Sensory Topography of Oral Structures

Area of Science:

• Neuroscience
• Biomedical Engineering
• Otolaryngology

Background:

• Oral and oropharyngeal sensory function is crucial for swallowing and speech.
• Evaluating tactile sensation in these areas is challenging due to a lack of reliable clinical tools.
• Diseases and treatments affecting the upper aerodigestive tract can significantly impact oral sensation.

Purpose of the Study:

• To develop and validate novel sensory testing monofilaments for assessing tactile thresholds.
• To map the tactile sensory function of oral cavity and oropharyngeal structures in healthy adults.
• To establish a reliable method for quantitative sensory assessment in the oropharynx.

Main Methods:

• Developed novel Cheung-Bearelly monofilaments using nylon sutures of varying sizes.
• Evaluated buckling force consistency and reliability of the monofilaments.
• Determined tactile sensory thresholds in 37 healthy adults using signal detection and staircase methods.
• Assessed test-retest reliability and cross-validated different measurement methods.

Main Results:

• Monofilaments demonstrated distinct, consistent, and logarithmically related buckling forces.
• High test-retest reliability was achieved for sensory threshold determination.
• Sensitivity varied across oral structures, with lower lip and anterior tongue being more sensitive than posterior structures.
• Threshold determination methods showed high correlation, and perceptual intensity growth was log-linear.

Conclusions:

• The developed Cheung-Bearelly monofilaments are accessible, disposable, and consistent esthesiometers.
• A topography of normal oral and oropharyngeal tactile sensation was established, showing anteroposterior gradients.
• This novel tool enables quantitative sensory function assessment, advancing clinical care for oropharyngeal conditions.