Microsurgical Repair of Inferior Alveolar Nerve Injuries Associated With Endodontic Treatment: Results on Sensory Function and Relief of Pain.

PURPOSE: An uncommon, but serious complication of endodontic treatment is inferior alveolar nerve (IAN) injury warranting operative intervention for exploration, debridement, and repair. The purpose of the study was to evaluate outcomes of microneurosurgical intervention for endotontic-related IAN injuries in terms of achievement of functional sensory recovery (FSR) and pain relief and to identify factors affecting outcomes. METHODS: A retrospective cohort study of patients who had microsurgical exploration and repair of IAN injuries sustained during endodontic therapy was performed. The primary predictor variable is time to surgery and the primary outcome variables were time to FSR, whether or not the patient regained FSR, and postoperative pain level at 12 months (1-10 on a visual analog scale). Secondary variables include intraoperative findings, surgical treatment rendered, sensory recovery, and preoperative pain level. Analyses include Kaplan-Meier estimation, Fisher exact test, 1-way and mixed-design analysis of variance, and paired t-test. RESULTS: The sample included 23 patients with a mean age of 48.6 years with a female:male ratio of 20:3. Painful sensation was present in 17 (73.9%) of 23 patients at initial consultation. Mean time to surgery was 10.9 months (median 4.8 months, standard deviation = ±16.9). FSR was achieved in 10 of 21 patients at 1 year. Pain level at 1 year following surgical intervention improved from 4.86 to 2.76 (P = .001) with no effect from other variables. CONCLUSIONS: Surgical exploration and repair of endodontic-related IAN injuries is shown to improve neuropathic pain levels, while only delivering a modest recovery of sensory function. These injuries can be severe and debilitating and present with a variety of diagnoses and surgical findings. While this study fails to identify any particular factors affecting outcome, the data presented can help with clinician recommendations for treatment in patient-centered care.

How Many Oral Surgeons Does It Take to Classify a Nerve Injury?

PURPOSE: There is inconsistency in clinical grading of peripheral trigeminal nerve (TN5) injuries that impact patient care. The study goal is to assess the current status of evaluation and classification of TN5 injuries by oral and maxillofacial surgeons (OMSs). PATIENTS AND METHODS: A cross-sectional study design used an electronic survey to 100 selected OMSs to determine their clinical TN5 injury practice, including neurosensory testing, confidence level with current protocols, and evaluation and treatment of a hypothetical TN5 injury case. The target sample was enhanced to reduce type 2 error, assuming prior experience in the diagnosis and management of TN5 injuries. RESULTS: The sample was composed of 90 respondents. Nerve injury classification systems used by OMSs include Seddon (44%), Sunderland (70%), and Medical Research Council Scale (31%). Neurosensory testing protocols varied considerably among survey respondents. A sample case for Medical Research Council Scale grading produced inconsistent and inaccurate results. There was no consensus on TN5 injury management, and recommendations for timely nerve repair varied from 1 month to up to 1 year after injury. Half of the respondents stated that OMSs are not adequately prepared to assess inferior alveolar/lingual nerve injuries, and most oral-maxillofacial surgery respondents evaluate fewer than 10 TN5 injuries each year. Most OMSs (92%) have had a temporary inferior alveolar/lingual nerve injury, while 54% have had a permanent injury; of which, 21% required microsurgical repair. The majority of OMSs (74%) believed that a uniform TN5 injury classification system is needed. CONCLUSIONS: Within the oral-maxillofacial surgery target group experienced in evaluation of TN5 injuries, respondents do not feel confident in the assessment of these injuries. There is inconsistency in evaluation methods, and there is agreement that a unified classification system is needed for more efficient patient evaluation and reporting of outcomes in the literature. The Medical Research Council Scale and clinical neurosensory testing is preferred for evaluation of TN5 injuries.

Incidence of Pre-Existing Lingual Cortex Perforation Before Removal of Mandibular Third Molars.

PURPOSE: The objective of this study was to determine the relationship between the mandibular third molar tooth (Md3) and the adjacent lingual cortical bone and determine the incidence of lingual cortex perforation by Md3s. PATIENTS AND METHODS: This retrospective study was designed and implemented from 100 cone-beam computed tomographic scans (CBCTs) of patients with age ranging from 18 to 65 years old. The primary outcome was to assess the incidence of mandibular third molars (Md3s) with existing lingual cortex perforation by their roots. Perforation was assessed at the level of root apex and the most lingual portion on the apical half of the root. Other outcome variables included average thickness of covering lingual bone in the nonperforation group, lingual cortex morphology, impaction, and demographics. Descriptive statistics were computed. RESULTS: More than half the radiographs showed lingual cortex perforation at the level of root apex and most lingual portion on the apical one half of the root (51.2% and 52.8%, respectively). The average thickness of the covering lingual bone was 1.25 mm around the root apex and 0.93 mm around the most lingual portion on the apical half of the root. The most common lingual cortex morphology was the undercut shape. There was statistically significant association between the presence of Md3 impaction and perforation at both root levels [(P value < .001, Effect size = 0.378) and (P value < .001, Effect size = 0.445)]. CONCLUSIONS: Perforation of the lingual cortex by Md3s, whether erupted or impacted, was found in >50% of patients as determined by a preoperative CBCT scan. Therefore, the finding of lingual cortex perforation after removal of Md3s is likely to be evidence of a pre-existing condition rather than a result of surgery.