Background: The human face is a highly specialized organ for receiving the sensory information from the environment and for its transmission to the cortex. The advent of facial transplantation has shown that excellent reconstruction of disfiguring defects can be achieved; thus, the expectations are now focused on functional recovery of the transplant. So far, restoration of facial sensation has not received the same attention as the recovery of motor function.
Methods: A thorough review of the literature was performed to investigate the current knowledge on the sensory pathways of the human face and their functions to evaluate current methods of sensory assessment and the available data on normal sensation.
Results: The presence of Meissner and Ruffini corpuscles, Merkel disks, hair-associated fibers, and intraepidermal free nerve endings was confirmed. Occurrence of extensive cross-communications between trigeminal and facial nerve was substantiated. Two-point discrimination and pressure thresholds represented the most objective measures of facial sensation. Age, sex, and smoker status of the patients were shown to influence normal sensibility values. The most suitable areas for sensory testing based on the tested modality and innervation were inferred. The anatomical course of the nerves and their variations had implications for the harvest of face allografts and repair of the sensory nerves.
Conclusions: This review has illustrated the complexity of sensory pathways of the face and their influence on somatic and visceral responses. In view of the discussed data, during facial transplantation, it is important to consider different mechanisms of restoration of facial sensation.
From the Dermatology and Plastic Surgery Institute, Cleveland Clinic.
Received for publication June 17, 2010; accepted August 18, 2010.
Disclosure: The authors certify that to the best of their knowledge no financial support or benefits have been received by any author, by any member of their immediate families, or any individual or entity with whom or with which they have a significant relationship from any commercial source that is related directly or indirectly to the scientific work that is reported on in the article. The work has been supported with institutional funds.
Maria Siemionow, M.D., Ph.D., D.Sc.; Cleveland Clinic; 9500 Euclid Avenue; Cleveland, Ohio 44195; firstname.lastname@example.org