Does mandibular osteotomy affect the infraorbital nerve? a prospective study

Area of Science:

• Oral and Maxillofacial Surgery
• Neurosurgery
• Sensory Neuroscience

Background:

• Orthognathic surgery (OS) aims to correct dentofacial deformities.
• The infraorbital nerve (ION) is susceptible to sensory changes after OS.
• Understanding ION sensory function post-OS is crucial for patient outcomes.

Purpose of the Study:

• To evaluate the sensory function of the infraorbital nerve (ION) following orthognathic surgery (OS).
• To compare sensory changes between patients undergoing single-jaw versus double-jaw OS.
• To assess the recovery patterns of ION somatosensory function.

Main Methods:

• Prospective study of 28 patients undergoing Le Fort I osteotomy with or without bilateral sagittal split osteotomy (BSSO).
• Patients grouped based on whether BSSO was performed (single vs. double jaw surgery).
• Sensory testing (Class A, B, C) used to quantify peripheral nerve damage and altered sensation.

Main Results:

• Statistically significant differences in nerve damage scale (NSD) scores were observed between pre- (T1) and post-operative (T2) periods (p<0.001).
• Mean NSD scores increased from T1 to T2, indicating sensory impairment.
• The mean NSD score was higher in the double jaw group compared to the single jaw group at all time points.

Conclusions:

• Bimaxillary surgeries negatively impact early somatosensory changes.
• Upper lip somatosensory recovery is faster than infraorbital nerve recovery.
• Single jaw surgery leads to faster recovery than double jaw surgery.