This study collected 11 parameters regarding the labial and lingual strength for maximum isometric and swallowing tasks among 150 healthy Chinese adults in Taiwan. Measurements were performed using the Iowa Oral Performance Instrument (IOPI). All of the labial and lingual strength parameters were measured three times. The maximal value of three trials represents the pressure of every parameter. The overall mean (±standard deviation) and maximum isometric pressures of the lips, anterior tongue, and posterior tongue were 24.81 ± 5.64, 55.95 ± 14.13, and 53.23 ± 12.24 kPa, respectively. The mean value of posterior tongue strength was less than that of the anterior tongue by approximately 5%. The percentages of maximum isometric tongue pressure during the swallowing of saliva and water were 85% and 80% for the anterior tongue and 90% and 81% for the posterior tongue, respectively. The average endurances for the anterior tongue and posterior tongue were 13.86 ± 7.08 and 10.06 ± 5.40 s, respectively. The maximum isometric pressures were greater than both the saliva and water swallowing pressures, and the saliva swallowing pressures were greater than the water swallowing pressures. A value of 33 kPa in maximum isometric pressure could serve as a demarcation of weak tongue strength for healthy Chinese adults. As for the repeated trials of labial and lingual strength, there were no statistically significant differences for any of the pressures obtained from the 11 labial and lingual strength parameters. The normative data can be used for the objective assessment of labial and lingual strength in healthy Chinese adults.
Keywords: endurance; labial strength; presbyphagia; tongue strength.