Purpose: The accuracy of the clinical neurosensory test to diagnose tr
igeminal nerve injuries has never been statistically evaluated. The pu
rpose of this study was to determine the statistical efficacy of the c
linical neurosensory test using surgical findings as the ''gold'' stan
dard, and to determine whether a correlation existed between the senso
ry impairment score obtained by preoperative testing and the degree of
nerve injury found at surgery. Materials and Methods: A multisite, ra
ndomized, prospective, blinded, clinical trial was conducted on 130 pa
tients with inferior alveolar nerve (IAN) and lingual nerve (LN) injur
ies. Preoperatively, patients mere provided a sensory impairment score
using a three-level drop-out clinical neurosensory test (NST), and bl
ind comparisons were made with the surgical findings postoperatively.
Results: The positive predictive and negative predictive values for LN
-injured patients were 95% and 100%, respectively. The positive predic
tive and negative predictive values for IAN patients were 77% and 60%,
respectively, There were statistically significant differences in the
distribution of age, duration of injury, cause of injury, presence of
neuropathic pain, presence of trigger pain, and degree of injury betw
een the LAN and LN patient populations. There was a statistically sign
ificant positive relationship found between the sensory impairment sco
re and the degree of nerve injury. Conclusions: The NST is a clinicall
y useful method to diagnose LAN and LN injuries, However, the NST resu
lts are less efficient for IAN injuries than LN injuries, and have a h
igh incidence of false-positive (23%) and false-negative (40%) results
when testing patients with IAN injuries, The different rates of stati
stical efficiency between the two groups of patients may be attributab
le to differences in prevalence and biologic covariates.