Background: Oro-facial myofunctional praxis assesses the muscular coordination and the degree of motor impairment of the lingual, mandibular and facial muscles necessary for articulation, mimicry and swallowing.
Purpose: The objective of this study was to create and validate the MBLF protocol, a French oro-facial myofunctional assessment in order to quantify patient's impairment and to specify the motor and functional deficit for an adapted management.
Methods: The MBLF was validated against the Sunnybrook Facial Grading System (criterion validity). The construct validity was tested by comparing healthy subjects (n = 102) from patients with facial palsy (n = 60). Internal and external consistency of face symmetry were reported. Normative data was provided.
Results: There was a statistically significant correlation between the MBLF protocol and the Sunnybrook Facial Grading System [F(59) = 310.51, p < 0.001, R2 = 0.843]. Significant differences were observed in Student's t test between healthy volunteers and patients with facial palsy [t(74.13) = 14,704, p < 0.001, r = 0.863]. A significant effect of the severity grades of facial palsy on the MBLF_TOTAL scores was found [F(158) = 268.469, p < 0.001]. The more severe the facial palsy, the lower the motor scores were.
Conclusion: This MBLF French validation provides a baseline for comparing and quantifying the performance of subjects. The MBLF protocol is valid for assessing facial symmetry in peripheral facial palsy. A prospective study is needed to validate its role in dynamic evaluation of facial palsy.
Keywords: Facial motor skills; Facial palsy; Oro-facial assessment; Oro-facial myofunctional; Validity.