3.0 Tesla MRI in the early evaluation of inferior alveolar nerve neurological complications after mandibular third molar extraction: a prospective study

Abstract

Objectives: To evaluate the use of 3.0 T MRI in the prognosis of inferior alveolar nerve (IAN) sensory disorders after mandibular third molar extraction, in the early post-operative period. Methods: 343 IANs were examined before and 3 days after surgery. Two radiologists evaluated the course of the nerve and the relative signal intensity (RSI). Cohen's kappa coefficient (k) and intraclass correlation coefficient (ICC) were used to evaluate the interobserver (k 5 0.891) and intra-observer variability (ICC 5 0.927; 0.914, respectively). The IANs were divided into four groups on the basis of neurosensory disorders recovery time. ANOVA was used to evaluate the differences among the RSIs of the four groups, and multiple comparisons were performed with Tukey's range test. Results: No differences in the course of IANs were found before and after surgery. In 280 IANs, no iatrogenic paraesthesia was found (Group A). 63 IANs showed a neurosensory impairment. 38 IANs showed recovery of post-operative paraesthesia at 3-month follow-up (Group B). 16 IANs showed a full recovery of iatrogenic paraesthesia at 6-month follow-up (Group C). Seven IANs displayed a full recovery at 12-month follow-up and two IANs showed persistence of neurosensory disorders at 18-month follow-up (Group D). The one-way ANOVA results indicated statistically significant difference among all groups (p , 0.05), except between Groups C and D (p 5 0.504). Conclusions: The early evaluation of RSI values represents a valid tool to determine the prognosis of IAN sensory disorders after mandibular third molar extraction.

Diffusion tensor imaging of the inferior alveolar nerve using 3T MRI: a study for quantitative evaluation and fibre tracking

“…[7][8][9] While on the other hand, the IAN was evaluated quantitatively using DTI and was visualized three-dimensionally by tractography in the present study. DTI can provide quantitative data based on the diffusivity and anisotropy of microscopic water motion within nerve fibres, and the nerve fibres can be visualized three-dimensionally.…”

“…Recently, several studies have evaluated the mandibular canal using MRI. [7][8][9] Among these, some researchers reported that changes to the neurovascular bundle including IAN could be evaluated on the basis of T 1 -and T 2 -related signal intensities on high-quality MR images.…”

Visualization techniques of the inferior alveolar nerve (IAN): a narrative review

“…A novel application of 3T MRI is to determine the prognosis of IAN sensory disorders after M3 removal, by evaluating the relative signal intensity (RSI) of the IAN in the early post-operative period. Cassetta et al concluded that there is a statistically significant difference in RSI among patients with a different grade of neurosensory impairment after M3 removal [ 7 ]. Finally, MRI is also used to evaluate regions of the TMJ, salivary glands, the floor of the mouth, and the paranasal sinuses [ 2 ].…”

Quantitative Assessment of the Age-related Change of Inferior Alveolar Neurovascular Bundle Using Diffusion Weighted Magnetic Resonance Imaging

“…In the past, it has been reported that such as assessment of the relationship between mandibular third molars and inferior alveolar nerve using CT and the early evaluation of inferior alveolar nerve neurological complications after mandibular third molar extraction using MRI (8,14) . In addition, in acute osteomyelitis, elevated intramedullary pressure also leads to direct compression of neurovascular bundles, accelerating thrombosis and ischemia, and is known to cause inferior alveolar nerve dysfunction known as Vincent's symptoms (15) .…”