Thirteen studies (92 patients) used a transnasal approach.
The remaining thirteen studies (1238 patients) performed a transoral approach.
Transoral odontoidectomy exhibited 90.0% neurologic improvement and 0.9% worsening.
Transnasal odontoidectomy showed 94.0% neurologic improvement and 0.0% worsening.
Transoral approach had a significantly higher rate of postoperative tracheostomy.