Evaluation of long-term sensory changes following mandibular augmentation procedures

Area of Science:

• Oral and Maxillofacial Surgery
• Neurosurgery
• Sensory Neuroscience

Background:

• Mandibular augmentation is a surgical procedure to increase the size or projection of the lower jaw.
• Osteotomy techniques are commonly used in mandibular augmentation, involving bone cutting and repositioning.
• The inferior alveolar neurovascular bundle, including the mental nerve, is often repositioned during these procedures.

Purpose of the Study:

• To evaluate long-term sensory changes in the mental nerve distribution following mandibular augmentation.
• To assess both subjective and objective neurosensory alterations.
• To determine the persistence of these sensory changes over time.

Main Methods:

• A cohort of 12 patients who underwent mandibular augmentation using various osteotomy techniques were evaluated.
• A mean follow-up period of 32 months was maintained.
• Subjective patient reports and objective testing (two-alternative forced-choice technique) for light touch, thermal, and brush directional discrimination were employed.

Main Results:

• All patients reported persistent subjective neurosensory alterations in the mental nerve distribution.
• Four patients exhibited dysesthesia.
• Objective sensory alterations were detected in all tested modalities, with brush directional discrimination most affected, followed by light touch and thermal discrimination.

Conclusions:

• Mandibular augmentation procedures that involve repositioning the inferior alveolar neurovascular bundle result in significant neurosensory alterations.
• These alterations are both subjective and objective.
• The neurosensory changes are persistent, as evidenced by long-term follow-up data.