Instrumented Assessment of Oral Motor Function in Healthy Subjects and People with Systemic Sclerosis

Abstract

The aim of the present study was to provide quantitative data of oral function in healthy subjects (HSs), validity of measurements and estimation of measurement bias, as well as quantify oral impairment in persons with scleroderma (SSc). 151 HSs and 12 subjects with SSc were recruited and assessed using instrumented tools, measuring maximal mouth opening; lip strength; and tongue strength, protrusion, retraction, and endurance. Twenty HSs were also retested 3-5 weeks later in order to assess the test-retest reliability of the measurements. Intraclass correlation coefficients proved to be satisfactory (>0.8) for both inter-rater and test-retest reliabilities of all measurements except for tongue retraction. In the HS group, maximal mouth opening and tongue and lips strength values were larger (P < 0.05) for males than females, while no significant differences were found for other variables. Older subjects had statistically significantly lower tongue retraction values and tongue endurance values than younger subjects. The SSc group showed a statistically significant decrease (P < 0.05) in almost all the measurements. Assessment procedures proved to be valid and reliable. Gender and height were predictors of mouth opening, lip and tongue strength, while age correlates with tongue retraction and endurance. Measurements highlighted the strong impact of SSc on oral functions and in particular on tongue protrusion, tongue strength, and endurance.

Effect of Impairment-Oriented and Function-Oriented Exercises on Mouth Function in Subjects with Systemic Sclerosis

“…Subjects 2, 3, and 4 showed large MPD changes, while improvements in subject 1 were less evident due to improvements already visible in phase A. At the beginning of the treatments, Tprot was below the 5th percentile [13], discriminating normal from abnormal performances, in all subjects compared to healthy ones. After treatment, Tprot improved in 3 subjects, who crossed the 5th percentile boundary.…”

“…Improvement in Tstren is important, since a previous study on SSc subjects showed a 23% reduction in Tstren compared to healthy subjects. This was associated with deficits over a wide range of activities including speech, bolus manipulation, and oral transit [13]. Visual analysis of Tstren data revealed a change in trend for subject 3, who showed the greatest MPD of 5.35 N. Subject 1 showed improvements with an MPD of 2.25 N without changes in trend, while no relevant improvements or changes in trend were observed for subjects 2 and 4.…”

“…Standardized and reliable instruments [13] were used to quantitatively assess four oral motor functions, which are severely impaired in subjects with SSc: MMO, Tprot, Tstren, and Lstren. Assessment instruments are described in Table 2 and in Figures 1 and 2.…”

“…Finally, we compared the final subject’s values with normative values [13]. Scores above the 5th percentile were considered within the healthy subject range: MMO = 33 mm, Tprot = 28.6 mm, Tstren = 5.5 N, Lstren = 2.7 N.…”

“…These manifestations can result in multiple functional debilitating sequelae, such as drooling and difficulty with mastication, swallowing, and speech [4], oral hygiene, and dental treatment [9, 10], thus deteriorating the quality of life of SSc subjects [11, 12]. Vitali et al [13] quantitatively assessed oral functions by comparing healthy subjects with SSc subjects. They found a 42% reduction in tongue protrusion (Tprot) and a 23% reduction in tongue strength (Tstren) with respect to healthy subjects.…”