**3. Natural history**

Most cases of postoperative dysphagia are mild and transient, resolving gradually within 3 months [19, 23, 24] without any specific treatment. Most of the cases *Dysphagia Following Anterior Cervical Spine Surgery DOI: http://dx.doi.org/10.5772/intechopen.101799*

of postoperative dysphagia resolve within 1 year, however, about 5–7% of cases of dysphagia after ACSS are still present 6–24 months after surgery [11].

Yue et al. reported 15% rate of dysphagia after 5 years of ACSS [24]. The predominant cause of persistent postoperative dysphagia appears to be an increase of the thickness of posterior pharyngeal wall above the upper esophageal sphincter [25].
