Sensory changes in the branches of infraorbital nerve following zygomatic complex fractures

Background: Zygoma is a prominent bone in face and most commonly injured during trauma. Sensory disturbance of the Infra Orbital region and a palpable fracture displacement of the Infra orbital margins are the typical clinical findings of zygomatic complex fracture. In most cases fracture lines involve the Infra Orbital foramen, canal, or fissure, therefore, fractures of the zygomatic complex are characterized by sensory neuropathy (specifically hypoesthesia) in the area of innervations of the Infra orbital nerve, both as a presenting symptom, and as a postoperative complication. Objectives: Our objectives of the study were to investigate sensory changes in the superior labial, lateral nasal, inferior palpebral branches of infra orbital nerve following zygomatic complex fractures by employing sensory testing over a 6-month period, to identify the most commonly involved branch of infra orbital nerve in zygomatic complex fracture and to document the pattern of sensory recovery in the study subjects. Patients & Methods: The study was carried out in ninety patients fulfilling the inclusion crtiteria were selected. In all patients the sensory changes in the superior labial, lateral nasal, inferior palpebral branches of infra orbital nerve following zygomatic complex fractures analyzed by employing sensory testing by means of mechanical detection threshold and reaction to pin prick, over a 6-month period and to identify the most commonly involved branch of infra orbital nerve in zygomatic complex fracture and its association with fracture severity and to document the pattern of sensory recovery in the study. Results: From our study we found that upper lip (73 cases out of 90 by mechanical method and 65 cases by pin prick test) is the most commonly involved area and hence superior labial branch is the most commonly involved branch in zygomatic complex fractures. All branches had significant recovery after 6 months. Study of pattern of recovery after treatment showed that there is no significant improvement in paresthesia of any branches of infra orbital nerve following closed reduction of zygomatic complex fracture. We had only two cases where open reduction was done and both did not recover from paresthesia