Posttraumatic trigeminal nerve impairment: a prospective analysis of recovery patterns in a series of 103 consecutive facial fractures.

Purpose: To report the incidence of peripheral trigeminal nerve posttraumatic impairments and to compare different recovery patterns as observed in consideration of different fracture-related variables within 12-month follow-up.

Patients And Methods: Ninety-seven consecutive patients with 103 facial fractures were included involving emergence areas of supraorbital nerve, infraorbital nerve, or the region between the mandibular and mental foramina. Presurgical and postsurgical clinical neurosensory testing sessions were performed in each patient. Results of these assessments were compared within fracture characteristics and different sites of trauma. Statistical analysis (chi-square test) was performed on clinical observations.

Results: The incidence of trigeminal nerve impairments was 70.9% (54.4% in nondisplaced fractures, 88.2% in dislocated fractures, 100% in fractures with a direct nerve injury). Severe impairment was found in direct nerve injures and in many dislocated fractures. Mean recovery time was smaller in nondisplaced fractures than in dislocated fractures. Considering fracture site, the highest incidence of initial trigeminal nerve impairment was found in midfacial nondisplaced fractures. Midfacial fractures had better prognosis than mandibular fractures, and best prognosis was encountered in nondisplaced midfacial fractures. Residual hypoesthesia persisted in 11 sides with direct nerve injury after 12 months and involved tactile and discriminative sensibilities.

Conclusion: Recovery patterns of posttraumatic trigeminal dysfunction are related to site and type of fracture; intraoperative assessment of involvement of nerve bundles within fracture rimes was associated with an incomplete recovery at the 12th month. Impairment of temperature and nociception are highly related to a direct nerve injury.