Cassetta M, Pranno N, Barchetti F, Sorrentino V, Lo Mele L
1 Department of Oral and Maxillofacial Sciences, School of Dentistry, Sapienza University of Rome, Rome, Italy.
Dentomaxillofac Radiol. 2014;43(7):20140152. doi: 10.1259/dmfr.20140152. Epub 2014 Jun 20.
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.
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 (κ) and intraclass correlation coefficient (ICC) were used to evaluate the interobserver (k = 0.891) and intra-observer variability (ICC = 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.
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 = 0.504).
The early evaluation of RSI values represents a valid tool to determine the prognosis of IAN sensory disorders after mandibular third molar extraction.
评估3.0 T磁共振成像（MRI）在下颌第三磨牙拔除术后早期对下牙槽神经（IAN）感觉障碍预后的评估价值。
对343条IAN在手术前及术后3天进行检查。两名放射科医生评估神经走行及相对信号强度（RSI）。采用Cohen卡方系数（κ）和组内相关系数（ICC）评估观察者间（κ = 0.891）及观察者内变异性（ICC分别为0.927；0.914）。根据神经感觉障碍恢复时间将IAN分为四组。采用方差分析评估四组RSI的差异，并采用Tukey范围检验进行多重比较。
手术前后IAN走行未见差异。在280条IAN中，未发现医源性感觉异常（A组）。63条IAN出现神经感觉损害。38条IAN在3个月随访时术后感觉异常恢复（B组）。16条IAN在6个月随访时医源性感觉异常完全恢复（C组）。7条IAN在12个月随访时完全恢复，2条IAN在18个月随访时神经感觉障碍持续存在（D组）。单因素方差分析结果表明，除C组和D组之间（p = 0.504）外，所有组之间差异均有统计学意义（p < 0.05）。
RSI值的早期评估是确定下颌第三磨牙拔除术后IAN感觉障碍预后的有效工具。
