Morphometric Study of the Muscles of the Skin in MRI 3 Tesla in Patients With Facial Paralysis.

The problem posed is the possibility of objectively assessing facial muscle mobility.

Today, in patients with facial paralysis, the assessment of the deficit is carried out using a subjective scale such as the House Brackman [1] or EMG scale of the facial nerve but does not distinguish each muscle individually . Objective measurements of skin muscles such as thickness and volume, in preoperative assessment of a facial paralysis rehabilitation surgery, would be useful in order to choose the most appropriate surgical technique. Indeed, too much amyotrophy will contraindicate hypoglosso-facial anastomosis (VII-XII) and it will be preferable to propose a temporal elongation myoplasty or a reinfused free muscle flap.

Similarly, it would be useful to be able to objectively evaluate the recovery of muscle function after facial allo-transplantation.

Although electromyography has been developed since the work of Duchenne de Boulogne, little research has been carried out on the development of noninvasive methods to objectively characterize in vivo skin muscles (variation, position, orientation, morphometry). The main morphometric data of the skin muscles come from anatomical dissections.

Imaging of the skin muscles has not been specifically developed. Some studies have been carried out to visualize these muscles in MRI 1.5 Tesla in pathologies such as myasthenia gravis, facial paralysis, and labio-alveolo-palatine clefts for example.

The originality of the project is to develop a method allowing to establish a quantitative correlation between the movements of the face and the muscular changes. This correlation will be achieved by associating muscular morphological data derived from MRI acquisitions and cutaneous deformations resulting from clinical examinations. This non-invasive approach should make it possible to establish objective and reproducible indicators in patients with facial paralysis sequelae.