An in-silico comparison of success rate of different methods for inferior alveolar nerve blockade

We present a comparison of five methods for inferior alveolar nerve blockade (Halsted’s, Fischer’s, Laguardia’s, Szokolóczy-Syllaba’s and Gow-Gates method -as control group) in our three-dimensional virtual model based on the radiological database of our Department. The injection canula was modelled as a vector in a coordinate system applied to the skull, a spherical model projected to the mandibular foramen was defined as target zone. The parallelism of these vectors and the targeting accuracy around the mandibular foramen was compared by independent statistician with Fisher’s test with a significance level of α= 5 %. 100 mandibular sides (50 left and 50 right mandibles) were measured in virtual model. There were no significant gender or age differences. In case of the Laguardia method the administration lines deviated in average 10°, in case of the other methods 5° in average. The hit rate at different target radius was worst with the Laguardia’s method than with the others, the results were statistically significant (p < 0.001). This in-silico model reproduced the literature results of the clinical accuracy (70 %-100 %) of inferior alveolar nerve blockade. Further anatomical studies of the pterygomandibular space are necessary to improve clinical accuracy.