Correction: Masticatory muscle index for indicating skeletal muscle mass in patients with head and neck cancer

• Sheng-Wei Chang, 
• Yuan-Hsiung Tsai, 
• Cheng-Ming Hsu, 
• Ethan I. Huang, 
• Geng-He Chang, 
• Ming-Shao Tsai, 
• Yao-Te Tsai