Using the "Sugarcane Chewing" Concept as the Directionality of Motor Neurotizer Selection for Facial Paralysis Reconstruction: Chang Gung Experiences.

BACKGROUND

Facial paralysis and postparalysis facial synkinesis both cause severe functional and aesthetic deficits. Functioning free muscle transplantation is the authors' preferred method for reconstructing both deformities.

METHODS

From 1985 to 2017, a total of 392 patients underwent 403 gracilis functioning free muscle transplantations for facial reanimation. Different motor neurotizers were used: cross-face nerve graft (74 percent), spinal accessory nerve (17 percent), and masseter nerve (8 percent). Smile excursion score, cortical adaptation stage, patient questionnaire, Hadlock lip excursion, and the Terzis evaluation systems were used to assess outcomes.

RESULTS

For smile excursion score, the spinal accessory and masseter nerve groups showed higher scores than the cross-face nerve graft group in the first 2 years, but no difference by 3-year follow-up. For cortical adaptation stage, nearly all cross-face nerve graft patients achieved stage IV or V spontaneity, the spinal accessory nerve group achieved at least stage III (independent) movement, but individuals in the masseter nerve group achieved only stage III or less. The cross-face nerve graft group also achieved higher scores according to the Hadlock system and the Terzis evaluation system compared with the other two groups.

CONCLUSIONS

The concept of "sugarcane chewing" where the sweetness is the least at the tail but the most at the head can be simply applied for surgeons and patients in weighing the benefits and drawbacks during the motor neurotizer selection. Cross-face nerve graft-innervated gracilis is analogous to chewing sugarcane from tail to head; despite lower outcome measures earlier, it yields the highest scores at 3 years postoperatively. Masseter-innervated gracilis is akin to chewing sugarcane from head to tail, with greater outcome scores initially but little improvement at longer follow-up. Spinal accessory-innervated gracilis results fall in between these two groups.

CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.