bivariate descriptive statistics, Kaplan-Meier analysis, and Cox hazards modeling were performed to evaluate the variables. RESULTS: We performed 116 coronectomies in 94 healthy patients (37 men and 57 women; mean age, 28.99 ± 8.9 years). At 5 years' follow-up, we re-evaluated 63 patients with 76 coronectomies. In total, 30 complications were verified. No cases of neurologic lesions to the IAN or lingual nerve were observed after surgery. In the first 3 years, the surgeons extracted migrated roots in 5 cases (6%) without any neurologic lesions to the IAN. No complications were observed from the third to fifth year. CONCLUSIONS: This prospective study on coronectomy of third molars in a close relationship with the mandibular canal found no cases of neurologic lesions, no cases of late infection of the retained roots at 5 years, and a low rate of immediate postoperative complications. Further investigations should include a follow-up study at 10 years and more research about the mechanism of pulp healing.

What Are the Types and Frequencies of Complications Associated With Mandibular Third Molar Coronectomy? A Follow-Up Study.

PURPOSE: Coronectomy has been proposed for impacted third molars in close proximity to the inferior alveolar nerve (IAN) to avoid neurologic injury. Immediate (up to 1 month) and late (2 to 36 months) postoperative complications were investigated. MATERIALS AND METHODS: A prospective cohort study was performed on healthy patients treated in the dental clinic of the Department of Oral Surgery, University of Bologna. The predictor variables examined were experience of the surgeon (<10 vs ≥10 yr), length of surgery, type of mandibular third molar inclusion, and patient age. To assess the rate of postoperative complications, outcome variables were neurologic injuries, postoperative pain, swelling, fever, alveolitis, pulpitis, and root exposure. The success rate and need for a second surgery also were investigated. Univariate and bivariate descriptive statistics, Kaplan-Meier analysis, and Cox hazards modeling were performed to evaluate the variables. RESULTS: The study involved 94 healthy patients (mean age, 28.99 ± 8.9 yr; range, 17 to 56 yr; 37 men and 57 women) who had 116 third mandibular molars treated with coronectomy. During the 3-year follow-up period, 28 patients (29 coronectomy procedures) dropped out of the study. There was no case of neurologic injury to the inferior alveolar nerve (IAN) or to the lingual nerve (LN). In total, 30 complications were observed (25 within 1 month; 5 at 2 to 12 months). Surgeons with less than 10 years of training exposed patients to a greater risk of complications (hazard ratio = 2.069; 95% confidence interval, 1.004-4.263). An overall success rate of 74% at 6 months was estimated, and a second surgery was needed in 6% of cases. Of the retained roots analyzed, 80% showed postoperative root migration. CONCLUSIONS: In this study, coronectomy of mandibular third molars did not result in temporary or permanent injury to the IAN or LN. Coronectomy showed a low rate of postoperative complications. However, within the first year, a second surgery was needed in 6% of coronectomy procedures to remove migrated root fragments. Additional studies with larger patient samples are recommended to further investigate differences in postoperative complications in relation to patient age.

Coronectomy: a surgical option for impacted third molars in close proximity to the inferior alveolar nerve.

BACKGROUND: Damage to the inferior alveolar nerve (IAN) during the extraction of impacted mandibular third molars in close proximity to the mandibular canal is a postoperative complication that most frequently occurs in patients 40 years and older. METHODS: The authors evaluated the postoperative complications of 43 coronectomies of impacted mandibular third molars in 37 patients (17 men and 20 women, mean age [standard deviation] 31 [2] years). The authors used cone-beam computed tomographic images to determine that all of the teeth that underwent a coronectomy were in close proximity to the IAN. RESULTS: The authors did not observe neurological injuries to the IAN or to the lingual nerve. One patient complained of intermittent pain and, 10 months after undergoing the coronectomy, underwent a second operation for extraction of the root fragments. The root extraction did not result in any neurological deficits, because the root fragments had migrated from the mandibular canal. One case of alveolitis was reported that manifested 15 days after the coronectomy. CONCLUSIONS: Coronectomies are safer to perform than complete extractions in situations in which the third molar is in close proximity to the mandibular canal. Root migration generally is asymptomatic, but in a case in which the patient underwent a second operation, the risk of the patient's experiencing neurological injuries was reduced. CLINICAL IMPLICATIONS: Coronectomy appears to be a valid surgical alternative in patients 40 years and older who are at a higher risk of experiencing neurological deficits than are younger patients.