Sensory retraining following orthognathic surgery: effect on threshold measures of sensory function
ABSTRACT The purpose of this analysis was to examine the effect of sensory retraining on sensory function after bilateral sagittal split osteotomy (BSSO). A total of 186 subjects were enrolled in a multi-centre double-blind two parallel group stratified block randomized clinical trial. Subjects were randomized to group immediately after surgery. Threshold measures for contact detection, two-point discrimination and two-point perception were obtained on the chin before and 1, 3 and 6 months and 1 and 2 years after surgery. The ratio of each threshold measure (post-surgery value/pre-surgery value) was calculated to characterize subjects' impairment. A general linear mixed model was fit for the impairment to examine the effect of the sensory retraining before and after adjusting for demographic, surgical and psychological factors. On average, two-point perception was less impaired in subjects who were retrained than in those who were not retrained (P = 0.04). Significant recovery continued up to 6 months after surgery for contact detection and two-point perception and up to 24 months for two-point discrimination. Older subjects experienced more impairment in two-point discrimination than younger subjects (P = 0.009). Subjects who received maxillary surgery in addition to mandibular surgery experienced more impairment on the chin in both two-point discrimination (P = 0.0003) and perception (P = 0.0013) than subjects who received mandibular surgery only. Psychological factors did not explain additional variability in subjects' impairment post-surgery. These finding indicate that a simple non-invasive exercise programme initiated shortly after orthognathic surgery can alter the way patients experience or respond to tactile stimulation long after the exercise regimen has stopped.
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ABSTRACT: Recovery of normal function in face transplantation is fundamental to justify the necessity for lifelong immunosuppressive therapy. However, extensive soft tissue damage and scarring in face transplant patients has often hampered the repair of the sensory nerves. Nonetheless, it seems that near full return of sensation has been achieved in these patients. In this chapter we assessed the sensory outcome in face-transplanted patients and investigated the factors which could have impacted the final result. The results were compared to sensory return following replantation of face and scalp, repair of divided sensory nerves of the face, and in innervated and noninnervated vascularized free flaps used for head and neck reconstruction. Sensory recovery following face transplantation, even when the sensory nerves were not repaired, showed results comparable or superior to free autologus innervated tissue. Results were also comparable with the outcome of the microsurgical repair of the peripheral branches of the trigeminal nerve. Therefore, near normal sensory recovery can be expected following facial allotransplantation. Restoration of normal end organ receptors within the facial allograft, repair of the facial nerve, and immunosuppressive therapy with FK506 probably affect and accelerate the final outcome. We suggest a guideline on quantitative sensory testing and timing of the follow-up to allow comparison of results between different centers and improve our understanding of the mechanisms of sensory recovery in face transplantation.
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ABSTRACT: Injury to branches of the trigeminal nerve is one of the possible complications associated with the removal of third molars. Fifty-two percent of patients referred to a university-based practice with trigeminal neurosensory complaints associated their nerve injury with third molar odontectomy. The inferior alveolar nerve (IAN) was the most commonly injured nerve (61.1%), followed by the lingual nerve (LN; 38.8%). There was a 1.5-times greater incidence in females, the mean age of the patients was 34.5 years, and the mean time to consultation from the third molar extraction date was 6.9 months. These data also showed that although the LN was the least commonly injured nerve, it was also the most likely to be severely damaged. It also showed that these patients were most likely to benefit from surgery. On the other hand, the IAN-injured patient often had less severe sensory impairment and therefore would not always benefit from surgical intervention. Therefore, the decision to observe or treat was generally based on which nerve is injured (LN or IAN), and this requires knowledge of the natural course of both LN and IAN recovery following injury, as well as the history of the injury; the physical findings; the results of the diagnostic procedures used to determine the degree of nerve injury; the characteristics of the neuropathic pain, if present; and the potential benefits and risks of surgery, if indicated.Alpha Omegan 07/2009; 102(2):79-84. DOI:10.1016/j.aodf.2009.04.014