• Perception of altered sensation
  
• Perception of altered function
  
• Two-point threshold
  
• Two point discrimination
  
• Contact detection
  

Abnormal facial sensation has a negative impact on patients' oral behaviors and may adversely affect a patient's quality of life if the altered sensation persists. Many patients with abnormal sensations retain some sensory function and do not develop chronic pain, and for those individuals there are currently no evidence-based noninvasive therapies. The goal of this project is to evaluate sensory re-training, a rehabilitative therapy that offers significant potential for patients who experience impaired sensory function regardless of the cause. This behavioral therapy approach has been used with substantial clinical success with hand injury patients since the 1970s. Re-training appears to enhance central reorganization of impulses from an injured sensory nerve to the cerebral cortex so that the altered sensory signals can be interpreted and translated into functionally meaningful motor functions.

Sensory re-training will be compared to a placebo jaw-opening exercise in a single blind, randomized two-arm parallel group stratified block clinical trial, using orthognathic surgery patients as subjects. Orthognathic surgery patients offer an uncompromised model for the evaluation of new rehabilitative therapies. These healthy individuals, treated to correct dentofacial deformity, present for surgery with no neurosensory impairment, but yet routinely experience substantial alterations in facial sensation following the surgical procedure. The effects of sensory re-training will be evaluated using three types of outcomes: patient-centered measures to assess the magnitude of the negative effect of altered sensation after surgery and the recovery time needed to reach little or no negative effect; neurosensory behavior measures to assess the patient's ability to learn alternate cues for touch perception and discrimination; and a conventional neurosensory contact threshold measure to assess the actual deficit. Our primary focus will be on the patient's perception of the negative impact of altered sensation on daily life.

Inclusion Criteria:

• Developmental dentofacial disharmony
• Receives mandibular advancement by mandibular osteotomy with or without a maxillary procedure.

Exclusion Criteria:

• Congenital anomaly or acute trauma affecting the face.
• Previous facial surgery
• Pregnant at baseline
• Inability to follow written English instructions
• Unwilling to sign informed consent.
• No altered sensation at one week post-surgery
• Altered sensation at baseline reported as numbness or unusual feeling.
• Medical condition associated with systemic neuropathy.