An Ex Vivo Investigation of Tactile Aesthesiometer Force in Laryngopharyngeal Sensory Testing

Background/Objective Cheung-Bearelly aesthesiometers can deliver buckling-force stimuli to the laryngopharynx and objectively evaluate sensation. Ambiguity surrounds the transformation of stimuli in the laryngopharyngeal environment. This study aims to evaluate the effect of aesthesiometer size, saliva, successive compressions, and angles of tissue contact on stimulus force delivered. Methods An ex vivo stimulus delivery device was constructed to measure the buckling force of aesthesiometers. Dry and saliva-saturated aesthesiometers (6-0, 5-0, 4.5-0, and 4-0) were each compressed six times on cadaveric buccal mucosa on an electronic balance. The force for each compression was recorded at 0, 15, 30, 45, and 60 degrees from the vertical plane. 240 compressions were analyzed utilizing a mixed-effects statistical model. Results The mean force delivered by the 6-0, 5-0, 4.5-0, and 4-0 aesthesiometers were 0.017, 0.082, 0.120, and 0.268 g respectively (p < 0.001). Mean force significantly reduced for the 4-0 aesthesiometer at 30 degrees (p = 0.003) and 60 degrees (p = 0.001). Force decreased by the 4th compression for the 5-0 aesthesiometer (p = 0.004) and after one compression for the 4.5-0 (p = 0.004) and 4-0 (p < 0.001) aesthesiometer. By the 4th compression, the 4.5-0 aesthesiometer was indistinguishable (p > 0.05) from the 5-0 aesthesiometer. The effect of saliva was insignificant (p = 0.83). Conclusion Aesthesiometers can deliver discrete buckling-force stimuli to evaluate laryngopharynx sensory function. Up to 60 degrees (15 degrees for 4-0 aesthesiometer) deviation from orthogonal tissue contact and salivary forces do not significantly alter force delivered. 4.5-0 aesthesiometers should be exchanged after three compressions. For all other aesthesiometers, force reduction after six compressions is likely clinically insignificant given current laryngopharyngeal sensory testing protocols. Level of Evidence N/A Ex Vivo Laboratory Design Laryngoscope, 2022