Infraorbital Nerve Located Medially to Postoperative Maxillary Cysts: A Risk of Endonasal Surgery

This study aimed to examine variations in the location of the infraorbital nerve relative to postoperative maxillary cysts to assess the potential risk of nerve injury during endonasal marsupialization.

Coronal computed tomography images of 130 patients (162 sides) with postoperative maxillary cysts who visited our clinic between 2003 and 2014 were reviewed from the viewpoint of the anatomical relationship between the infraorbital nerves and cysts.

The proportions of the six locations were as follows: upside 45.1% (n = 73), separate 13.0% (n = 21), medial 5.6% (n = 9), lateral 14.2% (n = 23), in-between 7.4% (n = 12), and unevaluable 14.8% (n = 24). The proportion of the cases with a potential risk of infraorbital nerve damage during endoscopic marsupialization, including medial, in-between, and unevaluable locations, was 27.8%. Retrospective chart review revealed that 2 patients with a postoperative maxillary cyst that were unevaluable complained of persistent postoperative hypoesthesia of the cheek.

The anatomical relationship between the infraorbital nerve and postoperative maxillary cysts varied among patients, with approximately one-fourth of the patients being at risk of infraorbital nerve injury even during endoscopic procedures.