Anatomical study of the masseteric and obturator nerves: Application to face transplant and reanimation procedures

Abstract

The masseteric nerve (MN) and the anterior branch of the obturator nerve (ON) that innervate the transferred gracilis muscle have proved highly efficient for reanimating paralyzed facial muscles when muscle transfer is required. Previous researchers have published the total axonal load for myelinated fibers in both nerves. However, the real motor axonal load has not been established. We performed the study on 20 MN and 13 ON. The segments of the MN and the ON were embedded in paraffin, sectioned at 10 μm, and stained following a standard immunohistochemical procedure using anti‐choline acetyltransferase to visualize the motor fibers. The MN has a higher axonal load than the ON. There were statistically significant differences between the axonal load of the proximal segment of the MN and the ON. These findings confirm that end‐to‐end anastomoses between the MN and the ON should preferably use the proximal segment. However, MN neurotomy should ideally be performed between the proximal and distal segments, preserving innervation to the deep fascicles. Our results show that the MN is ideal as a donor motor nerve for reinnervating transplanted muscle for dynamic reanimation of the paralyzed face. The neurotomy should ideally be performed between the first and second collateral branches of the MN. Clin. Anat. 32:612–617, 2019. © 2019 Wiley Periodicals, Inc.

Anatomic and histomorphometric study of the nerve to the vastus lateralis in cadaver for its clinical application in facial reanimation

“…As we previously observed in the obturator nerve of the gracilis muscle (Lasso et al, 2019), the number of ChAT negative fibers was higher than the ChAT positive ones. Likewise, the amount of ChAT positive fibers was similar in the proximal part of the femoral nerve in comparison to the obturator nerve, demonstrating that this muscle flap is as suitable for motility reconstruction as the gracilis flap.…”

“…IVLF has been previously described as muscle flap for FP reanimation (Agrogiannis et al, 2015; Arpa et al, 2016; Becker et al, 2010; Borschel et al, 2012; Chong et al, 2017; Hembd et al, 2017; Jirawatnotai et al, 2020; Lasso et al, 2019; Lóderer et al, 2018; Mahmood et al, 2020; Mathes & Nahai, 1997; Revenaugh et al, 2012; Taylor et al, 1994; Yang et al, 2006), but to the best of our knowledge, IVLF has not been described in long‐standing FP as a one‐stage procedure.…”

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“…11 When muscle transfer was considered, the masseteric nerve and the anterior division of the obturator nerve (with the gracilis muscle)were highly effective for recovery of paralyzed facial muscles. 12 The part of the facial nerve from its exit at the stylomastoid foramen till the parotid gland is commonly excised during radical parotidectomy for malignancy. The thoracodorsal nerve (nerve to latissimus dorsi muscle) was found to be morphologically identical with the facial nerve stump at its exit from the skull.…”