The relationship between orbital floor fracture patterns around the infraorbital groove and development of infraorbital nerve hypoesthesia: a computed tomographic study.

ABSTRACT

PURPOSE: To examine the relationship between patterns of orbital floor fracture around the infraorbital groove and development of infraorbital nerve hypoesthesia. METHODS: This retrospective, observational study included 200 patients (200 sides) of pure orbital floor fracture with or without medial orbital wall fracture. Data on the presence or absence of infraorbital nerve hypoesthesia were collected from medical records. Based on coronal computed tomographic images, patients were classified into 3 groups a fracture extending medially to (medial group), into (in-groove group), and laterally to the infraorbital groove (lateral group). RESULTS: Infraorbital nerve hypoesthesia was found in 72 patients (36.0%). A fracture extended into or laterally to the infraorbital groove in 86.2% of patients with infraorbital nerve hypoesthesia, while a fracture was limited to the portion medial to the infraorbital groove in 77.3% of patients without infraorbital nerve hypoesthesia (P < 0.001). A logistic regression analysis demonstrated that patients in the lateral and in-groove groups were highly associated with development of infraorbital nerve hypoesthesia, with an odds ratio of 134.788 in the lateral group (95% confidence interval, 30.496-595.735; P < 0.001) and that of 20.323 in the in-groove group (95% confidence interval, 6.942-59.499; P < 0.001) with the medial group as the reference. CONCLUSIONS: This study indicates that patients with orbital floor fracture extending into or laterally to the infraorbital groove have a high risk of infraorbital nerve hypoesthesia, compared to those with orbital floor fracture limited to the portion medial to the infraorbital groove.