The use of digital imaging to measure the tongue and unoccupied area in the oral cavity: An alternative technique for precise objective airway assessment

Abstract

Objective: Current predictive airway exams focus on the tongue, but are subjective in nature and vary largely depending on the clinician performing them. We aimed to develop a method using digital imaging to quantify the size and shape of the tongue and the area left unoccupied in the oral cavity. Our goal was to develop an alternative airway assessment that was precise and objective.
Methodology: Photographs were taken of our clinical research team. A total of 9 photographic images were taken and analyzed by 7 members via ImageJ software obtained from the National Institute of Health (NIH) to measure the size and shape of the tongue using an area (cm²) measurement, the area of the teeth, the area of the unoccupied space, the area of the entire oral cavity (minus lips). The ratio of the unoccupied area to the entire oral cavity was calculated by dividing the area of the unoccupied area by the area of the entire oral cavity and multiplying by 100. In addition, intra- and inter-rater reliabilities were also measured to assess the precision of the objective exam.
Results: A wide variety of sizes and shapes of tongues in the oral cavity was found. The ratio of the unoccupied area to the entire oral cavity ranged from 19.7 to 47.8. We also found a high precision defined by intra- and inter-rater reliability of 1.638×10^-4 and 3.347×10^-4, respectively.
Conclusion: Due to the variation in the sizes and shapes of the tongues, the unoccupied area left in the oral cavity differed among the images analyzed. Therefore, the ratio of the unoccupied area to the entire oral cavity varied extensively. Overall, our alternative method may allow for a more precise, objective airway assessment.