Effect of Facial Sensory Re-training on Sensory Thresholds

Abstract

Nearly 100% of patients experience trauma to the trigeminal nerve during orthognathic surgery, impairing sensation and sensory function on the face. In a recent randomized clinical trial, people who performed sensory re-training exercises reported less difficulty related to residual numbness and decreased lip sensitivity than those who performed standard opening exercises only. We hypothesized that re-training reduces the impaired performance on neurosensory tests of tactile function that is commonly observed post-surgically. We analyzed thresholds for contact detection, two-point discrimination, and two-point perception, obtained during the clinical trial before and at 1, 3, and 6 months after surgery, to assess tactile detection and discriminative sensitivities, and subjective interpretation of tactile stimulation, respectively. Post-surgery, the retrained persons exhibited less impairment, on average, than non-retrained persons only in two-point perception (P < 0.025), suggesting that retrained persons experienced or interpreted the tactile stimuli differently than did non-retrained persons.

Inferior alveolar nerve injury following orthognathic surgery: a review of assessment issues

“…Note that the time course of recovery differed for the three measures of somatosensory function, with less recovery observed for contact detection than either two-point perception or discrimination. To the clinician considering microsurgery for nerve repair the objective, electrophysiological measure of nerve integrity or stimulus detection measures may be most valuable; but if the consideration is the patient's accommodation to the altered sensitivity (32,33,(35)(36)(37) or the effect of medication (38), then stimulus perception measures or patient self-report may be the preferred measure. And to the patient, the changes in sensitivity and sensation and the extent to which the change causes discomfort or problems with daily life is paramount regardless of sensory testing estimates of residual nerve injury.…”

Sensory Retraining: A Cognitive Behavioral Therapy for Altered Sensation

“…Even at two years after surgery, patients who received only the opening exercises were about 2 times more likely to report an altered sensation than patients who used the sensory retraining exercises after surgery(Figure 3). (49) And patients in the sensory retraining group were less likely to report interference in daily life activities from numbness or loss of lip sensitivity (Figure 4a,b) (50) This difference between the two exercise groups appears to be related to the difference in how the “retrained” individual experienced or interpreted tactile stimuli rather than any difference in nerve recovery or repair (46,47). …”

“…Sensory experience or retraining results in somatosensory cortical maps that exhibit higher sensory resolution and greater topographical organization which facilitate better interpretation of sensory inputs. In contrast to the central neural changes, sensory re-training does not alter the course of nerve regeneration or the absolute thresholds to touch (39,46,47,48) but does improve both the patient’s cognitive and adaptive response to stimulation of the affected skin region. (12,30,49,50,51).…”

“…In addition to patient-reported outcomes, two-point perception, two – point discrimination, and contact detection thresholds were measured as secondary outcomes. The sensory re-training patients were more adept at perceiving touch (Figure 2), indicating accommodation, even though there was no improvement in the ability to discriminate two distinct points of contact from one (nerve recovery) (46). …”

Virtual Surgical Planning for Treatment of Severe Mandibular Retrognathia With Collapsed Occlusion Using Contemporary Surgical and Prosthodontic Protocols

“…23 Despite this patient's age and gender, the preoperative motivation, favorable psychosocial medical status, and exercise programs positively affected her recovery and perceived altered sensation. 24 The need for dental implant treatment in the older population remains high considering the prevalence of partial and complete edentulism and the predictability of implant therapy. 25 Skeletal and dentoalveolar reconstruction of the older adult patient can be predictably achieved with a multidisciplinary approach through a combination of contemporary virtual planning, immediate implant placement, and loading protocols.…”