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Preventable Sternocleidomastoid Muscular Atrophy after Neck Dissection
Nao Yamamoto1, Natsuko Yoshimura Sawai1, Shunsuke Ishimoto1
1First Department of Oral and Maxillofacial Surgery, Osaka University Dental Hospital, Osaka University Graduate School of Dentistry, Osaka, Japan.
Background:
Modified radical neck dissection (mRND) [preserving the sternocleidomastoid muscle (SCM) and the spinal accessory nerve] and supraomohyoid neck dissection have become common surgical procedures for treating head and neck cancer. Postoperative severe asymmetry of the neck and severe atrophy of the SCM, however, have been demonstrated.
Methods:
Using computed tomographic images, cross-sectional areas of the SCMs were measured in 99 patients with carcinoma of the oral cavity who underwent unilateral mRND or supraomohyoid neck dissection. An asymmetry index was used.
Results:
Innervation to the SCM was preserved in 91 patients. The spinal accessory nerve and the innervation were sacrificed in 3 patients; the innervation was repaired in 5 patients. Sacrifice of innervation to the SCM resulted in extremely severe asymmetry. Repair of the innervation prevented severe asymmetry in 40%. Preservation of the innervation prevented severe asymmetry in 75% at the middle portion of the neck and in 56% at the lower portion after mRND.
Conclusion:
Preserving innervation to the SCM and gentle handling of the nerve during neck dissection could prevent severe asymmetry after neck dissection.
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