title: Unilateral Multiple Facial Nerve Branch Reconstruction Using "End-to-side Loop Graft" Supercharged by Hypoglossal Nerve.
abstract: BACKGROUND
  Extensive facial nerve defects between the facial nerve trunk and its branches can be clinically reconstructed by incorporating double innervation into an end-to-side loop graft technique. This study developed a new animal model to evaluate the technique's ability to promote nerve regeneration.
  
  
  METHODS
  Rats were divided into the intact, nonsupercharge, and supercharge groups. Artificially created facial nerve defects were reconstructed with a nerve graft, which was end-to-end sutured from proximal facial nerve stump to the mandibular branch (nonsupercharge group), or with the graft of which other end was end-to-side sutured to the hypoglossal nerve (supercharge group). And they were evaluated after 30 weeks.
  
  
  RESULTS
  Axonal diameter was significantly larger in the supercharge group than in the nonsupercharge group for the buccal (3.78 ± 1.68 vs 3.16 ± 1.22; P < 0.0001) and marginal mandibular branches (3.97 ± 2.31 vs 3.46 ± 1.57; P < 0.0001), but the diameter was significantly larger in the intact group for all branches except the temporal branch. In the supercharge group, compound muscle action potential amplitude was significantly higher than in the nonsupercharge group (4.18 ± 1.49 mV vs 1.87 ± 0.37 mV; P < 0.0001) and similar to that in the intact group (4.11 ± 0.68 mV). Retrograde labeling showed that the mimetic muscles were double-innervated by facial and hypoglossal nerve nuclei in the supercharge group.
  
  
  CONCLUSIONS
  Multiple facial nerve branch reconstruction with an end-to-side loop graft was able to achieve axonal distribution. Additionally, axonal supercharge from the hypoglossal nerve significantly improved outcomes.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Global Center of Excellence (COE) Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Department of Oral and Maxillofacial Surgery, Global Center of Excellence Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; and Department of Physiology, School of Medicine, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Matsumine
authors.affiliation: Department of Plastic and Reconstructive Surgery, Global Center of Excellence (COE) Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Department of Oral and Maxillofacial Surgery, Global Center of Excellence Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; and Department of Physiology, School of Medicine, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Sasaki
authors.affiliation: Department of Plastic and Reconstructive Surgery, Global Center of Excellence (COE) Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Department of Oral and Maxillofacial Surgery, Global Center of Excellence Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; and Department of Physiology, School of Medicine, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Takeuchi
authors.affiliation: Department of Plastic and Reconstructive Surgery, Global Center of Excellence (COE) Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Department of Oral and Maxillofacial Surgery, Global Center of Excellence Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; and Department of Physiology, School of Medicine, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan.
authors.forename: Yorikatsu
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Department of Plastic and Reconstructive Surgery, Global Center of Excellence (COE) Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Department of Oral and Maxillofacial Surgery, Global Center of Excellence Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; and Department of Physiology, School of Medicine, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Niimi
authors.affiliation: Department of Plastic and Reconstructive Surgery, Global Center of Excellence (COE) Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Department of Oral and Maxillofacial Surgery, Global Center of Excellence Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; and Department of Physiology, School of Medicine, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sakurai
authors.affiliation: Department of Plastic and Reconstructive Surgery, Global Center of Excellence (COE) Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Department of Oral and Maxillofacial Surgery, Global Center of Excellence Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; and Department of Physiology, School of Medicine, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Miyata
authors.affiliation: Department of Plastic and Reconstructive Surgery, Global Center of Excellence (COE) Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; Department of Oral and Maxillofacial Surgery, Global Center of Excellence Program, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan; and Department of Physiology, School of Medicine, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamato